Clinical studies of the recurrence of urolithiasis (3). Influence of sodium intake on urinary excretion of calcium, uric acid, oxalate, phosphate and magnesium

Relationship between urinary sodium excretion and urinary excretion of calcium, uric acid, oxalate, phosphate and magnesium was analyzed in 93 ambulatory patients with urolithiasis. There was a significant correlationship between urinary sodium excretion and urinary excretion of calcium, uric acid, oxalate (only in male stone formers), phosphate and magnesium, respectively. Under a salt restricted diet (NaCl 3-5 gm/day) for 3 days, urinary sodium excretion of 16 inpatients with urolithiasis was reduced remarkably together with significant reduction of urinary excretion of calcium, uric acid and oxalate. Urinary excretion of phosphate and magnesium showed no change. From these findings we conclude that restriction of sodium intake is an effective treatment for prevention of stone recurrence.