Hydroxyapatite is a naturally occurring form of the mineral calcium apatite—calcium, phosphorous, and oxygen—that grows in hexagonal crystals. Pure hydroxyapatite is white in color. It makes up most of the human bone structure, builds tooth enamel, and collects in tiny amounts in part of the brain.

Is hydroxyapatite the same as calcium?

Most calcium is a building block of bone and tooth enamel. This is called calcium hydroxyapatite.

What elements are in hydroxyapatite?

Hydroxyapatite (HA) is an inorganic mineral that has a typical apatite lattice structure as (A10(BO4)6C2) where A, B, and C are defined by Ca, PO4, and OH. Pure HA contains 39.68% by weight calcium and 18% by weight phosphorus resulting in a Ca/P mole ratio of 1.67.