title: A Retrospective Evaluation of Response to Vitamin D Supplementation in Obese Versus Nonobese Patients.
abstract: OBJECTIVE
  To evaluate the impact of body mass index (BMI) on vitamin D status following ergocalciferol therapy.
  
  
  METHODS
  A retrospective evaluation of patients aged 18 years and older with a baseline serum 25(OH)D < 30 ng/mL who received prescription ergocalciferol 50 000 IU at any dose between July 2009 and November 2011 was conducted. Patients were included if pre- and posttreatment 25(OH)D levels were available within 3 months of therapy.
  
  
  RESULTS
  Two hundred and thirteen patients were included in the study with 52% having a BMI ≥30 kg/m(2). Thirty-eight different ergocalciferol regimens were prescribed, and the majority of patients (66.2%) received a regimen consisting of 50 000 IU once weekly for variable durations. Mean 25(OH)D levels increased from 18.8 ± 6.6 ng/mL at baseline to 35.0 ± 13.8 ng/mL with 61.0% (n = 130) of patients having attained vitamin D sufficiency, 25(OH)D ≥ 30 ng/mL, with their prescribed ergocalciferol regimen. Obese patients with a BMI ≥30 were less likely to attain vitamin D sufficiency following replacement than patients with a BMI <30 kg/m(2) (52% vs 71%; P = .0161).
  
  
  CONCLUSIONS
  Our study demonstrated an overall moderate response rate to replacement therapy with ergocalciferol and considerable variability in vitamin D replacement strategies initiated by primary care providers. Based on our findings, elevated BMI ≥30 kg/m(2) may impact the likelihood of attaining vitamin D sufficiency with ergocalciferol.
authors.affiliation: Department of Clinical Sciences, Drake University College of Pharmacy and Health Sciences, Des Moines, IA, USA ginelle.bryant@drake.edu.
authors.forename: Ginelle A
authors.initials: GA
authors.lastname: Bryant
authors.affiliation: Department of Clinical Sciences, Drake University College of Pharmacy and Health Sciences, Des Moines, IA, USA.
authors.forename: Carrie Foust
authors.initials: CF
authors.lastname: Koenigsfeld
authors.affiliation: Department of Clinical Sciences, Drake University College of Pharmacy and Health Sciences, Des Moines, IA, USA.
authors.forename: Nicholas P
authors.initials: NP
authors.lastname: Lehman
authors.affiliation: Medical Education, Iowa Methodist Medical Center, Des Moines, IA, USA Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
authors.forename: Hayden L
authors.initials: HL
authors.lastname: Smith
authors.affiliation: UnityPoint Health, Des Moines, IA, USA.
authors.forename: Craig D
authors.initials: CD
authors.lastname: Logemann
authors.affiliation: Strategic Analytics Department, UnityPoint Health, Des Moines, IA, USA.
authors.forename: Kirk T
authors.initials: KT
authors.lastname: Phillips
mesh_terms: D015652:25-Hydroxyvitamin D 2 / Q000097:blood / Q000172:deficiency*; D015992:Body Mass Index; D016022:Case-Control Studies; D004872:Ergocalciferols / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000188:drug therapy*; D012189:Retrospective Studies; D014815:Vitamins / Q000627:therapeutic use*
chemical_list: D004872:Ergocalciferols; D014815:Vitamins; D015652:25-Hydroxyvitamin D 2
keywords: ergocalciferol; obesity; vitamin D