A widely promoted B vitamin regimen for the prevention of heart attacks and strokes has shown no beneficial effects in people at high risk, researchers are reporting today. The hypothesis was that B vitamins € folic acid, vitamin B12 and vitamin B6 € can protect people against homocysteine, an amino acid that some doctors said was as important and dangerous a risk factor for heart disease as cholesterol. Studies of populations showed that the higher the homocysteine level in the blood, the greater the risk of heart attacks and strokes. And studies of animals indicated that homocysteine can actually damage tender linings of arteries, setting the stage for atherosclerosis. B vitamins, however, reduce blood levels of homocysteine. The vitamins, which are found in a variety of foods, including fruits and vegetables, have no known harmful effects. And if people take them as supplements, their homocysteine levels plummet. About 35 percent of Americans take B vitamins, mostly in the form of multivitamin pills, according to the Council on Responsible Nutrition, a trade group. So it seemed reasonable to many doctors and patients to expect that taking the vitamins would be protective. It might be even better than […]