Association of Vitamin D and Allergic Rhinitis: A Clinical Study in the Indian Population.

Introduction: Allergic rhinitis (AR) is a prevalent condition in India, driven by IgE-mediated inflammation, withpotential links to vitamin D deficiency due to its immunomodulatory effects. This study investigates serum 25-hydroxyvitamin D (25(OH)D) levels and AR severity in an Indian cohort.Materials and Methods: This cross-sectional study (May 2023–April 2024) at Pt. B.D. Sharma PGIMS, Rohtak,enrolled 138 adults (72 AR cases, 66 controls). AR was diagnosed per Allergic Rhinitis and its Impact on Asthma(ARIA) guidelines [1]. Serum 25(OH)D, IgE, and absolute eosinophil count (AEC) were measured; interleukin (IL-4, IL-5, IL-13) data were unavailable due to assay issues. Severity was assessed via Sino-Nasal Outcome Test-22(SNOT-22). Comparisons used t-tests or Mann-Whitney U tests; correlations used Spearman’s coefficient, adjustingfor age, sex, BMI, and sun exposure.Results: AR cases showed significant symptoms (nasal obstruction 90.3%, sneezing 100%, eye redness/itching81.9%; p≤0.01) and elevated IgE (p<0.001) vs. controls. No differences were found in 25(OH)D (79.2% cases vs.86.4% controls deficient, p=0.18) or AEC (p=0.16). 25(OH)D did not correlate with SNOT-22 scores (r_s=-0.12,p=0.31).Conclusion: AR’s burden and IgE-mediated etiology are confirmed, but 25(OH)D showed no association with ARprevalence or severity, likely due to high deficiency (82.6%) in India. These findings guide otorhinolaryngologypractice in high-deficiency populations.