title: Vitamin D deficiency as a risk factor for infection, sepsis and mortality in the critically ill: systematic review and meta-analysis.
abstract: BACKGROUND
  In Europe, vitamin D deficiency is highly prevalent varying between 40% and 60% in the healthy general adult population. The consequences of vitamin D deficiency for sepsis and outcome in critically ill patients remain controversial. We therefore systematically reviewed observational cohort studies on vitamin D deficiency in the intensive care unit.
  
  
  METHODS
  Fourteen observational reports published from January 2000 to March 2014, retrieved from Pubmed and Embase, involving 9,715 critically ill patients and serum 25-hydroxyvitamin D3 (25 (OH)-D) concentrations, were meta-analysed.
  
  
  RESULTS
  Levels of 25 (OH)-D less than 50 nmol/L were associated with increased rates of infection (risk ratio (RR) 1.49, 95% (confidence interval (CI) 1.12 to 1.99), P = 0.007), sepsis (RR 1.46, 95% (CI 1.27 to 1.68), P <0.001), 30-day mortality (RR 1.42, 95% (CI 1.00 to 2.02), P = 0.05), and in-hospital mortality (RR 1.79, 95% (CI 1.49 to 2.16), P <0.001). In a subgroup analysis of adjusted data including vitamin D deficiency as a risk factor for 30-day mortality the pooled RR was 1.76 (95% CI 1.37 to 2.26, P <0.001).
  
  
  CONCLUSIONS
  This meta-analysis suggests that vitamin D deficiency increases susceptibility for severe infections and mortality of the critically ill.
authors.affiliation: Department of Intensive Care, Erasmus Medical Centre, Mailbox 2040, H603a, 3000CA, Rotterdam, The Netherlands. k.dehaan@erasmusmc.nl.
authors.forename: Kim
authors.initials: K
authors.lastname: de Haan
authors.affiliation: Department of Intensive Care, Erasmus Medical Centre, Mailbox 2040, H603, 3000CA, Rotterdam, The Netherlands. a.b.j.groeneveld@erasmusmc.nl.
authors.forename: A B Johan
authors.initials: AB
authors.lastname: Groeneveld
authors.affiliation: Department of Intensive Care, Erasmus Medical Centre, Mailbox 2040, H619, 3000CA, Rotterdam, The Netherlands. h.degeus@erasmusmc.nl.
authors.forename: Hilde R H
authors.initials: HR
authors.lastname: de Geus
authors.affiliation: Department of Intensive Care, Erasmus Medical Centre, Mailbox 2040, H619, 3000CA, Rotterdam, The Netherlands. m.egal@erasmusmc.nl.
authors.forename: Mohamud
authors.initials: M
authors.lastname: Egal
authors.affiliation: Department of Intensive Care, Erasmus Medical Centre, Mailbox 2040, H603a, 3000CA, Rotterdam, The Netherlands. a.struijs@erasmusmc.nl.
authors.forename: Ard
authors.initials: A
authors.lastname: Struijs
mesh_terms: D000368:Aged; D015331:Cohort Studies; D016638:Critical Illness / Q000401:mortality*; D005260:Female; D017052:Hospital Mortality / Q000639:trends*; D006801:Humans; D007362:Intensive Care Units / Q000639:trends; D008297:Male; D008875:Middle Aged; D064887:Observational Studies as Topic; D012307:Risk Factors; D018805:Sepsis / Q000097:blood / Q000175:diagnosis / Q000401:mortality*; D014807:Vitamin D / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000175:diagnosis / Q000401:mortality*
chemical_list: D014807:Vitamin D