title: Efficacy and safety of oral continuous low-dose versus short-term high-dose vitamin D: a prospective randomised trial conducted in a clinical setting.
abstract: OBJECTIVE
  To compare the efficacy and safety of a 10-day, high-dose v a 3-month, continuous low-dose oral cholecalciferol course in a vitamin D deficient population. The primary end points were the change in serum 25-hydroxyvitamin D (25(OH)D) concentrations at 3 months and the development of hypercalcaemia and hypercalciuria.
  
  
  METHODS
  Fifty-nine vitamin D deficient inpatients (serum 25(OH)D < or = 50 nmol/L) were enrolled in a prospective, randomised, open-label trial. Participants were randomly assigned to a high-dose regimen of cholecalciferol 50 000 IU daily for 10 days or a 3-month, continuous low-dose cholecalciferol regimen of 3000 IU daily for 30 days, followed by 1000 IU daily for 60 days. Both groups received calcium citrate 500 mg daily.
  
  
  RESULTS
  Twenty-six patients completed the study within 3 - or + 1 months. The mean increases in serum 25(OH)D were similar in both the high- and low-dose groups (to 55 v 51 nmol/L, respectively; P = 0.9). There was no significant difference in the proportion of subjects who attained serum 25(OH)D concentrations > 50 nmol/L between the high- and low-dose groups (9/10 v 13/14, respectively; P = 1.0). Hypercalciuria (urine calcium > 7.5 mmol/day) occurred in three patients (two low-dose, one high-dose), while renal impairment worsened in one patient. No patient developed hypercalcaemia (corrected calcium > 2.6 mmol/L), vitamin D toxicity (25(OH)D > 200 nmol/L) or nephrolithiasis during the study.
  
  
  CONCLUSIONS
  Both the 10-day, high-dose and the 3-month, low-dose cholecalciferol regimens effectively increased serum 25(OH)D to within the normal range. The high-dose regimen may be an effective and cheap alternative for patients with vitamin D deficiency.
  
  
  BACKGROUND
  Australian Clinical Trials Registry ACTRN 12607000338460.
authors.affiliation: Department of Medicine, University of Melbourne, Melbourne, VIC, Australia.
authors.forename: Kathryn L
authors.initials: KL
authors.lastname: Hackman
authors.forename: Claudia
authors.initials: C
authors.lastname: Gagnon
authors.forename: Roisin K
authors.initials: RK
authors.lastname: Briscoe
authors.forename: Simon
authors.initials: S
authors.lastname: Lam
authors.forename: Mahesan
authors.initials: M
authors.lastname: Anpalahan
authors.forename: Peter R
authors.initials: PR
authors.lastname: Ebeling
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D002118:Calcium / Q000097:blood / Q000652:urine; D002762:Cholecalciferol / Q000008:administration & dosage* / Q000009:adverse effects; D003404:Creatinine / Q000097:blood; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000188:drug therapy*
chemical_list: D014807:Vitamin D; D002762:Cholecalciferol; C104450:25-hydroxyvitamin D; D003404:Creatinine; D002118:Calcium