calciumtophosphate

Calcium phosphate refers to a family of calcium salts and esters of phosphoric acid. The exact composition varies, yielding several common forms, including monocalcium phosphate (Ca(H2PO4)2), dicalcium phosphate (CaHPO4), and tricalcium phosphate (Ca3(PO4)2). In biological systems, hydroxyapatite, Ca5(PO4)3OH, is the principal calcium phosphate mineral in bone and dental enamel.

Natural occurrence and biological relevance: Calcium phosphate minerals occur widely in the Earth’s crust as part of the apatite group. In vertebrates, hydroxyapatite forms the mineral matrix of bone and teeth, contributing to rigidity and strength. The specific calcium-to-phosphate ratio and crystal form influence mineralization pathways and solubility. The body regulates calcium and phosphate homeostasis through hormonal and renal mechanisms to support skeletal maintenance and metabolic functions.

Industrial, medical, and nutritional uses: Calcium phosphates are used as dietary supplements and food additives, often as calcium sources or acidity regulators. Monocalcium phosphate is a common leavening agent in baking powders. In medicine and dentistry, calcium phosphate compounds serve as bone graft materials, bone cements, coatings for implants, and fillers due to their bioactivity and compatibility with bone mineral.

Properties and preparation: Many calcium phosphate phases are sparingly soluble in water, with solubility dependent on pH, carbonate content, and crystal form. They are typically produced by precipitation from aqueous solutions containing calcium ions and phosphate species, with crystallization influenced by temperature, pH, and additives. In physiological and dental contexts, the presence of carbonate and other ions can convert phases toward biological apatite.

Safety and regulation: Calcium phosphates are generally regarded as safe for approved uses in foods, supplements, and medical applications. Proper formulation and dosage are important to avoid aberrant calcification in soft tissues.