Role of Oral Calcium in the Treatment of Allergic Rhinitis

Abstract

Background: Allergic rhinitis is a common inflammatory disorder characterised by sneezing, nasal discharge, nasal obstruction and nasal itching. Oral calcium has been suggested as a potential adjunctive treatment, but evidence regarding its clinical effectiveness remains limited.

Objective: To evaluate the effect of oral calcium supplementation on symptoms and absolute eosinophil count (AEC) in patients with allergic rhinitis.

Materials and Methods: This prospective, single-blinded, placebo-controlled, randomised crossover study was conducted in the Department of Otorhinolaryngology, A.J. Institute of Medical Sciences, Mangalore, from August 2016 to October 2018. Eighty patients aged 18–60 years with allergic rhinitis and AEC >400 cells/mm³ were included. Participants received oral calcium 500 mg twice daily for 7 days and a matching placebo for 7 days, separated by a 1-week washout period. Total symptom score, individual symptoms and AEC were assessed at baseline and after each treatment period.

Results: Calcium treatment significantly reduced nasal obstruction (1.56 ± 0.67 to 1.29 ± 0.60; p=0.007745), nasal discharge (1.62 ± 0.62 to 1.43 ± 0.57; p=0.034697), and sneezing (1.35 ± 0.64 to 1.15 ± 0.53; p=0.030179). The total symptom score significantly decreased from 6.36 ± 1.71 to 5.45 ± 1.50 (p=0.001265), whereas the reduction with placebo was not significant (p=0.187967). No significant improvement was observed in nasal itching, ocular symptoms, palatal/pharyngeal itching or AEC. AEC decreased from 918.85 ± 448.78 to 872.91 ± 412.51 cells/mm³ after calcium treatment, but the change was not significant (p=0.493824).

Conclusion: Oral calcium supplementation was associated with significant improvement in selected nasal symptoms and overall symptom burden in allergic rhinitis. However, it did not significantly reduce AEC. Further larger studies with longer follow-up are required to establish its role as an adjunctive treatment.