title: Effects of high doses of cholecalciferol in normal subjects: a randomized double-blinded, placebo-controlled trial.
abstract: BACKGROUND
  Vitamin D repletion with high doses of vitamin D is often recommended to patients and healthy subjects. The safety, especially concerning changes in urinary calcium excretion is of great importance.
  
  
  METHODS
  In a double-blinded, placebo-controlled study in 40 healthy volunteers, we examined the changes in mineral metabolism during supplementation with 3000 IU of oral cholecalciferol daily during 4 months.
  
  
  RESULTS
  Both 25(OH)vitamin D and 1,25(OH)2vitamin D increased significantly in the active treated group as compared to the placebo group (186% versus 14% (P<0.001) and 28% versus -8% (P<0.001)). No change was observed in urinary calcium excretion in the active group compared to the placebo group (P = 0.891). Fibroblast growth factor 23 increased significantly by 10% (P<0.018) in the active group. However, there was no difference in changes in FGF23 between treatment groups (P = 0.457).
  
  
  CONCLUSIONS
  High dose cholecalciferol significantly increases 25(OH)vitamin D and 1,25(OH)2vitamin D levels compared to placebo. No changes in urinary calcium excretion or other measured components of the mineral metabolism were found between groups.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT00952562.
authors.affiliation: Department of Medicine, Roskilde University Hospital, Roskilde, Denmark.
authors.forename: Birgitte
authors.initials: B
authors.lastname: Nygaard
authors.affiliation: Department of Medicine, Roskilde University Hospital, Roskilde, Denmark.
authors.forename: Niels Erik
authors.initials: NE
authors.lastname: Frandsen
authors.affiliation: Department of Medicine, Roskilde University Hospital, Roskilde, Denmark.
authors.forename: Lisbet
authors.initials: L
authors.lastname: Brandi
authors.affiliation: Department of Medicine, Roskilde University Hospital, Roskilde, Denmark.
authors.forename: Knud
authors.initials: K
authors.lastname: Rasmussen
authors.affiliation: Department of Medicine, Roskilde University Hospital, Roskilde, Denmark.
authors.forename: Ove Vyff
authors.initials: OV
authors.lastname: Oestergaard
authors.affiliation: Department of Clinical Biochemistry, Roskilde University Hospital, Roskilde, Denmark.
authors.forename: Lars
authors.initials: L
authors.lastname: Oedum
authors.affiliation: Center for Clinical and Basic Research, Aalborg, Denmark.
authors.forename: Hans Christian
authors.initials: HC
authors.lastname: Hoeck
authors.affiliation: Department of Medicine, Roskilde University Hospital, Roskilde, Denmark.
authors.forename: Ditte
authors.initials: D
authors.lastname: Hansen
mesh_terms: D000328:Adult; D002118:Calcium / Q000652:urine*; D002762:Cholecalciferol / Q000494:pharmacology*; D004311:Double-Blind Method; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014815:Vitamins / Q000494:pharmacology*
chemical_list: C000717427:FGF23 protein, human; D014815:Vitamins; D014807:Vitamin D; D002762:Cholecalciferol; D005346:Fibroblast Growth Factors; C097949:1,25-dihydroxyvitamin D; D000089703:Fibroblast Growth Factor-23; C104450:25-hydroxyvitamin D; D002118:Calcium