This gene builds the receptor that vitamin D latches onto inside your cells. Even if your blood vitamin D looks fine, some versions of this receptor make it harder for your body to actually use it — which quietly affects bone strength, immunity, and energy.
See your VDR variants — freeOnce vitamin D is hydroxylated to calcitriol (1,25-(OH)2-D), it binds the vitamin D receptor (VDR) inside cells. The activated VDR translocates to the nucleus and regulates the expression of >1,000 genes involved in calcium absorption, bone remodeling, innate and adaptive immunity, insulin sensitivity, and inflammation control.
Less efficient VDR variants are linked to lower bone mineral density, weaker antimicrobial immune response, higher autoimmune risk (MS, type 1 diabetes, Hashimoto's), and worse outcomes in respiratory infections — even when serum 25(OH)D is in the normal range. Many people with VDR variants need higher D3 dosing or D3+K2 combinations to reach functional adequacy.
| rsID | Alias | Risk allele | Effect | Frequency |
|---|---|---|---|---|
rs2228570 | FokI (C→T, Met1Thr) | T (f allele) | T allele produces a longer, less active receptor protein. | T allele ≈35% globally |
rs1544410 | BsmI (G→A) | A (b allele) | Intronic; affects mRNA stability; A allele linked to lower BMD in some populations. | A allele ≈40% |
rs731236 | TaqI (T→C) | C (t allele) | Synonymous; in linkage with BsmI. | C allele ≈40% |
rs7975232 | ApaI | — | Often co-reported with BsmI/TaqI haplotype. | ≈50% |
| Genotype | Prevalence | What it means | What to do |
|---|---|---|---|
| FokI CC (FF) | ~40% | Most active receptor isoform. | Standard vitamin D guidance; aim 25(OH)D 30-50 ng/mL. |
| FokI CT or TT (Ff/ff) | ~60% | Less active receptor. | May need higher D3 dose to reach 40-60 ng/mL; pair with K2 and magnesium. |
| BsmI/TaqI variant haplotype | — | Lower BMD risk in some studies. | Prioritize weight-bearing exercise, calcium intake and adequate D3. |
| Condition | Relationship | Detail |
|---|---|---|
| Osteoporosis | Increased risk | VDR variants modestly increase fracture risk; effect amplified by low D and inadequate calcium. |
| Multiple sclerosis | Increased risk | Low D + VDR variants associated with MS risk and severity. |
| Type 1 diabetes | Increased risk | Childhood D deficiency + VDR variants increase risk. |
| Respiratory infections | Increased severity risk | Inadequate D + VDR variants linked to worse outcomes in flu, RSV and COVID-19. |
| Hashimoto's thyroiditis | Increased risk | VDR variants overrepresented in autoimmune thyroid disease. |
Diet alone rarely provides enough D; the priority is ensuring cofactors (magnesium, K2, calcium) needed to convert and use supplemental D effectively.
| Supplement | Typical dose | Form | Notes |
|---|---|---|---|
| Vitamin D3 (cholecalciferol) | 2000-5000 IU/day, titrated to 25(OH)D 40-60 ng/mL | D3, not D2 | Higher doses (>4000 IU) for VDR-variant carriers; retest after 8-12 weeks. |
| Vitamin K2 (MK-7) | 100-200 mcg/day | MK-7 (longer half-life than MK-4) | Routes calcium to bone, away from arteries; essential when supplementing D long-term. |
| Magnesium glycinate | 200-400 mg/day | Glycinate, malate or threonate | Required for vitamin D activation; deficiency mimics D deficiency. |
| Calcium (food first) | 1000-1200 mg total/day from food + supplement if needed | Calcium citrate if supplementing | Avoid mega-dose calcium supplements; food sources are safer. |
| Boron | 3-6 mg/day | Boron glycinate | Modestly raises calcitriol and supports bone matrix. |
There is no single dose — your serum 25(OH)D level is the target. Many VDR-variant carriers need 4,000-5,000 IU/day to reach 40-60 ng/mL. Test after 8-12 weeks and adjust. Always pair with K2 and magnesium.
Vitamin D3 (cholecalciferol) raises 25(OH)D more effectively than D2. Liquid or softgel forms are well absorbed; take with a fat-containing meal.
If you take D3 daily long-term, yes. K2 (MK-7, 100-200 mcg) directs calcium to bone and away from arteries. The combination is especially important for VDR-variant carriers needing higher D3 doses.
Three common reasons: (1) magnesium deficiency blocks D activation, (2) gut malabsorption (celiac, IBD), (3) obesity sequesters D in adipose tissue. VDR variants alone rarely cause refractory low D.
Yes — modestly. VDR variants are overrepresented in MS, type 1 diabetes and Hashimoto's. Maintaining 25(OH)D 40-60 ng/mL is a reasonable goal, though it does not guarantee prevention.
This page is informational and does not constitute medical advice, diagnosis or treatment. Genetic risk is one input among many — diet, exercise, sleep, environment and family history all matter. Consult a qualified healthcare professional before starting or stopping any supplement, medication or treatment.