title: Prevalence of vitamin D deficiency in critically ill patients and its influence on outcome: experience from a tertiary care centre in North India (an observational study).
abstract: BACKGROUND
  Limited studies are available on prevalence and severity of vitamin D deficiency in a critically ill population. To the best of our knowledge, this the first study of its kind in an Indian intensive care set-up.
  
  
  METHODS
  One hundred fifty-eight critically ill patients were prospectively enrolled for over 2 years. Demographic profile and clinical characteristics were noted. Blood sample for serum 25 (OH) D was collected on admission (4 ml). Serum 25 (OH) D was measured using radioimmunoassay kit. Vitamin D deficiency was labelled as insufficient (31-60 nmol/l), deficient (15-30 nmol/l) and undetectable (<15 nmol/l). Statistical tests used were t test, chi-square test and binary logistic regression.
  
  
  RESULTS
  Vitamin D deficiency (<60 nmol/l) was present in 127 patients (80.4%). Twenty-six patients had (20.47%) undetectable vitamin D levels. The mean vitamin D level was higher amongst survivors (43.17 + 39.22) than in non-survivors (39.72 + 29.31). Vitamin D was not significantly associated with mortality in univariate analysis. Multiple logistic regression showed admission APACHE II (p = 0.008), lactate (p = 0.013) and pre-ICU hospital stay (p = 0.041) as independent predictors of mortality in critically ill patients (p < 0.05).
  
  
  CONCLUSIONS
  Vitamin D deficiency is highly prevalent in critically ill patients. A causal association between vitamin D deficiency and mortality was not found in our study. Larger studies are needed to understand the relationship between vitamin D deficiency and ICU outcome.
authors.affiliation: Department of Critical Care Medicine, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Raebareli road, Lucknow, Pin-226014 India.
authors.forename: Afzal
authors.initials: A
authors.lastname: Azim
authors.affiliation: Department of Critical Care Medicine, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Raebareli road, Lucknow, Pin-226014 India.
authors.forename: Armin
authors.initials: A
authors.lastname: Ahmed
authors.affiliation: Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India.
authors.forename: Subhash
authors.initials: S
authors.lastname: Yadav
authors.affiliation: Department of Critical Care Medicine, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Raebareli road, Lucknow, Pin-226014 India.
authors.forename: Arvind K
authors.initials: AK
authors.lastname: Baronia
authors.affiliation: Department of Critical Care Medicine, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Raebareli road, Lucknow, Pin-226014 India.
authors.forename: Mohan
authors.initials: M
authors.lastname: Gurjar
authors.affiliation: Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India.
authors.forename: Madan M
authors.initials: MM
authors.lastname: Godbole
authors.affiliation: Department of Critical Care Medicine, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Raebareli road, Lucknow, Pin-226014 India.
authors.forename: Banani
authors.initials: B
authors.lastname: Poddar
authors.affiliation: Department of Critical Care Medicine, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Raebareli road, Lucknow, Pin-226014 India.
authors.forename: Ratender K
authors.initials: RK
authors.lastname: Singh
keywords: Critically ill; Outcome; Prevalence; Vitamin D deficiency