TUESDAY, September 2, (News Locale) - Vitamin B supplements, which are thought to help prevent progression of coronary artery disease, may not be helpful and may in fact cause harm. These are the findings of a Norwegian study involving over 3,000 participants.

Researchers at Haukeland University Hospital in Bergen, Norway, enrolled 3,096 participants with an average age of 61.7 years for the study. Among then 634 were female volunteers, while the rest were male. All participants had some degree of coronary heart disease with 83 percent having stable angina pectoris.

Another 59 percent had d double- or triple-vessel disease at the beginning of the study. The researchers led by Marta Ebbing assigned the participants to randomly receive varying doses of vitamin B and folic acid supplements or a placebo.

The study was halted after 38 months because ""we could not detect any preventive effect of intervention with folic acid plus vitamin B12 or with vitamin B6 on mortality or major cardiovascular events," the researchers wrote in the August 20 issue of the Journal of the American Medical Association.

The researchers also noted an increase in the incidence of cancer, but a decrease in the incidence of stroke among people who took the supplements.  They concluded these findings do not support the use of B vitamins as secondary prevention in patients with coronary artery disease.

Even the American Heart Association is not in favour of supplementation. "We don't recommend widespread use of folic acid and B vitamin supplements to reduce the risk of heart disease and stroke," the AHA says. “We advise a healthy, balanced diet that's rich in fruits and vegetables, whole grains, and fat-free or low-fat dairy products."