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A Little Sun Might Shield Against Skin Cancer
Posted: January 30, 2007
page 2 of 5Now, findings from a group led by immunologists at Stanford University may provide an answer. The study, led by professor of pathology Eugene Butcher, is expected to be published in the March issue of Nature Immunology.
In its study, the Stanford team worked with cells in the lab and discovered a biochemical chain of events that appears to link sunlight exposure to the skin's own immune defenses.
The researchers started from the notion that an inactive precursor of vitamin D, called vitamin D3, "is generated in the skin in response to sun exposure." That's been known for years. Specifically, a short-wavelength form of UV light, called UVB, is responsible for D3 generation.
D3 is inert and powerless, however. Through contact with various enzymes in the liver and kidneys, the body turns D3 into an active compound called 1,25(OH)2D3.
And that's where the immune-system connection kicks in, the Stanford authors said.