Vitamin A status of preterm infants: correlation between plasma retinol concentration and retinol dose response

Retinol dose response tests were performed on 83 preterm infants shortly before discharge by giving orally 5000 IU of an aqueous dispersion of retinol. Predose plasma retinol concentrations were 2.5-20.5 micrograms/dL (0.087-0.72 mumol/L) and the retinol dose responses were 0-59.8%. The regression of retinol dose response on predose retinol was -0.58. There was a parallel increase in both retinol and retinol-binding protein and an increase in the molar ratio of retinol-binding protein to prealbumin. Prealbumin did not increase. These findings suggest that preterm infants have reduced liver stores of vitamin A.