SEQUENTIAL EVALUATION OF PLASMA RETINOL-BINDING PROTEIN RESPONSE TO VITAMIN-A ADMINISTRATION IN VERY-LOW-BIRTH-WEIGHT NEONATES

Vitamin A (retinol) deficiency is associated with impaired healing fro m lung injury in very-low-birthweight (VLBW) neonates susceptible to b ronchopulmonary dysplasia (BPD). Vitamin A supplementation from birth may ameliorate this adverse outcome, We hypothesized that plasma retin ol-binding protein (REP) response to vitamin A administration, which p rovides a dynamic measure of vitamin A status, might be useful for ear ly recognition of vitamin A deficiency in VLBW neonates at risk for BP D. We prospectively studied 20 VLBW neonates (inclusion criteria: birt h weight <1300 g, gestational age <30 weeks, need for supplemental oxy gen and mechanical ventilation for >24 h after birth) who were eligibl e to receive vitamin A supplementation. In addition to sequential asse ssment of;vitamin A status, we measured plasma REP just before and 3 a nd 6 h after an intramuscular injection of vitamin A (2000 IU/kg retin yl palmitate) on Postnatal Days 1, 7, 15, 21, 29, and 43. The percenta ge increase in plasma REP (Delta-RBP) was calculated. A high plasma De lta-RBP value (>8%) is indicative of vitamin A deficiency. Based on pu lmonary outcome, the infants were divided into two groups: BPD (n = 12 ) and No BPD (n = 8). Mean vitamin A intake ranged from 1414 to 2114 I U/kg/day and did not differ between infant groups. Mean plasma vitamin A concentration increased from baseline levels on Postnatal Day 1 to levels within the desired range of 1.05-2.10 mu mol/liter (30.0-60.0 m u g/dl) during supplementation period in both infant groups. Infants w ith BPD, in contrast to those without BPD, had worsening plasma Delta- RBP values from Postnatal Day 15, indicative of persistence of vitamin A deficiency despite supplementation and normalization of plasma vita min A concentration. We conclude that plasma REP response to vitamin A administration is useful for early recognition of vitamin A deficienc y in VLBW neonates at risk for BPD. (C) 1995 Academic Press, Inc.