Vitamins as Possible Ergogenic Aids: A Focus on Vitamin D and Antioxidants

Résumé

Vitamins (namely A, C, E, and D) have not been widely established as ergogenic aids. Supplementing daily food intake with vitamins A, C, or E can be advantageous because of their anti-oxidizing properties. While excessive amounts of antioxidants lead to toxic effects on the liver and central nervous system, adequate levels may help clear the body of free radicals that accelerate cell damage. Antioxidant supplementation is important to athletes because of its perceived ability to lower levels of exercise-induced free radicals. However, current research suggests this is not the case; studies observing maximal oxygen uptake as a performance outcome show that supplementation can hamper training adaptations. That said, the impact of antioxidants on mitochondrial biogenesis and the cascading effect of that influence on reactive oxygen species are not fully understood. Research on the non-antioxidant vitamin D is particularly relevant to athletes because of the multi-functional role of this vitamin on overall fitness as well as on the muscle-related functions mobilizing calcium, which facilitate muscle movement and growth. Studies on vitamin D show that supplementation improves motor balance in the elderly, as well as endurance and resistance training performance, but experts are divided on the optimal levels of vitamin D supplementation. Thus, we propose a double-blind, randomized study to assess graded vitamin D supplementation in healthy individuals through a placebo-based, controlled trial with treatments of cellulose (2500 IU and 5000 IU of Vitamin D3 in resistance and endurance exercises). This study will help pinpoint the vitamin D serum levels needed for optimized athletic performance. Because vitamin D is fat-soluble, questions of toxicity will be addressed in this dose-dependent experiment.