Calcium is an essential mineral needed every day for proper health. 99% of the body's calcium can be found in the bones. This mineral provides the building blocks that help keep bones and teeth strong and healthy. In addition, calcium helps to support the health of other systems in the body, including the colon, heart, musculoskeletal and nervous systems, and is a component of enzymes that are required for blood clotting. This formulation contains Vitamin D3 to enhance the absorption of calcium. When combined with a healthy diet and physical activity, calcium may reduce the risk of osteoporosis.