Effects of Serum Vitamin D and Efficacy of Subcutaneous Immunotherapy in Adult Patients With Allergic Rhinitis.

Immunotherapy is the standard of treatment for long-life relief of symptoms of allergic rhinitis. Vitamin D may affect the outcomes of treatment. This study evaluated the clinical efficacy of subcutaneous allergen immunotherapy in adult patients with allergic rhinitis based on the serum level of vitamin D. Patients with persistent allergic rhinitis and positivity for skin prick test were evaluated by Sino-nasal Outcome Test (SNOT-22) and Mini Rhinoconjunctivitis Quality of Life Questionnaire (MiniRQLQ) before subcutaneous allergen immunotherapy and during the maintenance phase to assess the relation of the serum level of vitamin D and the clinical efficacy of immunotherapy. After immunotherapy, the greatest reduction in SNOT-22 scores were reported in patients with vitamin D sufficiency (39.0 ± 9.2), followed by vitamin D suboptimal provision (35.1 ± 12.1), insufficiency (25.0 ± 7.5), and deficiency (18.3 ± 6.0) ( < 0.001). The MiniRQLQ reduction in patients with vitamin D sufficiency, suboptimal provision, insufficiency, or deficiency was 30.7 ± 8.7, 27.1 ± 8.7, 20.0 ± 8.6, or 17.4 ± 7.1, respectively ( < 0.001). Both of SNOT-22 and MiniRQLQ scores decreased significantly following immunotherapy in patients with different levels of vitamin D. However, these effects were more pronounced when the level of vitamin D was sufficient.