NPA Challenges Findings of JAMA Study on Health Risks Associated with Folic Acid and B12 Treatment

On Tuesday, November 17, The Journal of the American Medical Association (JAMA) released a study that indicates an associated increased risk of cancer and death from any cause if the study subjects had received treatment with folic acid and vitamin B12. The study appears in the November 18 issue of JAMA; the abstract appears here.

In response to the findings, the Natural Products Association issued the following statement from Daniel Fabricant, Ph.D., vice president of scientific and regulatory affairs:

“This is an analysis of two studies -- the NORVIT [the Norwegian vitamin trial, a 2005 randomized trial of homocysteine-lowering with B-vitamins for secondary prevention of cardiovascular disease after acute myocardial infarction] and WENBIT [Western Norway B-vitamin intervention trial presented at the European Society of Cardiology Congress 2007].

“Despite the authors’ justification for the analysis, previous review has indicated the NORVIT might not have been adequately powered and the factorial design might have been too complex, thus rendering the trial incapable of isolating the effect of folate per se. Being combined with the WENBIT, which was terminated early, and which wasn’t without its design flaws, either, creates a scenario in which two flawed studies are combined to yield one larger flawed study. This does not seem to be in the best interest of medical science or public health.”

Fabricant also states that most of the subjects in both trials were also being treated with beta-blockers and statins, and some were also being treated with ACE inhibitors and diuretics, “yet there are no numbers, no analysis on the effects these interventions may have on the incidence of cancer. There is no adjustment of the baseline effect for these interventions, yet the authors adjusted the baseline for smoking, age and sex, which are all factors in the development of cancer. We have no way of determining these factors’ impact on this study as they just decided to leave that out, like ordering off of an a la carte menu, “said Fabricant.

The Natural Products Association has made these comments available to the media and is monitoring media coverage of the study. The association will continue to inform its members if new developments arise.

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