Influence of calcium content in mineral water on chemistry and crystallization conditions in urine of calcium stone formers.

19 idiopathic recurrent calcium stone formers were examined on a constant diet supplemented with mineral water of high (386 mg/l) and low (10 mg/l) calcium content. The effects of calcium and oxalate loading were studied separately. Ingestion of mineral water with high calcium content lead to an increase of urinary calcium and a decrease of urinary oxalate compared to mineral water with low calcium content. On the calcium-rich mineral water, urinary saturation with Whewellite was lower and it hardly reached the critical level for calcium oxalate crystallization after oxalate loading, which was in contrast to the results on low calcium mineral water. Urinary Brushite saturation was generally low and showed no significant differences between the two mineral waters.