title: Association between vitamin D status and the risk of gestational diabetes mellitus: a meta-analysis.
abstract: OBJECTIVE
  Vitamin D is widely used for bone growth and normal insulin secretion; however, the association between vitamin D status and gestational diabetes risk is controversial. This meta-analysis aimed to quantitatively evaluate the association between vitamin status and risk of gestational diabetes.
  
  
  METHODS
  We performed a systematic search on the PubMed, EmBase, and Cochrane Library databases in January 2015 to obtain observational studies studying gestational diabetes risk in relation to vitamin D status. Odds ratios (ORs) with 95 % confidence intervals (CIs) were used to measure the association between vitamin D status and the risk of gestational diabetes.
  
  
  RESULTS
  A total of 20 observational studies were included in the final analysis containing 16,515 individuals. Overall, maternal vitamin D insufficiency was found to be associated with a greater risk of gestational diabetes (RR 1.45; 95 % CI 1.15-1.83; P < 0.001). Subgroup analysis indicated that this association might differ based on countries, study design, assessment of vitamin D levels, sample size, age at baseline, adjusted models, and study quality.
  
  
  CONCLUSIONS
  This meta-analysis revealed that maternal vitamin D insufficiency is associated with increased risk of gestational diabetes.
authors.affiliation: Department of Clinical Laboratory, The First Affiliated Hospital of Anhui Medical University, No. 218, Jixi Road, 230022, Hefei, China.
authors.forename: Min
authors.initials: M
authors.lastname: Lu
authors.affiliation: Department of Clinical Laboratory, The First Affiliated Hospital of Anhui Medical University, No. 218, Jixi Road, 230022, Hefei, China. xyh20150428@126.com.
authors.forename: Yuanhong
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Clinical Laboratory, The First Affiliated Hospital of Anhui Medical University, No. 218, Jixi Road, 230022, Hefei, China.
authors.forename: Liying
authors.initials: L
authors.lastname: Lv
authors.affiliation: Department of Clinical Laboratory, The First Affiliated Hospital of Anhui Medical University, No. 218, Jixi Road, 230022, Hefei, China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
mesh_terms: D016640:Diabetes, Gestational / Q000097:blood / Q000209:etiology*; D005260:Female; D006801:Humans; D016017:Odds Ratio; D011247:Pregnancy; D012307:Risk Factors; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications*; D014815:Vitamins / Q000097:blood
chemical_list: D014815:Vitamins; D014807:Vitamin D
keywords: Association; Gestational diabetes; Meta-analysis; Vitamin D status