Effects of Vitamin D Supplementation on Asthma Control and Severity

Abstract

Background: Asthma is a major global health problem and one of the leading causes of childhood emergency visits. Management is often challenging because of comorbidities, poor adherence, improper inhaler technique, environmental factors, and severe therapy-resistant asthma.
Objective: To determine the effects of vitamin D supplementation on asthma control and severity.
Materials and Methods: This randomized clinical trial was conducted in the Department of Pediatric Respiratory Medicine at Bangladesh Shishu Hospital and Institute from January 2019 to December 2020 among children aged 6–15 years diagnosed with asthma. Eligible participants were randomly assigned into Group A and Group B with blinding. Group A received oral vitamin D3 (cholecalciferol) 400 IU daily for 4 months along with standard treatment, while Group B received standard treatment only. After 4 months, asthma severity, level of control, peak expiratory flow rate (PEFR), acute exacerbations, and emergency visits were assessed. A p-value <0.05 was considered significant.
Results: Asthma control improved significantly in Group A; 33 patients achieved well-controlled asthma compared to 21 in Group B (P=0.029). Moderate persistent asthma decreased from 42 to 20 patients in Group A versus 35 to 31 in Group B (P=0.033). PEFR <80% decreased significantly in Group A (P=0.014). Acute exacerbations and emergency visits were also significantly lower in Group A (P=0.031 and P=0.001, respectively).
Conclusion: Low-dose short-course vitamin D supplementation alongside standard therapy improved asthma control, reduced severity, decreased exacerbations, and lowered emergency hospital visits in children with asthma.

KYAMC Journal Vol. 16, No. 04, January 2026: 169-176.