What role does VDR play in Allergie?

The vitamin D receptor (VDR) is a nuclear receptor that regulates expression of immune-related genes. Polymorphisms in the VDR gene (e.g., FokI, BsmI, TaqI) have been associated in observational studies with altered vitamin D signaling and increased risk of allergic conditions such as asthma, atopic dermatitis, and hay fever. However, evidence is mostly associative (GWAS, case-control) and not causal. VDR influences T‑cell differentiation (Th1/Th2 balance) and skin barrier function. Direct clinical utility of VDR genotyping for allergy management is unproven; vitamin D supplementation shows only modest effects in RCTs. Caveat: genetics is one piece – environment, diet, and lifestyle matter more.