- Calcium phosphate refers to a family of minerals containing calcium ions (Ca²⁺) together with phosphate ions (PO₄³⁻), and sometimes hydrogen or hydroxide ions, depending on the specific type.
- The most biologically and industrially significant forms include monocalcium phosphate (Ca(H₂PO₄)₂), dicalcium phosphate (CaHPO₄), and tricalcium phosphate (Ca₃(PO₄)₂). These compounds are typically white, odorless powders that are sparingly soluble in water and occur both naturally and synthetically. Calcium phosphate plays vital roles in biology, medicine, food, and industry, particularly due to its function as a source of calcium and phosphorus—two essential nutrients.
- In the human body, calcium phosphate is the major mineral component of bones and teeth, where it exists in the form of hydroxyapatite [Ca₁₀(PO₄)₆(OH)₂]. This crystalline structure provides hardness and strength to skeletal tissues. Calcium phosphate is also involved in numerous metabolic processes, including cell signaling, energy production (as part of ATP), and enzyme function. Given its biological importance, it is often used in dietary supplements and fortified foods to support bone health and prevent or treat calcium and phosphorus deficiencies.
- In medicine and dentistry, calcium phosphate is used in bone graft materials, dental cements, and coatings for implants. Its high biocompatibility and osteoconductive properties allow it to integrate well with natural bone, promoting regeneration and repair. Calcium phosphate-based ceramics and pastes are commonly applied in orthopedic and maxillofacial surgeries to treat bone defects, fractures, or periodontal issues. Additionally, hydroxyapatite and related compounds are used in toothpaste formulations to help remineralize enamel and reduce tooth sensitivity.
- In the food industry, calcium phosphates serve multiple roles. They are approved as food additives (e.g., E341) and are used as leavening agents, acidity regulators, anti-caking agents, and mineral fortifiers in products such as baked goods, cereals, dairy products, and infant formulas. They are especially valuable in nutritional supplements aimed at populations with increased mineral needs, such as children, the elderly, and individuals with osteoporosis.
- In agriculture, calcium phosphate is a key component of phosphate fertilizers, particularly superphosphate fertilizers, which provide essential nutrients to support plant growth and development. These fertilizers are produced by treating natural rock phosphate (primarily composed of calcium phosphate) with sulfuric acid to make the phosphorus more soluble and bioavailable to plants.
- Calcium phosphate is also used in biomaterials research, ceramic manufacturing, and chemical synthesis. Its stability and compatibility with biological systems make it a promising material in the development of drug delivery systems and biodegradable scaffolds for tissue engineering.
- While generally recognized as safe, excessive intake of calcium phosphate—especially from supplements—can lead to hypercalcemia or phosphate imbalances, particularly in individuals with kidney disorders. Therefore, supplementation should be managed under medical guidance.
