Vitamin C Research Today is a free monthly online journal that collates and summarizes the latest research about Vitamin C, including details on benefits, dosage, supplements, information.

Does vitamin C supplementation influence the levels of circulating oxidized LDL, sICAM-1, sVCAM-1 and vWF-antigen in healthy male smokers?

Van Hoydonck PG, Schouten EG, Manuel-Y-Keenoy B, van Campenhout A, Hoppenbrouwers KP, Temme EH

Department of Public Health, Division of Nutritional Epidemiology, University of Leuven, Leuven, Belgium.

OBJECTIVE: To examine the effects of vitamin C supplementation on the concentration of oxidation markers, in particular, circulating oxidized LDL (OxLDL) and on endothelial activation markers. DESIGN: Randomized double-blind, placebo-controlled crossover trial. SETTING: Belgian population of the city of Leuven. SUBJECTS: A total of 34 healthy male smokers aged 26-73 y. INTERVENTION: Smokers were randomly assigned to receive either vitamin C (250 mg twice daily) or placebo capsules, each to be taken for 4 weeks. After a 1-week washout period, participants then crossed over to the alternative capsules for further 4 weeks. MEAN OUTCOME MEASURES: Markers of oxidation (bilirubin, uric acid, alpha-tocopherol, retinol, malondialdehyde, circulating Oxidized LDL (OxLDL)) and markers of endothelial activation (sICAM-1, sVCAM-1, vWF-antigen) were analysed. RESULTS: Plasma ascorbate concentrations significantly increased from 46.6+/-17.6 to 70.1+/-21.2 mumol/l after a 4-week treatment with 500 mg vitamin C per day. The other plasma antioxidants concentrations, including bilirubin, uric acid, alpha-tocopherol and retinol, were similar in both treatment periods. Vitamin C did not change plasma malondialdehyde and circulating OxLDL compared with placebo (vitamin C 0.73+/-0.25 mg/dl OxLDL; placebo 0.72+/-0.21 mg/dl OxLDL). After vitamin C supplementation, neither sICAM-1 and sVCAM-1 levels nor the concentration of vWF-antigen significantly differed from placebo condition. CONCLUSIONS: Oral supplementation of vitamin C is not associated with changes in markers of oxidation or endothelial activation in healthy male smokers.

Published 26 November 2004 in Eur J Clin Nutr, 58(12): 1587-93.
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