Handbook of Vitamin C Research

32Kelsey H. Fisher-Wellman and Richard J. Bloomerin regular exercise training. Vitamin C may be useful for purposes of attenuating exerciseinducedoxidative stress (when used alone or in conjunction with other antioxidants), inparticular in relation to short duration aerobic and anaerobic exercise protocols. While moreresearch is indeed needed, the following may be concluded based on the available evidence:If vitamin C is used as a dietary supplement for those involved in strenuous exercise, itshould be taken prophylactically for several days prior to exercise (i.e., regularly forindividuals who exercise regularly) and at a dosage of 1-3g/day. However, what may bemost important in terms of overall health and exercise recovery, coupled with theperformance of regular and strenuous exercise, is the regular consumption of adequateamounts of fruits, vegetables, whole grains, and antioxidant-rich oils (fish, flax, olive).Vitamin C supplementation alone will not make up for this lack of effort on the part of theindividual.References[1] Duarte TL, Lunec J. Review: When is an antioxidant not an antioxidant? A review ofnovel actions and reactions of vitamin C. Free Radic Res 2005; 39: 671-686.[2] Rose RC, Bode AM. Biology of free radical scavengers: an evaluation of ascorbate.FASEB J 1993; 7: 1135-1142.[3] Watson TA, Callister R, Taylor RD, Sibbritt DW, MacDonald-Wicks LK, Garg ML.Antioxidant restriction and oxidative stress in short-duration exhaustive exercise. MedSci Sports Exerc 2005; 37: 63-71.[4] Johnston CS. Biomarkers for establishing a tolerable upper intake level for vitamin C.Nutr Rev 1999; 57: 71-77.[5] Levine M, Padayatty SJ, Wang Y, et al. Vitamin C. In: Alexopolous Y, Hebberd K,editors. Biochemical, Physiological, & Molecular Aspects of Human Nutrition. SecondEdition ed. St. Louis, Missouri: Elsevier 2006; 760-760-796.[6] May JM, Cobb CE, Mendiratta S, Hill KE, Burk RF. Reduction of the ascorbyl freeradical to ascorbate by thioredoxin reductase. J Biol Chem 1998; 273: 23039-23045.[7] Johnston CS, Corte C, Swan PD. Marginal vitamin C status is associated with reducedfat oxidation during submaximal exercise in young adults. Nutr Metab (Lond) 2006; 3:35.[8] Halliwell B. Vitamin C and genomic stability. Mutat Res 2001; 475: 29-35.[9] Buettner GR, Jurkiewicz BA. Catalytic metals, ascorbate and free radicals:combinations to avoid. Radiat Res 1996; 145: 532-541.[10] Polidori MC, Mecocci P, Levine M, Frei B. Short-term and long-term vitamin Csupplementation in humans dose-dependently increases the resistance of plasma to exvivo lipid peroxidation. Arch Biochem Biophys 2004; 423: 109-115.[11] Carr AC, Frei B. Toward a new recommended dietary allowance for vitamin C basedon antioxidant and health effects in humans. Am J Clin Nutr 1999; 69: 1086-1107.[12] Halliwell B. Oxygen radicals: a commonsense look at their nature and medicalimportance. Med Biol 1984; 62: 71-77.