7-dehydrocholesterol is transformed into Vitamin D3 in the skin when it is irradiated by UVB light. People who don't get enough sunlight are at risk of suffering from a Vitamin D deficiency. This special anti-sunblock for those endowed with strong pigmentation contains 7-dehydrocholesterol, and it is to be applied during the winter months at the higher latitudes when UV rays are in short supply.
-- Cuit_au_Four, Jul 10 2012

Sounds like it'd work [+].
-- nineteenthly, Jul 10 2012


Seems like a Tom Sawyer approach to buttering vitamin D on the skin, where it will not be absorbed because skin is picky, and where sun will not hit it because it is under a coat, because it is snowing.

But it might be a good marketing pitch to sell some lotion so I will restrain my bone.
-- bungston, Jul 10 2012


I'm calling no idea here, because black people burn and tan just like us lily-white honkies, only maybe not as easily. I don't know about that last part, as I'm very, very Nordically white (I'm not Caucasian).

In the winter, it's actually easier to burn on exposed skin, because UV rays are reflected from the snow almost effectively as if the ground were mirrored. The occasional black people I meet up at the ski mountain often complain that their cheeks are burned. So, no, unless you're black or have access to a pool of live black test subjects, I'm not buying it. Sorry.
-- Alterother, Jul 10 2012


Some bituminous substances increase photosensitivity, thus acting as reverse sunscreen (creosote is notorious for this). They may or may not increase the production of osteoporosis-preventing vitamin D.

But it might be a good marketing notion to sell some pitch so that I will retain my bone.
-- spidermother, Jul 10 2012


At high latitudes in winter, *everybody* is short on UV exposure.

And considering the chemical root of 7-dehydrocholesterol, I think it would be only natural to give this product the scent (and flavor) of bacon.
-- lurch, Jul 10 2012



random, halfbakery