The Claim

UV irradiation of human skin in vivo increases CYP27B1 mRNA expression and decreases DHCR7 mRNA expression.

Source: UV increases skin-derived 1α,25-dihydroxyvitamin D3 production, leading to MMP-1 expression by altering the balance of vitamin D and cholesterol synthesis from 7-dehydrocholesterol.

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
27score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

How it works
1 study reviewed
In plain English

Exposure to ultraviolet light in human skin increases the activity of the CYP27B1 gene and reduces the activity of the DHCR7 gene.

See the scientific wording

UV irradiation in human skin in vivo increases CYP27B1 mRNA and decreases DHCR7 mRNA expression, supporting the relevance of the in vitro mechanism to living human skin.

Why this might work

When skin is exposed to UV light, it stops making cholesterol and starts making vitamin D instead. The gene that makes the enzyme for cholesterol production turns off, and the gene that activates vitamin D turns on. This causes more raw material to flow into vitamin D production, leading to higher levels of active vitamin D in the skin.

Verified mechanismbased on 1 study

What the research says

1 study

  1. Study: UV increases skin-derived 1α,25-dihydroxyvitamin D3 production, leading to MMP-1 expression by altering the balance of vitamin D and cholesterol synthesis from 7-dehydrocholesterol.

    When skin is exposed to sunlight, it turns up the gene that helps make vitamin D and turns down the gene that makes cholesterol — just like lab tests predicted. This proves the lab findings apply to real human skin.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.