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Coronary artery disease

B vitamins don't seem to keep heart problems at bay.

The question: Homocysteine, an amino acid present in the blood, has been linked to an increased risk for heart disease. Might taking B vitamins, which can lower homocysteine levels, help people with coronary artery disease reduce the likelihood of heart attack or stroke?

This study: Randomly assigned 3,096 adults (average age, 62) with narrowed or blocked coronary arteries or heart valves to one of four groups taking daily supplements: folic acid (Vitamin B9), B6 and B12; folic acid and B12; B6 alone; or a placebo. Homocysteine levels fell an average of 30 percent within a year among those taking folic acid and B12. After three years, 422 participants had had a serious heart problem, such as a heart attack or stroke, but the rate was roughly the same (about 14 percent) for each treatment group.

Caveats: The authors suggested that homocysteine levels might indicate cardiovascular risk rather than cause it. The study was stopped about a year early because a large number of participants quit after learning that another study involving B12 suggested a possible link between the vitamin and an increased risk for cancer. The authors wrote that preliminary results from this study "did not give any reason for concern."

Find this study: Aug. 20 issue of the Journal of the American Medical Association.