Sir.—In premature infants, hypercalciuria has been previously described in association with either hypophosphatemia or furosemide therapy.1,2 However, to our knowledge the simultaneous presence of these two calciuric stimuli in the same patient and their relative contribution to increased urinary calcium excretion have not been reported previously.
Patient Report.—An 830-g male infant was born at 27 weeks' gestation. His hospital course was complicated by respiratory distress syndrome and pharmacologic closure of a patent ductus arteriosus with indomethacin on day 5 of life. Feeding with commercial milk formula (calcium, 790 mg/dL; phosphorus, 398 mg/L) for premature infants was started on day 6, and
the patient was receiving full enteral feeding by day 23, providing him with 150 mL/kg/d and 504 kJ/kg/d (120 kcal/kg/d). Daily intakes of calcium and phosphorus were 118 mg/kg and 59 mg/kg, respectively. Weight gain averaged between 10 and 15 g/d after the first month of