Vitamin D supplementation in the critically ill: A systematic review and meta-analysis

Introduction: Vitamin D insufficiency is reported in up to 50% of the critically ill patients and is associated with increased mortality, length of stay (LOS) in intensive care unit (ICU) and hospital, and respiratory disorders with prolonged ventilation. Benefits of vitamin D supplementation remain unclear. The aim of this systematic review was to evaluate the clinical benefits of vitamin D administration in critically ill patients. Methods: We searched Medline, Embase, CINAHL and Cochrane database for randomized controlled trials (RCT) conducted on heterogeneous ICU patients comparing vitamin D administration to placebo. Evaluated outcomes included mortality, infectious complications, hospital/ICU LOS and length of mechanical ventilation. Two independent reviewers assessed eligibility, risk of bias and abstracted data. Data was pooled using a random effect model to estimate the risk ratio (RR) or weighted mean difference. Pre-defined subgroup analysis included oral-enteral vs. parenteral administration, high vs. low dose, vitamin d deficient patient, high vs. low quality trials. Results: Six RCTs (695 patients) met study inclusion. No reduction in mortality was found (P = 0.14). No differences in ICU and hospital LOS, infection rate and ventilation days existed. In the subgroup analysis, the oral-enteral group, there was no improvement in mortality (P = 0.12) or hospital LOS (P = 0.16). Daily doses >300,000 111 did not improve mortality (P = 0.12) and ICU LOS (P = 0.12). Conclusions: In critically ill patients, Vitamin D administration does not improve clinical outcomes. The statistical imprecision could be explained by the sparse number of trials. (C) 2017 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.