Folic acid, vitamin B12 do not reduce vascular events

Supplementation with folic acid and vitamin B₁₂ over an extended period does not have a beneficial effect on vascular outcomes in individuals who have had a myocardial infarction, but it also poses no excess cancer risk, according to a study in the June 23/30 issue of the Journal of the American Medical Association, reported HealthDay News.

Jane M. Armitage, of the University of Oxford in the United Kingdom, and colleagues conducted a prospective study of 12,064 survivors of myocardial infarction to assess the association of vitamin B supplementation and major vascular events. Patients were randomly assigned to receive either folic acid 2 mg per day plus vitamin B₁₂ 1 mg per day, or placebo.

The researchers found that patients in the treatment group had a reduction in homocysteine levels averaging 28%; 25.5% of this group had a major vascular event over the 6.7-year study period, while patients in the placebo group had a 24.8% risk of having a major vascular event in the same period (P=.28). The researchers found that supplementation has no apparent effect on major coronary events, stroke, or non-coronary revascularizations. There was no significant difference in the incidence of vascular-related or nonvascular-related deaths between the 2 groups. There was also no significant difference in the risk of cancer between the 2 groups, which had been previously speculated.

“These results highlight the importance of focusing on drug treatments (eg, aspirin, statins, and antihypertensive therapy) and lifestyle changes (in particular, stopping smoking and avoiding excessive weight gain) that are of proven benefit, rather than lowering homocysteine with folic acid-based vitamin supplements, for the prevention of cardiovascular disease,” the authors said.

The study was funded by Merck (manufacturer of simvastatin and supplier of the vitamins). One author disclosed financial ties to several pharmaceutical companies.