Calcium Supplement with Vitamin D3. Calcium (500 mg), vitamin D3 (600 IU). Natural and artificial flavor. Most vitamin D3 per pill of any leading brand. Helps reduce the risk of hip fractures by 29% (Based on a clinical study conducted by NIH. When used as directed). This Os-Cal brand of calcium supplements is the No. 1 pharmacist recommended among leading calcium supplements brands. Only Oscal is proven to help reduce the risk of hip fractures by 29%. Easy flip cap. Don't take chances - take OsCal.