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

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 \<6)
* Patients who plan to undergo neoadjuvant chemotherapy prior to definitive surgical management. Participants are eligible up to 2 weeks after initiating neoadjuvant chemotherapy.
* ECOG performance status of 0, 1 or 2.
* Age ≥ 18.
* The effects of high dose vitamin D on the developing human fetus are unknown. For this reason, women of child-bearing potential must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately.
* Ability to understand and the willingness to sign an IRB-approved informed consent document (either directly or via a legally authorized representative).

Exclusion Criteria:

* Patients with nephrolithiasis within the past year.
* Patients with known sarcoidosis.
* Patients with corrected calcium \>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.