Vitamin D deficiency is independently associated with mortality among critically ill patients

Rafael Barberena Moraes, Gilberto Friedman, Iuri Christmann Wawrzeniak, Leonardo S. Marques, Fabiano Márcio Nagel, Thiago Costa Lisboa, Mauro Antonio Czepielewski

Studies suggest an association between vitamin D deficiency and morbidity/mortality in critically ill patients. Several issues remain unexplained, including which vitamin D levels are related to morbidity and mortality and the relevance of vitamin D kinetics to clinical outcomes. We conducted this study to address the association of baseline vitamin D levels and vitamin D kinetics with morbidity and mortality in critically ill patients. In 135 intensive care unit (ICU) patients, vitamin D was prospectively measured on admission and weekly until discharge from the ICU. The following outcomes of interest were analyzed: 28-day mortality, mechanical ventilation, length of stay, infection rate, and culture positivity. Mortality rates were higher among patients with vitamin D levels <12 ng/mL (versus vitamin D levels >12 ng/mL) (32.2% vs. 13.2%), with an adjusted relative risk of 2.2 (95% CI 1.07-4.54; p< 0.05). There were no differences in the length of stay, ventilation requirements, infection rate, or culture positivity. This study suggests that low vitamin D levels on ICU admission are an independent risk factor for mortality in critically ill patients. Low vitamin D levels at ICU admission may have a causal relationship with mortality and may serve as an indicator for vitamin D replacement among critically ill patients.