How many zinc per day

We include products we think are useful for our readers. If you buy through links on this page, we may earn a small commission. Zinc is a nutrient that supports growth during childhood and the immune system. Zinc supports a number of functions in the human body. As well as supporting the immune system, it enables the body to make proteins and DNA, contributes to wound healing, and plays a role in childhood growth and development. It also has antioxidant properties. Zinc occurs naturally in many foods, such as beans, meat, and fish.

It is also available as a dietary supplement. This article looks at the health benefits of zinc, what happens if a person does not have enough zinc, and useful sources.

Zinc is crucial for various functions in the body, including:. The body needs zinc for the immune system to work properly.

Low levels of zinc can increase the risk of infections, such as pneumonia. How can you stay healthy with a weak immune system? There is evidence that it can shorten bouts of diarrhea, especially in those who do not have a nutritious diet. People with long-term wounds or ulcers often have low zinc levels. Healthcare professionals may recommend zinc supplements for people with persistent wounds. Research from notes that zinc plays a key role in every stage of wound healing, from skin repair to preventing infections.

The authors call for more studies to identify precisely how zinc works in healing wounds. This, they say, could lead to new treatments for wounds that are hard to heal. Find out how to make a wound heal faster.

Zinc has antioxidant properties. As such, it can help reduce oxidative stress. Scientists believe that there is a link between oxidative stress and chronic diseases, such as high blood pressure , diabetes , and other aspects of metabolic syndrome.

Research from suggests that zinc may help prevent metabolic syndrome. They recommend further studies to identify how zinc affects health and to see whether supplementation might be useful as a therapy. Zinc prevents cell damage in the retina, and it may help delay the progression of age-related macular degeneration and vision loss, according to the National Institutes of Health NIH. However, it is unlikely to prevent the degeneration. The authors of research from have found that a zinc deficiency may play a role in developing this degeneration.

They call for further studies and suggest that zinc might contribute to new treatment approaches. Low zinc levels may lead to delayed sexual development, fertility problems, and other sexual health issues in males. The authors of research from describe zinc as essential to male sexual health. Children in developing countries often die from diarrhea. Studies show that zinc dietary supplements help reduce the symptoms and duration of diarrhea in these children, many of whom are zinc deficient or otherwise malnourished.

It is not clear whether zinc dietary supplements can help treat diarrhea in children who get enough zinc, such as most children in the United States. Some studies suggest that zinc lozenges or syrup but not zinc dietary supplements in pill form help speed recovery from the common cold and reduce its symptoms if taken within 24 hours of coming down with a cold.

However, more study is needed to determine the best dose and form of zinc, as well as how long it should be taken before zinc can be recommended as a treatment for the common cold.

AMD is an eye disease that gradually causes vision loss. Research suggests that zinc might help slow AMD progression. In a large study among older people with AMD who were at high risk of developing advanced AMD, those who took a daily dietary supplement with 80 mg zinc, mg vitamin C, IU vitamin E, 15 mg beta-carotene , and 2 mg copper for about 6 years had a lower chance of developing advanced AMD and less vision loss than those who did not take the dietary supplement.

In the same study, people at high risk of the disease who took dietary supplements containing only zinc also had a lower risk of getting advanced AMD than those who did not take zinc dietary supplements. People who have or are developing the disease might want to talk with their doctor about taking dietary supplements. Yes, if you get too much. Signs of too much zinc include nausea, vomiting, loss of appetite, stomach cramps, diarrhea, and headaches.

When people take too much zinc for a long time, they sometimes have problems such as low copper levels, lower immunity, and low levels of HDL cholesterol the "good" cholesterol. The daily upper limits for zinc include intakes from all sources—food, beverages, and supplements—and are listed below.

These levels do not apply to people who are taking zinc for medical reasons under the care of a doctor:. Zinc dietary supplements can interact or interfere with medicines that you take and, in some cases, medicines can lower zinc levels in the body.

Here are several examples:. Tell your doctor, pharmacist, and other healthcare providers about any dietary supplements and medicines you take. They can tell you if those dietary supplements might interact or interfere with your prescription or over-the-counter medicines or if the medicines might interfere with how your body absorbs, uses, or breaks down nutrients.

