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Chemistry

Why the pH-Dependent Solubility of Calcium Phosphate Influences Biomineralization in Bones

Quick fact

The mineral in bone is hydroxyapatite, Ca₅(PO₄)₃(OH), whose solubility increases dramatically as pH drops below about 7.4. In fact, a small drop in blood pH can trigger the release of calcium and phosphate from bones.

Why this is interesting

You already know that bones are strong and rigid—but did you know that the mineral inside them can dissolve in acid? The very same chemical that builds your skeleton can also be dissolved away by a shift in pH.