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  • Title: Vitamin E supplementation does not increase the vitamin C radical concentration at rest and after exhaustive exercise in healthy male subjects.
    Author: Schneider M, Niess AM, Rozario F, Angres C, Tschositsch K, Golly I, Battenfeld N, Schäffer M, Northoff H, Dickhuth HH, Fehrenbach E, Trommer WE, Biesalski HK.
    Journal: Eur J Nutr; 2003 Aug; 42(4):195-200. PubMed ID: 12923650.
    Abstract:
    BACKGROUND: Extensive exercise may promote the formation of reactive oxygen species and subsequently contribute to tissue damage. A compound which can protect cells and tissues is vitamin E. The vitamin E radical, formed during the radical scavenging process, can be reduced by vitamin C resulting in a higher level of the vitamin C radical (semidehydroascorbate free radical). An increase of the vitamin C radical, however, is assumed to exert prooxidative effects. AIM OF THE STUDY: To elucidate whether supplementation of vitamin E and exhaustive exercise lead to an increase of the vitamin C radical in human plasma. METHODS: A placebo controlled, cross over study with 13 male volunteers was carried out. After an 8 day supplementation period with 500 I.U. D-alpha-tocopherol, the subjects performed two exhaustive treadmill runs. Blood samples were collected at rest, 0, 0.25, 1, 3, 24 and 48 h after exercise. Serum was separated and concentrations of D-alpha-tocopherol and ascorbic acid were determined by HPLC. Vitamin C radical levels in plasma were assessed by electron paramagnetic resonance (EPR). RESULTS: Vitamin E and C both showed a tendency to decrease between 3 h and 24 h after exercise. Vitamin C radical level remained stable during the whole period. Neither vitamin E supplementation nor exercise had any influence on the plasma concentration of the vitamin C radical. CONCLUSIONS: Vitamin E supplementation under conditions of mild oxidative stress does not result in an increased vitamin C radical concentration.
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