Prevention of recurrent calcium stones (which are usually composed primarily of calcium oxalate) is aimed at decreasing the concentrations of the lithogenic factors (calcium and oxalate) and at increasing the concentrations of inhibitors of stone formation, such as citrate.
Achieving these goals may require both dietary modification and the administration of appropriate medications. Medical therapy (and metabolic evaluation) is usually undertaken in individuals who have formed more than one stone. Even if a patient has only passed one stone, it is important to review the imaging studies to determine if other stones are present in the kidney since stone passage does not equal stone formation. At a minimum, those with a single kidney stone are encouraged to increase their fluid intake and should consider undergoing a metabolic evaluation and periodic monitoring (usually by renal ultrasonography) for evidence of new stone formation (image 1). (See "The first kidney stone and asymptomatic nephrolithiasis in adults".)
The management of patients with recurrent calcium stones will be reviewed here. The management of patients with other types of stones including those of unknown composition, and risk factors for recurrent calcium stones are discussed separately. (See "Evaluation of the adult patient with established nephrolithiasis and treatment if stone composition is unknown" and "Risk factors for calcium stones in adults".)
CALCIUM OXALATE STONES
A variety of dietary modifications and drug therapies can reduce the likelihood of recurrence of calcium oxalate stones.
Dietary modification — From the viewpoint of diet, increasing the intake of fluid, dietary calcium, potassium and phytate and decreasing the intake of oxalate, animal protein, sucrose, fructose, sodium, supplemental calcium and supplemental vitamin C may be beneficial . (See "Risk factors for calcium stones in adults".) The role of vitamin D in stone formation remains unclear.