Zinc affects many biological systems in our bodies because it plays vital roles at the cellular level. Indeed, it is the most abundant trace mineral in cells and, as an antioxidant, plays a part in protecting and repairing cellular DNA.
Severe deficiency in zinc may cause poor immune function and, in children, delayed behavioral and neurological growth. Zinc also protects against macular degeneration and prostate cancer; the element is found in high concentrations in ocular tissue and in the prostate.
In the U.S., severe zinc deficiency is rare, but a 1996 survey by the USDA found that more than 70 percent of Americans did not consume the daily recommended allowance of zinc, and 10 percent did not even consume half the necessary amount. Infants, young children and the elderly are especially vulnerable. Vegetarians and people who consume large amounts of seeds and cereal grains may be zinc deficient, since phytates in these plant foods bind to zinc and prevent its absorption by the body.
Although a number of zinc-containing lozenges promise to help you fight your cold, there's inconclusive evidence that it has any effect. Some studies show that zinc can reduce the severity of colds, while others show no effect.
How much you should have: Adult men should consume at least 11 mg of zinc per day, and adult women should have 8 mg. Pregnant and nursing women should take in 11 to 13 mg of zinc every day. The body has no storage facility for zinc, unlike other minerals such as calcium, so zinc must be included in the diet on a daily basis.