Vitamin D supplementation improves waist-to-hip ratio and fasting blood glucose in vitamin D deficient, overweight or obese Asians: A pilot secondary analysis of a randomised controlled trial

J Steroid Biochem Mol Biol. 2019 Feb;186:136-141. doi: 10.1016/j.jsbmb.2018.10.006. Epub 2018 Oct 12.

Abstract

Recent trials do not support a role for vitamin D supplementation in prevention or treatment of type 2 diabetes mellitus, although effects may differ in Asian populations. In this pilot secondary analysis of a placebo-controlled randomised trial of overweight or obese individuals with low 25-hydroxyvitamin D (25(OH)D < 50 nmol/L), we examined whether vitamin D supplementation improved insulin sensitivity or body composition in participants of Asian ethnicity. Amongst 65 trial participants, 33 reported being of Asian descent (mean ± SD age 30 ± 7 years; 67% male). Participants were block randomised to receive vitamin D (n = 14; initial bolus dose of 2500 μg cholecalciferol followed by 100 μg cholecalciferol/d) or placebo (n = 19; identical capsules) for 16 weeks. Primary outcome was change in insulin sensitivity (M-value) assessed by hyperinsulinemic-euglycemic clamp. Secondary outcomes were changes in 25(OH)D (chemiluminescent immunoassay), fasting blood glucose (YSI Stat 2300), and body composition including waist-hip ratio and total body fat percentage (dual-energy X-ray absorptiometry). Questionnaires assessed sun-exposure habits, physical activity, and diet. After the 16-week intervention, 25(OH)D concentrations increased significantly in the vitamin D group with no change in placebo (61.4 ± 21.1 vs -0.4 ± 12.7 nmol/L; P < 0.01). Vitamin D group participants demonstrated significant improvements in waist-hip ratio (-0.02 ± 0.03 vs 0.00 ± 0.02; P < 0.01) and fasting blood glucose (-0.1 ± 0.2 vs 0.2 ± 04 mmol/L; P < 0.04) compared with the placebo group, but changes in insulin sensitivity and other body composition measures did not differ significantly between groups (all P > 0.05). In conclusion, vitamin D supplementation improved waist-hip ratio and fasting blood glucose in overweight and obese Asian-Australians with low vitamin D concentrations. Further research is required to determine whether vitamin D supplementation is potentially more effective in specific ethnic groups.

Trial registration: ClinicalTrials.gov NCT02112721.

Keywords: Asian; Body composition; Glucose; Insulin; Supplementation; Vitamin D.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Asian Continental Ancestry Group
  • Blood Glucose / analysis*
  • Fasting
  • Female
  • Humans
  • Male
  • Obesity / blood
  • Obesity / complications
  • Obesity / drug therapy
  • Obesity / epidemiology
  • Overweight / blood
  • Overweight / complications*
  • Overweight / drug therapy*
  • Overweight / epidemiology
  • Vitamin D / therapeutic use*
  • Vitamin D Deficiency / blood
  • Vitamin D Deficiency / complications*
  • Vitamin D Deficiency / drug therapy*
  • Vitamin D Deficiency / epidemiology
  • Vitamins / therapeutic use*
  • Waist-Hip Ratio
  • Young Adult

Substances

  • Blood Glucose
  • Vitamins
  • Vitamin D

Associated data

  • ClinicalTrials.gov/NCT02112721