| Full Name | Vitamin D Receptor |
|---|---|
| Gene Symbol | VDR |
| Chromosomal Location | 12q13.11 |
| NCBI Gene ID | 7421 |
| OMIM | 601769 |
| Ensembl ID | ENSG00000111424 |
| UniProt | P11473 |
| Protein Length | 427 amino acids |
| Associated Diseases | [Alzheimer's Disease](/diseases/alzheimers-disease), [Parkinson's Disease](/diseases/parkinsons-disease), [Multiple Sclerosis](/diseases/multiple-sclerosis) |
The VDR (Vitamin D Receptor) gene encodes a nuclear receptor protein that mediates the biological effects of the active form of vitamin D (1,25-dihydroxyvitamin D3, calcitriol). VDR is a member of the nuclear receptor superfamily and functions as a ligand-dependent transcription factor, regulating gene expression through binding to vitamin D response elements (VDREs) in target gene promoters.
Beyond its classic role in calcium and phosphate homeostasis, VDR is expressed throughout the brain and has been implicated in neuroprotection, modulation of neurotrophic factors, reduction of neuroinflammation, and regulation of oxidative stress responses. Epidemiological and genetic studies have associated VDR polymorphisms with risk for Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS)[@vitamind2023][@vdrneuro2024].
The VDR protein consists of several functional domains:
| Domain | Residues | Function |
|---|---|---|
| N-terminal AF-1 domain | 1-100 | Transcriptional activation, protein-protein interactions |
| DNA-binding domain (DBD) | 101-215 | Two zinc-finger motifs, binds VDREs |
| Hinge region | 216-300 | Flexibility, nuclear localization, cofactor binding |
| Ligand-binding domain (LBD) | 301-427 | Calcitriol binding, AF-2 domain for coactivator recruitment |
| F domain | 427-427 | C-terminal transactivation domain |
VDR signaling occurs through multiple mechanisms:
Genomic (canonical) pathway: Ligand-bound VDR heterodimerizes with RXR (Retinoid X Receptor), binds to VDREs, and recruits coactivators to modulate transcription of target genes.
Non-genomic (rapid) signaling: VDR interacts with membrane-associated proteins (e.g., caveolae, PDIA3) to trigger rapid intracellular signaling cascades (e.g., MAPK, PI3K/Akt).
VDRE-independent mechanisms: VDR can interact with other transcription factors (e.g., NF-κB, β-catenin) to modulate their activity.
VDR signaling promotes neuronal survival through multiple mechanisms:
VDR regulates expression of neurotrophic factors:
VDR has profound effects on immune cell function:
VDR dysfunction may contribute to AD pathogenesis through several mechanisms[@some][@vitamind2023]:
Amyloid metabolism: Vitamin D deficiency and VDR polymorphisms have been associated with altered amyloid processing and increased Aβ accumulation.
Tau pathology: VDR signaling modulates tau phosphorylation through regulation of tau kinases and phosphatases.
Neuroinflammation: VDR deficiency exacerbitates microglial activation and neuroinflammation in AD.
Synaptic dysfunction: VDR regulates synaptic proteins and plasticity-related genes.
Epidemiological evidence: Low vitamin D levels and certain VDR polymorphisms have been associated with increased AD risk and cognitive decline.
VDR plays a protective role in dopaminergic neurons[@research][@vdrparkinson2025]:
Dopaminergic neuroprotection: VDR is expressed in dopaminergic neurons of the substantia nigra, where it promotes survival and function.
Mitochondrial protection: VDR signaling enhances mitochondrial function and protects against mitochondrial toxins (e.g., MPTP, 6-OHDA).
Neuroinflammation reduction: VDR activation reduces microglial activation and pro-inflammatory cytokine production in PD models.
Alpha-synuclein modulation: VDR may influence alpha-synuclein aggregation and clearance through autophagy regulation.
Clinical evidence: Vitamin D deficiency is common in PD patients and correlates with disease severity; supplementation studies show mixed but generally positive results for motor and non-motor symptoms.
VDR variants are associated with MS susceptibility and disease course[@vdr]:
Genetic association: VDR polymorphisms (e.g., TaqI, FokI, BsmI) have been linked to MS risk in multiple populations.
Demyelination protection: VDR signaling promotes oligodendrocyte precursor cell differentiation and myelination.
Autoimmunity modulation: VDR activation shifts immune response toward tolerogenic states.
Clinical trials: Vitamin D supplementation in MS shows beneficial effects on relapse rate and MRI activity in some studies.
VDR is expressed throughout the brain:
| Region | Expression Level | Cell Types |
|---|---|---|
| Cortex | High | Pyramidal neurons, interneurons, astrocytes |
| Hippocampus | High | CA1-CA3 neurons, dentate gyrus granule cells |
| Substantia nigra | High | Dopaminergic neurons |
| Cerebellum | High | Purkinje cells, granule cells |
| Thalamus | Moderate | Various neuronal populations |
| White matter | Moderate | Oligodendrocytes, astrocytes |
Vitamin D supplementation is being explored for neurodegenerative disease prevention and treatment:
Selective VDR agonists (calcifediol, paricalcitol) are being investigated:
Future directions include: