Frequency of Vitamin D Deficiency in Children Presenting with Acute Bronchiolitis at Paediatric Unit of Saidu Group of Teaching Hospital Swat

Abstract

Vitamin D plays a critical role in immune regulation and protection against respiratory infections. Acute bronchiolitis is one of the most common causes of hospitalization among infants and young children worldwide, including Pakistan. Previous studies have shown that vitamin D deficiency may predispose children to more severe respiratory illnesses, yet data from northern regions of Pakistan, particularly Swat, remain scarce. Objective: To determine the frequency of vitamin D deficiency in children with acute bronchiolitis presenting to a tertiary care hospital in Swat and to assess its association with disease severity and clinical outcomes. Methods: This cross-sectional study was conducted in the Department of Pediatrics, Saidu Group of Teaching Hospital, Swat, over a period of six months. A total of 135 children diagnosed with acute bronchiolitis were enrolled using non-probability consecutive sampling. Demographic details, socioeconomic status, and clinical features were recorded. Serum vitamin D levels were measured, and deficiency was defined as <20 ng/mL. Clinical severity was categorized into mild, moderate, and severe based on standardized criteria. Data were analyzed using SPSS, with chi-square and t-tests applied where appropriate. Results: Out of 135 children, the mean age was 12.4 ± 6.8 months, and 60.7% were male. Vitamin D deficiency was observed in 73.3% of the study population, while 17.8% had insufficiency and only 8.9% had sufficient levels. Children with vitamin D deficiency were significantly more likely to present with severe bronchiolitis (93.3% in severe category vs. 22.2% in sufficient group, p < 0.001). Deficient children also had longer mean hospital stays (6.1 ± 2.3 vs. 4.2 ± 1.6 days, p < 0.01) and higher rates of ICU admission (27.3% vs. 8.3%, p = 0.02). Conclusion: Vitamin D deficiency was highly prevalent among children with acute bronchiolitis in Swat and was significantly associated with increased severity, prolonged hospitalization, and higher need for intensive care. These findings highlight the importance of vitamin D screening and supplementation strategies in pediatric populations to improve respiratory health outcomes.

Keywords: Vitamin D deficiency, Acute bronchiolitis, Pediatrics, Respiratory infections, Swat, Pakistan