Vitamin A Concentration in the Liver Decreases with Age in Patients with Cystic Fibrosis

Abstract

Background:Vitamin A deficiency is a common manifestation in cystic fibrosis (CF), but high levels of vitamin A in the liver have also been described. High levels of vitamin A in the liver are toxic, while normal levels might be protective against liver damage. In order to investigate whether liver damage in patients with CF is related to vitamin A content of the liver, vitamin A status was investigated in 15 patients with CF aged 8 to 34 years.Methods:Liver biopsy was performed on clinical indication and the vitamin A concentration in the liver was determined as retinylpalmitate. Serum levels of retinol and retinol‐binding protein were investigated on the morning of the biopsy. Eight patients had morphologic signs of cirrhosis. Eight patinets had been on treatment with ursodeoxycholic acid for 1 to 3 years. All but three patients had been on vitamin A supplementation for years.Results:Five patients had serum concentrations of retinol below the reference range and seven patients had decreased serum levels of retinol‐binding protein. There was a strong correlation between serum levels of retinol and retinol‐binding protein (rs = 0.90, p = 0.01), but no correlations with age, Shwachamn score, or genotype. Six of the patients had vitamin A concentrations in the liver <40 μg/g wet weight, and the concentrations decreased significantly with age (rs = 0.77, p = 0.01), without correlation to clinical score or liver disease. There was no indication of hypervitaminosis, although younger patients had been or were being treated with vitamin A in fat‐water emulsion.Conclusions:Our results indicate that the risk of vitamin a deficiency in cystic fibrosis increases with age. The data do not support the view that patients are at risk for hypervitaminosis by long‐term supplementation with vitamin A. No correlation was found between the severity of liver disease and the vitamin A content in the liver.