title: Bioavailability of vitamins E and C: does Helicobacter pylori infection play a role?
abstract: BACKGROUND
  While the association between bioavailability of vitamins E and C and Helicobacter pylori infection has been extensively researched in gastritis and gastric cancer patients, little is known about this relationship in asymptomatic adults.
  
  
  OBJECTIVE
  To investigate the effect of H. pylori infection on bioavailability of vitamins E and C in asymptomatic adults.
  
  
  METHODS
  Volunteers from the University of Toronto, aged 18-45 years, were screened, for their H. pylori infection status. H. pylori-negative (n = 32) and asymptomatic H. pylori-positive (n = 27) participants received vitamin C (500 mg) and vitamin E (400 IU) supplements daily for 28 days. Plasma vitamins C, E and thiols concentrations were assessed before (baseline) and after supplementation.
  
  
  RESULTS
  Postsupplementation plasma levels of vitamin C and E were significantly higher than presupplementation levels in both groups. Yet, changes in plasma vitamins E and C were not significantly different between the two groups [vitamin C (mumol/l): 13.97 +/- 16.86 vs. 20.87 +/- 27.66, p > 0.05; vitamin E (mumol/l): 15.52 +/- 9.4 vs. 14.47 +/- 15.77; p > 0.05 for H. pylori-negative and H. pylori-positive groups, respectively]. In addition, no significant difference was found in plasma thiols levels between groups (p > 0.05).
  
  
  CONCLUSIONS
  These findings suggest that H. pylori does not influence antioxidants bioavailability in its asymptomatic stages of infection until a factor or combination of factors triggers the inflammation cascade which may lead to increased oxidative stress and possibly reduced bioavailability of vitamins E and C.
authors.affiliation: Department of Nutrition and Food Sciences, American University of Beirut, Lebanon. fn14@aub.edu.lb
authors.forename: Farah
authors.initials: F
authors.lastname: Naja
authors.forename: Nancy
authors.initials: N
authors.lastname: Kreiger
authors.forename: Gail
authors.initials: G
authors.lastname: McKeown Eyssen
authors.forename: Johane
authors.initials: J
authors.lastname: Allard
mesh_terms: D000293:Adolescent; D000328:Adult; D000975:Antioxidants / Q000493:pharmacokinetics*; D001205:Ascorbic Acid / Q000097:blood / Q000493:pharmacokinetics*; D001682:Biological Availability; D004032:Diet; D019587:Dietary Supplements; D002149:Energy Intake / Q000502:physiology; D005260:Female; D016481:Helicobacter Infections / Q000378:metabolism*; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D018384:Oxidative Stress; D013438:Sulfhydryl Compounds / Q000097:blood; D014810:Vitamin E / Q000097:blood / Q000493:pharmacokinetics*; D055815:Young Adult
chemical_list: D000975:Antioxidants; D013438:Sulfhydryl Compounds; D014810:Vitamin E; D001205:Ascorbic Acid