Evaluation the of Role of Vitamin D Supplement on Tumor Response, Inflammation and Apoptosis in Patients With Stage II or III Colorectal Cancer Receiving Chemotherapy.

This randomized, controlled parallel study will be conducted on 44 patients with Stage II or III colorectal cancer. Patients will be recruited from Clinical Oncology Department, Menoufia university Hospital, Menoufia, Egypt. The patients will be randomized using sealed envelope method into the following two groups: Group I (Control group; n=22) which will receive FOLFOX (leucovorin, fluorouracil, and oxaliplatin) or XELOX (capecitabine and oxaliplatin). Group II: (Vitamin D group; n=22) which will receive the same chemotherapy regimen plus Vitamin D for 6 months. Markers to be measured: * BAX protein as a marker for apoptosis will be measured at baseline and after 6 months. * Tumor necrosis factor - alpha (TNF- α) as a marker of inflammation will be measured at baseline and after 6 months.