Vitamin A to prevent bronchopulmonary dysplasia in very-low-birth-weight infants: Has the dose been too low?

Objective: Inconsistent effects of vitamin A supplementation on prevention of bronchopulmonary dysplasia have been reported. Meta-analysis of these reports resulted in a relative risk of 0.69-1.02 for death or bronchopulmonary dysplasia associated with vitamin A supplementation. Effective dosage regimens or serum retinol concentrations have not been determined in previous reports. The purpose of this pilot study was to define a vitamin A regimen that produces serum retinol concentrations of 25-55 mu g/dl. Study design: In this three-phase study, 91 infants (mean birth weight 799-864 g) were enrolled. Vitamin A was administered three times/week for 4 weeks at an average daily dose of 986-2143 IU/day. Physical examinations were performed and serum retinol specimens were collected weekly to assess clinical signs of toxicity. Results: The majority of serum retinol concentrations remained < 25 mu g/dl until an intramuscular vitamin A dose of 5000 IU/dose three times/week was used. No clinical signs of toxicity were associated with the higher dosage and higher serum concentrations of vitamin A. Conclusion: A large clinical trial of vitamin A supplementation with 5000 IU/dose three times/week (25-114% more than the dose used in the three published clinical trials) is needed to assess whether vitamin A supplementation safely reduces the risk of bronchopulmonary dysplasia in very-low-birth-weight infants. (C) 1997 Elsevier Science Ireland Ltd.