Vitamin D May Show Benefit in Fight Against Breast and Colorectal Cancers

Review and meta-analysis of several studies led researchers from several institutions to determine that an increased daily intake of vitamin D may significantly correlate with reduced incidences of colorectal and breast cancer. The breast cancer study pooled dose-response data from two earlier studies of 1,760 subjects. Subjects with the highest serum concentrations of 25-hydroxyvitamin D, or 25(OH)D (50 nanograms per milliliter), had a fifty percent lower risk of breast cancer compared to those with the lowest blood concentrations; less than or equal to 10 nanograms per milliliter. The colorectal cancer meta-analysis looked at five studies of 1,448 Caucasian subjects. The authors estimate a two-thirds reduction in incidence with serum concentrations of 46 nanograms per milliliter, corresponding to a daily intake of 2,000 IU of vitamin D3. The researchers state the best way to achieve these concentrations is a combination of diet, supplements and 10 to 15 minutes per day in the sun. (Journal of Steroid Biochemistry and Molecular Biology, doi: 10.1016/j.jsbmb.2006.12.007 and American Journal of Preventive Medicine, Volume 32, Number 3, Pages 210-216)