Vitamin D Cuts Risks of Cancer

A landmark new study is raising the tantalizing spectre that a simple and cheap vitamin supplement may offer a highly effective way of preventing cancer. But before you stock up on Vitamin D there are a couple of things to consider regarding this study: 1) It was conducted on women only, which means that the same might not hold true for me, and 2) taking excessive amounts of Vitamin D can be toxic.

The research, published in the online edition of the American Journal of Clinical Nutrition, finds that a combination of vitamin D3 and calcium has a substantially marked effect on reducing cancer incidence.

The four-year study out of Creighton University in Nebraska found that women who regularly took vitamin D3 had a 60 per cent reduction in cancer infections compared to a group taking placebos.

The study followed 1,179 healthy (operative word here being "healthy") women 55 years and older from rural eastern Nebraska between 2000 and 2005. Participants were randomly assigned to receive 1400-1500 mg of calcium alone, or supplemental calcium plus 1,100 IU vitamin D3, or placebo. The researchers studied only vitamin D3, which comes from animal sources and seems to be more active than vitamin D2, which is derived from plant sources. (As a sidebar: Vitamin D helps the body absorb calcium, and also helps the body keep the right amount of calcium and phosphorus in the blood. With that said, it's not clear as to how much of that 1400-1500 mg of calcium alone was actually being absorbed.)

Among the 288 women taking placebo, 20 developed breast, colon, lung or another form of cancer. Among the 445 women taking just calcium, 17 developed cancer. But among the largest group -- the 446 women taking vitamin D daily -- just 13 developed cancer.


Lappe JM, Travers-Gustafson D, Davies KM, Recker RR, Heaney RP. Vitamin D and Calcium Supplementation Reduces Cancer Risk: Results of a Randomized Trial. American Journal of Clinical Nutrition. (2007) 85.6 1586-1591.

National Institute of Health Office of Dietary Supplements: "Dietary Supplement Fact Sheet: Vitamin D." 2004 National Institute of Health Office of Dietary Supplements June 11, 2007.


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