Phase III Trial of High Dose vs. Standard Dose Vit D2 With Docetaxel in Met Breast ca

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).