title: Effect of annual intramuscular vitamin D on fracture risk in elderly men and women--a population-based, randomized, double-blind, placebo-controlled trial.
abstract: OBJECTIVE
  Low trauma fractures in older people incur enormous physical, social and economic costs. Previous research indicates that an annual intramuscular injection of vitamin D may reduce fracture rates in this group. This strategy requires validation in a population setting.
  
  
  METHODS
  Randomized, double-blind, placebo-controlled trial of 300,000 IU intramuscular (i.m.) vitamin D2 (ergocalciferol) injection or matching placebo every autumn over 3 years. 9440 people (4354 men and 5086 women) aged 75 yrs and over were recruited from general practice registers in Wessex, England. Primary outcome measure was all non-vertebral fracture. Secondary outcomes were hip and wrist fractures, and all falls.
  
  
  RESULTS
  585 subjects had incident non-spine fractures (hip 110, wrist 116, ankle 37). Hazard ratios (HRs) for fracture in the vitamin D group were: 1.09 [95% confidence interval (CI) 0.93-1.28, P = 0.29] for any first fracture, 1.49 (95% CI 1.02-2.18, P = 0.04) for hip and 1.22 (95% CI 0.85-1.76, P = 0.28) for wrist. There was no effect on falls: HR 0.98 (0.93-1.04). No protective effect was observed in any subgroup when the cohort was stratified by sex, age, previous fracture or mobility.
  
  
  CONCLUSIONS
  An annual i.m. injection of 300,000 IU vitamin D2 is not effective in preventing non-vertebral fractures among elderly men and women resident in the general population.
authors.affiliation: Department of Primary Care, Division of Community-based Clinical Sciences, Geriatric Medicine Group, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK.
authors.forename: H
authors.initials: H
authors.lastname: Smith
authors.forename: F
authors.initials: F
authors.lastname: Anderson
authors.forename: H
authors.initials: H
authors.lastname: Raphael
authors.forename: P
authors.initials: P
authors.lastname: Maslin
authors.forename: S
authors.initials: S
authors.lastname: Crozier
authors.forename: C
authors.initials: C
authors.lastname: Cooper
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004872:Ergocalciferols / Q000008:administration & dosage*; D005260:Female; D005500:Follow-Up Studies; D005598:Fractures, Spontaneous / Q000453:epidemiology* / Q000517:prevention & control*; D015577:Geriatric Assessment; D006801:Humans; D015994:Incidence; D007273:Injections, Intramuscular; D008297:Male; D010024:Osteoporosis / Q000517:prevention & control; D011336:Probability; D012016:Reference Values; D018570:Risk Assessment; D016896:Treatment Outcome
chemical_list: D004872:Ergocalciferols