Vitamin D may lower breast cancer risk

Vitamin D may lower breast cancer risk
Fri May 16, 2008 2:25am BST
By Maggie Fox, Health and Science Editor

WASHINGTON (Reuters) - Breast cancer patients with lower levels of vitamin D were far more likely to die and far more likely to have their cancer spread than women with normal levels, Canadian researchers reported on Thursday.

Women deficient in the "sunshine vitamin" when they were diagnosed with breast cancer were 94 percent more likely to have their cancer spread and were 73 percent more likely to die than women with adequate vitamin D levels, the researchers said.

More than three-quarters of women with breast cancer had a vitamin D deficiency, the researchers reported to an upcoming meeting of the American Society of Clinical Oncology.

"The women with the lowest vitamin D levels had the highest risk of death from breast cancer," Dr. Richard Schilsky, of the University of Chicago and president-elect of ASCO, told Reuters in an interview.

"We are seeing an association. It is possible that vitamin D is simply a marker for healthy lifestyle. We don't think that is the case," said Dr. Pamela Goodwin of Mount Sinai Hospital in Toronto, who led the study.

The study adds to a growing body of evidence that vitamin D, made when sunlight hits the skin and used to fortify many foods including milk, is important for preventing chronic diseases. It is key to maintaining strong bones.

Goodwin's team studied 512 women with a mean age of 50 with newly diagnosed breast cancer treated at three University of Toronto hospitals between 1989 and 1995. They were followed until 2006, a median of just under 12 years.

Only 24 percent of the patients had adequate levels of vitamin D when they were diagnosed with cancer.

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