Upregulation of the Vitamin D Receptor in the Nasal Mucosa of Patients With Allergic Rhinitis

Abstract

Vitamin D is an important hormone that has many physiologic roles. It’s major role is the regulation of serum level of calcium. In addition, it modulates bone metabolism, blood pressure, and electrolytes. Recently, new physiological functions of vitamin D have been identified. New evidence is that the most active form of vitamin D which was 25 (OH)2D3 regulates both innate and adaptive immune systems. Vitamin D deficiency is related with susceptibility to infection, especially respiratory infection, also to the occurrence of a various cancers, cardiovascular disease, and autoimmune diseases. The occurrence of atopic disease, for example, asthma and anaphylaxis, is also affected by vitamin D. Furthermore, epidemiological studies showed that serum 25 (OH)2D3 levels are linked to allergic rhinitis, and supplementing vitamin D in infancy increased the incidence of allergic rhinitis later. Vitamin D binds to the vitamin D receptors (VDR) and then exerts biological activities, regulating differentiation process of T helper cell and Th cytokine. Vitamin D receptors (VDR) are steroid thyroid of nuclear receptors which can be found in various cells like airway epithelial and immune cells. Dysregulation of the VDR contributes to increase prevalence of some autoimmune diseases such as Hashimoto’s thyroiditis. In animal study, mice deficient in VDR failed to make experimental allergic asthma. These results suggest that VDR are related to Th2 cell me-