Preclinical studies have described the role of Vitamin E in AD: it seems to reduce transepidermal water loss (TEWL), which is associated with AD pathogenesis, and to induce the expression of the transglutaminase-1 gene, involved in terminal differentiation of keratinocytes and in the formation of the stratum corneum (83–85). This evidence concerns the gene TGM1 and Alzheimer disease.