Vitamin D in atopic dermatitis, chronic urticaria and allergic contact dermatitis.

Vitamin D influences allergen-induced pathways in the innate and adaptive immune system, and its potential immunomodulatory role in allergic skin disorders has been explored. This comprehensive review article provides an overview of the role of vitamin D in three common dermatologic conditions: atopic dermatitis (AD), chronic urticaria, and allergic contact dermatitis (ACD). Whereas the literature regarding vitamin D and AD has resulted in mixed findings, several studies have described an inverse relationship between vitamin D levels and AD severity, and improvement in AD with vitamin D supplementation. Similarly, several studies report an inverse relationship between vitamin D levels and severity of chronic urticaria. Although current research in humans remains limited, an increased likelihood of ACD has been demonstrated in vitamin D-deficient mice. Additional well-designed clinical trials will be necessary to determine whether vitamin D supplementation should be recommended for prevention or adjuvant treatment of these common dermatologic conditions.