The evidence for how important vitamin D is keeps increasing.
The study reviewed here examined the association between breast cancer and plasma 25-hydroxy vitamin D levels (Crew KD. et al, 2009). 25-hydroxy vitamin D is the most common blood test used to check the status of vitamin D.
When women with vitamin D deficiency of less than 20 mg/ml of 25-hydroxy vitamin D were compared with women showing a level of more that 40 mg/ml, it was found that levels above 40 mg/ml were associated with decreased breast cancer risk. The reduction in risk was greater among postmenopausal women.
These results add to the growing body of evidence that adequate vitamin D stores may prevent the development of breast cancer.
Crew KD., et al. Association between Plasma 25-Hydrocyvitamin D and Breast Cancer Risk. Cancer Prev Res. 2009 Jun; 2(6):598-604.