title: The Effect of Vitamin D Supplementation on Metabolic Phenotypes in Thais with Prediabetes.
abstract: OBJECTIVE
  To investigate the effects of vitamin D supplement for three months on anthropometric and glucose homeostatic measures in Thai adults with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT).
  
  
  METHODS
  Forty-seven IFG and/or IGT subjects enrolled in the study. Subjects were randomized into three groups, control (n = 18), vitamin D₂ (20,000 IU weekly, n = 19) or vitamin D₃ (15,000 IU weekly, n = 10). Anthropometric variables were obtained at baseline and at 3-month. Oral glucose tolerance test was performed at baseline and at 3-month. Total serum 25(OH)D, 25(OH)D₃, and 25(OH)D2 were measured by LC-MS/MS. Insulin resistance (HOMA-IR) and insulin secretion index (HOMA%B) were calculated by the homeostasis model assessment.
  
  
  RESULTS
  The total 25(OH)D levels significantly increased from baseline in both the vitamin D₂ and the vitamin D₃ groups, while there was no change in the control group. D₃ supplementation raised 25(OH)D₃ significantly (+13.7 ± 4.9 ng/mL, p < 0.01) while D2 increased 25(OH)D2 levels (+25.9?4.2 ng/mL, p<0.001) but with a decrease in 25(OH)D3 (-13.1?3.1 ng/mL, p<0. 001). Subjects were classified into two groups, i.e., control (n = 18) and D₂ or D₃ supplementations (n = 29). After three months, waist circumference (WC) significantly decreased in subjects of vitamin D supplementation group. Body weight (BW p = 0.05), systolic blood pressure (SBP, p = 0.05), body mass index (BM, p = 0.06), and HOMA-IR (p = 0.09) also tended to decrease. Subjects with an increase of total 25(OH)D levels > 10 ng/mL (23 of 29 subjects) had significant decrease in HOMA-IR and increase in disposition index. Using robust regression analysis, we found the use of D3 was associated with a larger decrease in WC (coefficient = -3.5, p < 0.001) independent of the change in total 25(OH)D and baseline BMI. No difference between D₂ and D₃ was observed for other metabolic measures.
  
  
  CONCLUSIONS
  Weekly supplementations of vitamin D₂ (20,000 IU) or vitamin D₃ (15,000 IU) improve metabolic phenotypes in subjects with prediabetes. D₃ supplement may decrease waist circumference more than D₂ supplement.
authors.forename: Hataikarn
authors.initials: H
authors.lastname: Nimitphong
authors.forename: Rattanapan
authors.initials: R
authors.lastname: Samittarucksa
authors.forename: Sunee
authors.initials: S
authors.lastname: Saetung
authors.forename: Nuttapimon
authors.initials: N
authors.lastname: Bhirommuang
authors.forename: La-Or
authors.initials: LO
authors.lastname: Chailurkit
authors.forename: Boonsong
authors.initials: B
authors.lastname: Ongphiphadhanakul
mesh_terms: D000328:Adult; D000886:Anthropometry / Q000379:methods; D044466:Asian People; D001682:Biological Availability; D002112:Calcifediol / Q000097:blood; D002762:Cholecalciferol / Q000008:administration & dosage / Q000097:blood; D019587:Dietary Supplements; D016903:Drug Monitoring / Q000379:methods; D004872:Ergocalciferols / Q000008:administration & dosage / Q000097:blood; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011236:Prediabetic State / Q000188:drug therapy / Q000378:metabolism; D012044:Regression Analysis; D053719:Tandem Mass Spectrometry; D016896:Treatment Outcome; D014815:Vitamins / Q000008:administration & dosage / Q000097:blood
chemical_list: D004872:Ergocalciferols; D014815:Vitamins; D002762:Cholecalciferol; D002112:Calcifediol