Focusing Basics | Aperture and Depth of Field - lenses and depth of field

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While depletion has not been reported with benazepril, until more is known, it makes sense for people taking benazepril long term to consider, as a precaution, taking a zinc supplement or a multimineral tablet containing zinc. (Such multiminerals usually contain no more than 99 mg of potassium, probably not enough to trigger the above-mentioned interaction.) Supplements containing zinc should also contain copper, to protect against a zinc-induced copper deficiency.

Taking calcium, iron, magnesium, or zinc at the same time as minocycline can decrease the absorption of both the drug and the mineral. Therefore, calcium, iron, magnesium, or zinc supplements, if used, should be taken an hour before or after the drug.

In various studies of children treated with valproic acid for epilepsy compared with control groups, serum zinc levels remained normal or decreased, serum copper levels remained normal or decreased, and red blood cell zinc levels were decreased. The importance of these changes and how frequently they occur remain unclear.

A double-blind trial showed a 74% reduction in symptom duration in people using a zinc nasal spray four times daily, compared with the 42 to 53% reduction reported in trials using zinc gluconate or zinc acetate lozenges. The average duration of symptoms after the beginning of treatment was 2.3 days in the people receiving zinc, compared with 9.0 days in those receiving placebo. However, in another double-blind study, zinc nasal spray was no more effective than a placebo; in both groups the median duration of symptoms was seven days.

In a study of 34 people with hypertension, six months of captopril or enalapril (ACE inhibitors related to perindopril) treatment led to decreased zinc levels in certain white blood cells, raising concerns about possible ACE inhibitor–induced zinc depletion.

28. Nations SP, Boyer PJ, Love LA, et al. Denture cream. An unusual source of excess zinc, leading to hypocupremia and neurologic disease. Neurology 2008;71:639-43.

Refracting telescope partslist

is also needed for the repair of damaged tissue and has protected against stomach ulceration in animal studies. In Europe, zinc combined with acexamic acid, an anti-inflammatory substance, is used as a drug in the treatment of peptic ulcers. In a small controlled trial, high amounts of zinc accelerated the healing of gastric ulcers compared with placebo. Some doctors suspect that such an exceptionally high intake of zinc may be unnecessary, suggesting instead that people with ulcers wishing to take zinc supplements use only 25 to 50 mg of zinc per day. Even at these lower levels, 1 to 3 mg of copper per day must be taken to avoid copper deficiency that would otherwise be induced by the zinc supplementation.

Dietary deficiency is common, and a lack of zinc may reduce the activity of retinol dehydrogenase, an enzyme needed to help vitamin A work in the eye. Zinc helps night blindness in people who are zinc-deficient; therefore, many physicians suggest 15 to 30 mg of zinc per day to support healthy vision. Because long-term zinc supplementation may reduce copper levels, 1 to 2 mg of copper per day (depending on the amount of zinc used) is usually recommended for people who are supplementing with zinc for more than a few weeks.

Children with alopecia areata who supplemented 100 mg of zinc and 20 mg biotin each day, combined with topical clobetasol, showed more improvement compared to children who took oral corticosteroid drugs. Controlled research is needed to determine whether adding oral zinc and biotin to topical clobetasol therapy is more effective than clobetasol alone. However, until more information is available, caregivers should consider that children with alopecia who are currently taking oral corticosteroids might benefit from switching to supplements of zinc and biotin along with topical clobetasol.

30. Nishiyama S, Irisa K, Matsubasa T, et al. Zinc status relates to hematological deficits in middle-aged women. J Am Coll Nutr 1998;17:291-5.

Minerals including calcium, iron, magnesium, and can bind to fluoroquinolones, including ofloxacin, greatly reducing drug absorption. Ofloxacin should be taken four hours before or two hours after consuming antacids (Maalox®, Mylanta®, Tumms®, Rolaids® and others) that may contain these minerals and mineral-containing supplements.

A review of literature suggests that women who use oral contraceptives may experience decreased vitamin B1, B2, B3, B12, C, and levels. Oral contraceptive use has been associated with increased absorption of calcium and copper and with increased blood levels of copper and vitamin A. Oral contraceptives may interfere with manganese absorption. The clinical importance of these actions remains unclear.

Experimental animal studies have shown that a zinc salt of the amino acid carnosine exerts significant protection against ulcer formation and promotes the healing of existing ulcers. However, because zinc by itself has been shown to be helpful against peptic ulcer, it is not known how much of the beneficial effect was due to the carnosine. Clinical studies in humans demonstrated that this compound can help eradicate H. pylori, an organism that has been linked to peptic ulcer and stomach cancer. The amount of the zinc carnosine complex used in research studies for eradication of H. pylori is 150 mg twice daily.

In a double-blind study, children with ADHD who received 15 mg of per day for six weeks showed significantly greater behavioral improvement, compared with children who received a placebo. This study was conducted in Iran, and zinc deficiency has been found to be quite common in certain parts of that country. It is not clear, therefore, to what extent the results of this study apply to children living in other countries.

This photo shows the equatorial mounting of the telescope. Several main components are shown. The equatorial mount, when properly set up, allows the telescope to follow the stars more easily as compared to an alt-azimuth mount (technically speaking the stars are not moving, however they appear to move due to the rotation of the Earth). The mount has two axis, right ascension and declination. To track the stars, one only has to move the scope in the right ascension axis (whereas with an Alt-Azimuth mount one has to move two axis). Also shown are two setting circles. Any scope with an equatorial mount will have these circles. When used properly, they allow the user to "dial in" an object to view (by moving the scope so that the pointers match the coordinates of an object to be desired). The coordinates for objects to be observed can be obtained from most any star atlas. Setting circles do work, however the mount has to be level and aligned to the pole; typically the object to be observed will land within or near the field of low power eyepiece. It really depends on how carefully one sets up the scope and how carefully one dials in the object. Scopes with smaller (physically) setting circles will be less accurate than those with larger circles (larger circles allow finer graduations). The low motion control shown here is for right ascension; turning this wheel will allow smooth tracking of objects as they appear to move. This is very handy to have for higher magnifications (> 100x).

Zinc competes for absorption with copper, iron,12, 13calcium,14 and magnesium.15 A multimineral supplement will help prevent mineral imbalances that can result from taking high amounts of zinc for extended periods of time.

Many minerals can decrease the absorption of tetracycline, thus reducing its effectiveness. These minerals include aluminum (in antacids), calcium (in antacids, dairy products, and supplements), magnesium (in antacids and supplements), iron (in food and supplements), (in food and supplements), and others.

How does arefracting telescopework

interferes with viral replication in test tubes, may interfere with the ability of viruses to enter cells of the body, may help immune cells to fight a cold, and may relieve cold symptoms when taken as a supplement. In double-blind trials, zinc lozenges have reduced the duration of colds in adults but have been ineffective in children. Lozenges containing zinc gluconate, zinc gluconate-glycine, and, in most trials, zinc acetate have been effective; most other forms of zinc and lozenges flavored with citric acid, tartaric acid, sorbitol, or mannitol have been ineffective. Trials using these other forms of zinc have failed, as have trials that use insufficient amounts of zinc. For the alleviation of cold symptoms, lozenges providing 13 to 25 mg of zinc (as zinc gluconate, zinc gluconate-glycine, or zinc acetate) are used every two hours while awake but only for several days. The best effect is obtained when lozenges are used at the first sign of a cold.

Here is a photo of a typical equatorial refractor telescope. This scope is an old (early 1970s vintage) Tasco refractor (this was back when they were made with some degree of quality). Just about everything on this telescope is metal or glass (very little plastic unlike what is found in today's entry level scopes). Here's another view, a little closer Subsequent photos will show more of the individual components of the scope. This photo shows the observer end of the telescope. The main items here are the star diagonal (this scope has what is known as a "hybrid diagonal". A hybrid diagonal accepts 1.25" diameter eyepieces but it plugs into a focuser that accepts 0.965" eyepieces. The ability of a scope to accept 1.25" eyepieces is highly desirable for a number of reasons. First, there are very few eyepieces made in the .965" size these days. Beyond that, the types of eyepieces available in .965" size is very limited, and they tend to be of lower quality. The 1.25" diameter eyepieces are the standard today, and a great variety of types and focal lengths are available and quality ranges from acceptable to outstanding. If you have an older scope that has a diagonal that only accepts .965" eyepieces, the solution is to get a hybrid diagonal (about $40). The other items shown in this photo are the focusing knobs and part of the finderscope. This scope has machined metal focusing knobs, on modern entry level refractors they are almost all plastic. This photo shows the components above but at a slightly different angle. The drawtube is the part of the scope that moves in and out when the focusing knobs are rotated. This image shows the finderscope and the optical tube clamp. The finderscope on this telescope is a 6x30 model, this is an upgrade I did years ago. Most of the time scopes of this class come with a smaller 5x24 finder, and quite often the finder bracket only has 3 locking screws instead of six like on this one (superior). The finderscope shown here is a quality unit. The optical tube clamp basically holds the telescope tube in the mount. It allows the tube to be rotated or moved forward or backward (to allow balancing) if necessary. This photo shows the equatorial mounting of the telescope. Several main components are shown. The equatorial mount, when properly set up, allows the telescope to follow the stars more easily as compared to an alt-azimuth mount (technically speaking the stars are not moving, however they appear to move due to the rotation of the Earth). The mount has two axis, right ascension and declination. To track the stars, one only has to move the scope in the right ascension axis (whereas with an Alt-Azimuth mount one has to move two axis). Also shown are two setting circles. Any scope with an equatorial mount will have these circles. When used properly, they allow the user to "dial in" an object to view (by moving the scope so that the pointers match the coordinates of an object to be desired). The coordinates for objects to be observed can be obtained from most any star atlas. Setting circles do work, however the mount has to be level and aligned to the pole; typically the object to be observed will land within or near the field of low power eyepiece. It really depends on how carefully one sets up the scope and how carefully one dials in the object. Scopes with smaller (physically) setting circles will be less accurate than those with larger circles (larger circles allow finer graduations). The low motion control shown here is for right ascension; turning this wheel will allow smooth tracking of objects as they appear to move. This is very handy to have for higher magnifications (> 100x). Here's another view of the equatorial mount. Note that each axis has a locking clamp; these lock the position of the optical tube once an object has been located for viewing. The counterweight is used to balanced the weight of the optical tube (a well balanced mount will allow much smoother operation and better tracking). This view also shows the declination slow motion control. This allows the scope's position to be finely adjusted in declination (very handy for centering up the object to be viewed once it has been acquired in the eyepiece). Not all equatorial scopes will have slow motion controls, however they are very handy to have. Some scopes will have electronic versions. This view shows the most fundamental component of a refractor telescope: the objective lens. You know you have a refractor telescope if it has a lens up front (a lens with no center obstruction). If your scope has a mirror at the back, it is a reflector. Also shown here is the dew shield. This slows the formation of dew on the lens and allows longer viewing. Regarding the objective: you should NOT take it apart to clean it! The lenses on most entry level scopes are known as achromats, that is, they have 2 elements. DO NOT take these apart! They are lined up (in rotational position) at the factory for the best image, and if you take it apart and forget to mark it chances are it will not go back together in the proper orientation. The odds of crud getting in between the two optical components are slim, so there is no need to disassemble the objective. The only surface that should ever need cleaning (and this should only be occasional cleaning) is the portion of the objective that faces the sky. Not shown here is a lens cap, this should always be in place when the scope is not in use. Here's a close up of the finderscope. As mentioned, this finder is probably better than the finder that will come on an entry level scope (this is a 6x30 finderscope vs. the typical 5x24 finder that comes with many scopes). The bracket that holds this finder has six locking screws that hold it in place. When the scope is initially put together, one has to align the finder to the main scope (using the screws). Once adjusted, it should stay pretty much in line. Some of the entry level scopes come with only a 3 point adjustment, a setup that is not as secure. The finderscope is like a sight on a gun; one locates the object to be observed on the crosshairs of the finderscope (and if properly aligned) the object will then be centered in the main telescope. Finding objects without a finderscope is very difficult due to the relatively small field of view of the main scope. A typical finderscope will have a field of view that is several degrees wide, wide enough to easily locate and center objects. This photo shows a close up of the counterweight and declination shaft. The counterweight's position on the shaft is adjustable to allow fine balancing of the scope. This photo shows another control of the equatorial mount, the latitude adjustment lever. When using an equatorial mount, one has to set it to the latitude of the observing site in order to allow the mount to accurately be able to track objects. In general this setting is made once (unless you take the scope a significant distance north or south of the normal observing location. Also shown is the other side of the right ascension slow motion control (the control extends out of the photo, it has a knob at the end). "Back" links, e-mail and Copyright Use your browser's "back" button, or use links below if you arrived here via some other path: This page is part of the site Amateur Astronomer's Notebook. E-mail to Joe Roberts Images and HTML text © Copyright 2007 by Joe Roberts. Please request permission to use photos for purposes other than "personal use".

