Vitamin D May Reduce Breast Cancer Risk, Not Calcium

TORONTONo associations were found between overall vitamin D or calcium intake and breast cancer risk; however, vitamin D from supplements was independently associated with reduced breast cancer risk, according to a study published in the American Journal of Clinical Nutrition (2010;91(6):1699-1707). Breast cancer cases aged 25 to 74 years (diagnosed 2002 to 2003) were identified through the Ontario Cancer Registry. Controls were identified by using random digit dialing; 3,101 cases and 3,471 controls completed epidemiologic and food-frequency questionnaires.

Vitamin D and calcium intakes from food only and total combined intakes (food and supplements) were not associated with breast cancer risk, although the mean intake of vitamin D was low. Vitamin D supplement intake more than 10 µg/d (400 IU/d) compared with no intake was associated with a reduced risk of breast cancer. No categories of calcium supplement intake were significantly associated with reduced breast cancer risk, but a significant inverse trend was observed (P=0.04). There were no significant interactions involving vitamin D, calcium or menopausal status.