Zinc is an important trace mineral. This element is second only to iron in its concentration in the body.

Zinc is needed for the body's defensive (immune) system to properly work. It plays a role in cell division, cell growth, wound healing, and the break down of carbohydrates . Zinc is also needed for the senses of smell and taste.

High-protein foods contain high amounts of zinc. Beef, pork, and lamb contain more zinc than fish. The dark meat of a chicken has more zinc than the light meat.

Other good sources of zinc are peanuts, peanut butter, and legumes.

Fruits and vegetables are not good sources, because zinc in plant proteins is not as available for use by the body as the zinc from animal proteins. Therefore, low-protein diets and vegetarian diets tend to be low in zinc.

Symptoms of zinc deficiency include:

• Frequent infections
• Hypogonadism in males
• Loss of hair
• Poor appetite
• Problems with the sense of taste
• Problems with the sense of smell
• Slow growth
• Trouble seeing in the dark
• Various skin lesions
• Wounds that take a long time to heal

Zinc supplements in large amounts may cause diarrhea, abdominal cramps, and vomiting, usually within 3 - 10 hours of swallowing the supplements. The symptoms go away within a short period of time after the stopping the supplements.

The best way to get the daily requirement of essential vitamins and minerals is to eat a balanced diet that contains a variety of foods from the food guide pyramid.

The Food and Nutrition Board at the Institute of Medicine recommends the following dietary intake for zinc:

Infants

• 0 - 6 months: 2 milligrams per day (mg/day)
• 7 - 12 months: 3 mg/day

Children

• 1 - 3 years: 3 mg/day
• 4 - 8 years: 5 mg/day
• 9 - 13 years: 8 mg/day

Adolescents and Adults

• Males age 14 and over: 11 mg/day
• Females age 14 to 18 years: 9 mg/day
• Females age 19 and over: 8 mg/day

Specific recommendations depend on age, gender, and other factors (such as pregnancy). Women who are pregnant or producing breast milk (lactating) need higher amounts. Ask your health care provider which amount is best for you.

Institute of Medicine, Food and Nutrition Board. Dietary Reference Intakes: Vitamin C, Vitamin E, Selenium, and Carotenoids. National Academy Press, Washington, DC, 2000.

Hamrick I, Counts SH. Vitamin and mineral supplements. Wellness and Prevention. December 2008:35(4);729-747.

Rakel D, ed. Integrative Medicine. 2nd ed. Philadelphia, Pa: Saunders Elsevier; 2007.

Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007.