In a group of 37 postmenopausal women treated with conjugated estrogens and medroxyprogesterone for 12 months, urinary zinc and magnesium loss was reduced in those women who began the study with signs of osteoporosis and elevated zinc and magnesium excretion. The clinical significance of this interaction remains unclear.

interferes with viral replication in test tubes. The beneficial effect of zinc nasal sprays should be weighed against the potentially serious side effect of loss of smell. Since zinc supplements are also effective and do not carry such a risk, it is more advisable to take zinc orally.

In a study of 34 people with hypertension, six months of captopril or enalapril (ACE inhibitors related to benazepril) treatment led to decreased zinc levels in certain white blood cells, raising concerns about possible ACE inhibitor–induced zinc depletion.

Oral corticosteroids have been found to increase urinary loss of vitamin K, vitamin C, selenium, and . The importance of these losses is unknown.

Bile acid sequestrants, including colestipol, may prevent absorption of folic acid and the fat-soluble vitamins A, D, E, K. People taking colestipol should consult with their doctor about vitamin malabsorption and supplementation. People should take other drugs and vitamin supplements one hour before or four to six hours after colestipol to improve absorption.

Laboratory animals with severe, experimentally induced deficiency developed hypothyroidism, whereas moderate zinc deficiency did not affect thyroid function. In a small study of healthy people, thyroid hormone (thyroxine) levels tended to be lower in those with lower blood levels of zinc. In people with low zinc, supplementing with zinc increased thyroxine levels. One case has been reported of a woman with severe zinc deficiency (caused by the combination of alcoholism and malabsorption) who developed hypothyroidism that was corrected by supplementing with zinc. Although the typical Western diet is marginally low in zinc, additional research is needed to determine whether zinc supplementation would be effective for preventing or correcting hypothyroidism.

What is this page about? Basically its purpose is to show the basic parts of a refractor telescope. This page may be of help to those just starting out (or for those who have obtained a refractor scope with no manual), etc. Here is a photo of a typical equatorial refractor telescope. This scope is an old (early 1970s vintage) Tasco refractor (this was back when they were made with some degree of quality). Just about everything on this telescope is metal or glass (very little plastic unlike what is found in today's entry level scopes). Here's another view, a little closer Subsequent photos will show more of the individual components of the scope. This photo shows the observer end of the telescope. The main items here are the star diagonal (this scope has what is known as a "hybrid diagonal". A hybrid diagonal accepts 1.25" diameter eyepieces but it plugs into a focuser that accepts 0.965" eyepieces. The ability of a scope to accept 1.25" eyepieces is highly desirable for a number of reasons. First, there are very few eyepieces made in the .965" size these days. Beyond that, the types of eyepieces available in .965" size is very limited, and they tend to be of lower quality. The 1.25" diameter eyepieces are the standard today, and a great variety of types and focal lengths are available and quality ranges from acceptable to outstanding. If you have an older scope that has a diagonal that only accepts .965" eyepieces, the solution is to get a hybrid diagonal (about $40). The other items shown in this photo are the focusing knobs and part of the finderscope. This scope has machined metal focusing knobs, on modern entry level refractors they are almost all plastic. This photo shows the components above but at a slightly different angle. The drawtube is the part of the scope that moves in and out when the focusing knobs are rotated. This image shows the finderscope and the optical tube clamp. The finderscope on this telescope is a 6x30 model, this is an upgrade I did years ago. Most of the time scopes of this class come with a smaller 5x24 finder, and quite often the finder bracket only has 3 locking screws instead of six like on this one (superior). The finderscope shown here is a quality unit. The optical tube clamp basically holds the telescope tube in the mount. It allows the tube to be rotated or moved forward or backward (to allow balancing) if necessary. This photo shows the equatorial mounting of the telescope. Several main components are shown. The equatorial mount, when properly set up, allows the telescope to follow the stars more easily as compared to an alt-azimuth mount (technically speaking the stars are not moving, however they appear to move due to the rotation of the Earth). The mount has two axis, right ascension and declination. To track the stars, one only has to move the scope in the right ascension axis (whereas with an Alt-Azimuth mount one has to move two axis). Also shown are two setting circles. Any scope with an equatorial mount will have these circles. When used properly, they allow the user to "dial in" an object to view (by moving the scope so that the pointers match the coordinates of an object to be desired). The coordinates for objects to be observed can be obtained from most any star atlas. Setting circles do work, however the mount has to be level and aligned to the pole; typically the object to be observed will land within or near the field of low power eyepiece. It really depends on how carefully one sets up the scope and how carefully one dials in the object. Scopes with smaller (physically) setting circles will be less accurate than those with larger circles (larger circles allow finer graduations). The low motion control shown here is for right ascension; turning this wheel will allow smooth tracking of objects as they appear to move. This is very handy to have for higher magnifications (> 100x). Here's another view of the equatorial mount. Note that each axis has a locking clamp; these lock the position of the optical tube once an object has been located for viewing. The counterweight is used to balanced the weight of the optical tube (a well balanced mount will allow much smoother operation and better tracking). This view also shows the declination slow motion control. This allows the scope's position to be finely adjusted in declination (very handy for centering up the object to be viewed once it has been acquired in the eyepiece). Not all equatorial scopes will have slow motion controls, however they are very handy to have. Some scopes will have electronic versions. This view shows the most fundamental component of a refractor telescope: the objective lens. You know you have a refractor telescope if it has a lens up front (a lens with no center obstruction). If your scope has a mirror at the back, it is a reflector. Also shown here is the dew shield. This slows the formation of dew on the lens and allows longer viewing. Regarding the objective: you should NOT take it apart to clean it! The lenses on most entry level scopes are known as achromats, that is, they have 2 elements. DO NOT take these apart! They are lined up (in rotational position) at the factory for the best image, and if you take it apart and forget to mark it chances are it will not go back together in the proper orientation. The odds of crud getting in between the two optical components are slim, so there is no need to disassemble the objective. The only surface that should ever need cleaning (and this should only be occasional cleaning) is the portion of the objective that faces the sky. Not shown here is a lens cap, this should always be in place when the scope is not in use. Here's a close up of the finderscope. As mentioned, this finder is probably better than the finder that will come on an entry level scope (this is a 6x30 finderscope vs. the typical 5x24 finder that comes with many scopes). The bracket that holds this finder has six locking screws that hold it in place. When the scope is initially put together, one has to align the finder to the main scope (using the screws). Once adjusted, it should stay pretty much in line. Some of the entry level scopes come with only a 3 point adjustment, a setup that is not as secure. The finderscope is like a sight on a gun; one locates the object to be observed on the crosshairs of the finderscope (and if properly aligned) the object will then be centered in the main telescope. Finding objects without a finderscope is very difficult due to the relatively small field of view of the main scope. A typical finderscope will have a field of view that is several degrees wide, wide enough to easily locate and center objects. This photo shows a close up of the counterweight and declination shaft. The counterweight's position on the shaft is adjustable to allow fine balancing of the scope. This photo shows another control of the equatorial mount, the latitude adjustment lever. When using an equatorial mount, one has to set it to the latitude of the observing site in order to allow the mount to accurately be able to track objects. In general this setting is made once (unless you take the scope a significant distance north or south of the normal observing location. Also shown is the other side of the right ascension slow motion control (the control extends out of the photo, it has a knob at the end). "Back" links, e-mail and Copyright Use your browser's "back" button, or use links below if you arrived here via some other path: This page is part of the site Amateur Astronomer's Notebook. E-mail to Joe Roberts Images and HTML text © Copyright 2007 by Joe Roberts. Please request permission to use photos for purposes other than "personal use".

For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being.

12. Dawson EB, Albers J, McGanity WJ. Serum zinc changes due to iron supplementation in teen-age pregnancy. Am J Clin Nutr 1990;50:848-52.

