Vitamin D deficiency is correlated with poor outcomes in patients with luminal-type breast cancer.

Purpose: Vitamin D deficiency may be an indicator of poor prognosis in patients with breast cancer before surgery. We investigated the association between serum vitamin D concentration and breast cancer prognosis according to intrinsic cancer subtypes.

Methods: From June to December 2006, serum 25-OHD was measured in 310 Korean women with breast cancer who were treated at the Asan Medical Center, Korea.