Calcium and phosphate content of intravenous feeding regimens for very low birthweight infants.

Fifteen infants with birth weights below 1500 g, who required intravenous feeding from birth, were given one of two regimens differing only in their calcium and phosphate content. The duration of intravenous feeding varied from 26 to 75 days, and infants were studied after the age of 10 days when growth could be expected to have started. Five infants were given regimen A, which provided calcium and phosphate intakes of 0.55 and 0.44 mmol/kg/day, and 10 received regimen B, which provided intakes of 1.08 and 0.89 mmol/kg/day, respectively. Infants given regimen A had lower plasma and urine phosphate but similar urine calcium excretion to those given regimen B. Plasma calcium concentrations were higher in infants on regimen A than regimen B. In infants given regimen B plasma phosphate concentration was inversely related to weight gain, and urine phosphate and calcium concentrations were significantly correlated with urine sodium results.