Furthermore, Sr ions counteract osteoporotic bone loss and reduce the probability of related fractures.  Macroporous Ca carbonate biominerals, specifically skeletons of corals (aragonite) and sea urchins (Mg-substituted calcite), were hydrothermally converted into pseudomorphic CaP materials with their natural porosity preserved.  Sr ions were introduced to the mineral replacement reactions by temporarily stabilizing them in the hydrothermal phosphate solutions as Sr-EDTA complexes. 
THERM