title: The effect of pH on the risk of calcium oxalate crystallization in urine.
abstract: The risk of calcium oxalate (CaOx) crystallization at different pH levels was determined in urine from recurrent CaOx-stone formers and normal subjects. The highest crystallization risk was observed between pH 4.5 and 5.5. In the pH range 6.5-7.5, there was a marked increase in crystallization of calcium phosphate (CaP). The results suggest the beneficial effect of moderate alkalinization in terms of a reduced CaOx crystallization. Reduced CaOx crystallization occurs at the expense of an increased formation of CaP crystals. Whether this increases the risk of CaP-stone formation is not known, but the CaP crystals were usually small, at least below pH 7.5.
mesh_terms: D002118:Calcium / Q000652:urine; D002129:Calcium Oxalate / Q000652:urine*; D002130:Calcium Phosphates / Q000652:urine; D003460:Crystallization; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010070:Oxalates / Q000652:urine; D012306:Risk; D014545:Urinary Calculi / Q000209:etiology* / Q000652:urine
chemical_list: D002130:Calcium Phosphates; D010070:Oxalates; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; D002129:Calcium Oxalate; C485838:calcium phosphate, monobasic, anhydrous; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous; D002118:Calcium