Norwegian investigators report that supplementation with folate and vitamin B12 or vitamin B6 does not benefit patients with coronary heart disease, according to a study published in the August 20, 2008 issue of the Journal of the American Medical Association.

Prior observational studies reported associations between high levels of homocysteine, an amino acid, and an increased risk for cardiovascular disease and stroke. Because folate can lower homocysteine levels in the blood, these researchers used a study group of over 3000 heart disease patients to assess the effects of folate and vitamin B as prevention against the complications of heart disease. They found that, after an average follow-up period of 38 months, there was no significant difference in the risk of death or major cardiovascular events with folate or vitamin B supplementation.

The researchers also report a concerning finding - study participants who were treated with both folate and vitamin B12 seemed to be at a higher risk for cancer, although the results were not statistically significant. A previous clinical trial called the Norwegian Vitamin (NORVIT) trial also suggested a possible increase in cancer risk with vitamin B supplementation. Researchers are currently working on combining the results from these trials to further explore these effects.