title: The pro-oxidant activity of high-dose vitamin E supplements in vivo.
abstract: 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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Division of Respiratory Medicine, University of Nottingham, Nottingham City Hospital, Hucknall Road, Nottingham, UK.
authors.forename: Philip
authors.initials: P
authors.lastname: Pearson
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Lewis
authors.forename: John
authors.initials: J
authors.lastname: Britton
authors.forename: Ian S
authors.initials: IS
authors.lastname: Young
authors.forename: Andrew
authors.initials: A
authors.lastname: Fogarty
mesh_terms: D000293:Adolescent; D000328:Adult; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male; D008875:Middle Aged; D009026:Mortality; D010084:Oxidation-Reduction; D017382:Reactive Oxygen Species / Q000627:therapeutic use*; D014810:Vitamin E / Q000627:therapeutic use*
chemical_list: D017382:Reactive Oxygen Species; D014810:Vitamin E