Faster plasma vitamin E disappearance in smokers is normalized by vitamin C supplementation

Free Radic Biol Med. 2006 Feb 15;40(4):689-97. doi: 10.1016/j.freeradbiomed.2005.10.051. Epub 2005 Nov 15.


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.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Adult
  • Antioxidants / administration & dosage*
  • Ascorbic Acid / administration & dosage*
  • Biological Availability
  • Cross-Over Studies
  • Dietary Supplements*
  • Double-Blind Method
  • Female
  • Humans
  • Isoprostanes / metabolism
  • Male
  • Oxidative Stress
  • Placebos
  • Smoking*
  • Vitamin E Deficiency*
  • alpha-Tocopherol / blood
  • gamma-Tocopherol / blood


  • Antioxidants
  • Isoprostanes
  • Placebos
  • gamma-Tocopherol
  • alpha-Tocopherol
  • Ascorbic Acid