Severe vitamin D deficiency upon admission in critically ill patients is related to acute kidney injury and a poor prognosis.

Objectives: To evaluate the prevalence of vitamin D deficiency in critically ill patients upon admission to an Intensive Care Unit (ICU) and its prognostic implications.

Design: A single-center, prospective observational study was carried out from January to November 2015. Patients were followed-up on until death or hospital discharge.

Setting: The department of Critical Care Medicine of a university hospital.

Patients: All adults admitted to the ICU during the study period, without known factors capable of altering serum 25(OH)D concentration.

Interventions: Determination of serum 25(OH)D levels within the first 24h following admission to the ICU.

Main Variables Of Interest: Prevalence and mortality at 28 days.

Results: The study included 135 patients, of which 74% presented deficient serum 25(OH)D levels upon admission to the ICU. Non-survivors showed significantly lower levels than survivors (8.14ng/ml [6.17-11.53] vs. 12ng/ml [7.1-20.30]; P=.04], and the serum 25(OH)D levels were independently associated to mortality (OR 2.86; 95% CI 1.05-7.86; P=.04]. The area under the ROC curve was 0.61 (95% CI 0.51-0.75), and the best cut-off point for predicting mortality was 10.9ng/ml. Patients with serum 25(OH)D<10.9ng/ml also showed higher acute kidney injury rates (13 vs. 29%; P=.02).

Conclusion: Vitamin D deficiency is highly prevalent upon admission to the ICU. Severe Vitamin D deficiency (25[OH]D<10.9ng/ml) upon admission to the ICU is associated to acute kidney injury and mortality.