The effects of sucrose ingestion on the excretion of urinary calcium, zinc, phosphorus, sodium and potassium have been investigated and compared among 13 individuals to the magnitude of their postprandial serum insulin response. Fasted subjects consumed a beverage containing 2 g sucrose/kg, and urine and blood samples were taken at intervals during the next 3 h. As a result of sucrose consumption there were significant increases in serum insulin and decreases in serum phosphorus, but no change in serum total or filterable calcium, zinc, sodium or potassium. Urine calcium peaked at 1.5 h and was significantly increased from 10 through 2.5 h. Sucrose-induced increases in serum insulin and urine calcium were highly variable among subjects, and within the group were significantly correlated (r = 0.82, P less than 0.01). Urine calcium excretion was correlated with serum phosphorus (r = 0.41, P less than 0.05) and urine zinc (r = 0.80, P less than 0.01). Sucrose consumption also increased the urinary excretion of zinc and sodium, although renal reabsorption was not impaired. The effects of sucrose on urinary calcium are consistent with the hypothesis that insulin inhibits renal calcium reabsorption.