Vitamin and Mineral Supplements and Exercise

People who are physically active are frequently the target of advertisements claiming the need for vitamin and mineral supplementation. These advertisements assume that athletes, ranging from weekend warriors to Olympians are at risk of developing nutritional deficiencies and subsequent impairments in their performance and health. Nutritional supplement companies target anyone who wants to enhance performance, gain energy and prevent illness and injury. Unfortunately, scientific evidence to support these claims is lacking.

Sadly, surveys of athletes indicate their lack of knowledge and show that they are excellent targets for vitamin and mineral companies. Market estimates show that more than 50% of elite, female endurance athletes and about 40% of non-elite male athletes regularly consume vitamin and mineral supplements. Use of daily supplements is also prevalent among other groups of athletes (as many as 56% of male and 33% of female high school and collegiate athletes) report using vitamin and mineral supplements.

Physical activity may increase the need for some vitamins and minerals. However, the increased requirement can be attained by consuming a balanced diet (and replacing the carbohydrates and proteins needed). Individuals at risk for low vitamin and/or mineral intake are those who consume a low energy diet for extended periods of time (or those with congenital gastrointestinal absorptive defects). Although supplementation may enhance their physical performance there is no scientific evidence to support the general use of vitamin and mineral supplementation.

Some examples of foods that contribute vitamins and minerals:

MINERALS B VITAMINS VITAMIN A, C, AND E
Beef Beef Carrots
Chicken Chicken Peanuts
Tuna Tuna Milk
Kidney beans Refried beans Broccoli
Milk Milk Spinach
Yogurt Yogurt Strawberries

Take Home Points

  1. Performance will NOT be improved if individuals consuming nutritionally adequate diets use supplements.
  2. Only athletes with a defined nutrient deficiency will benefit from supplementation of that nutrient.
  3. Concerns about nutritional adequacy of an individual's diet should be evaluated by a registered dietician experienced in counseling athletes.
  4. Use of megadoses of vitamins and minerals is NOT recommended because of the potential adverse toxicity to the kidneys and/or liver.

 

Naomi L. Sklar, MD
Vitality Sports Medicine, PO BOX 1601 Wilson, WY 83014
Teton Valley Hospital, 120 East Howard Ave, Driggs, ID 83422