title: Vitamin D in corticosteroid-naïve and corticosteroid-treated Duchenne muscular dystrophy: what dose achieves optimal 25(OH) vitamin D levels?
abstract: Assessment of the efficacy of vitamin D replenishment and maintenance doses required to attain optimal levels in boys with Duchenne muscular dystrophy (DMD).
  
  
  
  25(OH)-vitamin D levels and concurrent vitamin D dosage were collected from retrospective case-note review of boys with DMD at the Dubowitz Neuromuscular Centre. Vitamin D levels were stratified as deficient at <25 nmol/L, insufficient at 25-49 nmol/L, adequate at 50-75 nmol/L and optimal at >75 nmol/L.
  
  
  
  617 vitamin D samples were available from 197 boys (range 2-18 years)-69% from individuals on corticosteroids. Vitamin D-naïve boys (154 samples) showed deficiency in 28%, insufficiency in 42%, adequate levels in 24% and optimal levels in 6%. The vitamin D-supplemented group (463 samples) was tested while on different maintenance/replenishment doses. Three-month replenishment of daily 3000 IU (23 samples) or 6000 IU (37 samples) achieved optimal levels in 52% and 84%, respectively. 182 samples taken on 400 IU revealed deficiency in 19 (10%), insufficiency in 84 (47%), adequate levels in 67 (37%) and optimal levels in 11 (6%). 97 samples taken on 800 IU showed deficiency in 2 (2%), insufficiency in 17 (17%), adequate levels in 56 (58%) and optimal levels in 22 (23%). 81 samples were on 1000 IU and 14 samples on 1500 IU, with optimal levels in 35 (43%) and 9 (64%), respectively. No toxic level was seen (highest level 230 nmol/L).
  
  
  
  The prevalence of vitamin D deficiency and insufficiency in DMD is high. A 2-month replenishment regimen of 6000 IU and maintenance regimen of 1000-1500 IU/day was associated with optimal vitamin D levels. These data have important implications for optimising vitamin D dosing in DMD.
authors.affiliation: Dubowitz Neuromuscular Centre, Great Ormond Street Hospital, UCL Institute of Child Health, London, UK.
authors.forename: Nahla
authors.initials: N
authors.lastname: Alshaikh
authors.affiliation: Dubowitz Neuromuscular Centre, Great Ormond Street Hospital, UCL Institute of Child Health, London, UK.
authors.forename: Andreas
authors.initials: A
authors.lastname: Brunklaus
authors.affiliation: Dubowitz Neuromuscular Centre, Great Ormond Street Hospital, UCL Institute of Child Health, London, UK.
authors.forename: Tracey
authors.initials: T
authors.lastname: Davis
authors.affiliation: Dubowitz Neuromuscular Centre, Great Ormond Street Hospital, UCL Institute of Child Health, London, UK.
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Robb
authors.affiliation: Dubowitz Neuromuscular Centre, Great Ormond Street Hospital, UCL Institute of Child Health, London, UK.
authors.forename: Ros
authors.initials: R
authors.lastname: Quinlivan
authors.affiliation: Dubowitz Neuromuscular Centre, Great Ormond Street Hospital, UCL Institute of Child Health, London, UK.
authors.forename: Pinki
authors.initials: P
authors.lastname: Munot
authors.affiliation: Dubowitz Neuromuscular Centre, Great Ormond Street Hospital, UCL Institute of Child Health, London, UK.
authors.forename: Anna
authors.initials: A
authors.lastname: Sarkozy
authors.affiliation: Dubowitz Neuromuscular Centre, Great Ormond Street Hospital, UCL Institute of Child Health, London, UK.
authors.forename: Francesco
authors.initials: F
authors.lastname: Muntoni
authors.affiliation: Dubowitz Neuromuscular Centre, Great Ormond Street Hospital, UCL Institute of Child Health, London, UK.
authors.forename: Adnan Y
authors.initials: AY
authors.lastname: Manzur
mesh_terms: D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008297:Male; D020388:Muscular Dystrophy, Duchenne / Q000188:drug therapy*; D012189:Retrospective Studies; D016896:Treatment Outcome; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood / Q000627:therapeutic use*; D014808:Vitamin D Deficiency / Q000188:drug therapy; D014815:Vitamins / Q000627:therapeutic use*
chemical_list: D000305:Adrenal Cortex Hormones; D014815:Vitamins; D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: General Paediatrics; Neurology; Neuromuscular; Nutrition; Paediatric Practice