title: Vitamin A intake and serum retinol levels in children and adolescents with cystic fibrosis.
abstract: Pancreatic insufficient cystic fibrosis (CF) patients receive vitamin A supplementation according to CF-specific recommendations to prevent deficiencies. Whether current recommendations are optimal for preventing both deficiency and toxicity is a subject of debate. We assessed the longitudinal relation between serum retinol levels and appropriate variables.
  
  
  
  We studied vitamin A intake, and the long-term effects of vitamin A intake, coefficient of fat absorption (CFA) and immunoglobulin G (IgG) on serum retinol levels in 221 paediatrics CF patients during a seven-year follow up period.
  
  
  
  Total vitamin A intake, derived from 862 dietary assessments, exceeded the tolerable upper intake level in 30% of the assessments, mainly up to age six. Although CF patients failed to meet the CF-specific recommendations, serum retinol deficiency was found in only 17/862 (2%) of the measurements. Longitudinally, we observed no association to serum retinol levels for total vitamin A intake, CFA, gender or age but serum retinol levels were associated with serum IgG levels. Each g/L increase in serum IgG level would result in a 2.49% (95% CI -3.60 to -1.36%) reduction in serum retinol levels.
  
  
  
  In this large sample of children and adolescents with CF, serum retinol deficiency was rare despite lower than the CF-specific recommendations. However, the TUL was commonly exceeded. A reduction in CF-specific vitamin A supplementation recommendations should therefore be considered. Moreover, serum retinol levels were not associated with vitamin A intake, CFA, gender or age, although a decreased serum retinol was associated with an increased serum IgG.
authors.affiliation: Internal Medicine and Dermatology, Dietetics and, Cystic Fibrosis Centre Utrecht, University Medical Centre Utrecht, KH.01.419.0, P.O. Box 85500, 3508 GA Utrecht, The Netherlands. Electronic address: j.w.woestenenk@umcutrecht.nl.
authors.forename: Janna W
authors.initials: JW
authors.lastname: Woestenenk
authors.affiliation: Department of Paediatric Pulmonology and, Cystic Fibrosis Centre Utrecht, University Medical Centre Utrecht, KH.01.419.0, P.O. Box 85500, 3508 GA Utrecht, The Netherlands.
authors.forename: Nancy
authors.initials: N
authors.lastname: Broos
authors.affiliation: Department of Biostatistics, Julius Centre, University Medical Centre Utrecht, STR.7.125, P.O. Box 85500, 3508 GA Utrecht, The Netherlands.
authors.forename: Rebecca K
authors.initials: RK
authors.lastname: Stellato
authors.affiliation: Department of Paediatric Pulmonology and, Cystic Fibrosis Centre Utrecht, University Medical Centre Utrecht, KH.01.419.0, P.O. Box 85500, 3508 GA Utrecht, The Netherlands.
authors.forename: Hubertus G M
authors.initials: HG
authors.lastname: Arets
authors.affiliation: Department of Paediatric Pulmonology and, Cystic Fibrosis Centre Utrecht, University Medical Centre Utrecht, KH.01.419.0, P.O. Box 85500, 3508 GA Utrecht, The Netherlands.
authors.forename: Cornelis K
authors.initials: CK
authors.lastname: van der Ent
authors.affiliation: Department of Paediatric Gastroenterology, and Cystic Fibrosis Centre, University Medical Centre Utrecht, KE.04.133.1, P.O. Box 85500, 3508 GA Utrecht, The Netherlands.
authors.forename: Roderick H J
authors.initials: RH
authors.lastname: Houwen
mesh_terms: D000293:Adolescent; D041923:Adolescent Development; D017195:Adolescent Nutritional Physiological Phenomena; D002648:Child; D002657:Child Development; D002664:Child Nutritional Physiological Phenomena; D002675:Child, Preschool; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003550:Cystic Fibrosis / Q000097:blood* / Q000378:metabolism / Q000503:physiopathology; D019587:Dietary Supplements / Q000009:adverse effects; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007408:Intestinal Absorption; D008286:Malabsorption Syndromes / Q000097:blood* / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology; D009426:Netherlands / Q000453:epidemiology; D015596:Nutrition Assessment; D010349:Patient Compliance; D012189:Retrospective Studies; D014801:Vitamin A / Q000009:adverse effects / Q000097:blood / Q000378:metabolism / Q000627:therapeutic use*; D014802:Vitamin A Deficiency / Q000453:epidemiology / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*
chemical_list: D014801:Vitamin A
keywords: Coefficient of fat absorption; Cystic fibrosis; Immunoglobulin G; Retinol; Vitamin A