Body Mass Index, Vitamin D, and Type 2 Diabetes: A Systematic Review and Meta-Analysis

Nutrients. 2018 Aug 28;10(9):1182. doi: 10.3390/nu10091182.


The deficiency of vitamin D is prevalent all over the world. Studies have shown that vitamin D may play an important role in the development of obesity. The current study was conducted to quantitatively evaluate the association between serum 25-(OH) vitamin D levels and the risk of obesity in both diabetic and non-diabetic subjects. A systematic review and meta-analysis of observational studies was carried out for that purpose. We searched the Medline, PubMed, and Embase databases throughout all of March 2018. A total of fifty five observational studies for both diabetic and non-diabetic subjects were finally included in the meta-analysis. The data were analyzed by comprehensive meta-analysis software version 3 and the random effects model was used to analyze the data. The meta-analysis showed an overall inverse relationship between serum vitamin D status and body mass index (BMI) in studies of both diabetic (r = -0.173, 95% = -0.241 to -0.103, p = 0.000) and non-diabetic (r = -0.152, 95% = -0.187 to -0.116, p = 0.000) subjects. The evidence of publication bias was not found in this meta-analysis. In conclusion, the deficiency of vitamin D is associated with an increased level of BMI in the studies of both diabetic and non-diabetic subjects. Reliable evidence from well-designed future randomized controlled trials is required to confirm the findings from observational studies and to find out the potential regulatory effects of vitamin D supplementation to lower BMI.

Keywords: BMI; Vitamin D; body mass index; hypovitaminosis D; type 2 diabetes.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Biomarkers / blood
  • Blood Glucose / metabolism
  • Body Mass Index*
  • Diabetes Mellitus, Type 2 / blood
  • Diabetes Mellitus, Type 2 / diagnosis
  • Diabetes Mellitus, Type 2 / epidemiology*
  • Humans
  • Obesity / blood
  • Obesity / diagnosis
  • Obesity / epidemiology*
  • Prognosis
  • Risk Factors
  • Vitamin D / blood*
  • Vitamin D Deficiency / blood
  • Vitamin D Deficiency / diagnosis
  • Vitamin D Deficiency / epidemiology*


  • Biomarkers
  • Blood Glucose
  • Vitamin D