Saturday, September 6, 2008

Vitamin D you can get for free

Recently someone told me you can't get your vitamin D from sunlight if the sun is coming through glass. I looked this up online, and according to this site only about 5% of the Vitamin-D-forming UV-B form of ultraviolet light makes it through a pane of glass.

UV-B is also filtered out by the angled sun slanting through more of the atmosphere, so that it's really only possible to make much vitamin D through sun exposure if you go out in the direct sun between 10 am and 2 pm. (The source didn't say if this was standard or daylight time!) You should also expose as much of your skin as you can on this walk, to give more of your skin a chance to do the job. If you expose 85% of your skin, basically, go out in a bathing suit, you can pick up about 4000 international units, which is good. The darker your skin, the more sun time you need. And the oilier your skin, the more D you make and absorb (so all this bathing probably really does weaken us).

So, the dogs are right when they nag me to go for a walk in the middle of the day. We should all be out taking the sun - like "Englishmen" - around lunchtime. Then, you can eat some D-bearing foods for lunch, like egg yolks, shellfish, oily fish, organ meats, menudo and insects (so, don't throw away the worm!).

Not getting enough Vitamin D can cause lots of problems, and is suspected as the reason that MS (multiple sclerosis) is so much more prevalent in northern latitudes than farther south.

See ya in the park! Wreck beach, anybody?

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