Courtesy of the Gatorade Sports Science Institute

Many athletes consume vitamin supplements on a regular basis, and others worry that perhaps they should. Still, we know that over consumption of vitamins can have toxic effects. So what is the athlete to do? Here are some questions and answers that may help you make the right decisions about vitamin supplementation.

Is it possible that my normal diet contains too few vitamins?

It is unlikely that you are consuming too few vitamins UNLESS:

* You are restricting your calorie (and vitamin) intake to lose body weight; * You have unusual eating habits such as eating too much fast food;
* You tend to eat on the run, consuming snacks and other foods low in vitamin content;
* You eat less than five servings per day of fruits and vegetables.
* You smoke and drink too much alcohol;
* You have a disease, e.g., pernicious anemia, that reduces absorption or metabolism of vitamins.

If you do have insufficient vitamin intake in your diet, the vitamin shortages are most likely for:

* Some of the B-complex vitamins - thiamin, riboflavin, niacin, vitamin B-12 (vegetarians only), and especially vitamin B-6 and folate (folic acid, folacin).
* The antioxidant vitamins vitamin C, vitamin E, and beta carotene.

How can I know for certain that I have a vitamin deficiency?

* The first step is to ask a dietitian to provide an analysis of your normal nutrient intake. If you consistently consume lower than recommnded amounts of a vitamin or vitamins, you could have a vitamin deficiency. However, this does not prove a deficiency because some people need less than others.

* The next step is to have a blood test to determine the amount and functional activity of vitamins stored in your body.

* Final confirmation of a vitamin deficiency would be the appearance of clinical symptons such as cracks in the corners of your mouth, which suggest a riboflavin deficiency. Unfortunately, many of these clinical symptons require a long time to develop.

If I suspect that I have a vitamin deficiency, what should I do about it?

* You should correct deficiencies in vitamin intake by correcting your diet. Getting vitamins from normal foods is better than getting them from supplements because normal foods contain extra nutrients? phytochemicals? that supplements do not contain.
* Avoid diets that place too heavy an emphasis on any one nutrient, e.g., too much carbohydrate or too much protein, that leads to insufficient intake of vitamin-rich foods.
* Get help from a dietitian or nutritionist to make sure your diet contains five servings daily of fruit and vegetables and that your diet contains sufficient whole grains, lean meat, and dairy products. (If you are a vegetarian, a dietitian can modify your diet to compensate for the absence of meat and dairy products.) If you follow this advice, your diet should be adequate in vitamins and minerals.

Just for insurance, is it O.K. if I take a daily vitamin supplement?

* Although it is unlikely that you need such a supplement, it probably will not cause any harm, as long as the supplement contains no more than the Recommended Dietary Allowances (RDA) or Adequate Intake (AI) for vitamins on a daily basis. But remember, if you rely on the supplement for your vitamins, you could be missing out on other important nutrients in normal foods.

* If you want a "vitamin-insurance policy," many experts recommend that you only take a multi-vitamin pill every two or three days, not every day. This strategy would minimize the possibility that you might get an overdose of one or more vitamins.

Under what conditions might I consume an overdose of vitamins?

* If you consume more than the RDA or Upper Limit of vitamin supplements on a regular basis.
* If you eat many servings of vitamin-fortified foods such as breakfast cereals that contain 100% of the RDA for vitamins and minerals in each serving.

Will vitamin supplements improve my athletic performance?

* Experts agree that vitamin supplements will improve performance only if the athlete has an existing vitamin deficiency. As indicated earlier, such a deficiency is not common.
* If you do not have a vitamin deficiency, vitamin supplements will do nothing to improve your performance and will be a waste of money.