Abstract
This review examines the scientific evidence behind the hypothesis that vitamin D plays a role in the pathogenesis of allergic diseases, along with a focus on emerging data regarding vitamin D and atopic dermatitis. Elucidated molecular interactions of vitamin D with components of the immune system and clinical data regarding vitamin D deficiency and atopic diseases are discussed. The rationale behind the sunshine hypothesis, laboratory evidence supporting links between vitamin D deficiency and allergic diseases, the clinical evidence for and against vitamin D playing a role in allergic diseases, and the emerging evidence regarding the potential use of vitamin D to augment the innate immune response in atopic dermatitis are reviewed.