Vitamin D deficiency as a risk factor for infection, sepsis and mortality in the critically ill: systematic review and meta-analysis

Introduction: 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 D-3 (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.