This phase III trial studies how well vitamin D3 given with standard chemotherapy and bevacizumab works in treating patients with colorectal cancer that has spread to other parts of the body (advanced or metastatic). Vitamin D3 helps the body use calcium and phosphorus to make strong bones and teeth. Vitamin D3 may also modulate the immune system and is being studied in the prevention and treatment of some types of cancer. Chemotherapy drugs, such as leucovorin calcium, fluorouracil, oxaliplatin, and irinotecan hydrochloride, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Bevacizumab is a monoclonal antibody that binds to vascular endothelial growth factor (VEGF). VEGF is a substance made by cells that helps the formation of new blood vessels. Bevacizumab may prevent the growth of new blood vessels that tumors need to grow. Giving vitamin D3 with chemotherapy and bevacizumab may work better in shrinking or stabilizing colorectal cancer. It is not yet known whether giving high-dose vitamin D3 in addition to chemotherapy and bevacizumab would extend patients time without disease compared to the usual approach (chemotherapy and bevacizumab).