title: Vitamin D deficiency is independently associated with mortality among critically ill patients.
abstract: OBJECTIVE
  Studies suggest an association between vitamin D deficiency and morbidity/mortality in critically ill patients. Several issues remain unexplained, including which vitamin D levels are related to morbidity and mortality and the relevance of vitamin D kinetics to clinical outcomes. We conducted this study to address the association of baseline vitamin D levels and vitamin D kinetics with morbidity and mortality in critically ill patients.
  
  
  METHODS
  In 135 intensive care unit (ICU) patients, vitamin D was prospectively measured on admission and weekly until discharge from the ICU. The following outcomes of interest were analyzed: 28-day mortality, mechanical ventilation, length of stay, infection rate, and culture positivity.
  
  
  RESULTS
  Mortality rates were higher among patients with vitamin D levels <12 ng/mL (versus vitamin D levels >12 ng/mL) (32.2% vs. 13.2%), with an adjusted relative risk of 2.2 (95% CI 1.07-4.54; p< 0.05). There were no differences in the length of stay, ventilation requirements, infection rate, or culture positivity.
  
  
  CONCLUSIONS
  This study suggests that low vitamin D levels on ICU admission are an independent risk factor for mortality in critically ill patients. Low vitamin D levels at ICU admission may have a causal relationship with mortality and may serve as an indicator for vitamin D replacement among critically ill patients.
authors.affiliation: Division of Critical Care Medicine, Department of Internal Medicine, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Rafael Barberena
authors.initials: RB
authors.lastname: Moraes
authors.affiliation: Division of Critical Care Medicine, Department of Internal Medicine, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Gilberto
authors.initials: G
authors.lastname: Friedman
authors.affiliation: Division of Critical Care Medicine, Department of Internal Medicine, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Iuri Christmann
authors.initials: IC
authors.lastname: Wawrzeniak
authors.affiliation: Division of Critical Care Medicine, Department of Internal Medicine, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Leonardo S
authors.initials: LS
authors.lastname: Marques
authors.affiliation: Division of Critical Care Medicine, Department of Internal Medicine, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Fabiano Márcio
authors.initials: FM
authors.lastname: Nagel
authors.affiliation: Division of Critical Care Medicine, Department of Internal Medicine, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Thiago Costa
authors.initials: TC
authors.lastname: Lisboa
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Mauro Antonio
authors.initials: MA
authors.lastname: Czepielewski
mesh_terms: D018806:APACHE; D000328:Adult; D000368:Aged; D001938:Brazil / Q000453:epidemiology; D016638:Critical Illness; D003956:Dialysis; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D063305:Organ Dysfunction Scores; D010281:Parathyroid Hormone / Q000097:blood; D010343:Patient Admission; D010351:Patient Discharge; D011446:Prospective Studies; D012121:Respiration, Artificial; D012306:Risk; D012680:Sensitivity and Specificity; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood* / Q000401:mortality*
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D