RecruitingPhase 2Drug trialImpact of Vitamin D Supplementation on the Rate of Pathologic Complete Response in Vitamin D Deficient PatientsA 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.