Comparison of indices of vitamin A status in children with chronic liver disease.

Malabsorption of fat-soluble vitamins is a major complication of chronic cholestatic liver disease. The most accurate way to assess vitamin A status in children who have cholestasis is unknown. The goal of this study was to assess the accuracy of noninvasive tests to detect vitamin A deficiency. Children with chronic cholestatic liver disease (n = 23) and noncholestatic liver disease (n = 10) were studied. Ten cholestatic patients were identified as vitamin A-deficient based on the relative dose response (RDR). Compared with the RDR, the sensitivity and specificity to detect vitamin A deficiency for each test was, respectively: serum retinol, 90% and 78%; retinol-binding protein (RBP), 40% and 91%; retinol/RBP molar ratio, 60% and 74%; conjunctival impression cytology, 44% and 48%; slit-lamp examination, 20% and 66%; tear film break-up time, 40% and 69%; and Schirmer's test, 20% and 78%. We developed a modified oral RDR via oral coadministration of d-alpha tocopheryl polyethylene glycol-1000 succinate and retinyl palmitate. This test had a sensitivity of 80% and a specificity of 100% to detect vitamin A deficiency. In conclusion, vitamin A deficiency is relatively common in children who have chronic cholestatic liver disease. Our data suggest that serum retinol level as an initial screen followed by confirmation with a modified oral RDR test is the most effective means of identifying vitamin A deficiency in these subjects.