Liver levels of vitamin a and cellular retinol-binding protein for patients wth biliary atresia

We have examined whether the amount of cellular retinol-binding protein in human liver is related to the amount of vitamin A stored in the liver. Levels of vitamin A, as retinol and retinol esters, and of cellular retinol-binding protein have been determined in liver samples from 6 normal adults and 11 children with biliary atresia, with and without vitamin A treatment. The level of cellular retinol-binding protein in the liver was not related to the liver vitamin A concentration examined over a 300-fold range of vitamin A levels. Also, biliary atresia did not appear to interfere with storage of vitamin A, and the level of cellular retinol-binding protein was comparable to that observed in the liver of normal adults. The demonstration of proper vitamin A storage in treated children as well as normal levels of cellular retinol-binding protein suggest the vitamin A deficiency frequently observed in children with biliary atresia may be due primarily to faulty absorption rather than a combination of poor absorption and impaired hepatic vitamin A metabolism.