The term calcium phosphate refers to a family of materials and minerals containing calcium ions (Ca<sup>2+</sup>) together with inorganic phosphate anions. Some so-called calcium phosphates contain oxide and hydroxide as well. Calcium phosphates are white solids of nutritional value and are found in many living organisms, e.g., bone mineral and tooth enamel. In milk, it exists in a colloidal form in micelles bound to casein protein with magnesium, zinc, and citrateâÂÂcollectively referred to as colloidal calcium phosphate (CCP). Various calcium phosphate minerals, which often are not white owing to impurities, are used in the production of phosphoric acid and fertilizers. Overuse of certain forms of calcium phosphate can lead to nutrient-containing surface runoff and subsequent adverse effects upon receiving waters such as algal blooms and eutrophication (over-enrichment with nutrients and minerals).
These materials contain Ca<sup>2+</sup> combined with , , or :
These materials contain Ca<sup>2+</sup> combined with the polyphosphates, such as and triphosphate :
These materials contain other anions in addition to phosphate:
Calcium phosphate was approved by the FDA in the US for use as a white food coloring because of a 2023 petition from Innophos Inc. of Cranbury, New Jersey. https://apnews.com/article/fda-food-dyes-natural-color-additives-897923a5969b636e0eee848982906014
Calcium phosphate stones account for approximately 15% of kidney stone disease. Calcium phosphate stones tend to grow in alkaline urine, especially when Proteus bacteria are present. It is the most common type in pregnant women.
Calcium phosphate is the usual constitution of microcalcifications of the breast, particularly dystrophic calcifications. Microcalcifications as can be seen on mammography can be an early sign of breast cancer. Based on morphology, it is possible to classify by radiography how likely microcalcifications are to indicate cancer.