TitleFaster plasma vitamin E disappearance in smokers is normalized by vitamin C supplementation.
Publication TypeJournal Article
Year of Publication2006
AuthorsBruno RS, Leonard SW, Atkinson J, Montine TJ, Ramakrishnan R, Bray TM, Traber MG
JournalFree Radic Biol Med
Date Published2006 Feb 15
KeywordsAdministration, Oral, Adult, alpha-Tocopherol, Antioxidants, Ascorbic Acid, Biological Availability, Cross-Over Studies, Dietary Supplements, Double-Blind Method, Female, gamma-Tocopherol, Humans, Isoprostanes, Male, Oxidative Stress, Placebos, Smoking, Vitamin E Deficiency

Vitamin E disappearance is accelerated in cigarette smokers due to their increased oxidative stress and is inversely correlated with plasma vitamin C concentrations. Therefore, we hypothesized that ascorbic acid supplementation (500 mg, twice daily; 2 weeks) would normalize smokers' plasma alpha- and gamma-tocopherol disappearance rates and conducted a double-blind, placebo-controlled, randomized crossover investigation in smokers (n=11) and nonsmokers (n=13) given a single dose of deuterium-labeled alpha- and gamma-tocopherols (50 mg each d6-RRR-alpha and d2-RRR-gamma-tocopheryl acetate). During the placebo trial, smokers, compared with nonsmokers, had significantly (P<0.05) greater alpha- and gamma-tocopherol fractional disappearance rates and shorter half-lives. Ascorbic acid supplementation doubled (P<0.0001) plasma ascorbic acid concentrations in both groups and attenuated smokers', but not nonsmokers', plasma alpha- and gamma-tocopherol (P<0.05) fractional disappearance rates by 25% and 45%, respectively. Likewise, smokers' plasma deuterium-labeled alpha- and gamma-tocopherol concentrations were significantly higher (P<0.05) at 72 h during ascorbic acid supplementation compared with placebo. Ascorbic acid supplementation did not significantly change (P>0.05) time of maximal or maximal-labeled alpha- and gamma-tocopherol concentrations. Smokers' plasma F2alpha-isoprostanes were approximately 26% higher than nonsmokers (P>0.05) and were not affected by ascorbic acid supplementation in either group (P>0.05). In summary, cigarette smoking increased plasma alpha- and gamma-tocopherol fractional disappearance rates, suggesting that the oxidative stress from smoking oxidizes tocopherols and that plasma ascorbic acid reduces alpha- and gamma-tocopheroxyl radicals to nonoxidized forms, thereby decreasing vitamin E disappearance in humans.

Alternate JournalFree Radic. Biol. Med.
PubMed ID16458200
Grant ListAG05144 / AG / NIA NIH HHS / United States
AG16835 / AG / NIA NIH HHS / United States
DK 59576 / DK / NIDDK NIH HHS / United States