› Health Benefits
Scientists are studying zinc to learn about its effects on the immune system and other health issues.
Immune system and wound healing
The immune system needs zinc to function correctly. Those with lower levels of zinc may have a higher risk of getting pneumonia and other infections. It also helps the skin stay healthy. Some people with skin ulcers may benefit from zinc dietary supplements, but only if they have low levels of zinc.
Children in developing countries often die from diarrhea. Studies have shown that zinc supplements help reduce the symptoms and duration of diarrhea in these children, many of whom are zinc deficient or malnourished.
The common cold
Some studies suggest that zinc lozenges or syrup (not pill supplements) help speed recovery from the common cold and reduce its symptoms if taken within 24 hours of coming down with a cold. More study is needed to determine the best dose and form of zinc and how long it should be taken.
Age-related macular degeneration
AMD is an eye disease that gradually causes vision loss. Research suggests that zinc may help slow AMD progression. In a large study, older people who took a daily zinc supplement had a lower chance of developing advanced AMD and had less vision loss than those who did not take the supplement.
Zinc and thyroid health are deeply interconnected: Adequate amounts of zinc are required for the body to make and use thyroid hormones, and thyroid hormones are required for the body to adequately absorb zinc. Healthy zinc levels are required to produce thyroid-stimulating hormone, which tells the pituitary glands to produce thyroid hormones T3 and T4. Zinc also plays a role in the conversion of T4 to T3, which is the form of the hormone that can be used by the body.
› How much do I need?
The daily amount of zinc needed depends on age and gender. For women, it increases during pregnancy and when lactating. Adults age 19-plus: 11 milligrams daily for men and 8 milligrams for women. Pregnant women: 11 milligrams; breastfeeding women: 12 milligrams.
Zinc deficiency is rare in North America. It causes slow growth in infants and children, delayed sexual development in adolescents, and impotence in men. It also could cause hair loss, diarrhea, eye and skin sores, and loss of appetite. Weight loss, problems with wound healing, decreased ability to taste food and lower alertness levels can also occur.
Zinc can be harmful if you get too much. Signs include nausea, vomiting, loss of appetite, stomach cramps, diarrhea and headaches. Getting too much zinc for long periods of time may cause low copper levels, lower immunity and low levels of HDL cholesterol.
Zinc may interact or interfere with medications, and you should talk to your doctor before using zinc as a supplement.
› In food
Zinc can be found in many foods; the best source is oysters. Red meat, poultry, seafood such as crab and lobsters, fortified breakfast cereals, beans, nuts, whole grains and dairy products are also good sources of zinc.
› Dietary Supplements
Zinc is present in almost all multivitamin/mineral supplements. It is also available alone or combined with calcium, magnesium or other ingredients. Supplements can have several different forms of zinc, including zinc gluconate, zinc sulfate and zinc acetate. It is not clear if one form is better than the others.
Please consult your health care provider before making changes to your vitamin/supplement regimen.