Levels of in both blood and bone have been reported to be low in people with osteoporosis, and urinary loss of zinc has been reported to be high. In one trial, men consuming only 10 mg of zinc per day from food had almost twice the risk of osteoporotic fractures compared with those eating significantly higher levels of zinc in their diets. Whether zinc supplementation protects against bone loss has not yet been proven, though in one trial, supplementation with several minerals including zinc and calcium was more effective than calcium by itself. Many doctors recommend that people with osteoporosis, as well as those trying to protect themselves from this disease, supplement with 10 to 30 mg of zinc per day.

Updated 16 October 2007 Amateur Astronomer's Notebook Anatomy of a Refractor Telescope What is this page about? Basically its purpose is to show the basic parts of a refractor telescope. This page may be of help to those just starting out (or for those who have obtained a refractor scope with no manual), etc. Here is a photo of a typical equatorial refractor telescope. This scope is an old (early 1970s vintage) Tasco refractor (this was back when they were made with some degree of quality). Just about everything on this telescope is metal or glass (very little plastic unlike what is found in today's entry level scopes). Here's another view, a little closer Subsequent photos will show more of the individual components of the scope. This photo shows the observer end of the telescope. The main items here are the star diagonal (this scope has what is known as a "hybrid diagonal". A hybrid diagonal accepts 1.25" diameter eyepieces but it plugs into a focuser that accepts 0.965" eyepieces. The ability of a scope to accept 1.25" eyepieces is highly desirable for a number of reasons. First, there are very few eyepieces made in the .965" size these days. Beyond that, the types of eyepieces available in .965" size is very limited, and they tend to be of lower quality. The 1.25" diameter eyepieces are the standard today, and a great variety of types and focal lengths are available and quality ranges from acceptable to outstanding. If you have an older scope that has a diagonal that only accepts .965" eyepieces, the solution is to get a hybrid diagonal (about $40). The other items shown in this photo are the focusing knobs and part of the finderscope. This scope has machined metal focusing knobs, on modern entry level refractors they are almost all plastic. This photo shows the components above but at a slightly different angle. The drawtube is the part of the scope that moves in and out when the focusing knobs are rotated. This image shows the finderscope and the optical tube clamp. The finderscope on this telescope is a 6x30 model, this is an upgrade I did years ago. Most of the time scopes of this class come with a smaller 5x24 finder, and quite often the finder bracket only has 3 locking screws instead of six like on this one (superior). The finderscope shown here is a quality unit. The optical tube clamp basically holds the telescope tube in the mount. It allows the tube to be rotated or moved forward or backward (to allow balancing) if necessary. This photo shows the equatorial mounting of the telescope. Several main components are shown. The equatorial mount, when properly set up, allows the telescope to follow the stars more easily as compared to an alt-azimuth mount (technically speaking the stars are not moving, however they appear to move due to the rotation of the Earth). The mount has two axis, right ascension and declination. To track the stars, one only has to move the scope in the right ascension axis (whereas with an Alt-Azimuth mount one has to move two axis). Also shown are two setting circles. Any scope with an equatorial mount will have these circles. When used properly, they allow the user to "dial in" an object to view (by moving the scope so that the pointers match the coordinates of an object to be desired). The coordinates for objects to be observed can be obtained from most any star atlas. Setting circles do work, however the mount has to be level and aligned to the pole; typically the object to be observed will land within or near the field of low power eyepiece. It really depends on how carefully one sets up the scope and how carefully one dials in the object. Scopes with smaller (physically) setting circles will be less accurate than those with larger circles (larger circles allow finer graduations). The low motion control shown here is for right ascension; turning this wheel will allow smooth tracking of objects as they appear to move. This is very handy to have for higher magnifications (> 100x). Here's another view of the equatorial mount. Note that each axis has a locking clamp; these lock the position of the optical tube once an object has been located for viewing. The counterweight is used to balanced the weight of the optical tube (a well balanced mount will allow much smoother operation and better tracking). This view also shows the declination slow motion control. This allows the scope's position to be finely adjusted in declination (very handy for centering up the object to be viewed once it has been acquired in the eyepiece). Not all equatorial scopes will have slow motion controls, however they are very handy to have. Some scopes will have electronic versions. This view shows the most fundamental component of a refractor telescope: the objective lens. You know you have a refractor telescope if it has a lens up front (a lens with no center obstruction). If your scope has a mirror at the back, it is a reflector. Also shown here is the dew shield. This slows the formation of dew on the lens and allows longer viewing. Regarding the objective: you should NOT take it apart to clean it! The lenses on most entry level scopes are known as achromats, that is, they have 2 elements. DO NOT take these apart! They are lined up (in rotational position) at the factory for the best image, and if you take it apart and forget to mark it chances are it will not go back together in the proper orientation. The odds of crud getting in between the two optical components are slim, so there is no need to disassemble the objective. The only surface that should ever need cleaning (and this should only be occasional cleaning) is the portion of the objective that faces the sky. Not shown here is a lens cap, this should always be in place when the scope is not in use. Here's a close up of the finderscope. As mentioned, this finder is probably better than the finder that will come on an entry level scope (this is a 6x30 finderscope vs. the typical 5x24 finder that comes with many scopes). The bracket that holds this finder has six locking screws that hold it in place. When the scope is initially put together, one has to align the finder to the main scope (using the screws). Once adjusted, it should stay pretty much in line. Some of the entry level scopes come with only a 3 point adjustment, a setup that is not as secure. The finderscope is like a sight on a gun; one locates the object to be observed on the crosshairs of the finderscope (and if properly aligned) the object will then be centered in the main telescope. Finding objects without a finderscope is very difficult due to the relatively small field of view of the main scope. A typical finderscope will have a field of view that is several degrees wide, wide enough to easily locate and center objects. This photo shows a close up of the counterweight and declination shaft. The counterweight's position on the shaft is adjustable to allow fine balancing of the scope. This photo shows another control of the equatorial mount, the latitude adjustment lever. When using an equatorial mount, one has to set it to the latitude of the observing site in order to allow the mount to accurately be able to track objects. In general this setting is made once (unless you take the scope a significant distance north or south of the normal observing location. Also shown is the other side of the right ascension slow motion control (the control extends out of the photo, it has a knob at the end). "Back" links, e-mail and Copyright Use your browser's "back" button, or use links below if you arrived here via some other path: This page is part of the site Amateur Astronomer's Notebook. E-mail to Joe Roberts Images and HTML text © Copyright 2007 by Joe Roberts. Please request permission to use photos for purposes other than "personal use".

Taking risedronate at the same time as iron, , or magnesium may reduce the amount of drug absorbed. Therefore, people taking risedronate who wish to supplement with these minerals should take them an hour before or two hours after the drug.

Zinc is so effective in lessening the body’s burden of copper that a copper deficiency was reported in someone with Wilson’s disease who took too much (480 mg per day) zinc. Nonetheless, zinc may not help everyone with Wilson’s disease. Sometimes increased copper levels can occur in the liver after zinc supplementation; however, leading researchers believe this increase is temporary and may not be not harmful.

1 Star For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.

16. Brumas V, Hacht B, Filella M, Berthon G. Can N-acetyl-L-cysteine affect zinc metabolism when used as a paracetamol antidote? Agents Actions 1992;36:278-88.

This photo shows the observer end of the telescope. The main items here are the star diagonal (this scope has what is known as a "hybrid diagonal". A hybrid diagonal accepts 1.25" diameter eyepieces but it plugs into a focuser that accepts 0.965" eyepieces. The ability of a scope to accept 1.25" eyepieces is highly desirable for a number of reasons. First, there are very few eyepieces made in the .965" size these days. Beyond that, the types of eyepieces available in .965" size is very limited, and they tend to be of lower quality. The 1.25" diameter eyepieces are the standard today, and a great variety of types and focal lengths are available and quality ranges from acceptable to outstanding. If you have an older scope that has a diagonal that only accepts .965" eyepieces, the solution is to get a hybrid diagonal (about $40). The other items shown in this photo are the focusing knobs and part of the finderscope. This scope has machined metal focusing knobs, on modern entry level refractors they are almost all plastic.

Irradiation treatment, especially of head and neck cancers, frequently results in changes to normal taste sensation. Zinc supplementation may be protective against taste alterations caused or exacerbated by irradiation. A double-blind trial found that 45 mg of zinc sulfate three times daily reduced the alteration of taste sensation during radiation treatment and led to significantly greater recovery of taste sensation after treatment was concluded.

In a double-blind study, supplementing with (23 mg three times per day for three months) decreased the severity of rosacea by about 75%, whereas no improvement occurred in the placebo group. Mild gastrointestinal upset was reported by 12% of the people taking zinc, but no other significant side effects occurred. Long-term zinc supplementation should be accompanied by a copper supplement, in order to prevent zinc-induced copper deficiency.

Zinc is important for normal pancreatic insulin production and release. Zinc deficiency is very common in people with type 2 diabetes and may be related to genetic susceptibility. In one study, zinc deficiency was present in 77% of subjects being treated with metformin (a widely used anti-diabetes drug) and 90% of subjects being treated with both metformin and glimepiride (another anti-diabetes drug). A growing body of evidence shows zinc supplementation may be helpful in preventing and treating type 2 diabetes, but only those with poor zinc status appear to benefit.

1. Cherry FF, Sandstead HH, Rojas P, et al. Adolescent pregnancy: associations among body weight, zinc nutriture, and pregnancy outcome. Am J Clin Nutr 1989;50:945-54.

Exercise increases losses from the human body, and severe zinc deficiency can compromise muscle function. Athletes who do not eat an optimal diet, especially those who are trying to control their weight or use fad diets while exercising strenuously, may become deficient in zinc to the extent that performance or health is compromised. One double-blind trial in women found that 135 mg per day of zinc for two weeks improved one measure of muscle strength. Whether these women were zinc deficient was not determined in this study. A double-blind study of male athletes with low blood levels of zinc found that 20 mg per day of zinc improved the flexibility of the red blood cells during exercise, which could benefit blood flow to the muscles. No other studies of the effects of zinc supplementation in exercising people have been done. A safe amount of zinc for long-term use is 20 to 40 mg per day along with 1 to 2 mg of copper. Higher amounts should be taken only under the supervision of a doctor.

