rs2228570
The vitamin D receptor, FokI
What this position does
Having vitamin D and responding to it are different things. This change alters where the receptor protein starts, producing a slightly longer or shorter version, and the shorter one is somewhat more active.
Skin. Shaped by responding to vitamin d once you have it. This is one of the variants that differs sharply between human populations, because something in the environment made one version worth having.
Sunlight and vitamin D
Skin has to let in enough ultraviolet light to make vitamin D, and block enough to protect the folate in your blood. The right answer depends entirely on where you live, so it changed every time people moved.
What changed: Industry, roughly the last two centuries. Indoor work, heated buildings, refined food, cheap salt and sugar, tobacco at scale, and a collapse in infectious disease. This is where most of the deals in your genome came undone.
Why it spread: nobody knows. The frequency difference between populations is real and measured. What the variant was worth having for is not known, and any site that tells you is guessing.
Spiral Staircase, chapter 19: The Largest Organ Spiral Staircase is written by the same author as this site.
What each result means
| If you carry | What it means |
|---|---|
| No copies of the effect version GG | You have the more active receptor on both copies The shorter, more transcriptionally active form. |
| One copy AG | You carry one of each The most common genotype. |
| Two copies AA | You have the longer receptor on both copies Slightly less active in laboratory work. The consequences for health are much less clear than the molecular difference, and studies disagree. |
How common each version is
| Ancestry group | A (the effect version) | |
|---|---|---|
| African | 18.9% | |
| American | 48.3% | |
| East Asian | 41.8% | |
| European | 37.8% | |
| South Asian | 26.5% |
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.
How many people carry each result
| Ancestry group | GG | AG | AA |
|---|---|---|---|
| African | 435 / 661 | 202 / 661 | 24 / 661 |
| European | 203 / 503 | 220 / 503 | 80 / 503 |
| East Asian | 175 / 504 | 237 / 504 | 92 / 504 |
| South Asian | 263 / 489 | 193 / 489 | 33 / 489 |
| American | 95 / 347 | 169 / 347 | 83 / 347 |
Counts of people, not modelled frequencies: every one of the 2,504 individuals sequenced by the 1000 Genomes Project phase 3, tallied by the genotype they carry. Deriving these from allele frequencies instead would assume random mating inside each group and undercount the homozygotes.
How to find out which you have
If you have taken a test with 23andMe, AncestryDNA, MyHeritage, Family Tree DNA, TellMeGen or Living DNA, this position is very likely already in the raw data file they gave you. You do not need another test.
One thing to watch if you look it up by hand: testing companies report some positions from one DNA strand and some from the other, and the file does not say which. Read the letters as they appear and you will get the opposite of the truth for some positions. Sequencings resolves that automatically.
Source
Uitterlinden et al., Genetics and biology of vitamin D receptor polymorphisms, Gene (2004)
Coordinates and allele pair verified against Ensembl GRCh37. Direction of effect verified against VEP protein consequences or 1000 Genomes population frequency. Category: Population adaptation.
Where this fits
Common questions
What is rs2228570?
rs2228570 is a position in the VDR gene on chromosome 12. Having vitamin D and responding to it are different things. This change alters where the receptor protein starts, producing a slightly longer or shorter version, and the shorter one is somewhat more active.
What does it mean if I have AA at rs2228570?
You have the longer receptor on both copies. Slightly less active in laboratory work. The consequences for health are much less clear than the molecular difference, and studies disagree.
What does it mean if I have GG at rs2228570?
You have the more active receptor on both copies. The shorter, more transcriptionally active form.
How do I find out my rs2228570 genotype?
If you have taken a home DNA test, this position is very likely in the raw data file you were given. Sequencings reads that file in your browser without uploading it, and resolves which DNA strand each position was reported from, which is the step most manual lookups get wrong.
This is reference information, not medical advice, and not a diagnosis. See the medical disclaimer. Category: Population adaptation.