title: Vitamin K status in cystic fibrosis.
abstract: Appearance of PIVKA-II (protein induced by vitamin K absence-II) in serum is a biochemical sign of insufficient vitamin K-dependent carboxylation of prothrombin. Plasma concentrations of PIVKA-II and vitamin K1 were determined in 24 children with cystic fibrosis. Eight were supplemented with vitamin K1. The purpose of the study was to determine the occurrence of vitamin K deficiency in cystic fibrosis and to evaluate the effect of vitamin K supplementation. PIVKA-II was detectable in only one unsupplemented child. In this patient, the concentration of vitamin K1 was below the limit of detection of 60 ng/l. Vitamin K1 levels in the other unsupplemented children were normal (mean 476 ng/l = 1 mmol/l). The supplemented patients showed extremely high levels of vitamin K1 (mean 22445 ng/l = 50 nmol/l). In conclusion, vitamin K deficiency occurs infrequently in cystic fibrosis. Checking the coagulation system is advised, but routine vitamin K supplementation is not recommended. If additional vitamin K is needed, the starting dose should not exceed 1 mg daily.
authors.affiliation: Department of Paediatrics, University Hospital Nijmegen, The Netherlands.
authors.forename: E A
authors.initials: EA
authors.lastname: Cornelissen
authors.forename: A F
authors.initials: AF
authors.lastname: van Lieburg
authors.forename: K
authors.initials: K
authors.lastname: Motohara
authors.forename: C G
authors.initials: CG
authors.lastname: van Oostrom
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003550:Cystic Fibrosis / Q000097:blood / Q000150:complications*; D003653:Decarboxylation; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D017293:Protein S / Q000032:analysis; D011516:Prothrombin / Q000032:analysis; D014812:Vitamin K / Q000627:therapeutic use; D014813:Vitamin K Deficiency / Q000150:complications* / Q000517:prevention & control
chemical_list: D017293:Protein S; D014812:Vitamin K; D011516:Prothrombin