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.
Where are minerals in foods?
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.
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
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.(published with permission in writing from:http://btc.montana.edu)
