To assess association between bronchial asthma control and vitamin D levels, inflammatory markers, and pulmonary function tests in adult patients in chest outpatient department in Bundelkhand region

Background: Bronchial asthma is a chronic inflammatory airway disorder with varying degrees of airflow limitation and symptoms. Emerging evidence suggests that vitamin D has an immunomodulatory role in asthma and may influence systemic inflammation. However, data on its association with asthma control and inflammatory markers such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) in Indian adults, particularly in semi-urban populations, remain scarce. Aims and Objectives: The aims and objectives of the study are to assess the association between asthma control and serum vitamin D levels, inflammatory markers (CRP and ESR), and lung function forced expiratory volume in 1 s (FEV₁) in adult asthma patients. Materials and Methods: A hospital-based observational study was conducted over 12 months among 130 adult asthmatic patients attending the chest outpatient department at Maharani Laxmi Bai Medical College, Jhansi. Patients were categorized based on asthma control status (Global Initiative for Asthma 2024), and their serum vitamin D, ESR, CRP, and spirometry (FEV₁) were measured. Statistical analysis included Chi-square and Analysis of Variance tests, with P<0.05 considered significant. Results: Vitamin D deficiency (<20 ng/mL) was present in 76.92% of patients, with only 3.08% showing sufficient levels. A significant association was observed between poor asthma control and low vitamin D levels (P<0.05). Inflammatory markers ESR and CRP were elevated in 93.08% and 66.92% of patients, respectively. FEV₁ values declined significantly with worsening asthma control (P=0.0001) and improved with higher vitamin D levels (P=0.006). Conclusion: Vitamin D deficiency is highly prevalent among adult asthmatics and is significantly associated with poor asthma control, increased inflammation, and reduced lung function. Vitamin D may serve as an adjunctive marker and potential therapeutic target in asthma management.