The first large-scale, randomized, placebo-controlled study on vitamin D and cancer has shown that vitamin D can cut cancer risks by as much as 60 percent.
In response, the Canadian Cancer Society is now recommending vitamin D for all adults, the first time a major public-health organization has endorsed the vitamin as a cancer-prevention therapy.
The study looked at almost 1,200 women, aged 55 and older, over the course of four years. Those in a group that was given supplemental calcium and vitamin D had a 60 percent lower risk for all cancers than those who received a placebo.
American Journal of Clinical Nutrition, 85(6):1586-91 June 2007