Study Questions Vitamin B12, Folic Acid's Link to Heart Health

OXFORD, EnglandAccording to English researchers, substantial long-term reductions in blood homocysteine levelswhich are positively associated with cardiovascular disease (CVD), but may be a causal associationwith folic acid and vitamin B12 supplementation did not have beneficial effects on vascular outcomes, but were also not associated with adverse effects on cancer incidence (JAMA. 2010;303(24):2486-94). A double blind, randomized control trial of 12,064 survivors of myocardial infarction (MI) in secondary care hospitals was conducted in the United Kingdom between 1998 and 2008. Subjects received either 2 mg/d of folic acid plus 1 mg/d of vitamin B12 or a matching placebo.

Allocation to the study vitamins reduced homocysteine by a mean of 3.8 µmol/L (28 percent). During 6.7 years of follow-up, major vascular events occurred in 1,537 of 6,033 participants (25.5 percent) allocated folic acid plus vitamin B12 versus 1,493 of 6,031 participants (24.8 percent) allocated placebo. There were no apparent effects on major coronary events (vitamins, 1,229 [20.4 percent]) versus placebo, 1,185 [19.6 percent, stroke (vitamins, 269 [4.5 percent] versus placebo, 265 [4.4 percent]) or non-coronary revascularizations (vitamins, 178 [3.0 percent] versus placebo, 152 [2.5 percent]). Nor were there significant differences in the numbers of deaths attributed to vascular causes (vitamins, 578 [9.6 percent] versus placebo, 559 [9.3 percent]) or nonvascular causes (vitamins, 405 [6.7 percent] versus placebo, 392 [6.5 percent]) or in the incidence of any cancer (vitamins, 678 [11.2 percent] versus placebo, 639 [10.6 percent]).

 Duffy MacKay, N.D., vice president of scientific & regulatory affairs for Council for Responsible Nutrition (CRN), commented on the study resulting, stating: The concern with this study I it focused on treating individuals who have already had a heart attack. It didnt answer the question of whether a B vitamintaken over time and in combination with other healthy lifestyle habitscould have helped prevent CVD before it occurred at all. We may need to re-evaluate expectations when designing studies on nutrients used to treat serious chronic disease because it is unrealistic to expect a vitamin to undo a lifetime of unhealthy behaviors. The Study of the Effectiveness of Additional Reductions in Cholesterol and Homocysteine (SEARCH) demonstrated vitamin B supplementation lowered blood homocysteine levels, a biomarker for which lower levels are assumed to be associated with lower risk of heart disease and stroke. We should remember scientific knowledge grows in increments, and not to sacrifice the potential positive relationship between B vitamins and cardiovascular health given the results of one study. The researchers may have gotten too far ahead of themselves by expecting to see successful disease treatment without first understanding if the positive relationship between homocysteine levels and CVD is causal.

MacKay reminded consumers that vitamins and other supplements are not a cure or treatment for any disease, but when incorporated into a healthy lifestyle may help to reduce the risk of several health-related issues and can play an important role in maintaining overall health and wellness.