M.C.H.A. or microcrystalline calcium hydroxyapatite, prepared from raw bone, is in an extremely bioavailable form of calcium. Additional minerals are present in the natural ratios occurring in normal bone. Vitamin D has been added to assist in the formation of new bone cells. Boron is added because it has shown to promote calcium and magnesium absorption. Calcium from M.C.H.A. and calcium citrate are readily absorbed and utilized by the body. While other forms of calcium may halt bone loss, only M.C.H.A. has been shown to restore bone density. Adequate calcium and Vitamin D throughout life, as part of a well-balanced diet, may reduce the risk of osteoporosis.