Foods contain vitamins, minerals, dietary fiber , and other components that benefit health. In some cases, fortified foods and dietary supplements are useful when it is not possible to meet needs for one or more nutrients e. For more information about building a healthy dietary pattern, see the Dietary Guidelines for Americans and the U. This fact sheet by the Office of Dietary Supplements ODS provides information that should not take the place of medical advice.

We encourage you to talk to your healthcare providers doctor, registered dietitian, pharmacist, etc. Any mention in this publication of a specific product or service, or recommendation from an organization or professional society, does not represent an endorsement by ODS of that product, service, or expert advice.

Updated: March 22, History of changes to this fact sheet. Find ODS on:. Zinc 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. 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. Long-term zinc supplementation should be accompanied by a copper supplement, in order to prevent zinc-induced copper deficiency.

Alcoholic liver cirrhosis is associated with zinc deficiency. In a double-blind trial, zinc acetate supplementation mg three times daily, providing a total of 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 mg three times per day of zinc sulfate providing 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. Zinc 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. 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 another report, a group of adolescent girls with anorexia, some of whom were hospitalized, was found to be consuming 7. 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.

In a double-blind study, children with ADHD who received 15 mg of zinc 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. Zinc deficiency has also been linked with recurrent canker sores in preliminary studies and in one case report.

However, a double-blind trial that did not test people for zinc deficiency did not find zinc supplements helpful for recurrent canker sores. 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. Zinc 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.

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. Zinc 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. 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.

The amount of zinc used in this seven-month study was 15 mg per day for children with an average age of 5. The amount of supplemental zinc was doubled at the onset of a cold, and this higher amount was continued until symptoms resolved. 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 zinc , 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 , mcg of folic acid, and mcg of vitamin B12 daily. Iron status should be evaluated by a doctor before considering supplementation.

In a test tube, zinc 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. 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. While topical zinc has been shown to be helpful, there is no convincing evidence that oral zinc offers the same benefits. Preliminary research has also demonstrated the ability of zinc 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. Supplementation with 17 mg of zinc 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.

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.

Marginal deficiencies of zinc 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. Two important enzymes in the retina that are needed for vision require zinc. 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. Zinc 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.

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.

The amount of the zinc carnosine complex used in research studies for eradication of H. Deficient zinc 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.

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. This effect was maintained as long as supplementation continued.

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 mg zinc , IU vitamin E , mg vitamin C , and ml about 14 ounces of soybean oil containing 11 grams of linoleic acid and 1.

The second combination included IU vitamin E, 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.

Fish oil alone has also been studied. In a double-blind trial, supplementation with menhaden oil, in the amount of mg per 2. This treatment may work by correcting an imbalance between omega-3 and omega-6 fatty acids that occurs in people with sickle cell anemia.

The zinc 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. 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.

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 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 mg of zinc per day improved healing in a preliminary study of elderly patients suffering from chronic leg ulcers. Double-blind trials using to 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 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. 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. 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.

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 mg of L-carnitine per 2. Some studies have found people with thalassemia to be frequently deficient in folic acid , vitamin B12 , and zinc. Researchers have reported improved growth rates in zinc-deficient thalassemic children who were given zinc supplements of 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. Zinc supplements have been used to treat people who had both tinnitus and hearing loss usually age-related. 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. 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. 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.

In a placebo-controlled trial that included 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.

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. 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.

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. The amount of zinc used was based on body weight, with a maximum of 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. Exercise increases zinc 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 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. Prostatic secretions are known to contain a high concentration of zinc ; that observation suggests that zinc plays a role in normal prostate function. In one preliminary study, 19 men with benign prostatic hyperplasia took mg of zinc daily for two months, and then 50 to mg daily.

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. Zinc 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.

The malabsorption produced by CF may adversely affect mineral absorption as well. Blood concentrations of zinc 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.

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. 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 zinc. 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.

Zinc 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 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.

Zinc 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.

Zinc 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. When iodine deficiency is present, other nutrient levels become important in the development of goiter.

Deficiencies of zinc 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 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. Research has shown that supplementing with chromium mcg per day or magnesium 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 , zinc , 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. Laboratory animals with severe, experimentally induced zinc 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. 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 mcg per day of selenium and 20 mg per day of zinc , 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. Zinc supplements have been reported to increase immune function. This effect may be especially important in the elderly according to double-blind studies.