title: Effect of vitamin D on clinical and biochemical parameters in polycystic ovary syndrome women: A meta-analysis.
abstract: OBJECTIVE
  Using a meta-analysis framework, we investigated the association between the serum level of vitamin D and the risk of polycystic ovary syndrome (PCOS) and further examined the therapeutic effect of vitamin D on the clinical features of PCOS.
  
  
  METHODS
  Multiple databases were searched to retrieve studies. We chose clinical studies that investigated the relation between the serum level of vitamin D and the risk of PCOS or the therapeutic effect of vitamin D on PCOS. The search results were screened according to strict inclusion and exclusion criteria to select high-quality studies for inclusion. Statistical analyses were carried out using stata 12.0.
  
  
  RESULTS
  Seventeen studies were eligible in this meta-analysis. The levels of 25-hydroxyvitamin D and the quantitative insulin-sensitivity check index in the PCOS group were remarkably lower than in the controls, whereas the homeostasis model assessment of insulin resistance in the PCOS group was markedly higher than in the controls. No statistically significant difference was observed in serum parathyroid hormone levels between the two groups. The 25-hydroxyvitamin D levels were significantly elevated after PCOS patients received vitamin D3 treatment, but serum parathyroid hormone concentration, homeostasis model assessment of insulin resistance and quantitative insulin-sensitivity check index did not show any significant changes, indicating a lack of therapeutic response.
  
  
  CONCLUSIONS
  Our results suggest that the serum level of vitamin D is associated with the risk of PCOS, but the therapeutic effect of vitamin D on PCOS remains to be further explored.
authors.affiliation: Department of Reproductive Medicine, Fourth Hospital of Hebei Medical University, Shijiazhuang, China.
authors.forename: Xin-Zhuan
authors.initials: XZ
authors.lastname: Jia
authors.affiliation: Department of Obstetrics and Gynecology, Fourth Hospital of Hebei Medical University, Shijiazhuang, China.
authors.forename: Yong-Mei
authors.initials: YM
authors.lastname: Wang
authors.affiliation: Department of Reproductive Medicine, Fourth Hospital of Hebei Medical University, Shijiazhuang, China.
authors.forename: Na
authors.initials: N
authors.lastname: Zhang
authors.affiliation: Department of Reproductive Medicine, Fourth Hospital of Hebei Medical University, Shijiazhuang, China.
authors.forename: Li-Na
authors.initials: LN
authors.lastname: Guo
authors.affiliation: Department of Reproductive Medicine, Fourth Hospital of Hebei Medical University, Shijiazhuang, China.
authors.forename: Xiu-Li
authors.initials: XL
authors.lastname: Zhen
authors.affiliation: Department of Thoracic Surgery, Hebei Chest Hospital, Shijiazhuang, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Thoracic Surgery, Hebei Chest Hospital, Shijiazhuang, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Wei
mesh_terms: D005260:Female; D006801:Humans; D011085:Polycystic Ovary Syndrome / Q000097:blood* / Q000188:drug therapy*; D016896:Treatment Outcome; D014807:Vitamin D / Q000097:blood* / Q000627:therapeutic use*
chemical_list: D014807:Vitamin D
keywords: endocrine disorder; polycystic ovary syndrome; therapeutic effect; vitamin D; vitamin D3 supplementation