Effects of Vitamin A in Neonates and Young Infants

Vitamin A is the generic name given to a group of fat-soluble compounds including retinol (the alcohol form), retinyl esters, retinaldehyde and retinol acid. Deficiency, first recognized in 1912, can damage the epithelial cells lining the respiratory tract. It can also affect immunocompetence, the reproductive function, growth and vision. The dose of vitamin A for neonates is 5,000 IU given intramuscularly 3 times weekly for 4 weeks. Retinol concentrations < 0.70 µmol/l in serum and <1.05 µmol/l in milk are indicative of vitamin A deficiency. The supplementation of vitamin A to pregnant women with deficiency of vitamin A has protective effects against neonatal morbidity and mortality and has a positive impact on maternal vitamin A status. High cord vitamin A levels increase placenta weight and birth weight and length of the newborn. Vitamin A has been considered a therapeutic alternative in the reduction of the rate of bronchopulmonary dysplasia. The kidneys are target organs for vitamin A action. The vitamin A status of the mother profoundly affects the kidney organogenesis of the newborn. Retinoic acid regulates nephron mass. Intramuscular vitamin A (10,000 IU) 3 times weekly improves retinal sensitivity in preterm neonates. Vitamin A increases the neonatal body size. A dose of ≤10,000 IU vitamin A is not teratogenic.