Vitamin C as an Antioxidant: Evaluation of Its Role in Disease Prevention

Vitamin C as an Antioxidant: Evaluation of Its Role in Disease Prevention

Sebastian J. Padayatty, MRCP, PhD, Arie Katz, MD, Yaohui Wang, MD, Peter Eck, PhD, Oran Kwon, PhD, Je-Hyuk Lee, PhD, Shenglin Chen, PhD, Christopher Corpe, PhD, Anand Dutta, BS, Sudhir K Dutta, MD, FACN and Mark Levine, MD, FACN

Molecular and Clinical Nutrition Section, Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda (S.J.P., A.K., Y.W., P.E., O.K., J.-H.L., S.C., C.C., M.L.), Maryland
Division of Gastroenterology, Sinai Hospital of Baltimore, University of Maryland School of Medicine, Baltimore (A.D., S.K.D.), Maryland

View larger version (14K):

[in a new window]

Fig. 1. Steady-state plasma vitamin C concentrations (mean ± SD) as a function of dose for all doses for seven men. Subjects consumed a vitamin C deficient diet, resulting in plasma and tissue vitamin C depletion. Vitamin C in solution was then administered by mouth at the doses shown until steady state was reached for each dose. Doses through 400 mg daily were received by seven subjects, through 1000 mg daily by six subjects and through 2500 mg daily by three subjects. Reproduced with permission from Proceedings of The National Academy of Sciences, from which details of the study can be obtained [50].

View larger version (14K):

[in a new window]

Fig. 2. Steady-state plasma vitamin C concentrations (mean ± SD) as a function of dose for all doses for 15 women. Subjects consumed a vitamin C deficient diet, resulting in plasma and tissue vitamin C depletion. Vitamin C in solution was then administered by mouth at the doses shown until steady state was reached for each dose. Doses through 200 mg daily were received by 15 subjects, through 1000 mg daily by 13 subjects and through 2500 mg daily by 10 subjects. Reproduced with permission from Proceedings of The National Academy of Sciences, from which details of the study can be obtained [51].

View larger version (21K):

[in a new window]

Fig. 3. Intracellular vitamin C concentrations (mean ± SD) in circulating cells as a function of dose in women. Cells were isolated when steady-state was achieved for each dose. For neutrophils, samples were available from 13 women at doses 0–200 mg daily; from 11 women at doses of 400 and 100 mg daily, and from 10 women at 2500 mg daily. For lymphocytes, monocytes and platelets, samples were available from 13 women at 30 mg daily; from 12 women at 60 mg daily; from six women at 100 mg daily; from two women at 400 and 1000 mg daily; from nine women at 2500 mg daily. Reproduced with permission from Proceedings of The National Academy of Sciences, from which details of the study can be obtained [51].