Role of Vitamin D in Hospitalized Children With Lower Tract Acute Respiratory Infections

ABSTRACT Background: Vitamin D is known to have modulatory actions in the immune system. Its influence on the severity of lower tract acute respiratory infections (LT‐ARIs) is unclear. Objectives: The aim of the present study was to evaluate the role of vitamin D on LT‐ARI in paediatric patients. Methods: Children admitted to hospital with LT‐ARI were prospectively recruited through the GENDRES network (March 2009–May 2013). The 25‐hydroxyvitamin D (25‐OHD) levels were measured by immunoassay. The severity of the illness was evaluated according to clinical scales, length of hospital stay, ventilatory requirements, and pediatric intensive care unit admission. Results: A total of 347 patients with a median (interquartile range) age of 8.4 (2.6–21.1) months were included. The mean (SD) 25‐OHD levels in our series were 27.1 (11.3) ng/mL. In this study, a cutoff value of ≥30 ng/mL was considered optimal vitamin status. Patients with 25‐OHD levels