Effects of vitamin D supplementation on mortality in critically ill patients: a systematic review and meta-analysis.

Objective: This study aimed to use a meta-analysis to evaluate whether vitamin D supplementation can improve critically ill patients' parameters.Materials and Methods: A systematic review of the literature and meta-analysis was performed using the electronic databases PubMed, Cochrane, Medline, and Scielo. The selected studies are randomized controlled trials (RCTs) that evaluate the effect of vitamin D supplementation in critically ill patients over 18 years of age and are available in full. All of the articles involved randomized clinical trials that analyzed the effects of vitamin supplementation on mortality, length of ICU stay, length of hospital stay, and use of mechanical ventilation. Results: The meta-analysis revealed that vitamin D supplementation in critically ill patients can reduce mortality in 28-30 days [RR =0.76 (95%CI: 0.57-1.00, p=0.05)] (p=0.85), hospital mortality (p=0.14), length of ICU stays (p=0.11), length of hospital stays (p=0.08) and time of mechanical ventilation (p=0.32).Conclusion: This meta-analysis demonstrated that vitamin D supplements in critically ill patients show a reduction in mortality in 28-30 days. Thus, it is suggested that critically ill patients who are 18 years of age or older should receive a dose of vitamin D greater than 150,000IU to obtain this benefit.