Vitamin D levels in patients admitted to the internal medicine intensive care unit and the association with mortality and other clinical outcomes

Aim: To evaluate the effect of vitamin D levels on mortality and disease course in intensive care unit (ICU) patients. Methods: This single-center retrospective study included 549 patients who had been treated in the Internal Medicine ICU of Kayseri City Hospital in the past year. The patients were divided into two groups according to their vitamin D levels. Patients with vitamin D levels less than 20 ng/ml were considered to have severe vitamin D deficiency (Group 1), whereas those with levels greater than 20 ng/ml did not have vitamin D deficiency (Group 2). The patients’ 25-OH vitamin D levels, ICU stays, mortality status, and blood parameters were recorded. Results: The median ICU stay durations of the studied patient groups were 4 (1–97) days in group 1 and 3 (1–17) days in group 2 (p<0.001). The patients’ 25-OH vitamin D levels and ICU stay durations were negatively correlated (r=−0.863, p=0.005). The average 25-OH vitamin D levels were 17.2±11.07 ng/mL in the surviving group and 9.3±10.17 ng/mL in the nonsurviving group (p=0.043). The median C-reactive protein (CRP) values of the patient groups were 54.3 (0.2–398.4) mg/L in Group 1 and 87.5 (0.6–387.0) mg/L in Group 2 (p= 0.035).In the surviving group, the median Acute Physiology and Chronic Health Evaluation II (APACHE II) score was 20.5 (14–34.5), whereas the median score in the nonsurviving group was 35.5 (30.5–52). Additionally, the median Sequential Organ Failure Assessment (SOFA) scores were 7 (5–10; p = 0.001) in the surviving group and 10 (6–12; p = 0.034) in the nonsurviving group. Conclusions: The results of our study show that vitamin D deficiency is a common condition in critically ill patients admitted to intensive care and is associated with higher mortality rates and longer hospital stays. Supplementation with vitamin D may be considered as part of the recommended treatment for ICU patients.