Prealbumin as a biochemical marker of nutritional adequacy in premature infants.

To determine whether serum prealbumin would be useful in identifying adequacy of protein and calorie intake in premature infants, 17 infants between 26 and 33 weeks gestational age were studied throughout hospitalization. Serial anthropometric measurements, nutritional intake, and serum prealbumin concentrations were correlated. When mean intake of calories and protein was lower than 100 kcal/kg/day and less than 2 gm/kg/day, respectively, there was a significant difference in mean prealbumin values, compared with those in infants with a higher intake (P much less than 0.001). For infants with birth weights of 1000 gm or less, prealbumin correlated with protein intake (r = 0.66) and calorie intake (r = 0.64). In these infants, when protein intake exceeded 2 gm/kg/day, prealbumin concentrations increased to values reported for full-term infants in the first months of life. There was no significant correlation between intake of calories or protein and prealbumin values for infants born weighing greater than 1000 gm. Anthropometric measurements did not correlate with protein or calorie intake. We conclude that prealbumin is a sensitive measure of protein and calorie intake in premature infants, and that the definition of adequate nutrition may be different for premature infants of different birth weights and at various postconceptional ages.