Markers / Gene
DHCR7
One position in this gene is readable from a home DNA test.
How much vitamin D your skin can make
rs12785878 · chr11:71,167,449 · G/T · evidence: established
DHCR7 controls the supply of the precursor your skin turns into vitamin D under ultraviolet light. Variants here rose in frequency in northern populations, which is what you would expect where sunlight is scarce for half the year.
| If you carry | What it means |
|---|---|
| No copies | You have the lower-vitamin-D version on both copies |
| One copy | You carry one higher-vitamin-D copy |
| Two copies | You carry two higher-vitamin-D copies |
| Ancestry group | T (the effect version) | |
|---|---|---|
| African | 17.0% | |
| American | 45.0% | |
| East Asian | 38.0% | |
| European | 70.1% | |
| South Asian | 15.1% |
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.
Read my file