title: Effects of Cholecalciferol vs Calcifediol on Total and Free 25-Hydroxyvitamin D and Parathyroid Hormone.
abstract: BACKGROUND
  Vitamin D deficiency disproportionately affects nonwhite individuals. Controversy persists over how to best restore low 25D levels, and how to best define vitamin D status [total (protein bound plus free) vs free 25D].
  
  
  OBJECTIVE
  To assess the effects of vitamin D3 (cholecalciferol, or D3) vs 25-hydroxyvitamin D3 (calcifediol, or 25D3) on total and free 25D in a multiethnic cohort of adults, and whether change in parathyroid hormone (PTH) is more strongly associated with total vs free 25D.
  
  
  METHODS
  Sixteen-week randomized controlled trial. Biochemistries at 0, 4, 8, and 16 weeks.
  
  
  METHODS
  Academic medical center.
  
  
  METHODS
  Thirty-five adults ≥18 years of age with 25D levels <20 ng/mL.
  
  
  METHODS
  Sixty micrograms (2400 IU)/d of D3 or 20 μg/d of 25D3.
  
  
  METHODS
  Total and free 25D, and PTH.
  
  
  RESULTS
  Baseline total (16.2 ± 3.7 vs 17.0 ± 2.5 ng/mL; P = 0.4) and free (4.2 ± 0.8 vs 4.7 ± 1.0 pg/mL; P = 0.2) 25D were similar between D3 and 25D3 groups, respectively; 25D3 increased total (+25.5 vs +13.8 ng/mL; P = 0.001) and free (+6.6 vs +3.5 pg/mL; P = 0.03) 25D more than D3. By 4 weeks, 87.5% of 25D3 participants had total 25D levels ≥30 ng/mL, compared with 23.1% of D3 participants (P = 0.001). Change in PTH was associated with both total (P = 0.01) and free 25D (P = 0.04).
  
  
  CONCLUSIONS
  25D3 increased total and free 25D levels more rapidly than D3, regardless of race/ethnicity. Free and total 25D were similarly associated with change in PTH.
authors.affiliation: Department of Medicine.
authors.forename: Albert
authors.initials: A
authors.lastname: Shieh
authors.affiliation: David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095.
authors.forename: Christina
authors.initials: C
authors.lastname: Ma
authors.affiliation: Department of Orthopaedic Surgery, and.
authors.forename: Rene F
authors.initials: RF
authors.lastname: Chun
authors.affiliation: Department of Orthopaedic Surgery, and.
authors.forename: Sten
authors.initials: S
authors.lastname: Witzel
authors.affiliation: Department of Orthopaedic Surgery, and.
authors.forename: Brandon
authors.initials: B
authors.lastname: Rafison
authors.affiliation: Department of Orthopaedic Surgery, and.
authors.forename: Hannah T M
authors.initials: HTM
authors.lastname: Contreras
authors.affiliation: DSM Nutritional Products, 4303 Kaiseraugst, Switzerland.
authors.forename: Jonas
authors.initials: J
authors.lastname: Wittwer-Schegg
authors.affiliation: Future Diagnostics, 6603 BN Wijchen, the Netherlands.
authors.forename: Leon
authors.initials: L
authors.lastname: Swinkels
authors.affiliation: Future Diagnostics, 6603 BN Wijchen, the Netherlands.
authors.forename: Tonnie
authors.initials: T
authors.lastname: Huijs
authors.affiliation: Institute of Metabolism and Systems Research, The University of Birmingham, Birmingham B15 2TT, United Kingdom.
authors.forename: Martin
authors.initials: M
authors.lastname: Hewison
authors.affiliation: Department of Orthopaedic Surgery, and.
authors.forename: John S
authors.initials: JS
authors.lastname: Adams
mesh_terms: D000328:Adult; D002112:Calcifediol / Q000494:pharmacology* / Q000627:therapeutic use; D002118:Calcium / Q000097:blood / Q000652:urine; D002762:Cholecalciferol / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood* / Q000188:drug therapy / Q000652:urine; D055815:Young Adult
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; D002762:Cholecalciferol; C104450:25-hydroxyvitamin D; D002112:Calcifediol; D002118:Calcium