It makes sense for people taking captopril long term to consider taking a zinc supplement or a multimineral tablet containing zinc as a precaution. (Such multiminerals usually contain no more than 99 mg of potassium, probably not enough to trigger the above-mentioned interaction.) Supplements containing zinc should also contain copper, to protect against a zinc-induced copper deficiency.

24. Reiser S, Powell A, Yang CY, Canary JJ. Effect of copper intake on blood cholesterol and its lipoprotein distribution in men. Nutr Rep Int 1987;36:641-9.

deficiency leads to reduced numbers of sperm and impotence in men. The correlation between blood levels of zinc and sperm quality remains controversial. Infertile men have been reported to have lower levels of zinc in their semen, than do men with normal fertility. Similarly, men with normal sperm density tend to have higher amounts of zinc in their semen, than do men with low sperm counts. However, other studies have found that a high concentration of zinc in the semen is related to decreased sperm motility in infertile men. A few studies have shown that oral zinc supplementation improves both sperm count motility, and the physical characteristics of sperm in some groups of infertile men. For infertile men with low semen zinc levels, a preliminary trial found that zinc supplements (240 mg per day) increased sperm counts and possibly contributed to successful impregnation by 3 of the 11 men. However, these studies all included small numbers of volunteers, and thus the impact of their conclusions is limited. In a controlled trial, 100 men with low sperm motility received either 57 mg of zinc twice daily or a placebo. After three months, there was significant improvement in sperm quality, sperm count, sperm motility, and fertilizing capacity of the sperm. The ideal amount of supplemental zinc remains unknown, but some doctors recommend 30 mg two times per day. Long-term zinc supplementation requires 1–2 mg of copper per day to prevent copper deficiency.

People with type 1 diabetes may be more likely to be zinc-deficient than their healthy counterparts. Low zinc status leads to impaired immune function and increased oxidative stress and has been linked to poorer glucose control. Zinc supplements have been found to increase antioxidant capacity and reduce lipid peroxidation in people with type 1 diabetes.

This image shows the finderscope and the optical tube clamp. The finderscope on this telescope is a 6x30 model, this is an upgrade I did years ago. Most of the time scopes of this class come with a smaller 5x24 finder, and quite often the finder bracket only has 3 locking screws instead of six like on this one (superior). The finderscope shown here is a quality unit. The optical tube clamp basically holds the telescope tube in the mount. It allows the tube to be rotated or moved forward or backward (to allow balancing) if necessary.

The deficiency associated with sickle cell anemia appears to play a role in various aspects of the illness. For example, preliminary research has correlated low zinc levels with poor growth in children with sickle cell anemia. In a preliminary trial, 12 people with sickle cell anemia received 25 mg of zinc every four hours for 3 to 18 months. The number of damaged red blood cells fell from 28% to 18.6%. Addition of 2 mg of copper per day did not inhibit the effect of zinc. (Zinc supplementation in the absence of copper supplementation induces a copper deficiency.) Patients with the highest number of damaged red blood cells had a marked response to zinc, but those with lower levels of damaged cells (less than 20% irreversibly sickled cells) had little or no response.

Despite evidence that zinc may be beneficial in people with type 1 diabetes, some doctors remain skeptical of high doses due to one 1994 study in which zinc supplementation, at a dose of 50 mg per day for 28 days, increased glycosylation (glucose-induced protein damage). This trial is hard to evaluate because zinc supplementation increases the life of blood cells and such an effect artificially increases the lab test results for glycosylation. In fact, laboratory studies suggest zinc can inhibit glycation. Until this issue is resolved, those with type 1 diabetes should consult a doctor before considering high-dose supplementation with zinc.

In a double-blind study, supplementation with oral , in the form of zinc sulfate, for two months resulted in complete disappearance of warts in 87% of people treated, whereas none of those receiving a placebo improved. The amount of zinc used was based on body weight, with a maximum of 135 mg per day. Similar results were seen in another double-blind study. These large amounts of zinc should be used under the supervision of a doctor. Side effects included nausea, vomiting, and mild abdominal pain.

The malabsorption produced by CF may adversely affect mineral absorption as well. Blood concentrations of were low in a group of children with CF. One child with CF was reported to have a severe generalized dermatitis that resolved upon correction of zinc and fatty acid deficiencies by using a formula containing zinc (about 3 mg per day) and medium chain triglycerides (amount not reported).[REF] In a double-blind trial, supplementation with 30 mg of zinc per day for one year significantly decreased the number of days that children with CF needed antibiotics to treat respiratory infections. The beneficial effect of zinc was more pronounced in children who had low or low–normal plasma zinc levels than in those who had higher levels.

The malabsorption that occurs in celiac disease can lead to multiple nutritional deficiencies. The most common nutritional problems in people with celiac disease include deficiencies of essential fatty acids, iron, vitamin D, vitamin K, calcium, magnesium, and folic acid. malabsorption also occurs frequently in celiac disease and may result in zinc deficiency, even in people who are otherwise in remission. People with newly diagnosed celiac disease should be assessed for nutritional deficiencies by a doctor. Celiac patients who have not yet completely recovered should supplement with a high-potency multivitamin-mineral. Some patients may require even higher amounts of some of these vitamins and minerals—an issue that should be discussed with their healthcare practitioner. Evidence of a nutrient deficiency in a celiac patient is a clear indication for supplementation with that nutrient.

6. Björksten B, Back O, Gustavson KH, et al. Zinc and immune function in Down's syndrome. Acta Paediatr Scand 1980;69:183-7.

Deficient levels have been reported in people with RA. Some trials have found that zinc reduced RA symptoms, but others have not. Some suggest that zinc might only help those who are zinc-deficient, and, although there is no universally accepted test for zinc deficiency, some doctors check white-blood-cell zinc levels.

A study found that adding 200 mg zinc per day to AZT treatment decreased the number of Pneumocystis carinii pneumonia and Candida infections in people with AIDS compared with people treated with AZT alone. The zinc also improved weight and CD4 cell levels. The amount of zinc used in this study was very high and should be combined with 1–2 mg of copper to reduce the risk of immune problems from the zinc long term.

In a study of 34 people with hypertension, six months of captopril or enalapril (ACE inhibitors related to quinapril) treatment led to decreased zinc levels in certain white blood cells, raising concerns about possible ACE inhibitor–induced zinc depletion.

10. Prasad A. Discovery of human zinc deficiency and studies in an experimental human model. Am J Clin Nutr 1991;53:403-12 [review].

Individuals who are bedridden for long periods may become deficient in zinc, which can affect the strength of bone that is formed. In a controlled study of healthy adults who were confined to bed, fluoride supplementation prevented zinc loss from the body. Bedridden individuals should consult a qualified healthcare practitioner for guidance in using fluoride to prevent zinc deficiency.

Refracting telescope partsand functions

and vitamin A, nutrients that aid in healing, are commonly used to help people with peptic ulcers. For example, the ulcers of people taking 50 mg of zinc three times per day healed three times faster than those of people who took placebo. Since some types of gastritis can progress to peptic ulcer, it is possible that taking it may be useful. Nevertheless, the research does not yet show that zinc specifically helps people with gastritis. The amount of zinc used in this study is very high compared with what most people take (15–40 mg per day). Even at these lower levels, it is necessary to take 1–3 mg of copper per day to avoid a zinc-induced copper deficiency.

The information presented by TraceGains is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires December 2024.

N-acetyl cysteine (NAC) may increase urinary excretion of zinc.16 Long-term users of NAC may consider adding supplements of zinc and copper.

Caution: Using zinc nasal spray has been reported to cause severe or complete loss of smell function. In some of those cases, the loss of smell was long-lasting or permanent.19

It makes sense for people taking enalapril long term to consider, as a precaution, taking a zinc supplement or a multimineral tablet containing zinc. (Such multiminerals usually contain no more than 99 mg of potassium, probably not enough to trigger the above-mentioned interaction.) Supplements containing zinc should also contain copper, to protect against a zinc-induced copper deficiency.

Fish oil alone has also been studied. In a double-blind trial, supplementation with menhaden oil, in the amount of 250 mg per 2.2 pounds of body weight per day for one year, reduced the frequency of severe pain episodes by approximately 45%, compared with placebo. This treatment may work by correcting an imbalance between omega-3 and omega-6 fatty acids that occurs in people with sickle cell anemia.

Though some studies indicate that supplementing with folic acid reduces blood levels of zinc, most show no interaction between the two nutrients when folic acid is taken at moderate levels. Therefore, until more convincing evidence is available, people taking moderate amounts of folic acid do not need to supplement with zinc. Zinc supplementation is recommended when folic acid intake is high. A doctor should be consulted to determine the appropriate time to add zinc supplementation to folic acid therapy.

Oral corticosteroids have been found to increase urinary loss of vitamin K, vitamin C, selenium, and . The importance of these losses is unknown.

People with liver cirrhosis appear to be commonly deficient in zinc.3 This deficiency may be due to cirrhosis-related zinc malabsorption.4

While zinc depletion has not been reported with ramipril, until more is known, it makes sense for people taking ramipril long term to consider, as a precaution, taking a zinc supplement or a multimineral tablet containing zinc. (Such multiminerals usually contain no more than 99 mg of potassium, probably not enough to trigger the above-mentioned interaction.) Supplements containing zinc should also contain copper, to protect against a zinc-induced copper deficiency.

7. Bucci I, Napolitano G, Giuliani C, et al. Zinc sulfate supplementation improves thyroid function in hypozincemic Down children. Biol Trace Elem Res 1999;67:257-68.

Refracting telescope partsdiagram

Even in developed countries, low-income pregnant women and pregnant teenagers are at risk for marginal zinc deficiencies. Supplementing with 25–30 mg per day improves pregnancy outcome in these groups.1, 2

Several double-blind trials indicate that supplements reduce the severity of acne. In one double-blind trial, though not in another, zinc was found to be as effective as oral antibiotic therapy. Doctors sometimes suggest that people with acne take 30 mg of zinc two or three times per day for a few months, then 30 mg per day thereafter. It often takes 12 weeks before any improvement is seen. Long-term zinc supplementation requires 1–2 mg of copper per day to prevent copper deficiency.

