title: The effect of vitamin D supplementation on selected inflammatory biomarkers in obese and overweight subjects: a systematic review with meta-analysis.
abstract: OBJECTIVE
  The objective of this systematic review was to assess the effect of vitamin D supplementation on selected inflammatory biomarkers in obese and overweight subjects.
  
  
  METHODS
  The search process was based on the selection of publications (DB-RCT and RCT) listed in the following databases: PubMed, Web of Knowledge, Scopus, the Cochrane Library and Embase. To assess the study quality, a nine-point scoring system according to the Newcastle-Ottawa scale was used, and a high-quality study was defined by a threshold of ≥7 points. Thirteen randomized controlled trials were included. The analysed population consisted of 1955 overweight and obese subjects. The mean age ranged from 13.6 to 71.7 years. Changes in the concentration of 25-hydroxycholecalciferol (25(OH)D), C-reactive protein (CRP), tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) were assessed. To combine individual study results, a meta-analysis was performed.
  
  
  RESULTS
  The baseline levels of 25(OH)D suggested vitamin D deficiency or insufficiency in the analysed population. The vitamin D supplementation did not influence on CRP (std. mean differences -0.11; 95 % CI -0.27-0.04; p = 0.15), TNF-α (std. mean differences -0.13; 95 % CI -0.38-0.12; p = 0.31) and IL-6 concentrations (std. mean differences 0.1; 95 % CI -0.43-0.63; p = 0.71).
  
  
  CONCLUSIONS
  This meta-analysis suggests that supplementation with vitamin D does not have a significant influence on changes in the concentration of selected inflammatory biomarkers in the obese and overweight subjects.
authors.affiliation: Department of Human Nutrition and Hygiene, Poznan University of Life Sciences, 31 Wojska Polskiego Str., 60-624, Poznan, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Jamka
authors.affiliation: Department of Human Nutrition and Hygiene, Poznan University of Life Sciences, 31 Wojska Polskiego Str., 60-624, Poznan, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Woźniewicz
authors.affiliation: Department of Paediatric Gastroenterology and Metabolic Diseases, Poznan University of Medical Sciences, 27/33 Szpitalna Str., 60-572, Poznan, Poland.
authors.forename: Jarosław
authors.initials: J
authors.lastname: Walkowiak
authors.affiliation: Department of Education and Obesity Treatment and Metabolic Disorders, Poznan University of Medical Sciences, 84 Szamarzewskiego Str., 60-596, Poznan, Poland.
authors.forename: Paweł
authors.initials: P
authors.lastname: Bogdański
authors.affiliation: Department of Human Nutrition and Hygiene, Poznan University of Life Sciences, 31 Wojska Polskiego Str., 60-624, Poznan, Poland.
authors.forename: Jan
authors.initials: J
authors.lastname: Jeszka
authors.affiliation: Department of Paediatric Gastroenterology and Metabolic Diseases, Poznan University of Medical Sciences, 27/33 Szpitalna Str., 60-572, Poznan, Poland. stelmach@dife.de.|Department of Epidemiology, German Institute of Human Nutrition Potsdam-Rehbrücke, 114-116 Arthur-Scheunert-Allee, 14558, Nuthetal, Germany. stelmach@dife.de.
authors.forename: Marta
authors.initials: M
authors.lastname: Stelmach-Mardas
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood*; D002097:C-Reactive Protein / Q000378:metabolism; D016208:Databases, Factual; D019587:Dietary Supplements; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D008875:Middle Aged; D009765:Obesity / Q000097:blood*; D050177:Overweight / Q000097:blood*; D016032:Randomized Controlled Trials as Topic; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D014807:Vitamin D / Q000008:administration & dosage* / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood / Q000175:diagnosis; D055815:Young Adult
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D014807:Vitamin D; D002097:C-Reactive Protein
keywords: Adipokines; C-reactive protein; Cytokines; Dietary supplements; Obesity; Vitamin D