Inclusion Criteria:

- Histologically proven metastatic adenocarcinoma of the breast.

- Gender: female.

- Age ≥18 years.

- ECOG performance status ≤ 2.(see appendix I)

- 25 (OH) Vitamin D level ≤ 100nmol/L (40ng/L).

- No more than 1 prior chemotherapy regimen not including Docetaxel or Paclitaxel for
metastatic breast cancer.

- Patients progressed on Doxorubicin or epirubicin as first line for metastatic breast
cancer is eligible.

- Concurrent bisphosphonate therapy allowed.

- Life expectancy more than 6 months

- At least 12 months since prior adjuvant or neo-adjuvant chemotherapy including
Taxanes regimens.

- Adequate hematologic, hepatic and renal function.

- Written informed consent.

Exclusion Criteria:

- Pregnant or lactating women.

- Male breast cancer.

- Women of childbearing potential unless surgically sterile or using adequate measures
of contraception.

- Metastatic inflammatory breast cancer.

- CNS metastasis.

- Leptomeningeal carcinomatosis.

- Malignant hypercalcemia.

- History of kidney stones.

- History of active primary hyperparathyroidism.

- Normal 25 (OH) Vitamin D level ≥100 nmol/L or ≥ 40 ng/L.

- Previous or concomitant malignancy of any type, except adequately treated basal cell
carcinoma of the skin or in situ cervix cancer.

- Patient on any anti-Psychotic medications or Steroid therapy.

- History of malabsorption syndrome (pancreatic insufficiency, celiac disease and
tropical sprue).

- Any of the following abnormal baseline hematological values:

- ANC < 1.0 x109/L, or platelets < 100.000 x 109/L.

- Any of the following abnormal laboratory tests: total serum bilirubin >2.00 x ULN
(upper limit of normal), AST, ALT > 2.5 x ULN or ALP >2.50 x ULN (upper limit of
normal).