Associations between vitamin D deficiency and risk of aggressive breast cancer in African-American women

▸ Results from previous studies of vitamin D and breast cancer risk are inconsistent. ▸ Vitamin D may exert stronger effects against aggressive breast cancer subtypes. ▸ Vitamin D levels are lower in African-Americans than in European-Americans. ▸ African-American women are at high risk of aggressive breast cancer. ▸ Vitamin D may be related to breast cancer racial disparities in the US.