The sun signal receptor.
VDR variants affect how cells respond to vitamin D. But the variants only matter when vitamin D is low.
What VDR does.
VDR is a nuclear receptor—a protein that sits in cells waiting for vitamin D. When vitamin D binds, VDR activates hundreds of genes.
VDR controls genes for:
Calcium & Bones
Regulates calcium absorption and bone mineralization
Immune Function
Activates antimicrobial peptides and modulates inflammation
Cell Growth
Regulates cell division and differentiation (cancer prevention)
Mood & Brain
Influences serotonin synthesis and neuroprotection
Key insight: VDR is found in almost every tissue—brain, immune cells, gut, skin, prostate, breast. Vitamin D signaling is systemic.
The main VDR polymorphisms.
Fok1 (rs2228570)
Affects the start codon—determines which version of VDR protein is made.
Bsm1 (rs1544410)
Located in an intron—affects mRNA stability and VDR expression levels.
Taq1 (rs731236)
Also affects mRNA stability. Often inherited together with Bsm1.
Variants only matter when vitamin D is low.
This is the crucial point. VDR variants are like having a slightly different shaped lock—but if you have enough keys (vitamin D), it still works.
Low vitamin D + VDR variant
- • Weak signal through the receptor
- • Gene activation is impaired
- • Bone, immune, mood effects more likely
- • Variant becomes clinically relevant
Optimal vitamin D + VDR variant
- • Plenty of signal to activate VDR
- • Gene activation proceeds normally
- • Variant effect is minimized
- • Clinically irrelevant for most people
Fix the vitamin D first. Then worry about the variant.
Genes don't act alone.
VDR doesn't determine your fate. It reveals where the system might need support.
Where it matters
VDR is expressed in almost every tissue—immune cells, brain, gut, bone, skin, prostate, breast. The same variant can have different effects depending on which tissue you're looking at and local vitamin D availability.
Expression depends on
- • Nutrient availability
- • Sunlight exposure
- • Toxin burden
- • Cell turnover rate
- • Age and hormonal status
SNPs are throttles, not defects
Genetic variants often slow down pathways to protect the system from overwhelm. They reveal where you need to go slower, not that you're broken.
The real question
Not "what does this gene do?" but "what is this pathway already struggling with that makes this gene relevant?"
Related patterns
"Genes don't cause outcomes. They reveal where the system is already under pressure."
Optimizing VDR function.
Optimize Vitamin D Levels
The most important factor. Target 40-60 ng/mL for most people. With VDR variants, some may need higher levels.
Vitamin K2
Works with vitamin D to direct calcium to bones, not arteries. Essential partner for vitamin D supplementation.
Magnesium
Required for vitamin D activation. Low magnesium = vitamin D can't convert to its active form.
Sunlight Exposure
Natural vitamin D production. Also has effects beyond vitamin D—infrared, circadian signaling.
What VDR connects to.
Vitamin D
VDR is the receptor—vitamin D is the signal. They work together.
Calcium
VDR controls genes for calcium absorption in the gut and bone.
Immune System
VDR activates antimicrobial peptides like cathelicidin. Critical for innate immunity.
Light & Circadian
Sunlight makes vitamin D. VDR connects light exposure to gene expression.