Evaluation of Peak Expiratory Flow Rate (PEFR) In Vitamin D Deficient Asthmatics

Abstract

Background: Bronchial asthma is a chronic inflammatory airway disorder influenced by multiple environmental and immunological factors. Vitamin D, a secosteroid hormone known for its anti-inflammatory and immunomodulatory properties, has been implicated in the pathogenesis and control of asthma. Vitamin D deficiency is prevalent in India and may adversely affect airway function and disease control. This study aimed to evaluate the association between serum Vitamin D levels and Peak Expiratory Flow Rate (PEFR) among Vitamin D deficient asthmatics and to assess changes in PEFR following Vitamin D supplementation.

Methods: This cross-sectional interventional study was conducted in the Department of Pulmonary Medicine, a tertiary care hospital in South India, among 38 stable adult asthmatics with serum 25(OH) Vitamin D levels ≤20 ng/mL. Baseline demographic, clinical, and asthma-related parameters were recorded. PEFR was measured using a mini-Wright peak flow meter, and the best of three attempts was taken. Participants received oral Vitamin D supplementation (60,000 IU weekly for 8 weeks) as per Endocrine Society guidelines. PEFR was reassessed after 8 weeks of therapy. Data were analyzed using paired t-test, with p<0.05 considered statistically significant.

Results: The study population demonstrated a female predominance (63.2%) with most participants aged 18–30 years. Severe Vitamin D deficiency (≤10 ng/mL) was present in 23.7% of subjects. There was no significant correlation between baseline Vitamin D levels and PEFR values. However, a statistically significant improvement in mean PEFR was observed following Vitamin D supplementation (p<0.05).

Conclusion: Vitamin D supplementation in deficient asthmatics resulted in improved PEFR, suggesting a beneficial effect on airway function and respiratory muscle performance. These findings highlight the potential role of Vitamin D optimization as an adjunctive measure in asthma management, particularly in populations with high prevalence of deficiency.