Topically applied zinc using zinc-containing bandages has improved healing of leg ulcers in double-blind studies of both zinc-deficient and elderly individuals. Most controlled comparison studies have reported that these bandages are no more effective than other bandages used in the conventional treatment of skin ulcers, but one controlled trial found non-elastic zinc bandages superior to alginate dressings or zinc-containing elastic stockinettes. Two controlled trials of zinc-containing tape for foot ulcers due to leprosy concluded that zinc tape was similarly effective, but more convenient than conventional dressings.

is a component of many enzymes, including some that are needed to repair wounds. Even a mild deficiency of zinc can interfere with optimal recovery from everyday tissue damage as well as from more serious trauma. Trace minerals, such as manganese, copper, and silicon are also known to be important in the biochemistry of tissue healing. However, there have been no controlled studies of people with sprains or strains to explore the effect of deficiency of these minerals, or of oral supplementation, on the rate of healing.

In a preliminary study, pregnant women who used a -containing nutritional supplement in the three months before and after conception had a 36% decreased chance of having a baby with a neural tube defect, and women who had the highest dietary zinc intake (but took no vitamin supplement) had a 30% decreased risk.

is a mineral nutrient important for proper immune system function and wound healing. One study found most surgery patients recovering at home had low dietary intakes of zinc. Low blood levels of zinc have been reported in patients after lung surgery. In one study this deficiency lasted for up to seven days after surgery and was associated with higher risk of pneumonia, while another study found an association between post-operative zinc deficiency and fatigue. Poor post-operative wound healing is also more common in people with zinc deficiency. Zinc supplements given to patients before surgery prevented zinc deficiency in one study, but the effect of these supplements on post-surgical health was not evaluated.

In a placebo-controlled trial that included 200 participants with prediabetes, average zinc levels were noted to be lower than normal and taking 20 mg of zinc per day for one year resulted in reduced blood glucose, cholesterol, and LDL-cholesterol levels, and improved the fasting response to glucose ingestion (glucose tolerance), measures of insulin resistance, and pancreatic cell function. Moreover, 25% of those in given placebo progressed to type 2 diabetes, while only 11% of those given zinc developed diabetes. Nevertheless, the relationship between zinc status and type 2 diabetes risk remains unclear, as some research has noted a correlation between higher blood zinc levels and increased diabetes risk.

Caution: Using zinc nasal spray has been reported to cause severe or complete loss of smell function. In some of those cases, the loss of smell was long-lasting or permanent.

Preliminary research had suggested that people with Alzheimer’s disease should avoid zinc supplements.20 More recently, preliminary evidence in four patients actually showed improved mental function with zinc supplementation.21 In a convincing review of zinc/Alzheimer’s disease research, perhaps the most respected zinc researcher in the world concluded that zinc does not cause or exacerbate Alzheimer’s disease symptoms.22

Prostatic secretions are known to contain a high concentration of ; that observation suggests that zinc plays a role in normal prostate function. In one preliminary study, 19 men with benign prostatic hyperplasia took 150 mg of zinc daily for two months, and then 50 to 100 mg daily. In 74% of the men, the prostate became smaller. Because this study did not include a control group, improvements may have been due to a placebo effect. Zinc also reduced prostatic size in an animal study but only when given by local injection. Although the research supporting the use of zinc is weak, many doctors recommend its use. Because supplementing with large amounts of zinc (such as 30 mg per day or more) may potentially lead to copper deficiency, most doctors recommend taking 2 to 3 mg of copper per day along with zinc.

After commencement of a gluten-free diet, overall nutritional status gradually improves. However, deficiencies of some nutrients may persist, even in people who are strictly avoiding gluten. For example, magnesium deficiency was found in 8 of 23 adults with celiac disease who had been following a gluten-free diet and were symptom-free. When these adults were supplemented with magnesium for two years, their bone mineral density increased significantly.

While zinc depletion has not been reported with lisinopril, until more is known, it makes sense for people taking lisinopril long term to consider, as a precaution, taking a zinc supplement or a multimineral tablet containing zinc. (Such multiminerals usually contain no more than 99 mg of potassium, probably not enough to trigger the above-mentioned interaction.) Supplements containing zinc should also contain copper, to protect against a zinc-induced copper deficiency.

is a component of many enzymes, including some that are needed to repair wounds. Even a mild deficiency of zinc can interfere with optimal recovery from everyday tissue damage, as well as from more serious trauma. One controlled trial found the healing time of a surgical wound was reduced by 43% with oral supplementation of 50 mg of zinc three times per day, in the form of zinc sulfate.

supplementation (20 mg per day) was reported to reduce the incidence of GH in one double-blind trial studying a group of low-income Hispanic pregnant women who were not zinc deficient.

deficiency has also been linked with recurrent canker sores in preliminary studies and in one case report. A preliminary trial found that supplementation with up to 150 mg of zinc per day reduced recurrences of canker sores by 50 to 100%; participants who were zinc deficient experienced the most consistent benefit. However, a double-blind trial (that did not test people for zinc deficiency) did not find zinc supplements helpful for recurrent canker sores.

preparations have been shown to inhibit the replication of herpes simplex in the test tube. In one study, people with recurrent herpes simplex infections applied a zinc sulfate solution daily to the sores. After healing occurred, the frequency of applications was reduced to once a week for a month, then to twice a month. During an observation period of 16 to 23 months, none of these people experienced a recurrence of their cold sores.

Chronic leg ulcers occur in about 75% of adults with sickle cell disease. In a controlled trial, sickle cell patients with low blood levels of zinc received 88 mg of zinc three times per day for 12 weeks. Ulcer healing rate was more than three times faster in the zinc group than in the placebo group. Zinc supplementation (25 mg 3 times per day for 3 months) also decreased the number of infections in adults with sickle cell anemia.

Zinc oxide, the only commercially available form of zinc for topical application, is probably ineffective as a treatment for herpes simplex. Other forms of topical zinc can be obtained by prescription, through a compounding pharmacist. However, because an excessive concentration of zinc may cause skin irritation, topical zinc should be used only with the supervision of a doctor knowledgeable in its use.

Taking methyltestosterone increased the amount of zinc in the blood and hair of boys with short stature or growth retardation. It is not known whether this increase would occur in other people or whether zinc supplementation by people taking methyltestosterone would result in zinc toxicity. Until more is known, zinc supplementation should be combined with methyltestosterone therapy only under the supervision of a doctor.

deficiency has been detected in people with anorexia or bulimia in most, though not all, studies. In addition, some of the manifestations of zinc deficiency, such as reduced appetite, taste, and smell, are similar to symptoms observed in some cases of anorexia or bulimia.

A controlled trial in people with type 2 diabetes with urinary protein loss (a sign of diabetes-related kidney damage) found that adding 50 mg of zinc (as zinc sulphate) to their diabetes treatment for 12 weeks improved blood glucose and triglyceride levels and reduced urinary protein loss. Studies have also shown that supplementing with a combination of melatonin (10 mg per day) plus zinc (50 mg per day [as zinc acetate]), can improve blood glucose and lipid levels and reduce urinary protein loss in people with type 2 diabetes.

Marginal zinc deficiency may be a contributing factor in some cases of anemia. In a study of women with normocytic anemia (in other words, their red blood cells were of normal size) and low total iron-binding capacity (a blood test often used to assess the cause of anemia), combined iron and zinc supplementation significantly improved the anemia, whereas iron or zinc supplemented alone had only slight effects.30 Supplementation with zinc, or zinc and iron together, has been found to improve vitamin A status among children at high risk for deficiency of the three nutrients.31

Iron , magnesium, and may bind with warfarin, potentially decreasing their absorption and activity. People on warfarin therapy should take warfarin and iron/magnesium/zinc-containing products at least two hours apart.

Preliminary research has found significant loss of zinc in urine triggered by taking captopril. In this trial, depletion of zinc reduced red blood cell levels of zinc. Although details remain unclear, it now appears that chronic use of captopril may lead to a zinc deficiency.

While zinc lozenges have been shown to be effective for reducing the symptoms and duration of the common cold in some controlled studies, it is not clear whether this effect is due to an enhancement of immune function or to the direct effect of zinc on the viruses themselves.

This photo shows the components above but at a slightly different angle. The drawtube is the part of the scope that moves in and out when the focusing knobs are rotated.

Zinc supplementation (25 mg or 50 mg three times daily) has also been used to successfully treat pregnant women with Wilson’s disease. Management of Wilson’s disease with zinc should only be undertaken with the close supervision of a doctor.

Alcoholic liver cirrhosis is associated with deficiency. In a double-blind trial, zinc acetate supplementation (200 mg three times daily, providing a total of 215 mg of elemental zinc per day), given to cirrhosis patients for seven days, significantly improved portal-systemic encephalopathy (PSE). A second trial achieved similar results after three months of treatment and a third trial found a beneficial effect from 6 months of treatment with 51 mg per day of zinc in the form of zinc L-carnosine complex. People with cirrhosis sometimes have impaired taste function, and it has been suggested that zinc deficiency may be the cause of this abnormality. Although one study demonstrated that taste problems in cirrhosis are due to the disease process itself and not to zinc deficiency, a double-blind trial showed that 200 mg three times per day of zinc sulfate (providing 135 mg of elemental zinc per day) for six weeks significantly improved taste function in people with alcoholic liver cirrhosis. A doctor should supervise long-term supplementation of zinc in these amounts.

Moderate intake of zinc, approximately 15 mg daily, is adequate to prevent deficiencies. Higher levels (up to 50 mg taken three times per day) are reserved for people with certain health conditions, under the supervision of a doctor. For the alleviation of cold symptoms, lozenges providing 13–25 mg of zinc in the form zinc gluconate, zinc gluconate-glycine, or zinc acetate are generally used frequently but only for several days.

Supplementation with 17 mg of twice a day (in the form of a zinc complex of L-carnosine) enhanced the response to interferon therapy in patients with chronic hepatitis C, in a preliminary trial. It is not known whether this benefit was due primarily to the zinc or the carnosine, or whether other forms of zinc would have the same effect.

supplements have been used to treat people who had both tinnitus and hearing loss (usually age-related). Of those who had initially low blood levels of zinc, about 25% experienced an improvement in tinnitus after taking zinc (90–150 mg per day for three to six months). Such large amounts of zinc should be monitored by a doctor. Two controlled clinical trials found no benefit from zinc supplementation (66 mg per day in one double-blind trial) in people with tinnitus. However, participants in these studies were not zinc deficient. Preliminary research suggests that zinc supplementation is only helpful for tinnitus in people who are zinc deficient. A doctor can measure blood levels of zinc.

