Admission 25-Hydroxyvitamin D Levels Are Associated With Functional Status at Time of Discharge from Intensive Care Unit in Critically Ill Surgical Patients

Background Vitamin D status is associated with length of stay (LOS) and discharge destination in critically ill patients. To further understand this relationship, we investigated whether admission 25-hydroxyvitaminD (25OHD) levels are associated with discharge functional status in the intensive care unit (ICU). Methods In this retrospective study, data from 2 surgical ICUs at a large teaching hospital were analyzed. 25OHD levels were measured within 24 hours of ICU admission and Functional Status Score for the ICU (FSS-ICU) was calculated within 24 hours of ICU discharge for all patients. To investigate the association of vitamin D status with FSS-ICU, we constructed linear and logistic regression models, controlling for body mass index, Nutrition Risk in the Critically Ill score, ICU LOS, and cumulative protein or caloric deficit during ICU admission. Results Mean 25OHD level and FSS-ICU was 19 (SD 8) ng/mL and 17 (SD 4), respectively, in the analytic cohort (n = 300). Each unit increase in 25OHD level was associated with a 0.2 increment in FSS-ICU (beta = .20; 95% CI 0.14-0.25). Patients with 25OHD levels 3-fold risk of low FSS-ICU (<17) compared with patients with 25OHD >20 ng/mL (OR 3.45; 95% CI 1.96-6.08). Conclusions Our results suggest that vitamin D status at admission is associated with discharge FSS-ICU in critically ill surgical patients. Future studies are needed to validate our results, to build upon our findings, and to determine whether optimizing 25OHD levels can improve functional status and other important clinical outcomes in ICU patients.