Calcium provides the building blocks that help keep bones and teeth strong and healthy. It also supports the musculoskeletal and nervous systems, and involved with heartbeat regulation. Magnesium helps to regulate calcium transport and stimulates the secretion of calcitonin, a hormone that aids in the influx of calcium into bone. It plays an important role in protein formation and healthy muscle function. This formulation contains the highly absorbable citrate form of calcium.* Adequate calcium throughout life, as part of a well-balanced diet, may reduce the risk of osteoporosis.