rs7041
The vitamin D carrier protein, second marker
What this position does
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.
Skin. Shaped by carrying vitamin d around the body. 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: a strong case, not settled. There is a clear signal of recent selection and a widely favoured explanation for it, which is not the same as a proven one.
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 AA | You have the tighter-binding version on both copies Associated with a higher measured total but a smaller free fraction. |
| One copy AC | You carry one of each The intermediate result, and the most common one in Europe. |
| Two copies CC | You have the looser-binding version on both copies Associated with a lower measured total. Whether that means less usable vitamin D is genuinely debated, which is worth knowing before anyone sells you a supplement on the strength of it. |
How common each version is
| 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.
How many people carry each result
| Ancestry group | AA | AC | CC |
|---|---|---|---|
| African | 544 / 661 | 110 / 661 | 7 / 661 |
| European | 81 / 503 | 257 / 503 | 165 / 503 |
| East Asian | 248 / 504 | 210 / 504 | 46 / 504 |
| South Asian | 116 / 489 | 221 / 489 | 152 / 489 |
| American | 78 / 347 | 165 / 347 | 104 / 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
Coordinates and allele pair verified against Ensembl GRCh37. Direction of effect verified against VEP protein consequences or 1000 Genomes population frequency. Category: Population adaptation.
Related
- rs2282679 — Vitamin D binding protein
Where this fits
Common questions
What is rs7041?
rs7041 is a position in the GC gene on chromosome 4. 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.
What does it mean if I have CC at rs7041?
You have the looser-binding version on both copies. Associated with a lower measured total. Whether that means less usable vitamin D is genuinely debated, which is worth knowing before anyone sells you a supplement on the strength of it.
What does it mean if I have AA at rs7041?
You have the tighter-binding version on both copies. Associated with a higher measured total but a smaller free fraction.
How do I find out my rs7041 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.