What role does VDR play in Haut?

The Vitamin D Receptor (VDR) is a nuclear receptor expressed in skin cells (keratinocytes, fibroblasts, immune cells). It regulates cell differentiation, proliferation, and epidermal barrier function. Activated by 1,25-dihydroxyvitamin D (calcitriol), VDR promotes antimicrobial peptide production (e.g., cathelicidin) and modulates immune responses – relevant in inflammatory skin conditions like psoriasis. VDR polymorphisms (e.g., FokI, TaqI) are associated with altered skin barrier and increased risk for atopic dermatitis. However, evidence is mostly observational; clinical testing for VDR variants has no established utility for skin health. Vitamin D deficiency can impair skin function, but supplementation without medical indication is not recommended. Caveat: VDR genetic tests are not diagnostic and should not be used as sole basis for therapy.