Study: Vitamin D
protects against cancer

People with the highest levels of a form of vitamin D in their blood have the lowest risk of breast cancer, according to a study in the Journal of Steroid Biochemistry and Molecular Biology.

"And the breast cancer rates dropped as the blood levels of 25-hydroxyvitamin D increased," study coauthor Cedric Garland said in a release. Garland went on to say that risk of breast cancer could be halved by taking 2,000 international units of vitamin D3 daily and spending 10 to 15 minutes a day in the sun.

A related study, published online by the American Journal of Preventive Medicine, found the same form of vitamin D could prevent colorectal cancer. A daily intake of 2,000 IU of vitamin D3 reduces the incidence of the disease by two thirds, said coauthor Edward D. Gorham in the same release. "This would be best achieved with a combination of diet, supplements, and 10 to 15 minutes per day in the sun."

Vitamin D3 is available through diet, supplements and exposure of the skin to sunlight, or ultraviolet B. Researchers emphasized the importance of limiting sun exposure so the skin doesn't tan or burn. Typical fair-skinned Caucasians who spend 10 to 15 minutes in the midday sun will photosynthesize adequate vitamin D. Darker-skinned individuals may require as much as 25 minutes. (The Advocate)