Mediator1: An important intermediary of vitamin D receptor-regulated epidermal function and hair follicle biology

Considerable data in the literature support the idea that 1,25-dihydroxyvitamin D3 and the vitamin D receptor (VDR) are involved in regulating skin biology. Studies using cultured keratinocytes, artificial human skin, and transgenic mouse models, as well as observations in patients with rickets, provide evidence of this pathways importance in epidermal proliferation and differentiation and the hair growth cycle. The report by Oda et al. in this issue also indicates an important role of the VDR coactivator mediator 1 in these processes.