The Claim
UV irradiation increases the production of 1α,25-dihydroxyvitamin D3 in human epidermal keratinocytes, leading to upregulation of MMP-1 expression via reduced DHCR7 activity and increased availability of 7-dehydrocholesterol as a substrate.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
UV light exposure on human skin cells increases the production of a specific form of vitamin D, which directly increases the activity of an enzyme that breaks down collagen through a biochemical pathway involving reduced DHCR7 activity and more available 7-dehydrocholesterol.
See the scientific wording
UV irradiation increases the production of 1α,25-dihydroxyvitamin D3 in human epidermal keratinocytes, which in turn upregulates MMP-1 expression, a key enzyme involved in collagen degradation, through a pathway involving reduced DHCR7 activity and increased substrate availability from 7-dehydrocholesterol.
Sunlight on the skin reduces the activity of a protein that normally makes cholesterol, causing more raw material to flow into vitamin D production. This boosts levels of an active vitamin D molecule that turns on a gene responsible for breaking down collagen in skin cells.
What the research says
1 studyUV light hits your skin and changes how it makes vitamin D and cholesterol. It slows down the cholesterol-making machine and speeds up the vitamin D-making machine, which causes a molecule to rise that breaks down collagen — the stuff that keeps skin firm.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.