Positive Health Online

Abstract

BRUNO and co-workers, Linus Pauling Institute, 571 Weniger Hall, Oregon State University, Corvallis, OR 97331, USA, have found that the metabolism of vitamin E in smokers is positively influenced by vitamin C.

Background

Vitamin E disappearance is accelerated in cigarette smokers due to their increased oxidative stress and is inversely correlated with plasma vitamin C concentrations. The aim of this study was to test the hypothesis that vitamin C supplementation (500 mg, twice daily; 2 weeks) would normalize smokers’ plasma vitamin E disappearance rates.

Methodology

In a double-blind, placebo-controlled, randomized crossover investigation, smokers (n=11) and nonsmokers (n=13) were given a single dose of radio-labelled vitamin E. The disappearance of the radioactive material from their bloodstream was then followed.

Results

During the placebo trial, smokers, compared with nonsmokers, had significantly (p<0.05) greater vitamin E disappearance rates and shorter half-lives. Vitamin C supplementation attenuated smokers’, but not nonsmokers’, plasma vitamin E disappearance rates by 25% to 45% (p<0.05). Likewise, smokers’ plasma vitamin E concentrations were significantly higher (p<0.05) at 72 h during vitamin C supplementation compared with placebo.

Conclusion

Cigarette smoking increased plasma vitamin E disappearance rates, suggesting that the oxidative stress from smoking oxidizes vitamin E. Vitamin C reduces vitamin E radicals to nonoxidized forms, thereby normalizing vitamin E disappearance in smokers.

References

Bruno RS, Leonard SW, Atkinson J, Montine TJ, Ramakrishnan R, Bray TM, Traber MG. Faster plasma vitamin E disappearance in smokers is normalized by vitamin C supplementation.  Free Radical Biology & Medicine 40 (4): 689-697, Feb 15, 2006.