Publication:

Vitamin D status of children with recurrent lower respiratory tract infection: a comparative observational study

Background Lower respiratory tract infections (LRTIs) are one of the major causes of morbidity and mortality in children under five. Recurrent LRTIs which is defined as three or more episodes in one year or two or more in six months pose a significant health burden. Emerging evidence suggests that vitamin D deficiency in may increase susceptibility of children to such infections.

Methods This comparative observational study was conducted over one year (January 2024 to December 2024) in the pediatric department of Bidar Institute of Medical Sciences, Karnataka, India. The study was undertaken to assess the association between vitamin D status and recurrent LRTIs in children aged 6 months to 5 years. The study included 80 children with recurrent LRTIs (group A) and 80 age matched healthy controls (group B). Detailed demographic details, clinical findings and nutritional status of cases was collected using a structured questionnaire. Serum 25-hydroxyvitamin D [25(OH)D] levels were measured using chemiluminescent immunoassay and categorized as deficient ( 30 ng/ml). Statistical analysis was performed using statistical package for the social sciences (SPSS) version 21.0 with significance set at p<0.05.

Results No significant differences were noted between groups regarding age and gender distribution. Bronchiolitis and pneumonia were the most common types of LRTIs observed. The mean serum vitamin D level in group A (18.7±7.3 ng/ml) was significantly lower than in group B (26.1±8.5 ng/ml) (p<0.0001). Vitamin D deficiency was observed in 47.5% of children with recurrent LRTIs compared to 27.5% in controls (p=0.0002).

Conclusions Children with recurrent LRTIs were found to have significantly lower serum vitamin D levels compared to healthy counterparts. These findings suggest that vitamin D deficiency may be a modifiable risk factor for recurrent respiratory infections.