Association between vitamin D deficiency and clinical outcomes in critically ill patients: A retrospective cohort study.

ObjectiveTo evaluate the association between vitamin D status and clinical outcomes in critically ill patients using the Medical Information Mart for Intensive Care IV database.MethodsAmong 73,181 intensive care unit admissions recorded in the MIMIC-IV database, 1221 patients whose serum 25(OH)D levels were available and who had stayed in the intensive care unit for ≥24 h were included. Patients were classified as vitamin D deficient (<20 ng/mL) or non-deficient (≥20 ng/mL). Primary outcomes were hospital mortality and length of hospital stay; secondary outcomes included intensive care unit length of hospital stay and prolonged mechanical ventilation. Multivariable linear and Cox proportional hazards regression analyses were performed after adjusting for demographic and clinical covariates.ResultsMedian patient age was 63 years, and 57% were female. Vitamin D deficiency prevalence was 46.0%. Median length of hospital stay was longer in the deficient group than in the non-deficient group (23.45 (12.29-43.84) vs. 20.15 (10.94-36.77); p < 0.05). After adjustment, deficiency remained an independent predictor of increased length of hospital stay (β = 2.530; 95% confidence interval = 1.181-6.241; p = 0.027). The overall hospital mortality rate was 22.6% (24.4% vs. 21.1%; p = 0.171). In fully adjusted Cox models, vitamin D deficiency was not significantly associated with hospital mortality (hazard ratio = 1.637; 95% confidence interval = 0.696-3.846; p = 0.258).ConclusionsVitamin D deficiency is common among critically ill patients and independently associated with longer hospital stay, but not with increased hospital mortality. Further studies are needed to evaluate whether supplementation modifies these outcomes.