4. Karayalcin S, Arcasoy A, Uzunalimoglu O. Zinc plasma levels after oral zinc tolerance test in nonalcoholic cirrhosis. Dig Dis Sci 1988;33:1096-102.

While zinc depletion has not been reported with ramipril, until more is known, it makes sense for people taking fosinopril long term to consider, as a precaution, taking a zinc supplement or a multimineral tablet containing zinc. (Such multiminerals usually contain no more than 99 mg of potassium, probably not enough to trigger the above-mentioned interaction.) Supplements containing zinc should also contain copper, to protect against a zinc-induced copper deficiency.

2. Goldenberg RL, Tamura T, Neggers Y, et al. The effect of zinc supplementation on pregnancy outcome. JAMA 1995;274:463-8.

Preliminary research has also demonstrated the ability of to reduce the concentration of volatile sulfur compounds in the mouth. One study found that the addition of zinc to a baking soda toothpaste lessened halitosis by lowering the levels of these compounds. A mouthrinse containing zinc chloride was seen in another study to neutralize the damaging effect of methyl mercaptan on periodontal tissue in the mouth.

In a study of 34 people with hypertension, six months of captopril or enalapril (ACE inhibitors related to trandolapril) treatment led to decreased zinc levels in certain white blood cells, raising concerns about possible ACE inhibitor–induced zinc depletion.

Animal studies suggest calcium and may be depleted by taking cholestyramine, another bile acid sequestrant. Whether these same interactions would occur with colestipol is not known.

People taking penicillamine should discuss with their doctor whether it would be appropriate to take a zinc supplement (at a separate time of day from the penicillamine). However, people taking penicillamine should not supplement with zinc, unless they are being supervised by a doctor.

Zinc deficiencies are quite common in people living in poor countries. Phytate, a substance found in unleavened bread (pita, matzos, and some crackers) significantly reduces absorption of zinc, increasing the chance of zinc deficiency. However, phytate-induced deficiency of zinc appears to be a significant problem only for people already consuming marginally low amounts of zinc.

Marginal deficiencies of result in immune function impairments. In a double-blind study of healthy elderly people, supplementing with 45 mg of zinc per day for one year significantly reduced the frequency of infections. Some doctors recommend lower amounts of supplemental zinc for people experiencing recurrent infections, such as 25 mg per day for adults and even lower amounts for children (depending on body weight). Zinc lozenges have been found helpful in some studies for the common cold. Long-term zinc supplementation should in most cases be accompanied by a copper supplement in order to prevent zinc-induced copper deficiency.

A review of literature suggests that women who use OCs may experience decreased vitamin B1, B2, B3, B12, C, and levels. OC use has been associated with increased absorption of calcium and copper and with increased blood levels of copper and vitamin A. OCs may interfere with manganese absorption. The clinical importance of these actions remains unclear.

Blood levels of both zinc and selenium are frequently low in people with HIV infection. Zinc supplements (45 mg per day) have been shown to reduce the number of infections in people with AIDS. Zinc supplementation (12 mg per day for women, 15 mg per day for men) also slowed the decline in immune function in HIV-infected adults with low blood levels of zinc.

Here's a close up of the finderscope. As mentioned, this finder is probably better than the finder that will come on an entry level scope (this is a 6x30 finderscope vs. the typical 5x24 finder that comes with many scopes). The bracket that holds this finder has six locking screws that hold it in place. When the scope is initially put together, one has to align the finder to the main scope (using the screws). Once adjusted, it should stay pretty much in line. Some of the entry level scopes come with only a 3 point adjustment, a setup that is not as secure. The finderscope is like a sight on a gun; one locates the object to be observed on the crosshairs of the finderscope (and if properly aligned) the object will then be centered in the main telescope. Finding objects without a finderscope is very difficult due to the relatively small field of view of the main scope. A typical finderscope will have a field of view that is several degrees wide, wide enough to easily locate and center objects.

In another preliminary trial, 13 patients with sickle cell anemia were given two supplement combinations for seven to eight months each. The first combination included 109 mg , 153 IU vitamin E, 600 mg vitamin C, and 400 ml (about 14 ounces) of soybean oil containing 11 grams of linoleic acid and 1.5 grams of alpha linolenic acid. The second combination included 140 IU vitamin E, 600 mg vitamin C, and 20 grams of fish oil containing 6 grams of omega-3 fatty acids. Reduction in diseased cells was observed only during the administration of the first protocol. The authors concluded that zinc was the important difference between the two combinations and may be a protector of red blood cell membranes.

29. Johnson AR, Munoz A, Gottlieb JL, Jarrard DF. High dose zinc increases hospital admissions due to genitourinary complications. J Urol 2007;177:639-43.

This photo shows a close up of the counterweight and declination shaft. The counterweight's position on the shaft is adjustable to allow fine balancing of the scope.

This photo shows another control of the equatorial mount, the latitude adjustment lever. When using an equatorial mount, one has to set it to the latitude of the observing site in order to allow the mount to accurately be able to track objects. In general this setting is made once (unless you take the scope a significant distance north or south of the normal observing location. Also shown is the other side of the right ascension slow motion control (the control extends out of the photo, it has a knob at the end).

A number of different forms of zinc are used in supplements. Zinc oxide appears to be less bioavailable than other forms, whereas zinc sulfate is not as well tolerated as other forms; therefore, forms other than zinc oxide and zinc sulfate are preferable. There is some evidence indicating that zinc picolinate has better bioavailability than other forms, although zinc citrate, zinc acetate, zinc gluconate, zinc methionine, and zinc aspartate also appear to be acceptable to use. When used in lozenges for colds, zinc acetate and zinc gluconate are the preferred forms.11

While zinc depletion has not been reported with ramipril, until more is known, it makes sense for people taking perindopril long term to consider, as a precaution, taking a zinc supplement or a multimineral tablet containing zinc. (Such multiminerals usually contain no more than 99 mg of potassium, probably not enough to trigger the above-mentioned interaction.) Supplements containing zinc should also contain copper, to protect against a zinc-induced copper deficiency.

Crohn’s disease often leads to malabsorption. As a result, deficiencies of many nutrients are common. For this reason, it makes sense for people with Crohn’s disease to take a high potency multivitamin-mineral supplement. In particular, deficiencies in , folic acid, vitamin B12, vitamin D, and iron have been reported. Zinc, folic acid, and vitamin B12 are all needed to repair intestinal cells damaged by Crohn’s disease. Some doctors recommend 25 to 50 mg of zinc (balanced with 2 to 4 mg of copper), 800 mcg of folic acid, and 800 mcg of vitamin B12 daily. Iron status should be evaluated by a doctor before considering supplementation.

Bile acid sequestrants may prevent absorption of folic acid and the fat-soluble vitamins A, D, E, and K. Other medications and vitamin supplements should be taken one hour before or four to six hours after bile acid sequestrants for optimal absorption. Animal studies suggest calcium and may also be depleted by taking cholestyramine.

14. Argiratos V, Samman S. The effect of calcium carbonate and calcium citrate on the absorption of zinc in healthy female subjects. Eur J Clin Nutr 1994;48:198-204.

In healthy men, prostatic secretions contain a significant amount of , which has antibacterial activity and is a key factor in the natural resistance of the male urinary tract infection. In CBP and NBP these zinc levels are significantly reduced; however, it is not clear whether this indicates a predisposition to, or is the result of, prostatic infection. Zinc supplements increased semen levels of zinc in men with NBP in one study,but not in another. While zinc supplements have been associated with improvement of benign prostatic hyperplasia (BPH), according to one preliminary report, no research has examined their effectiveness for prostatitis. Nonetheless, many doctors of natural medicine recommend zinc for this condition.

plays an important role in tissue growth processes important for skin ulcer healing. One study reported that patients with pressure ulcers had lower blood levels of zinc and iron than did patients without pressure ulcers, and preliminary reports suggested zinc supplements could help some types of skin ulcer. Supplementation with 150 mg of zinc per day improved healing in a preliminary study of elderly patients suffering from chronic leg ulcers. Double-blind trials using 135 to 150 mg of zinc daily have shown improvement only in patients with low blood zinc levels, and no improvement in leg ulcer healing. A double-blind trial of 150 mg zinc per day in people with skin ulcers due to sickle cell anemia found that the healing rate was almost three times faster in the zinc group than in the placebo group after six months. Lastly, a preliminary study of patients with skin ulcers due to leprosy found that 50 mg of zinc per day in addition to anti-leprosy medication resulted in complete healing in most patients within 6 to 12 weeks. Long-term zinc supplementation at these levels should be accompanied by supplements of copper and perhaps calcium, iron, and magnesium. Large amounts of zinc (over 50 mg per day) should only be taken under the supervision of a doctor.

is known for its ability to reduce copper absorption and has been used successfully in patients with Wilson’s disease, with some trials lasting for years years. Researchers have called zinc a “remarkably effective and nontoxic therapy for Wilson’s disease.” The U.S. Food and Drug Administration has approved the use of zinc to treat Wilson’s disease for maintenance therapy following drug therapy, although some scientists recommend that it be considered for initial therapy as well.

20. Bush AI, Pettingell WH, Multhaup G, et al. Rapid induction of Alzheimer A8 amyloid formation by zinc. Science 1994;265:1464-5.

A review of literature suggests that women who use oral contraceptives may experience decreased vitamin B1, B2, B3, B12, C, and levels. Oral contraceptive use has been associated with increased absorption of calcium and copper and with increased blood levels of copper and vitamin A.Oral contraceptives may interfere with manganese absorption. The clinical importance of these actions remains unclear.

In a study of 34 people with hypertension, six months of captopril or enalapril (ACE inhibitors related to fosinopril) treatment led to decreased zinc levels in certain white blood cells, raising concerns about possible ACE inhibitor–induced zinc depletion.

Test tube studies have shown that propionyl-L-carnitine (a form of L-carnitine) protects red blood cells of people with thalassemia against free radical damage. In a preliminary study, children with beta thalassemia major who took 100 mg of L-carnitine per 2.2 pounds of body weight per day for three months had a significantly decreased need for blood transfusions. Some studies have found people with thalassemia to be frequently deficient in folic acid, vitamin B12, and . Researchers have reported improved growth rates in zinc-deficient thalassemic children who were given zinc supplements of 22.5 to 90 mg per day, depending on age.Magnesium has been reported to be low in thalassemia patients in some, but not all, studies. A small, preliminary study reported that oral supplements of magnesium, 7.2 mg per 2.2 pounds of body weight per day, improved some red blood cell abnormalities in thalassemia patients.

