Development of Vitamin D as a Therapy for Breast Cancer - Phase 2

Patients undergoing core needle biopsy of breast abnormalities suspicious for breast cancer will be identified and enrolled in study. As well as those who have had a core needle biopsy demonstrating breast cancer, but who have not yet undergone local surgical treatment, chemotherapy, or hormonal therapy are also eligible. patients with breast cancer on core biopsy will be eligible.

Participants will be assigned to treatment (0, 2000, 4000, 6000 IU/day vitamin D by mouth) based solely on their serum vitamin D levels (Normal: >40 ng/mL; Low-normal: 31-40 ng/mL; Low: 20-30 ng/mL; Very-low: <20 ng/mL). Prior to definitive breast cancer surgery, vitamin D level, parathyroid level, and calcium will be reassessed. Samples of the patients original core biopsy and pathology specimen from their definitive surgical therapy will undergo gene expression profiling.

The ultimate plan is to correlate baseline vitamin D levels with classic prognostic and predictive markers to see if breast cancer biology is impacted by baseline vitamin D level and by vitamin D supplementation and to see if vitamin D supplementation results in gene expression changes similar to those of the vitamin D sufficient group.