Calcium Hydroxyapatite, 240 Capsules, Source NaturalsSource Naturals Calcium Hydroxyapatite Dietary Supplement. Microcrystalline Bone Support. At around the age of 30, our bone mass begins to decline. Support healthy bones with calcium hydroxyapatite, made from a form of calcium that gives bones their strength and rigidity. Bones consist of living cells embedded in a mineralized organic matrix. The more bone mass, the stronger the bone. This form of calcium contains phosphorus in the appropriate ratio