Posted on 03/05/2010 9:35:58 AM PST by decimon
Young punks ping.
Soft Canadians ping.
I remember reading that a deficiency of vitamin E results in vitamin D oxidizing, thereby resulting in a deficiency of vitamin D.
Vitamin D ping!
Heh Heh, not this time.
study subjects all healthy young women living in California
Really, kids, and adults for that matter, should be spending much more time outside in the spring and fall.
I'd think it would be great if April and October were spring and fall breaks for school kids -- at least in the more southern states.
D-R-I-N-K-Y-O-U-R-O-V-A-L-T-I-N-E
I hate to get shown up for not reading the article!
Soft Californians ping!
Vitamin D. From the Sun. But the cancer scares have instructed young America to limit Sun exposure.
Been around that block a few times. I think the bottom line is that, in the US, it is difficult-to-impossible to get enough vitamin D producing sunlight north of south Florida.
Too much time in front of the XBox, Internet, and boob tube.
The internetz is/are the boob tube now.
“...just 20 minutes in the summer sun is enough to deplete all the cholesterol in the skin necessary for the production of D.”
I don’t understand that statement.
Depends on your ancestry. If a population is in a given area for more than about 500 years, the general skin tone of that population adjusts to maximize vit D production while minimizing skin damage, for the available sunlight in that area. There’s actually a mathematical formula somewhere for skin tone and average yearly sunlight. The exception is Inuit populations, who have historically gotten most of their vit D from fatty fish.
So, those of us whose ancestors came from northern latitudes are better adapted for living in the northern states. Provided we actually get out in the sun once in a while :p
This may have been a contributing factor for why black slavery wasn’t as predominant in the northernmost areas of North America or Europe. While I was doing research on this, I came across reports of African slaves imported to England, getting sick and dying rather quickly. The reports are centuries old so its hard to be sure, but I’m hypothesizing here that they suffered severe vitamin D deficiencies, which made them quite vulnerable to a number of things. Combine that with diseases they’d never encountered, they probably didn’t stand much of a chance.
All theory, of course. My time machine’s in the shop :p
"Sun exposure Most people meet their vitamin D needs through exposure to sunlight [5,31]. Ultraviolet (UV) B radiation with a wavelength of 290-315 nanometers penetrates uncovered skin and converts cutaneous 7-dehydrocholesterol to previtamin D3, which in turn becomes vitamin D3 [9,32,33]. Season, geographic latitude, time of day, cloud cover, smog, skin melanin content, and sunscreen are among the factors that affect UV radiation exposure and vitamin D synthesis [33]. The UV energy above 42 degrees north latitude (a line approximately between the northern border of California and Boston) is insufficient for cutaneous vitamin D synthesis from November through February [5]; in far northern latitudes, this reduced intensity lasts for up to 6 months. In the United States, latitudes below 34 degrees north (a line between Los Angeles and Columbia, South Carolina) allow for cutaneous production of vitamin D throughout the year [27]."
http://ods.od.nih.gov/factsheets/vitamind.asp
“Cholesterol is what the skin uses to make vitamin D.”
I’m aware of that (zoology major, chemistry minor, postgraduate research in molecular biology and genetics). What I don’t understand is his statement that “20 minutes in the summer sun is enough to deplete all the cholesterol in the skin necessary for the production of D”, and then he goes on to encourage more sun exposure. That’s contradictory.
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