Effects of B Vitamins on Cardiovascular Events and Total Mortality Among Women at High Risk for Cardiovascular Disease
Several years and many studies later, a newer more controversial study recently emerged from the Journal of the American Medical Association (JAMA) that indicates B vitamins might not lower the risk for cardiovascular disease. The study design included 5442 women aged 42 years or older with either a history of CVD or 3 or more coronary risk factors. It was a randomized, double-blind, placebo –controlled trial using either a placebo or a supplement containing folic acid, vitamin B-12, and vitamin B6. They were treated for seven years. The women were concurrently receiving a trial of antioxidant therapy.
The dosages for the supplements were 2.5 mg folic acid, 50 mg of B6 and 1 mg of B12.
The outcome measures were composite outcomes of heart attack, stroke, coronary revascularization or CVD mortality.
Compared with the placebo, 796 women experienced a CVD event (406 in the active group and 390 in the placebo group). The conclusion of this study was that after 7.3 years of treatment and follow-up, a combination pill of folic acid, B6 and B12 did not reduce a combined endpoint of total cardiovascular events among high-risk women, despite significant homocysteine lowering.
Obviously, one study does not tell the whole story. We need to test this hypothesis in men, different age groups and with different outcome measures. For example can supplementation prolong the development of CVD symptoms as opposed to decreasing mortality in high-risk women? What about other risk categories and prevention measures? Too many questions are left unanswered. Also this trial was confounded with the on-going treatment with antioxidant vitamins. Antioxidants can have variable effects on CVD. To test this hypothesis within a group already receiving test doses of antioxidants definitely added a confounding variable not controlled for thus clouding the interpretation of the data.
About the Author
Kathy Shattler received her Master of Science degree from Michigan State University in E. Lansing Michigan in Human Nutrition. Her twenty-two years of practice includes holding positions as a Lecturer, Chief Clinical Dietitian and Program Manager. Kathy is the Founder of Nutri-Care Consulting and is currently the Nutrition Director of www.CEU4U.COM, an online continuing education management company for Registered Dietitians and Dietetic Technicians.
