AHA: No Cardiovascular Benefit from Folic Acid and B Vitamins

November 14, 2006

CHICAGO -- Supplementation with folic acid and vitamins B6 and B12 does not appear to help the heart, investigators reported here.

CHICAGO, Nov. 14 -- Supplementation with folic acid and vitamins B6 and B12 does not appear to help the heart, investigators reported here.

Heart attacks, strokes, coronary revascularization procedures, and cardiovascular-related deaths were no less common in high-risk women receiving the supplements, said Christine M. Albert, M.D., M.P.H., of Brigham and Women's Hospital in Boston, and colleagues, at the American Heart Association meeting.

On the other hand, the analysis of 5,442 female health care professionals in the larger, double-blind Women's Antioxidant Cardiovascular Study., found that there did not appear to be any adverse effect from the antioxidant vitamins.

The women, who were 40 or older and had preexisting cardiovascular disease or at least three coronary risk factors, were randomized to placebo or the combination of 2.5 mg of folic acid, 50 mg of vitamin B6, and 1 mg vitamin B12 daily.

After about seven years of taking the supplements, the researchers reported, there was no overall decrease in the primary endpoint of myocardial infarction, stroke, revascularization, and cardiovascular death combined (relative risk 1.04, 95% CI 0.91 to 1.19, P=0.58).

The secondary endpoints also showed no significant benefit from supplementation versus placebo. The findings were:

  • No significant effects on MI (RR 0.87, 95% CI 0.63 to 1.22, P=0.42),
  • No improvement in stroke (RR 1.14, 95% CI 0.82 to 1.57, P=0.44),
  • Essentially no reduction in revascularization (RR 0.99, 95% CI 0.83 to 1.17, P=0.87), and
  • No drop in cardiovascular-related death (RR 1.03, 95% CI 0.78 to 1.36, P=0.82).

During the study, 805 participants had a cardiovascular event, which included 139 MIs, 148 strokes, 508 coronary revascularizations, and 200 related deaths.

At this point, Dr. Albert said, "all of the data from all of the studies taking B6, B12 and folic acid suggest that there is no benefit" for cardiovascular health.

Folic acid, the synthetic form of folate that began being added to cereal and grain products around 1997, has been of interest because it and the other B vitamins reduce levels of the amino acid homocysteine. Homocysteine has been associated with increased cardiovascular risk in some observational studies.

To clarify what effect the folic acid fortification was having, the researchers also looked at blood samples collected before it began and near the end of the study in a subgroup of 300 women.

The investigators found that folic acid levels increased significantly in both groups but substantially more in the supplement group. They reported:

  • Folic acid increased from 9.2 to16.4 ng/ml in the placebo group (P