Wednesday October 1, 2008 (foodconsumer.org) -- A new study published  online on August 27, 2008 in American Journal of Epidemiology Advance Access  suggests increased intake of dietary vitamin D such as taking vitamin D supplements and exposure to sunlight may reduce the risk for breast cancer by more than 20 percent. 

The effect does not seem to depend on the hormone receptor status of the cancer. Vitamin D may reduce the risk for hormone-sensitive estrogen-receptor (ER) positive and progesterone-receptor (PR) positive tumors, the study found.

For the study, Kristina M. Blackmore at Samuel Lunenfeld Research Institute, Mount Sinai Hospital in Toronto, Canada compared 759 women with breast cancer with 1,135 healthy controls for their intake of vitamin D.

They found increased intake of vitamin D was associated with a 24 percent reduced risk of ER+ and PR+ breast cancers.

Specifically, the risk for receptor-negative (ER–/PR–) tumors were reduced by 26 percent and mixed receptor (ER+/PR–) tumors by 21 percent among those who had high intake of vitamin D.

Early studies have already suggested that taking vitamin D at high doses could cut breast cancer risk by up to 70 percent.

Breast cancer is diagnosed in 180,000 women and kills 40,000 each year in the United States. Vitamin D is found in oily fish and supplemented foods.   Exposure to sunlight triggers biosynthesis of this vitamin.