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, because most diets provide more than the recommended dietary allowance.
Why do people take zinc?
Zinc has become a popular treatment for the common cold. Some studies have found that zinc lozenges may reduce the duration of cold, perhaps by a day or so, and may reduce the number of upper respiratory infections.
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.
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, 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.
Recommended Dietary Allowance (RDA) of Zinc
7 months to 3 years
19 years and up
14-18 years: 12 mg/day
14-18 years: 13 mg/day
14 years and up
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.
Tolerable Upper Intake Level (UL) of Zinc
19 years and up
To avoid irritating the stomach, take zinc with food. For the common cold, zinc lozenges are typically taken every 2 to 3 hours within 48 hours of the start of symptoms. Then, take the zinc lozenges every 2 to 3 hours while awake until the symptoms go away. There are zinc supplements in pill and liquid form.
Can you get zinc naturally from foods?
Good food sources of zinc are:
- Red meat
- Fortified cereals
- Whole grains
- Beans and nuts
What are the risks of taking zinc?
- Side effects. Zinc supplements can irritate the stomach and mouth. Zinc lozenges can alter your sense of smell and taste for a few days. If taken long-term, zinc lozenges may lower copper levels in the body. Zinc nasal sprays have been associated with a loss of smell, which may be permanent.
- Interactions. Zinc may interact with some medicines such as birth control pills and some antibiotics. Zinc can also interact with other supplements, such as calcium, magnesium, copper, and iron. If you take daily medicine or supplements, ask your healthcare provider about taking zinc.
- Risks. People who are allergic to zinc, have HIV, or have hemochromatosis should not take zinc supplements without talking to their doctor first. Too much zinc can cause fever, cough, nausea, reduced immune function, mineral imbalances, cholesterol changes, and other issues. In pregnant women, high doses may harm the fetus.