title: Differential effects of vitamin D2 and D3 supplements on 25-hydroxyvitamin D level are dose, sex, and time dependent: a randomized controlled trial.
abstract: BACKGROUND
  Vitamin D (D) supplements are indispensable for its world-wide deficiency. Controversy continues on ergocalciferol (D2) and cholecalciferol (D3) relative potency as well as on dosing-schedule and sex role in raising 25-hydroxy D (25(OH)D) level, the best indicator of D status.
  
  
  METHODS
  We randomized 279 adults to daily D2, D3, D2/D3, or placebo; 2-weekly D2 or D3; or 4-weekly D2 or D3 (250,000 IU over/140 days). Randomization sequence, stratified by body-mass-index (BMI) and sex, was concealed from study coordinators and participants who were then blinded to capsules' content. D2, D3, 25(OH)D2, and 25(OH)D3 Serum levels were determined blindly on days 0,1,2,3,4,7,14, and 2-weekly thereafter by high performance liquid chromatography assay. The results of 269 participants were available for analysis. Primary endpoint was area-under-the-curve (AUC) of 25(OH)D (25(OH)D2 + 25(OH)D3) adjusted for sex, BMI, and baseline 25(OH)D level.
  
  
  RESULTS
  Mean(SD) age was 33.0(8.5) year, 41% were males, and 85% completed follow-up. Baseline 25(OH)D level was 39.8(11.9) and increased by 3.3(11.6) and 28.6(16.3) nmol/L, in the placebo and active-treatment groups, respectively. AUC from day 0 to 140 (AUC140) of 25(OH)D was 40% (D3 daily) to 55% (D3 2-weekly) higher with active-treatment than placebo (p < 0.001). 25(OH)D2 AUC140was higher in daily than 2-weekly (17%, p = 0.006) and 4-weekly (20%, p = 0.001) D2-treated groups. 25(OH)D3 AUC140was lower in daily than 2-weekly (11%, p = 0.002) and 4-weekly D3-treated groups (10%, p = 0.008). In D2-treated groups, there was 16.4 nmol/L decrease in 25(OH)D3 level that correlated (p < 0.001) with 25(OH)D2 level increase (r = 0.48) and baseline 25(OH)D level (r = 0.58), in one participant with measurable baseline 25(OH)D2 level, D3 caused a similar decrease in 25(OH)D2 level, while in the D2/D3-treated group, 25(OH)D3 level didn't increase. Incremental AUC from day 0 to 7 (AUC7) of D3 and 25(OH)D3 in D3-treated groups were 118-243% higher and 31-39% lower, respectively, than incremental AUC7of D2 and 25(OH)D2 in D2-treated groups. Incremental AUC7of D3 and 25(OH)D3 in D3-treated groups and D2 and 25(OH)D2 in D2-treated groups were higher in females than males (55, 13, 64, and 28%, respectively). Baseline 25(OH)D level predicted response to D2 and D3 (p < 0.001), whereas, BMI was significant predictor only for early response to D2.
  
  
  CONCLUSIONS
  Effects of D2 and D3 supplements on 25 (OH)D level may be dosing-schedule and sex-dependent. D2-associated reduction in 25(OH)D3 level may be related to total 25(OH)D level rather than being D2-specific. D2 may be 25-hydroxylated faster than D3.
  
  
  BACKGROUND
  ClinicalTrial.gov identifier: NCT01170494 (registered July 25, 2010).
authors.affiliation: Clinical Studies and Empirical Ethics Department, King Faisal Specialist Hospital and Research Center, P O Box # 3354 (MBC 03), Riyadh, 11211, Saudi Arabia. Muhammad@kfshrc.edu.sa.|Alfaisal University College of Medicine, Riyadh, Saudi Arabia. Muhammad@kfshrc.edu.sa.
authors.forename: Muhammad M
authors.initials: MM
authors.lastname: Hammami
authors.affiliation: Clinical Studies and Empirical Ethics Department, King Faisal Specialist Hospital and Research Center, P O Box # 3354 (MBC 03), Riyadh, 11211, Saudi Arabia.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Yusuf
mesh_terms: D000328:Adult; D002762:Cholecalciferol / Q000494:pharmacology*; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004872:Ergocalciferols / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008297:Male; D010919:Placebos; D012737:Sex Factors; D013997:Time Factors; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D055815:Young Adult
chemical_list: D004872:Ergocalciferols; D010919:Placebos; D014807:Vitamin D; D002762:Cholecalciferol; C104450:25-hydroxyvitamin D
keywords: 25-hydroxyvitamin D2 level; 25-hydroxyvitamin D3 level; BMI; Cholecalciferol supplement; Creatinine production; D2 level; D3 level; Dose effect; Ergocalciferol supplement; Sex effect