Vitamin D deficiency linked with acute bronchiolitis in children: Study

The study is published in the BMC Pediatrics Journal.

Previous studies have suggested that cord 25(OH) vitamin D levels are significantly and inversely associated to the prevalence of respiratory infections and childhood wheezing.

Furthermore, vitamin D deficiency was found to be associated with acute bronchiolitis, poor asthma control, severe asthma exacerbations, and high consumption of asthma medications.

However, to understand the role of vitamin D in acute bronchiolitis further, researchers Inbal Golan-Tripto and colleagues from the Department of Pediatrics, Soroka University Medical Center, Israel Pediatric Pulmonary Unit, Soroka University Medical Center, Israel Clinical Research Center, Soroka University Medical Center, Beer Sheva, Israel Faculty of Health Sciences, Ben-Gurion University, Israel examined serum levels of 25(OH) vitamin D in infants younger than 24 months, that were clinically diagnosed with acute bronchiolitis.

The authors carried out a prospective cross-sectional case-control study which compared serum 25(OH) vitamin D levels between infants and toddlers diagnosed with acute bronchiolitis to subjects with non-respiratory febrile illness.

One hundred twenty-seven patients aged < 24 months were recruited; 80 diagnosed with acute bronchiolitis and 47 patients with non- respiratory febrile illnesses. Both groups had similar demographics aside from age (median [IQR] 5 [3–9] vs. 9 [5–16] months in the bronchiolitis group compared to control group (p = 0.002)).

Multivariate logistic regression, adjusted for age, sex, ethnicity and nutrition was performed. Correlation between serum vitamin D levels and bronchiolitis severity was assessed via Modified Tal Score and length of hospital stay (LOS).

The authors mentioned the following interesting findings-

a. Serum 25(OH) vitamin D levels were significantly lower in the bronchiolitis group; median [IQR] 28[18–52] vs. 50[25–79] nmol/L, respectively, (p = 0.005).

b. Deficient vitamin D levels (< 50 nmol/L) was found more frequently in the bronchiolitis group than controls; 73% vs. 51% (p = 0.028).

c. Multivariate logistic regression showed vitamin D deficiency was more probable in bronchiolitis patients; OR [95% CI] 3.139[1.369–7.195].

d. No correlation was found between serum vitamin D levels and bronchiolitis severity, which was assessed via Modified Tal Score and by length of hospital stay.

Therefore, the authors concluded that "Children with acute bronchiolitis displayed significantly lower vitamin D levels than children with non-respiratory acute febrile illnesses."