It does this by stimulating osteoclasts, the cells that break bone down, to release hydrogen ions which dissolves the hard, mineralized hydroxyapatite.
In the body, about 85% of the phosphate is stored in the bones, where it combines with calcium to make a tough compound called hydroxyapatite which is the stuff that makes bones hard.
All of this from body parts that are about 70% mineral, made of an inorganic material called hydroxyapatite that is stiff when compressed, combined with flexible protein called collagen to keep you from shattering.