title: B vitamin and/or ω-3 fatty acid supplementation and cancer: ancillary findings from the supplementation with folate, vitamins B6 and B12, and/or omega-3 fatty acids (SU.FOL.OM3) randomized trial.
abstract: BACKGROUND
  To advance knowledge about the cancer-chemopreventive potential of individual nutrients, we investigated the effects of B vitamin and/or ω-3 fatty acid supplements on cancer outcomes among survivors of cardiovascular disease.
  
  
  METHODS
  This was an ancillary study of the Supplementation With Folate, Vitamins B(6) and B(12) and/or Omega-3 Fatty Acids (SU.FOL.OM3) secondary prevention trial (2003-2009). In all, 2501 individuals aged 45 to 80 years were randomized in a 2 × 2 factorial design to one of the following 4 daily supplementation groups: (1) 5-methyltetrahydrofolate (0.56 mg), pyridoxine hydrochloride (vitamin B(6); 3 mg) and cyanocobalamin (vitamin B(12); 0.02 mg); (2) eicosapentaenoic and docosahexaenoic acid (600 mg) in a 2:1 ratio; (3) B vitamins and ω-3 fatty acids; or (4) placebo. Overall and sex-specific hazard ratios (HRs) and 95% CIs regarding the cancer outcomes were estimated with Cox proportional hazards models.
  
  
  RESULTS
  After 5 years of supplementation, incident cancer was validated in 7.0% of the sample (145 events in men and 29 in women), and death from cancer occurred in 2.3% of the sample. There was no association between cancer outcomes and supplementation with B vitamins (HR, 1.15 [95% CI, 0.85-1.55]) and/or ω-3 fatty acids (HR, 1.17 [95% CI, 0.87-1.58]). There was a statistically significant interaction of treatment by sex, with no effect of treatment on cancer risk among men and increased cancer risk among women for ω-3 fatty acid supplementation (HR, 3.02 [95% CI, 1.33-6.89]).
  
  
  CONCLUSIONS
  We found no beneficial effects of supplementation with relatively low doses of B vitamins and/or ω-3 fatty acids on cancer outcomes in individuals with prior cardiovascular disease. Trial Registration  isrctn.org Identifier: ISRCTN41926726.
authors.affiliation: Nutritional Epidemiology Research Unit, University of Paris XIII, France. v.andreeva@uren.smbh.univ-paris13.fr
authors.forename: Valentina A
authors.initials: VA
authors.lastname: Andreeva
authors.forename: Mathilde
authors.initials: M
authors.lastname: Touvier
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Kesse-Guyot
authors.forename: Chantal
authors.initials: C
authors.lastname: Julia
authors.forename: Pilar
authors.initials: P
authors.lastname: Galan
authors.forename: Serge
authors.initials: S
authors.lastname: Hercberg
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016588:Anticarcinogenic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D018890:Chemoprevention / Q000379:methods; D019587:Dietary Supplements; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology* / Q000401:mortality / Q000517:prevention & control*; D016017:Odds Ratio; D016016:Proportional Hazards Models; D012107:Research Design; D012307:Risk Factors; D055502:Secondary Prevention / Q000379:methods*; D012737:Sex Factors; D017211:Treatment Failure; D014481:United States / Q000453:epidemiology; D014805:Vitamin B 12 / Q000008:administration & dosage / Q000627:therapeutic use*; D025101:Vitamin B 6 / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D016588:Anticarcinogenic Agents; D015415:Biomarkers; D015525:Fatty Acids, Omega-3; D025101:Vitamin B 6; D005492:Folic Acid; D014805:Vitamin B 12