title: The same annual dose of 292000 IU of vitamin D (cholecalciferol) on either daily or four monthly basis for elderly women: 1-year comparative study of the effects on serum 25(OH)D concentrations and renal function.
abstract: OBJECTIVE
  Daily dosing of vitamin D supplements may be difficult among older people. Infrequent administration of 'megadoses' controlled by health care personnel may overcome adherence problem. We compared the efficacy and safety of two oral dosages (800 IU daily or 97333 IU four monthly) of vitamin D(3) resulting in the equal annual dose of 292000 IU.
  
  
  METHODS
  Randomized, double-blind, double-dummy parallel group comparison. Patients Forty women aged 69.3-78.8 years.
  
  
  METHODS
  Vitamin D(3) 400 IU twice daily (D group) or vitamin D(3) oil 97333 IU every 4 months (4 M group) for 1 year. All received 1 g of calcium daily.
  
  
  METHODS
  Serum 25-hydroxyvitamin D(3) [25(OH)D(3)] in relation to the target levels of 50-75 nmol/l, PTH, serum type I procollagen aminoterminal propeptide (PINP), serum and urine calcium, renal function.
  
  
  RESULTS
  A quantity of 25OHD(3) increased more in D group than in 4 M group (P < 0.0001). All participants in D group and 67% in 4 M group had 25(OH)D(3) above 50 nmol/l at 12 months; the target level of 75 nmol/l was reached by 47% and 28% respectively. PTH did not show any seasonal perturbation in either group. PINP declined and urinary calcium rose similarly in the study groups over time (P < 0.0001). Renal function did not worsen in either group.
  
  
  CONCLUSIONS
  In terms of serum 25(OH)D(3) concentrations, 800 IU daily was more efficient than a 97333 IU every 4 months. However, to increase adherence, the latter is still worth developing. Both treatments increased urinary excretion of calcium, but did not worsen renal function.
authors.affiliation: Department of Internal Medicine, Peijas Hospital, Helsinki University Central Hospital, Vantaa, Finland.
authors.forename: Tuula
authors.initials: T
authors.lastname: Pekkarinen
authors.forename: Ville-Valtteri
authors.initials: VV
authors.lastname: Välimäki
authors.forename: Stiina
authors.initials: S
authors.lastname: Aarum
authors.forename: Ursula
authors.initials: U
authors.lastname: Turpeinen
authors.forename: Esa
authors.initials: E
authors.lastname: Hämäläinen
authors.forename: Eliisa
authors.initials: E
authors.lastname: Löyttyniemi
authors.forename: Matti J
authors.initials: MJ
authors.lastname: Välimäki
mesh_terms: D000368:Aged; D002118:Calcium / Q000097:blood / Q000652:urine; D002762:Cholecalciferol / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007677:Kidney Function Tests; D010281:Parathyroid Hormone / Q000097:blood; D010349:Patient Compliance; D010446:Peptide Fragments / Q000097:blood; D011347:Procollagen / Q000097:blood; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000188:drug therapy*
chemical_list: D010281:Parathyroid Hormone; D010446:Peptide Fragments; D011347:Procollagen; C047202:procollagen Type I N-terminal peptide; D014807:Vitamin D; D002762:Cholecalciferol; C104450:25-hydroxyvitamin D; D002118:Calcium