Supplementation with brings about complete remission in hereditary acrodermatitis enteropathica. Zinc supplements in the amount of 30 to 150 mg per day are used by people with this condition. People with acrodermatitis enteropathica need to be monitored by a healthcare professional to ensure that their level of zinc supplementation is adequate and that the zinc supplements are not inducing a copper deficiency.

In a double-blind study of children in Turkey, oral zinc supplementation significantly reduced both the incidence (by 29%) and the duration (by 11%) of the common cold. The amount of zinc used in this seven-month study was 15 mg per day for children with an average age of 5.6 years. The amount of supplemental zinc was doubled at the onset of a cold, and this higher amount was continued until symptoms resolved.

Preliminary human research suggests AZT therapy may cause a reduction in copper and blood levels. The practical importance of these findings remains unclear.

Oral corticosteroids have been found to increase urinary loss of vitamin K, vitamin C, selenium, and . The importance of these losses is unknown.

Taking mineral supplements or antacids that contain aluminum, calcium, iron, magnesium, or at the same time as tetracyclines inhibits the absorption of the drug. Therefore, individuals should take tetracyclines at least two hours before or after products containing minerals.

In a test tube, is capable of inactivating the type of herpes virus responsible for the majority of genital herpes cases. Topical zinc may therefore help prevent outbreaks of genital herpes. One preliminary study treated people (four of whom had genital herpes) with a 4% zinc sulfate solution applied to the site of the initial outbreak. In all cases, the pain, burning, and tingling stopped within 24 hours of beginning the topical zinc therapy. The use of lower concentrations of zinc (0.025–0.05%) has also been shown effective against oral and genital herpes outbreaks. While topical zinc has been shown to be helpful, there is no convincing evidence that oral zinc offers the same benefits.

Research has shown that supplementing with chromium (200 mcg per day) or magnesium (340 mg per day) can prevent blood sugar levels from falling excessively in people with hypoglycemia. Niacinamide (vitamin B3) has also been found to be helpful for hypoglycemic people. Other nutrients, including vitamin C, vitamin E, , copper, manganese, and vitamin B6, may help control blood sugar levels in diabetics. Since there are similarities in the way the body regulates high and low blood sugar levels, these nutrients might be helpful for hypoglycemia as well, although the amounts needed for that purpose are not known.

In a study of 34 people with hypertension, six months of captopril or enalapril (ACE inhibitors related to ramipril) treatment led to decreased zinc levels in certain white blood cells, raising concerns about possible ACE inhibitor–induced zinc depletion.

People with renal failure or on hemodialysis often have low blood levels of zinc, which may produce symptoms such as abnormal taste or smell, reduced sexual functions, and poor immunity. One controlled study showed that taking zinc at the same time as calcium acetate reduces absorption of zinc. Therefore, people should avoid taking calcium acetate and zinc supplements together. Another controlled study revealed that neither short-term nor long-term treatment with calcium acetate results in reduced blood zinc levels. Thus, while calcium acetate reduces the amount of zinc absorbed from supplements, long-term treatment with the drug does not appear to affect overall zinc status. However, people with renal failure who experience symptoms of zinc deficiency might benefit from supplementing with zinc, regardless of whether or not they take calcium acetate.

5. Stabile A, Pesaresi MA, Stabile AM, et al. Immunodeficiency and plasma zinc levels in children with Down's syndrome: a long-term follow-up of oral zinc supplementation. Clin Immunol Immunopathol 1991;58:207-16.

31. Muñoz EC, Rosado JL, Lopez P, et al. Iron and zinc supplementation improves indicators of vitamin A status of Mexican preschoolers. Am J Clin Nutr 2000;71:789-94.

The average diet frequently provides less than the Recommended Dietary Allowance for zinc, particularly in vegetarians. To what extent (if any) these small deficits in zinc intake create clinical problems remains unclear. Nonetheless, a low-potency supplement (15 mg per day) can fill in dietary gaps. Zinc deficiencies are more common in alcoholics and people with sickle cell anemia, malabsorption problems, and chronic kidney disease.10

Using a topical zinc solution with topical erythromycin increases the effectiveness of the antibiotic in the treatment of inflammatory acne.

3. Scholmerich J, Lohle E, Kottgen E, Gerok W. Zinc and vitamin A deficiency in liver cirrhosis. Hepatogastroenterology 1983;30:119-25.

Zinc intake in excess of 300 mg per day has been reported to impair immune function.17 Some people report that zinc lozenges lead to stomach ache, nausea, mouth irritation, and a bad taste. One source reports that gastrointestinal upset, metallic taste in the mouth, blood in the urine, and lethargy can occur from chronic oral zinc supplementation over 150 mg per day,18 but those claims are unsubstantiated. In topical form, zinc has no known side effects when used as recommended.

8. Wollowa F, Jablonska S. Zinc in the treatment of alopecia areata. In: Kobori Y, Montagna W (eds). Biology and Diseases of the Hair. Tokyo: University Park Press, 1976, 305.

Blood levels of the antioxidant minerals selenium and were normal in one study of people with Down syndrome, but others have found selenium and zinc levels to be low. In some studies more than 60% of patients with Down syndrome had low zinc levels. A preliminary study of selenium supplementation in children with Down syndrome found that the antioxidant activity in the body improved; however, the implications of this finding on the long-term health of these people is unclear. Zinc is critical for proper immune function, and in one preliminary study the majority of patients with Down syndrome examined had low zinc levels and low immune cell activity. Supplementation with zinc resulted in improved immune cell activity. In preliminary intervention trials, improved immune cell activity was associated with reduced rates of infection in Down syndrome patients given supplemental zinc in the amount of 1 mg per 2.2 pounds of body weight per day. A controlled trial, however, did not find zinc, at 25 mg daily for children under 10 years of age and 50 mg for older children, to have these benefits. Zinc has other roles in the body; preliminary data have indicated that zinc supplementation, at 1 mg per 2.2 pounds of body weight per day, improved thyroid function in Down syndrome patients, and increased growth rate in children with Down syndrome.

This view shows the most fundamental component of a refractor telescope: the objective lens. You know you have a refractor telescope if it has a lens up front (a lens with no center obstruction). If your scope has a mirror at the back, it is a reflector. Also shown here is the dew shield. This slows the formation of dew on the lens and allows longer viewing. Regarding the objective: you should NOT take it apart to clean it! The lenses on most entry level scopes are known as achromats, that is, they have 2 elements. DO NOT take these apart! They are lined up (in rotational position) at the factory for the best image, and if you take it apart and forget to mark it chances are it will not go back together in the proper orientation. The odds of crud getting in between the two optical components are slim, so there is no need to disassemble the objective. The only surface that should ever need cleaning (and this should only be occasional cleaning) is the portion of the objective that faces the sky. Not shown here is a lens cap, this should always be in place when the scope is not in use.

Zinc inhibits copper absorption. Copper deficiency can result in anemia, lower levels of HDL (“good”) cholesterol, neurological disorders, and cardiac arrhythmias.23, 24, 25 Copper intake should be increased if zinc supplementation continues for more than a few days (except for people with Wilson’s disease).26 Some sources recommend a 10:1 ratio of zinc to copper. Evidence suggests that no more that 2 mg of copper per day is needed to prevent zinc-induced copper deficiency. Many zinc supplements include copper in the formulation to prevent zinc-induced copper deficiency. Zinc-induced copper deficiency has been reported to cause reversible anemia and suppression of bone marrow.27 In addition, there are case reports of neurologic abnormalities due to copper deficiency occurring in people who had been using large amounts of certain widely available denture creams that contained high concentrations of zinc.28

13. Crofton RW, Gvozdanovic D, Gvozdanovic S, et al. Inorganic zinc and the intestinal absorption of ferrous iron. Am J Clin Nutr 1989;50:141-4.

Antioxidant nutrients protect the body’s cells from oxygen-related damage. Many studies show that sickle cell anemia patients tend to have low blood levels of antioxidants, including carotenoids, vitamin A, vitamin E, and vitamin C, despite adequate intake. Low blood levels of vitamin E in particular have been associated with higher numbers of diseased cells in children and with greater frequency of symptoms in adults. A small, preliminary trial reported a 44% decrease in the average number of diseased cells in six sickle cell anemia patients given 450 IU vitamin E per day for up to 35 weeks. This effect was maintained as long as supplementation continued.

Intake of 3 grams of aspirin per day has been shown to decrease blood levels of zinc. Aspirin appeared to increase loss of zinc in the urine in this study, and the effect was noted beginning three days after starting aspirin.

Refracting telescopeexamples

Reflectingtelescopediagram

9. Lutz G. The value of zinc in treatment of alopecia areata. 2nd Meeting of the European Hair Research Society, Bologna, April 14, 1991.

One trial studying postmenopausal women combined hormone replacement therapy with magnesium (600 mg per day), calcium (500 mg per day), vitamin C, B vitamins, vitamin D, zinc, copper, manganese, boron, and other nutrients for an eight- to nine-month period. In addition, participants were told to avoid processed foods, limit protein intake, emphasize vegetable over animal protein, and limit consumption of salt, sugar, alcohol, coffee, tea, chocolate, and tobacco. Bone density increased a remarkable 11%, compared to only 0.7% in women receiving hormone replacement alone.

Our proprietary “Star-Rating” system was developed to help you easily understand the amount of scientific support behind each supplement in relation to a specific health condition. While there is no way to predict whether a vitamin, mineral, or herb will successfully treat or prevent associated health conditions, our unique ratings tell you how well these supplements are understood by the medical community, and whether studies have found them to be effective for other people.

In a study of elderly people with macular degeneration, supplementing with 80 mg of zinc per day for an average of about six years increased by about 50% the incidence of hospitalizations due to genitourinary causes (such as urinary tract infections, kidney stones, and urinary retention).29 In that study, copper was also given, but in a form that cannot be absorbed by humans (cupric oxide). The reported adverse effect of zinc may have been due in large part to zinc-induced copper deficiency, which could be prevented by taking copper in a form other than cupric oxide. Nevertheless, it would be prudent for elderly people wishing to take large amounts of zinc to consult with a doctor.

