Vitamin D and Cancer: Existing Evidence Shows No Clear Benefit

Bad news for the cure du jour and Whore Foods.

The idea that vitamin D reduces both cancer incidence and mortality, which stems from observational studies, is biologically plausible and has been promulgated with widespread enthusiasm. But the evidence is "inconsistent and inconclusive as to causality," say vitamin D experts who were on the Institute of Medicine (IOM) panel that recently published a definitive report on vitamin D and health outcomes.

Although the IOM report covered all aspects of vitamin D and its effects on health, a new pronouncement — published online March 23 as a Perspective in the New England Journal of Medicine — focuses specifically on cancer.

"Given that the potential role of vitamin D in cancer prevention has been widely touted, many people were surprised that cancer-related considerations didn't figure prominently" in the IOM report, write the authors, headed by JoAnn Manson, MD, DrPH, from the Department of Medicine at Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.

"The committee's comprehensive review of the evidence regarding vitamin D's role in preventing cancer, however, revealed that the research is inconsistent and doesn't establish a cause–effect relationship," they explain.

Most of the evidence is derived from laboratory studies, ecologic correlation, and observation investigations of serum vitamin D levels in association with cancer outcomes. There have been no large-scale randomized clinical trials with vitamin D and cancer as the primary prespecified end point, they noted.

"Existing evidence falls short" of showing clear benefits from vitamin D on cancer, they conclude.

You can stop wasting your money and life on this supplement.