The Vitamin D Receptor (VDR) antibody is a crucial tool in studying the molecular mechanisms of vitamin D signaling. VDR, a nuclear hormone receptor, mediates the effects of calcitriol (active vitamin D) by regulating gene expression involved in calcium homeostasis, cell differentiation, immune modulation, and apoptosis. It is expressed in diverse tissues, including intestine, kidney, bone, and immune cells. VDR antibodies are designed to detect and quantify VDR protein levels in research applications such as Western blotting, immunohistochemistry (IHC), and immunofluorescence (IF). These antibodies target specific epitopes, often within the receptor’s ligand-binding or DNA-binding domains, enabling studies on VDR expression patterns, localization, and interactions. Dysregulation of VDR signaling is linked to pathologies like osteoporosis, autoimmune diseases, and cancer, making these antibodies valuable for investigating disease mechanisms. For example, reduced VDR expression has been observed in colorectal cancer and inflammatory bowel disease. Additionally, VDR antibodies aid in diagnosing rare hereditary conditions like hereditary vitamin D-resistant rickets (HVDRR), caused by VDR mutations. Recent research also explores VDR’s role in non-classical pathways, such as membrane-associated rapid signaling. Validation of antibody specificity through knockout controls or blocking peptides is critical to ensure reliable data. Overall, VDR antibodies are indispensable for advancing understanding of vitamin D’s pleiotropic roles in health and disease.