The pro-oxidant activity of high-dose vitamin E supplements in vivo

BioDrugs. 2006;20(5):271-3. doi: 10.2165/00063030-200620050-00002.


Background: A recent meta-analysis has demonstrated that the regular administration of high-dose vitamin E supplements may be associated with increased mortality. The biological mechanism for this effect is uncertain.

Methods: A ferrous oxidation xylenol assay was used to assess plasma oxidation activity levels in samples from a randomized, placebo-controlled, 6-week trial of daily vitamin E supplementation in adults with asthma (n = 72).

Results and conclusion: A 27% increase in plasma oxidation activity levels was observed in patients receiving vitamin E. We demonstrate a pro-oxidant effect of high-dose vitamin E supplementation that may explain the increase in mortality observed in intervention studies using this nutrient.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Dietary Supplements
  • Dose-Response Relationship, Drug
  • Female
  • Humans
  • Lipid Peroxidation*
  • Male
  • Middle Aged
  • Mortality
  • Oxidation-Reduction
  • Reactive Oxygen Species / therapeutic use*
  • Vitamin E / therapeutic use*


  • Reactive Oxygen Species
  • Vitamin E