26. Fischer PWF, Giroux A, Labbe MR. Effect of zinc supplementation on copper status in adult man. Am J Clin Nutr 1984;40:743-6.

15. Spencer H, Norris C, Williams D. Inhibitory effects of zinc on magnesium balance and magnesium absorption in man. J Am Coll Nutr 1994;13:479-84.

25. Sandstead HH. Requirements and toxicity of essential trace elements, illustrated by zinc and copper. Am J Clin Nutr 1995;61(suppl):621S-24S [review].

Whether oral zinc helps tissue healing when no actual zinc deficiency exists is unclear, but doctors often recommend 30 mg of zinc per day for four to six weeks to aid in the healing of wounds. Topical zinc-containing treatments, on the other hand, have improved healing of skin wounds even when there is no deficiency. Long-term oral zinc supplementation must be accompanied by copper supplementation to prevent a zinc-induced copper deficiency. Typically, if 30 mg of zinc are taken each day, it should be accompanied by 2 mg of copper. If 60 mg of zinc are used, it should be accompanied by 3 mg of copper each day.

is another mineral antioxidant nutrient that the immune system requires. Zinc deficiency results in lowered immune defenses, and zinc supplementation increases immune activity in people with certain illnesses. As with vitamin A, zinc levels have been observed to fall during the early stages of measles infection and to return to normal several days later. There is evidence that zinc supplements are helpful in specific viral infections, but there are no data on the effect of zinc on childhood exanthemous infections.

In an uncontrolled trial, supplementation with 45–90 mg per day of zinc resulted in weight gain in 17 out of 20 anorexics after 8–56 months. In a double-blind study, 35 women hospitalized with anorexia, given 14 mg of zinc per day, achieved a 10% increase in weight twice as fast as the group that received a placebo. In another report, a group of adolescent girls with anorexia, some of whom were hospitalized, was found to be consuming 7.7 mg of zinc per day in their diet—only half the recommended amount. Providing these girls with 50 mg of zinc per day in a double-blind trial helped diminish their depression and anxiety levels, but had no significant effect on weight gain. Anyone taking zinc supplements for more than a few weeks should also supplement with 1 to 3 mg per day of copper to prevent a zinc-induced copper deficiency.

PeaceHealth endeavors to provide comprehensive health care information, however some topics in this database describe services and procedures not offered by our providers or within our facilities because they do not comply with, nor are they condoned by, the ethics policies of our organization.

Use your browser's "back" button, or use links below if you arrived here via some other path: This page is part of the site Amateur Astronomer's Notebook. E-mail to Joe Roberts Images and HTML text © Copyright 2007 by Joe Roberts. Please request permission to use photos for purposes other than "personal use".

People with Down’s syndrome are also commonly deficient in zinc.5 Giving zinc supplements to children with Down’s syndrome has been reported to improve impaired immunity6 and thyroid function,7 though optimal intake of zinc for people with Down’s syndrome remains unclear.

When iodine deficiency is present, other nutrient levels become important in the development of goiter. Deficiencies of and manganese can both contribute to iodine-deficiency goiter; however, an animal study found that manganese excess can also be goitrogenic. It has been suggested that selenium deficiency may contribute to goiter. However, when selenium supplements were given to people deficient in both iodine and selenium, thyroid dysfunction was aggravated, and it has been suggested that selenium deficiency may provide some protection when there is iodine deficiency. A study of the effects of selenium supplementation at 100 mcg daily in women without selenium deficiency but with slightly low iodine intake found no effect on thyroid function. The authors concluded that selenium supplementation seems to be safe in people with only iodine deficiency but not in people with combined selenium and iodine deficiencies. In those cases, iodine supplementation has been shown to be most useful. No studies have been done to evaluate the usefulness of supplementation with zinc or manganese to prevent or treat goiter.

People with DH frequently have mild malabsorption (difficulty absorbing certain nutrients) associated with low stomach acid (hypochlorhydria) and inflammation of the stomach lining (atrophic gastritis). Mild malabsorption may result in anemia and nutritional deficiencies of iron, folic acid,vitamin B12, and . More severe malabsorption may result in loss of bone mass. Additional subtle deficiencies of vitamins and minerals are possible, but have not been investigated. Therefore, some doctors recommend people with DH have their nutritional status checked regularly with laboratory studies. These doctors may also recommend multivitamin-mineral supplements and, to correct the low stomach acid, supplemental betaine HCl (a source of hydrochloric acid).

Most, but not all, double-blind studies have shown that elderly people have better immune function and reduced infection rates when taking a multiple vitamin-mineral formula. In one double-blind trial, supplements of 100 mcg per day of selenium and 20 mg per day of , with or without additional vitamin C, vitamin E, and beta-carotene, reduced infections in elderly people, though vitamins without minerals had no effect. Burn victims have also experienced fewer infections after receiving trace mineral supplements in double-blind research. These studies suggest that trace minerals may be the most important micronutrients for enhancing immunity and preventing infections in the elderly.

Here's another view of the equatorial mount. Note that each axis has a locking clamp; these lock the position of the optical tube once an object has been located for viewing. The counterweight is used to balanced the weight of the optical tube (a well balanced mount will allow much smoother operation and better tracking). This view also shows the declination slow motion control. This allows the scope's position to be finely adjusted in declination (very handy for centering up the object to be viewed once it has been acquired in the eyepiece). Not all equatorial scopes will have slow motion controls, however they are very handy to have. Some scopes will have electronic versions.

Two important enzymes in the retina that are needed for vision require . In a double-blind trial, supplementation with 45 mg of zinc per day for one to two years significantly reduced the rate of visual loss in people with macular degeneration. However, in another double-blind trial, supplementation with the same amount of zinc did not prevent vision loss among people with a particular type of macular degeneration (the exudative form).

23. Broun ER. Greist A, Tricot G, Hoffman R. Excessive zinc ingestion. A reversible cause of sideroblastic anemia and bone marrow depression. JAMA 1990;264:1441-3.

Many doctors recommend that people with type 2 diabetes and low zinc levels supplement with 15 to 25 mg of zinc per day to normalize zinc levels. Taking high doses of supplemental zinc long term increases the risk of copper deficiency. Most multivitamin-mineral supplements provide adequate copper to prevent deficiency.

A review of literature suggests that women who use oral contraceptives may experience decreased vitamin B1, B2, B3, B12, C, and levels. Oral contraceptive use has been associated with increased absorption of calcium and copper and with increased blood levels of copper and vitamin A.Oral contraceptives may interfere with manganese absorption. The clinical importance of these actions remains unclear.

In a study of 34 people with hypertension, six months of captopril or enalapril treatment led to decreased zinc levels in certain white blood cells.

21. Potocnik FCV, van Rensburg SJ, Park C, et al. Zinc and platelet membrane microviscosity in Alzheimer's disease. S Afr Med J 1997;87:1116-9.

An analysis of the major zinc trials has claimed that evidence for efficacy is “still lacking.” However, despite a lack of statistical significance, this compilation of data from six double-blind trials found that people assigned to zinc had a 50% decreased risk of still having symptoms after one week compared with those given placebo. Some trials included in this analysis used formulations containing substances that may inactivate zinc salts. Other reasons for failure to show statistical significance, according to a recent analysis of these studies, may have been small sample size (not enough people) or not enough zinc given. Thus, there are plausible reasons why the authors were unable to show statistical significance, even though positive effects are well supported in most trials using gluconate, gluconate-glycine, or acetate forms of zinc.

Refracting telescopediagram

Zinc is an essential mineral that is a component of more than 300 enzymes needed to repair wounds, maintain fertility in adults and growth in children, synthesize protein, help cells reproduce, preserve vision, boost immunity, and protect against free radicals, among other functions.

27. Broun ER. Greist A, Tricot G, Hoffman R. Excessive zinc ingestion. A reversible cause of sideroblastic anemia and bone marrow depression. JAMA 1990;264:1441-3.

This information does not replace the advice of a doctor. Ignite Healthwise, LLC disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use and Privacy Policy. Learn how we develop our content.

supplements have been reported to increase immune function. This effect may be especially important in the elderly according to double-blind studies. Some doctors recommend zinc supplements for people with recurrent infections, suggesting 25 mg per day for adults and lower amounts for children (depending on body weight). However, too much zinc (300 mg per day) has been reported to impair immune function.

In a study of 34 people with hypertension, six months of captopril or enalapril treatment led to decreased zinc levels in certain white blood cells.

Oral corticosteroids have been found to increase urinary loss of vitamin K, vitamin C, selenium, and . The importance of these losses is unknown.

This page is part of the site Amateur Astronomer's Notebook. E-mail to Joe Roberts Images and HTML text © Copyright 2007 by Joe Roberts. Please request permission to use photos for purposes other than "personal use".

While zinc depletion has not been reported with ramipril, until more is known, it makes sense for people taking trandolapril long term to consider, as a precaution, taking a zinc supplement or a multimineral tablet containing zinc. (Such multiminerals usually contain no more than 99 mg of potassium, probably not enough to trigger the above-mentioned interaction.) Supplements containing zinc should also contain copper, to protect against a zinc-induced copper deficiency.

Another group of doctors has reported good results using a combination of , manganese, and vitamin B6 for people with Osgood-Schlatter disease; however, the amounts of these supplements were not mentioned in the report. Most physicians would consider reasonable daily amounts of these nutrients for adolescents to be 15 mg of zinc, 5 to 10 mg of manganese, and 25 mg of vitamin B6. Larger amounts might be used with medical supervision.

supplements have also been reported to increase immune function. As a result, some doctors recommend zinc supplements for people with recurrent ear infections, suggesting 25 mg per day for adults and lower amounts for children. For example, a 30-pound child might be given 5 mg of zinc per day while suffering from OM. Nonetheless, zinc supplementation has not been studied in people with ear infections.

In a study of 34 people with hypertension, six months of captopril or enalapril (ACE inhibitors related to lisinopril) treatment led to decreased zinc levels in certain white blood cells, raising concerns about possible ACE inhibitor–induced zinc depletion.

Zinc has also been used to keep normal copper levels from rising in people with Wilson’s disease who had previously been treated successfully with prescription drugs. Zinc (50 mg taken three times per day) has been used for such maintenance therapy, though some researchers have used the same amount of zinc to successfully treat people with Wilson’s disease who had not received drug therapy.

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