Vitamin D is one of the thoroughly studied risk factors in the pathogenesis of allergic rhinitis (AR). Low serum level of vitamin D is well documented in the urban population of India. The supplementation policy of vitamin D is not uniform among practitioners. The study aims to assess the impact of vitamin D deficiency on AR & long-term quality of life in perennial AR patients with low vitamin D levels after its supplementation in the urban population. The policy for evaluation of serum level of vitamin D & its supplementation in deficit patients in AR is not uniform in our hospital. The data was extracted from the hospital records & the patients came to OPD in the year 2018–2019. Inclusion criteria were the clinical diagnosis (ARIA guideline) of the perennial form of AR where vitamin D assessment was performed before prescribing treatment & the patients received a complete course of vitamin D as per the recommendation followed in our Institute. The patients received oral antihistaminic & topical steroids based nasal spray and were clubbed together as a control group whereas, in the study group, the patients were pooled together who received vitamin D supplementation along with oral antihistaminic & topical steroids based nasal spray. Pre-treatment & post-treatment (at 8 weeks, 6 months, and 12 months) SNOT-22 scores were obtained from the records. The data were analyzed statistically using repeated measures ANOVA test. The study showed a significant decrease in the SNOT-22 score in both Groups in comparison to pre-treatment scores, but post-treatment group comparison was not found statistically significant at each point of comparison. The scores were found on the lower side in the study group at the initial two evaluation points whereas it was higher at the third point of evaluation. This study showed the additional therapeutic effect of vitamin D supplementation as an adjunct in the treatment of perennial AR patients but the effectiveness of the treatment does not last forever so maintenance therapy is required especially in areas following the Indian lifestyle.