title: A randomized, controlled trial of vitamin D supplementation upon musculoskeletal health in postmenarchal females.
abstract: BACKGROUND
  There has been a resurgence of vitamin D deficiency rickets throughout the developed world, with infants and adolescents being primarily affected. Adolescence is a crucial period for muscle and bone mineral accumulation.
  
  
  OBJECTIVE
  The aim was to determine the effect of vitamin D supplementation on the adolescent musculoskeletal system.
  
  
  METHODS
  We conducted a community-based, double-blind, randomized controlled trial in a secondary school.
  
  
  METHODS
  Postmenarchal 12- to 14-yr-old females participated in the trial. Ninety-nine were screened, 73 were included in randomized controlled trial, and 69 completed the trial. There were no adverse events.
  
  
  METHODS
  Four doses of 150,000 IU vitamin D(2) (ergocalciferol) were given over 1 yr.
  
  
  METHODS
  Dual-energy x-ray absorptiometry, peripheral quantitative computed tomography, and jumping mechanography were used.
  
  
  RESULTS
  At follow-up, 25-hydroxyvitamin D [25(OH)D] status was 56.0 ± 8.9 nmol/liter in the intervention group and 15.8 ± 6.6 nmol/liter in controls. There were no effects of supplementation on bone; however, for muscle function, efficiency of movement improved in the vitamin D-treated group. There was an interaction between baseline 25(OH)D concentration and response to vitamin D supplementation for muscle jump velocity.
  
  
  CONCLUSIONS
  Despite improvements in 25(OH)D status, treatment with vitamin D(2) was not shown to increase mineral accretion, bone geometry or strength, muscle force, or power. There were greater increases in jump velocity in girls with the lowest baseline 25(OH)D concentrations. Lack of effect of intervention after the period of peak mineral and muscle mass accretion suggests that earlier action is required.
authors.affiliation: Medical Research Council Human Nutrition Research, Elsie Widdowson Laboratory, Cambridge, United Kingdom. Kate.Ward@mrc-hnr.cam.ac.uk
authors.forename: K A
authors.initials: KA
authors.lastname: Ward
authors.forename: G
authors.initials: G
authors.lastname: Das
authors.forename: S A
authors.initials: SA
authors.lastname: Roberts
authors.forename: J L
authors.initials: JL
authors.lastname: Berry
authors.forename: J E
authors.initials: JE
authors.lastname: Adams
authors.forename: R
authors.initials: R
authors.lastname: Rawer
authors.forename: M Z
authors.initials: MZ
authors.lastname: Mughal
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D015519:Bone Density / Q000187:drug effects / Q000502:physiology; D002648:Child; D019587:Dietary Supplements; D004311:Double-Blind Method; D005240:Feasibility Studies; D005260:Female; D018737:Hand Strength / Q000502:physiology; D006304:Health Status; D006801:Humans; D008572:Menarche / Q000187:drug effects* / Q000502:physiology*; D009142:Musculoskeletal Physiological Phenomena / Q000187:drug effects*; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use*; D014808:Vitamin D Deficiency / Q000097:blood / Q000503:physiopathology / Q000517:prevention & control
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D