US Pharm. 2015;40(11):11.

Cleveland, OH—Although eating foods high in calcium is protective against kidney stones, calcium supplements may increase the risk of stone recurrence, according to a recent study. Researchers at the Cleveland Clinic Lerner College of Medicine reviewed 24-hour urine collections and CT scans from patients with a history of kidney stones. Of the 6,050 patients, 1,486 were taking supplemental calcium. Patients who took calcium supplements had lower total calcium and oxalate concentrations in the urine; however, they also had a faster rate of kidney stone growth, suggesting that the mechanism of calcium supplementation in stone formation is complex. It was concluded that supplemental calcium, unlike dietary calcium, may worsen stone disease in patients known to form kidney stones.

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