Calcium supplement with vitamin D3. 500 mg calcium. 600 IU vitamin D3. New look! Easy flip cap. Helps reduce the risk of hip fractures by 29% (Based on a clinical study conducted by NIH. When used as directed). Vitamin D3 helps optimize calcium absorption. Most vitamin D3 per pill of any leading brand. Don't take chances - Take Os-Cal. Questions or comments? Call toll-free 1-800-245-1040 (English/Spanish) weekdays or visit us at www.oscal.com. The Os-Cal brand of calcium supplements is the number 1 pharmacist recommended among leading calcium supplement brands. Only Os-Cal is proven to help reduce the risk of hip fractures by 29% (Based on a clinical study conducted by NIH. When used as directed).