The present invention is directed to a method for the tunable precipitation of apatite induced by a chemical reaction within a polymeric hydrogel, and the product made thereof. The present invention includes a pH dependent pathway for the hydrolysis of DCPD precursor phase. In addition to pH the stoichiometry of the CaP reactants can contribute to the composition of the CaP phase incorporated into the PVA hydrogels. At elevated pH the direct conversion of DCPD to apatite is observed. However, decreasing the reaction pH to 7.4 to mimic physiological conditions results in the inclusion of OCP as a transition step.