title: 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 patients 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 micrograms/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.
authors.affiliation: Department of Pediatrics, Huddinge University Hospital, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Lindblad
authors.forename: U
authors.initials: U
authors.lastname: Diczfalusy
authors.forename: R
authors.initials: R
authors.lastname: Hultcrantz
authors.forename: A
authors.initials: A
authors.lastname: Thorell
authors.forename: B
authors.initials: B
authors.lastname: Strandvik
mesh_terms: D000293:Adolescent; D000328:Adult; D000375:Aging; D001706:Biopsy; D002648:Child; D003550:Cystic Fibrosis / Q000378:metabolism*; D004224:Diterpenes; D005260:Female; D006801:Humans; D008099:Liver / Q000378:metabolism*; D008297:Male; D012016:Reference Values; D012177:Retinol-Binding Proteins / Q000378:metabolism; D000084562:Retinyl Esters; D014801:Vitamin A / Q000031:analogs & derivatives / Q000097:blood / Q000378:metabolism*
chemical_list: D004224:Diterpenes; D012177:Retinol-Binding Proteins; D000084562:Retinyl Esters; D014801:Vitamin A; C014794:retinol palmitate