This is adapted from the book, Eat Smart, Play Hard, by RW USA Nutrition Editor Liz Applegate.
A little zinc goes a long way. Though you have only about 2 grams of it in your body, zinc works in tandem with more than 100 different enzymes, many of which participate in energy metabolism. Its essential for a healthy immune system. It makes wound healing and injury recovery possible, and its vital for male sexual functioning.
Despite its importance, studies have shown that most people dont consume the DV (15 milligrams) for this mineral. Since you sweat out small amounts of it each time you exercise, you can quickly run the risk of a zinc deficiency. In one study, athletes had twice the zinc loss through urination following a 6-mile run compared to when they didnt exercise.
Up to 40 percent of athletes may have below-normal levels of zinc; a telltale sign of a deficiency is frequent colds. You may also be easily susceptible to infections and bronchitis. Unfortunately, many fit people tend to shy away from the best sources of zinc oysters, clams, liver, and several kinds of meat because of the relatively high fat content.
If youre watching the fat in your diet, or if youre a vegetarian, you can get zinc from low-fat foods such as wheat germ, fortified breakfast cereals (they have 25 to 100 percent of the DV per serving), and black-eyed peas, although the zinc found in beef, poultry, pork, lamb, and seafood is absorbed the best.
My recommendation: Supplementation may be the best way to ensure that you get your DV for zinc. Look for a multivitamin/mineral supplement that contains no more than the DV. Remember that high-fiber foods and the tannins found in coffee, some teas, and wine can hamper zinc absorption, so plan your zinc intake accordingly. Also remember that too much zinc blocks the absorption of copper, which in turn impedes iron absorption. You would have to get a lot of zinc to do this, however, since copper deficiency normally results from zinc intakes of six times the DV. You should also know that oversupplementation with zinc has been shown to lower good HDL cholesterol levels and raise harmful LDL cholesterol levels.