Hydroxocobalamin is a man-made (synthetic) form of vitamin B12; a vitamin that helps the body with blood and nerve function, cell production, and growth. Some medical conditions (e.g., various GI problems, cancer, infections) may cause low levels of vitamin B12 in the body. OTHER USES: This vitamin may also be used to treat a variety of other medical conditions including: multiple sclerosis, nerve problems (e.g., neuropathies), viral hepatitis, certain thyroid conditions (e.g., thyrotoxicosis), sterility, and malnutrition.