How are VDR and Haut related?

The vitamin D receptor (VDR) is a nuclear receptor expressed in many tissues, especially skin. In keratinocytes, VDR regulates cell proliferation, differentiation, and barrier function. Adequate vitamin D status and functional VDR are critical for skin health. VDR polymorphisms (e.g., rs2228570, rs1544410) have been associated with psoriasis, atopic dermatitis, and skin cancer risk, but effect sizes are small and clinical utility is limited. MyBody-X does not directly test VDR; its GC variant (rs2282679) affects vitamin D levels, not the receptor. The claim that 4000 IU vitamin D is needed based on a GC risk allele lacks evidence (marketing). High-dose vitamin D can be toxic; medical supervision is essential. For skin concerns, blood tests (25-hydroxyvitamin D) and clinical evaluation are more actionable than DNA tests.