Effect of different vitamin A intakes on very-low-birth-weight infants

Abstract

Formula-fed infants with birth weights < or = 1500 g (n = 61) were stratified by 250-g birth-weight ranges and randomly assigned to receive one of three preterm infant formulas (vitamin A contents of 820 IU, 1640 IU, or 2900 IU/MJ; 1 RE = 3.3 IU vitamin A activity) when subjects tolerated 0.314 MJ.kg-1.d-1. Experimental formula feedings were continued until infants weighed approximately 2 kg or until hospital discharge. Vitamin A status as indicated by serum retinol and retinol-binding protein (RBP) concentrations significantly decreased during experimental formula feeding at the lowest vitamin A intake. All subjects fed the formula providing the lowest vitamin A intake had hyporetinolemia (< 0.70 mumol/L, or < 20 micrograms/dL), which occurred less frequently (P < 0.05) with the intermediate (6 of 20) and the high (6 of 21) vitamin A intakes. Other outcome measures, including increases in weight, length, and head circumference, and ventilatory support and oxygen therapy, were not different among groups. After the end of the experimental formula-feeding period, all infants were fed standard infant formulas with a vitamin A content of 715 IU/MJ. In a subset of 19 of these infants, subsequent vitamin A status was monitored at ages 6-12 mo and was found to be comparable with that of older children and adults, regardless of the vitamin A content of the formula fed during hospitalization.(ABSTRACT TRUNCATED AT 250 WORDS)