title: Serum Vitamin D Levels and Polycystic Ovary syndrome: A Systematic Review and Meta-Analysis.
abstract: Vitamin D deficiency (VDD) is common in women with and without polycystic ovary syndrome (PCOS) and may be associated with metabolic and endocrine disorders in PCOS. The aim of this meta-analysis is to assess the associations of serum vitamin D levels with metabolic and endocrine dysregulations in women with PCOS, and to determine effects of vitamin D supplementation on metabolic and hormonal functions in PCOS patients. The literature search was undertaken through five databases until 16 January 2015 for both observational and experimental studies concerning relationships between vitamin D and PCOS. A total of 366 citations were identified, of which 30 were selected (n = 3182). We found that lower serum vitamin D levels were related to metabolic and hormonal disorders in women with PCOS. Specifically, PCOS patients with VDD were more likely to have dysglycemia (e.g., increased levels of fasting glucose and homeostatic model assessment-insulin resistance index (HOMA-IR)) compared to those without VDD. This meta-analysis found no evidence that vitamin D supplementation reduced or mitigated metabolic and hormonal dysregulations in PCOS. VDD may be a comorbid manifestation of PCOS or a minor pathway in PCOS associated metabolic and hormonal dysregulation. Future prospective observational studies and randomized controlled trials with repeated VDD assessment and better characterization of PCOS disease severity at enrollment are needed to clarify whether VDD is a co-determinant of hormonal and metabolic dysregulations in PCOS, represents a consequence of hormonal and metabolic dysregulations in PCOS or both.
authors.affiliation: Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, 101 Buck Road, Health Sciences Campus, B.S. Miller Hall, Athens, GA 30602, USA. willahe@uga.edu.
authors.forename: Chunla
authors.initials: C
authors.lastname: He
authors.affiliation: Institute of Computational Comparative Medicine (ICCM), Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA. zhoumeng@ksu.edu.
authors.forename: Zhoumeng
authors.initials: Z
authors.lastname: Lin
authors.affiliation: Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, 101 Buck Road, Health Sciences Campus, B.S. Miller Hall, Athens, GA 30602, USA. swagner@uga.edu.
authors.forename: Sara Wagner
authors.initials: SW
authors.lastname: Robb
authors.affiliation: Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, 101 Buck Road, Health Sciences Campus, B.S. Miller Hall, Athens, GA 30602, USA. aezeamam@uga.edu.
authors.forename: Amara E
authors.initials: AE
authors.lastname: Ezeamama
mesh_terms: D001786:Blood Glucose / Q000378:metabolism; D016208:Databases, Factual; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D024821:Metabolic Syndrome / Q000097:blood; D064887:Observational Studies as Topic; D011085:Polycystic Ovary Syndrome / Q000097:blood* / Q000188:drug therapy; D014807:Vitamin D / Q000008:administration & dosage / Q000097:blood*
chemical_list: D001786:Blood Glucose; D014807:Vitamin D
keywords: metabolic and endocrine disorders; polycystic ovary syndrome; systematic review and meta-analysis; vitamin D