Vitamin A plays an important role in the regulation of cellular differentiation and proliferation, and may be particularly important for neonatal lung development due to its role in lung surfactant synthesis. Very low birthweight (VLBW) neonates have low tissue levels of vitamin A, which may contribute to the development of acute and chronic lung disease. VLBW infants, however, may not receive vitamin A supplementation for several days after birth. The objective of the present study was to determine if the relatively permeable skin of a newborn could be used as a vehicle to administer vitamin A. Methods: 20 μl (1000 International Units) of retinyl A palmitate were applied to the skin surface of 22 one day old rat pups; 21 one day old pups served as controls. After being held for five hours in a 37°C chamber, pups were euthanized and lungs and livers were removed.Results: Levels of retinyl palmitate (μg/gm tissue) were 33% higher in lungs of pups administered vitamin A. Levels of retinyl palmitate in the liver, and levels of retinol (μg/gm tissue) in liver and lung were not significantly different. Table
Conclusion: Topical administration is an effective means of delivering vitamin A to the lungs of newborn rat pups. Topically applied vitamin A was preferentially taken up by lung versus liver tissue. Future studies will determine if transdermal absorption may be an effective means of improving the vitamin A status of VLBW neonates.
