BOSTON, March 15 (UPI) -- Three studies find that taking three B vitamins does not prevent heart attacks, at least in people who already have heart disease.
The combination of folic acid, vitamin B12 and vitamin B6 was thought to reduce homocysteine, an amino acid associated with heart disease.
The studies showed that the B vitamins did indeed reduce homocysteine. But subjects who took the B vitamin regimen had as many heart attacks as those who took a placebo in the double-blind study, the New York Times reported.
Two of the studies were published in the April 13 New England Journal of Medicine, while the other was published in 2004.
Some of the doctors involved in the study suggested that the B vitamin regimen might still help people who took the vitamins before they developed heart disease.
But Dr. Salim Yusuf of McMaster University in Ontario, author of one of the papers, said that therapies usually do not distinguish between those who are well and sick. He told the Times that homocysteine is probably a marker of heart disease, the way fever is a marker of infection. Reducing the fever will not eliminate the infection and cutting homocysteine will not cure heart disease.