| Vitamins and minerals perform the same essential functions for athletes and non-athletes alike. The key to obtaining the vitamins and minerals that athletes need is to eat a wide variety of nutrient-dense foods in amounts that will maintain energy balance. Using the Food Guide Pyramid, this goal can be achieved by consuming 1,200-1,500 kcal/day. Meeting vitamin and mineral requirements when energy intake is 3,000 kcal/day or higher, e.g. male and female ice hockey and cross country skiers, is quite easy. Even female figure skaters whose energy intakes may be about 2,000 kcal/day can meet their vitamin and mineral needs from food alone. |
Fruits and vegetables are particularly high in vitamins. Many are sources of antioxidants as well. Focus on high color (yellow-orange, red, deep green, and blue) choices. Yes, blueberries have high antioxidant value! An athlete's meal plan has ample room to fit the five to nine fruit and vegetable servings recommended each day. Meat and dairy foods are especially high in minerals. Foods in the grain group contain both vitamins and minerals.
Athlete Profiles provides sample menus. Note that the daily menus for these athletes meet two thirds or more of the Recommended Dietary Allowances (RDAs) for vitamins and minerals. Athletes who have high calorie intakes (5,000 to 6,000 kcal/day) may achieve 200% (or more) of the RDA for some vitamins and minerals just from foods they eat.
Is more better? Because B-vitamins participate in energy metabolism (releasing energy from nutrients), athletes with high energy expenditures have increased requirements for B vitamins. However, eating more food (energy intake that achieves energy expenditure) provides the extra B-vitamins that are needed. Beyond meeting RDA requirements, do athletes benefit from supplementation with vitamins and minerals in amounts greater than the RDA? Despite high vitamin/mineral supplement use among athletes, the answer appears to be no. While vitamin/mineral deficiencies impair physical performance, research indicates that supplementation of a nutritionally adequate sports diet does not improve physical work capacity, endurance, oxygen consumption, cardiovascular function, muscle strength, or resistance to fatigue.
Although more research is needed, Vitamin E may be one exception. Vitamin E, found mostly in vegetable fat, is an antioxidant that protects cells against oxidative damage associated with intense exercise. So, does supplemental Vitamin E benefit active people? The answer is unclear. Aerobic exercise training actually increases antioxidant enzyme production. Thus, increased need for antioxidant protection may be met by adaptations to exercise training. More research is needed before recommendations can be made.
| What if an athlete's diet is less than the best? Vitamin supplements are commonly used by athletes to make up for less than optimal diets. To provide a dose of "health insurance," choosing a multivitamin supplement with no more than 100% of the Daily Value (DV) provides a safe and adequate balance of vitamins. But keep your eye on the ball -- the real goal is to eat a variety of foods. Food contains fiber and a host of phytochemicals that provide health benefits. Add more fruits, vegetables, and whole grains to the foods already being consumed. Supplements are not replacements for food. |
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While many supplements contain
beta carotene, an antioxidant, at least 450 carotenoids are found
in foods. Antioxidant value exists in other carotenoids as well as
in beta carotene.
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Calcium, iron, and zinc perform especially important functions for athletes. The latest calcium recommendations are based on levels of intake to promote calcium retention, maximize bone mineral density, and inhibit bone loss. Increased risk of stress fracture among athletes is associated with lower calcium intake and lower bone density compared to control athletes. Dairy products, fish with bones, broccoli, and fortified cereals and juices are good calcium sources.
Iron affects oxygen transport and aerobic metabolism as a component of hemoglobin, myoglobin, and oxidative enzymes. Immune function is dependent on iron-containing enzymes. Consuming adequate amounts of iron is essential for optimal aerobic endurance performance. Iron depletion is the first stage of iron deficiency and the most common type of iron deficiency among athletes. Lean red meats, dark poultry, fortified cereals, whole grains, and legumes are good iron sources.
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Zinc is essential for protein synthesis, it aids in healing and immune function, and is present in antioxidant enzymes and enzymes involved in energy metabolism. Zinc is found in meat, poultry, seafood, and whole grains. When is more too much? While 15 mg of zinc (100% DV) is commonly added to multivitamin/mineral supplements, larger amounts of zinc (50-100 mg/day) consumed over extended periods have negative effects on copper and iron status. In fact, consuming an excess of any mineral can interfere with digestion and absorption of other minerals and lead to mineral imbalances. In large enough doses, all minerals can be toxic. |
Vitamins and minerals are team players; they work together with nutrients in food. While antioxidant vitamins E and C and beta-carotene appear to have low toxicity, the effects of long-term supplement use are not known. In contrast, habitual consumption of foods high in antioxidant value (fruits, vegetables, whole grains) is associated with significant health benefits. Hundreds of antioxidants, some of which act synergistically, are available in foods. Supplementing here and there with one or several vitamins or minerals is unlikely to help and may waste an athlete's precious time and resources. Keep the focus where it belongs Ð making healthful food choices that benefit exercise training and performance.
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