NMA: Nonprescription Medicines Academy

Supplementation With B Vitamins, Omega-3 Fatty Acids Does Not Protect Against Cancer

April 4th, 2012

Secondary analyses of data from the Supplementation With Folate, Vitamins B6 and B12 and/or Omega-3 Fatty Acids (SU.FOL.OM3) secondary prevention trial found no beneficial effects of supplementation with relatively low doses of B vitamins and/or omega-3 fatty acids on cancer incidence or mortality in individuals with prior cardiovascular disease.

The SU.FOL.OM3 trial was conducted in France from February 2003 to July 2009. A total of 2,501 participants (1,987 men and 514 women) 45 to 80 years of age who had experienced an acute myocardial infarction, unstable angina, or ischemic stroke within the preceding 12 months were randomized in a 2 x 2 factorial design to one of four daily supplementation groups:

  • 5-Methyltetrahydrofolate (0.56 mg), pyridoxine hydrochloride (vitamin B6; 3 mg) and cyanocobalamin (vitamin B12; 0.02 mg).
  • Eicosapentaenoic and docosahexaenoic acid (600 mg) in a 2:1 ratio.
  • B vitamins and omega-3 fatty acids.
  • Placebo

Overall and sex-specific hazard ratios (HRs) and 95% CIs regarding the cancer outcomes were estimated with Cox proportional hazards models.

After 5 years of supplementation, 174 participants (7.0%) developed incident primary cancer (145 events in men and 29 in women). There were 58 deaths from cancer (2.3% of the sample). No association was found between cancer outcomes and supplementation with B vitamins (HR, 1.15; 95% CI, 0.85–1.55) and/or omega-3 fatty acids (HR, 1.17; 95% CI, 0.87–1.58). The risk of cancer was increased among women who received omega-3 fatty acid supplements (HR, 3.02; 95% CI, 1.33–6.89).

Arch Intern Med. 2012 Feb 13. [Epub ahead of print]