On Sat, 29 Jan 2005 14:33:04 -0500, "scott gallant"
<[log in to unmask]> said:
> Is it the same rays though that have vitamin D that are also blocked
> from other rays? I don't know that you couldn't get a tan, because
> people get sun burn sitting in their cars for too long with the
> windows up. Can you tell me where you read about this? Either way, I
> was just sharing the point that we get natural vitamin D from the
> sun that doesn't cost us a single penny. That's why people who are
> Muslem don't make their baby girls wear head coverings until they're
> a ceratin age because the mothers know the sun is their vitamin D
> sourse. I'm not Muslem myself, but i've studied diiferent cultures
> and that is one thing I learned about theirs. I just thought the
> information would be helpful. Sue
"Exposure of the skin to sunlight that has passed through plexiglas
(Dupont Chemical Company, Memphis, TN, USA), most other plastics, or
window pane glass (e.g., in buildings, motorized vehicles, covered
strollers or prams, etc.) does not allow the endogenous production of
vitamin D because these materials efficiently absorb ultraviolet B
radiation (Holick 1994). Without UVB radiation, the skin cannot initiate
the body's process of making vitamin D."
-- Holick, M. F. McCollum Award Lecture: Vitamin D: New horizons for the
21st century. Am J Clin Nutr 60: 619-30, 1994.
Best wishes,
Alex.
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