Vitamin D and allergic rhinitis: A mini-review

Table 3 Standard protocols in clinical randomized controlled trials on vitamin D supplementation for allergic rhinitis

Protocol component	Details
Patient selection	Clinical diagnosis of allergic rhinitis. Confirmed vitamin D deficiency (< 20 ng/mL). Exclusion: Chronic systemic illness, immunodeficiency, high-dose steroids
Supplementation regimen	Vitamin D3 (cholecalciferol): 1000–2000 IU/day. Oral route preferred. Duration: 8-12 weeks
Concomitant treatments	Standard antihistamines (e.g., cetirizine, loratadine). Some trials include intranasal corticosteroids. Medications maintained at stable doses
Outcome measures	Symptom scores (e.g., total nasal symptom scores, visual analog scale) at baseline and end of study. Serum 25-hydroxyvitamin D levels pre-intervention and post-intervention
Immunological assessments	(In select trials) CD4+CD25+Foxp3+, Treg levels, cytokine profiling (e.g., IL-4, IL-10, interferon-γ)
Monitoring and follow-up	Follow-ups every 4 weeks. Supplement compliance via pill count/self-report. Monitoring for side effects/toxicity

IL: Interleukin.