1. What data in particular will be shared?
   Response - All of the individual participant data collected during the trial, after de-identification.
   


2. What additional supporting information will be shared?
   Response -  Study Protocol
   Response -  Statistical Analysis Plan
   Response - Informed Consent Form
   Response - Clinical Study Report
   
   
3. Who will be able to view these files?
   Response - Researchers whose proposed use of the data has been approved by an independent review committee identified for this purpose.
   


4. For what types of analyses will this data be available?
   Response - Any purpose.
   


5. By what mechanism will data be made available?
   Response - Proposals should be directed to [arindammalik1@gmail.com].
   


6. For how long will this data be available start date provided 01-01-2026 and end date provided 01-04-2026?
   Response - Beginning 3 months and ending 5 years following article publication.
   


7. Any URL or additional information regarding plan/policy for sharing IPD? 
   Additional Information - nil

Allergic rhinitis (AR) is the most common type of chronic rhinitis, affecting 10–25% of the population worldwide and in India its incidence is 20–30% ¹, and evidence suggests that the prevalence of the disorder is increasing ². Severe allergic rhinitis has been associated with significant impairments in quality of life (QOL), sleep and work performance. Despite the recent epidemiologic evidence that the incidence of allergic rhinitis is increasing worldwide, less than 12% of allergy sufferers seek medical recommendations from a physician, resulting in allergic rhinitis being frequently under recognized, misdiagnosed, and ineffectively treated ^{3, 4}. It poses psychosocial and financial burden on society. Allergic rhinitis is typically manifested by patients having nasal congestion, rhinorrhoea, sneezing, and nasal itching as well as ocular redness, tearing, and itching. Nearly 50% of allergic rhinitis patients will experience symptoms for at least 4 months of the year. Allergic rhinitis, as a non-life threatening disease, has not been regarded as a serious health problem, despite the evidence suggesting it has important short-term and long-term health consequences ⁵. The economic burden is further enhanced as allergic rhinitis and asthma are often comorbid conditions. Approximately 85% of asthmatic patients have allergic rhinitis, whereas up to 40% of allergic rhinitis patients have or will develop asthma ^{6, 7}. Treatment options consist of drugs like anti-histamines, intranasal corticosteroids, decongestants, and more recently immunotherapy. In recent years, there has been worldwide increase in allergic diseases more so in developed countries and this has been associated with low vitamin D. Current lifestyle has led to people spending more times indoors, leading to less sun exposure and less cutaneous vitamin D production. In present study efficacy of vitamin d supplementation and serum vitamin d levels will be evaluated in patients suffering from moderate to severe allergic rhinitis in both seasonal and perennial cases.

It is an immune (IgE) mediated inflammatory reaction of upper airway after allergen exposure. Despite of being treated there is lack of satisfaction among patients. Thus, it is necessary to focus on other causes and treatment modalities of allergic rhinitis. In current scenario, Vitamin D deficiency is increasingly contributed as a potential etiologic or disease-modifying factor in various allergic conditions including allergic rhinitis. The US National Health and Nutritional Examination Survey (NHANES) revealed that mean serum 25-hydroxyvitamin D (25(OH)D) decreased from 30 ng/ mL in 1988–1994 to 24 ng/mL in 2001–2004. National population surveys found that both vitamin D deficiency and allergic diseases are increasing year by year possibly due to increased westernization ⁸. Previous literatures revealed that Vitamin D plays an important role in decreasing sensitivity to allergens and its deficiency is associated with increased serum IgE levels. Limited literature is there which delineate relationship between serum vitamin D level and allergic rhinitis and its use as a therapeutic agent for its treatment. Several studies have investigated the role of vitamin D in the treatment of allergic diseases and asthma, however the results are still controversial ^{9, 10}.