Vitamins and Supplements Lifestyle Guide

Zinc is a mineral that's important to the body in many ways. Zinc keeps the immune system strong, helps heal wounds, and supports normal growth. 

Zinc deficiency occurs frequently in developing countries. Zinc deficiency in the U.S. is rare since most diets provide more than the recommended dietary allowance.

Why do people take zinc?

Zinc has become a popular treatment for the common cold. The evidence for zinc is controversial and contradictory. Some studies have found that zinc lozenges may reduce the duration of cold, perhaps by as much as 50%. However, many other studies have found no benefit from zinc for colds.

Zinc helps fight infection and heal wounds. However, if you already have enough zinc from your diet, it is not clear that getting even more -- from supplements -- has a benefit.

Topical zinc is used to treat diaper rash and skin irritations. Zinc has also been shown to help with ulcers, ADHD, acne, sickle cell anemia, and other conditions.

In addition, zinc has also been studied as a treatment for herpes, high cholesterol, rheumatoid arthritis, HIV, and more. However, the evidence of zinc's benefit for these conditions is inconclusive.

Zinc may be part of an effective treatment for age-related macular degeneration, but more proof is needed.

Health care providers may recommend zinc supplements for people who have zinc deficiencies. Strict vegetarians, breastfeeding women, alcohol abusers, and people who have a poor diet are at higher risk for zinc deficiency. So are those with certain digestive problems, such as Crohn's disease.

How much zinc should you take?

The recommended dietary allowance (RDA) includes the zinc you get from both the food you eat and any supplements you take.

The tolerable upper intake level (UL) of a supplement is the highest amount that most people can take safely. Never take more unless your health care provider says so. Keep in mind that this upper limit includes the zinc you get from foods and supplements.

To avoid irritating the stomach, take zinc with food. For the common cold, zinc lozenges are supposed to be started within 24 hours of the onset of cold symptoms. Then, take the zinc lozenges every two to three hours -- while you're awake, of course -- until the symptoms go away.