Markers / Gene
GC
2 positions in this gene are readable from a home DNA test.
Vitamin D binding protein
rs2282679 · chr4:72,608,383 · T/G · evidence: established
GC makes the protein that carries vitamin D around the body. This is the strongest common genetic influence on measured vitamin D levels, and it works by changing how much circulating vitamin D is bound.
| If you carry | What it means |
|---|---|
| No copies | You do not carry the lower-level version |
| One copy | One copy, so modestly lower vitamin D on a blood test |
| Two copies | Two copies, so the lowest average vitamin D on a blood test |
| Ancestry group | G (the effect version) | |
|---|---|---|
| African | 5.0% | |
| American | 20.9% | |
| East Asian | 26.1% | |
| European | 24.7% | |
| South Asian | 29.7% |
1000 Genomes Project phase 3, via Ensembl, retrieved 2026-09-23. These groupings are coarse and flatten a great deal of internal diversity, particularly within Africa. A variant being common somewhere tells you where a piece of your ancestry probably comes from, and nothing else.
The vitamin D carrier protein, second marker
rs7041 · chr4:72,618,334 · A/C · evidence: established
A second position in the gene for the protein that transports vitamin D in blood. The two common forms bind it with different strength, which changes both your measured total and how much is actually free to use.
| If you carry | What it means |
|---|---|
| No copies | You have the tighter-binding version on both copies |
| One copy | You carry one of each |
| Two copies | You have the looser-binding version on both copies |
| Ancestry group | C (the effect version) | |
|---|---|---|
| African | 9.4% | |
| American | 53.7% | |
| East Asian | 30.0% | |
| European | 58.3% | |
| South Asian | 53.7% |
1000 Genomes Project phase 3, via Ensembl, retrieved 2026-09-23. These groupings are coarse and flatten a great deal of internal diversity, particularly within Africa. A variant being common somewhere tells you where a piece of your ancestry probably comes from, and nothing else.
Where this gene fits
If you have taken a home DNA test, these positions are already in your file.
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