Vitamin A Supplementation in Very Low Birth Weight Neonates: Rationale and Evidence

Bronchopulmonary dysplasia (BPD) is the most prevalent form of chronic lung disease in infancy. Among the 3.9 million births in the United States in 1997, approximately 55 000 newborn infants weighed <1500 g at birth.1 Among these very low birth weight (VLBW) infants, 49 000 infants would be expected to be discharged alive at the end of their first hospitalization (Vanderbilt experience 1998). At an estimated incidence of 24% among the VLBW survivors (Vanderbilt experience 1998), 12 000 new cases of BPD would be expected to emerge annually, making BPD the leading cause of chronic lung disease in infancy. The pathogenesis of BPD involves factors causing injury to an immature lung and factors inhibiting its healing.2,,3 The lung injury can result from such insults as hyaline membrane disease, barotrauma or volutrauma from mechanical ventilation, oxygen toxicity, and airway infection associated with prolonged tracheal intubation.4 The lung healing can be influenced by nutrients, antioxidants, inflammatory cells, eicosanoids, growth factors, peptide hormones, and components of extracellular matrix.5 The role of the essential micronutrient vitamin A (retinol) in the promotion of orderly growth and differentiation of regenerating epithelial tissues makes vitamin A an important nutrient during recovery from lung injury.6,,7 This review focuses on the pathophysiology of vitamin A deficiency in relation to BPD, examines the evidence for vitamin A deficiency in VLBW neonates, and provides guidelines for vitamin A supplementation as an approach toward amelioration of lung disease among the VLBW survivors. Vitamin A promotes normal growth and differentiation of epithelial cells. Vitamin A deficiency, therefore, affects various organ systems, including the lung.6 The histopathologic changes in the respiratory system generally precede other consequences of vitamin A deficiency involving the genitourinary system, eye, and skin.6 Vitamin A deficiency results in a progressive sequence of …