title: Significant association between vitamin D deficiency and sepsis: a systematic review and meta-analysis.
abstract: BACKGROUND
  A number of observational studies have found an association between low vitamin D levels and risk of sepsis. We conducted a systematic review and meta-analysis to determine the overall estimate of risk.
  
  
  METHODS
  This was a systematic review and meta-analysis conducted by online searches (CENTRAL, PubMed/MEDLINE, and EMBASE) was registered in PROSPERO (CRD42014014767). Primary outcome was incidence, prevalence, relative risk or odds ratio of having sepsis or bloodstream infection between patients with vitamin D deficiency and controls.
  
  
  RESULTS
  The initial search yielded 647 articles. Twenty-one articles underwent full-length review and data were extracted from 10 observational studies. Pooled odds ratio of sepsis in participants with vitamin D deficiency was 1.78 (95% confidence interval [CI] = 1.55 to 2.03, p < 0.01) compared with controls in studies that reported participant numbers and was 1.45 (95% CI = 1.26 to 1.66, p < 0.01) in studies that reported an adjusted odds ratio of vitamin D deficiency for developing sepsis. Statistical between-study heterogeneity was low (I(2) = 0% and 5%, respectively). Standardized mean difference of 25-hydroxyvitamin D levels in patients with sepsis and controls was -0.24 (95% CI = -0.49 to 0.00, p = 0.05) and lower in the sepsis group compared with non-sepsis or control participants. The statistical between-study heterogeneity (I(2)) was 0%.
  
  
  CONCLUSIONS
  Vitamin D deficiency were associated with an increased susceptibility of sepsis.
authors.affiliation: Department of Internal Medicine, Bassett Medical Center and Columbia University College of Physicians and Surgeons, Cooperstown, NY, USA. sikarin.upala@bassett.org.|Department of Preventive and Social Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand. sikarin.upala@bassett.org.
authors.forename: Sikarin
authors.initials: S
authors.lastname: Upala
authors.affiliation: Department of Internal Medicine, Bassett Medical Center and Columbia University College of Physicians and Surgeons, Cooperstown, NY, USA. anawin.sanguankeo@bassett.org.|Department of Preventive and Social Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand. anawin.sanguankeo@bassett.org.
authors.forename: Anawin
authors.initials: A
authors.lastname: Sanguankeo
authors.affiliation: Department of Internal Medicine, Bassett Medical Center and Columbia University College of Physicians and Surgeons, Cooperstown, NY, USA. nitipong.permpalung@bassett.org.
authors.forename: Nitipong
authors.initials: N
authors.lastname: Permpalung
mesh_terms: D006801:Humans; D015994:Incidence; D015995:Prevalence; D012307:Risk Factors; D018805:Sepsis / Q000453:epidemiology / Q000209:etiology*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000150:complications*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D