Association of vitamin D deficiency with severe pneumonia in hospitalized children under 5 years

Pneumonia is the leading cause of childhood mortality accounting for 19 % of the 10.6 million deaths that occur each year. Vitamin D influences antimicrobial activity by acting on lymphocytes, neutrophils, macrophages, and respiratory epithelial cells. In addition, the immunomodulatory properties of vitamin D may influence the severity of infection. The objective of this study was to investigate whether vitamin D deficiency is a risk factor for severe pneumonia in children under 5 years. This case–control study was conducted in Cairo University Children Hospital, Egypt, from the first of February 2012 to the end of July 2012. It enrolled 81 patients hospitalized with severe pneumonia and 89 age- and sex-matched apparently healthy controls. Both cases and controls were subjected to questionnaire for pneumonia risk factors and were assessed for vitamin D status by measuring serum 25-hydroxyvitamin D [25(OH)D] concentrations using radioimmunoassay. This study included 170 subjects; the median age of the cases was 7 months and that of the controls was 9 months. The median serum concentration of 25(OH)D in cases [median (range) 32.4 (0–192.1) nmol/L] was significantly lower than that in controls [median (range) 52.4 (0–244.6) nmol/L] (P value 0.005). Breastfeeding provides significant protective effect against severe pneumonia compared to bottlefeeding (P value 0.04). Also, vitamin D deficiency was significantly related to breastfeeding compared to bottlefeeding (P value 0.04). There was a significant association between vitamin D deficiency and severe pneumonia in children below 5 years.