Impact of Vitamin D Supplementation on the Rate of Pathologic Complete Response in Vitamin D Deficient Patients

A two arm pilot study investigating the rate of pathologic complete response in patients with vitamin D deficiency and triple negative breast cancer undergoing standard neoadjuvant chemotherapy + vitamin D supplementation, including an observational arm to describe response in patients who are not deficient. Investigators hypothesize that vitamin D supplementation during neoadjuvant chemotherapy in operable triple negative breast cancer patients with vitamin D deficiency will increase the rate of pathologic complete response chain reaction to that of vitamin D sufficient patients based on historical controls.

Inclusion Criteria: * Women or men with histologically confirmed invasive mammary carcinoma. * Known triple negative ER/PR/HER2 receptor status as defined by: * ER and PR less than or equal to 10% and HER2 negative based on one of the following: * IHC 0 or 1+ * IHC 2+ and FISH negative * IHC 2+ and FISH equivocal and no indication for HER2 targeted therapy based on the treating investigators discretion (i.e., HER2: CEP17 ratio \< 2.0 or HER2 total copy number \10.5 mg/dL within 30 days prior to initiation of chemotherapy. * History of allergic reactions attributed to compounds of similar chemical or biologic composition to vitamin D. * Pregnant women are excluded from this study because vitamin D supplementation greater than the recommended daily allowance (RDA) is a pregnancy class C agent with no adequate or well controlled studies in humans. * Because there is an unknown but potential risk for adverse events in nursing infants secondary to treatment of the mother with high dose vitamin D (greater than RDA), women who are breastfeeding are excluded from this study. * Prior treatment for this malignancy including surgery, radiation therapy, chemotherapy, hormonal therapy or investigational agent prior to study entry. * Patients currently taking Vitamin D at a dose of 50,000 International Units (IU) once weekly.