UV B LEDs More Effective in Producing Vitamin D3 in Human Skin (2017)
nature.com
nature.com
How am I gonna build short duration dosing unit for my shower without access to these parts.
For the purposes of getting this into the public domain...
I propose a small, waterproof, battery powered device that mounts to the shower wall which directs UVB radiation at 293 uM wavelength at the midsection of the user for a timed duration when activated by the presence of water
Activation is delayed once water is detected to ensure the user is actually in the shower. The time duration is limited to ensure nobody gets cooked like Ron Popeil rotisserie.
Everything is open source because everyone needs this
https://www.nationalgeographic.com/content/dam/photography/p... (might be a bit nsfwish for some people)
The PDF also says that D3 is produced from lights all the way up to 320 nm, so the 311 ones sold on Amazon would work. But given the 293 vs 305 effectiveness, how much exposure would you need to actually make a meaningful difference? Probably a lot!
(I have a condition that requires UVb. I wasted so much money, and skin burns, on Amazon's shitty medical grey-market... )
The book provides a high-level overview of the biological functions of the body and why we need certain components (essential amino acids, vitamins, minerals, etc.). Certain elements of it are dated (scientists didn't understand the purpose of cholesterol back then), but the general principles hold true.
If you're a tech-minded person who understands very little about biology, you may find the book illustrative. You can find a used copy on Amazon for relatively cheap.
Asimov's broad strokes in here are correct, even if specific details aren't. His presentation of biological principles is lucid to a degree few can match.
Note that while older scientific materials (ie research papers, not topical sources) often have huge gaps compared to current knowledge, they are still generally impressively accurate in what they do say. Good science really does operate as a refinement process for the most part.
Looks like other mammals definitely need Vitamin D and produce it in the skin.
I have a suspicion that a lot of these things have a biochemistry that goes back a hell of a long way, and I think there's synthesis of various vitamin D's in fungi. Nearest I can find is https://en.wikipedia.org/wiki/Ergosterol
"Ergosterol (ergosta-5,7,22-trien-3β-ol) is a sterol found in cell membranes of fungi and protozoa, serving many of the same functions that cholesterol serves in animal cells. Because many fungi and protozoa cannot survive without ergosterol, the enzymes that synthesize it have become important targets for drug discovery. In human nutrition, ergosterol is a provitamin form of vitamin D2; exposure to ultraviolet (UV) light causes a chemical reaction that produces vitamin D2"
So nothing to do with humans, and may go back to a common ancestor of fungi and protozoa.
Note the particular arrangement of the four carbon rings https://en.wikipedia.org/wiki/File:Ergosterol_structure.svg I believe that's a steroid. You see the same thing in https://en.wikipedia.org/wiki/File:Testosteron.svg and much to my surprise the same thing appears in digitalis (the foxglove plant) https://en.wikipedia.org/wiki/File:Digitoxin_structure.svg Which suggests these chemical families go back a very long way indeed and most likely are radiate rather than parallel (edit: I mean convergent) evolution.
Anyone who actually knows something about this, please correct or elaborate on anything.
> It has also been speculated that in some species, preen oil contains a precursor of vitamin D; this precursor is converted to vitamin D by the action of sunlight and then absorbed through the skin.
Why did we decide to leave warmer climates where sun was available ?
and then... yeah. I think the risks are pretty predictable but we might have forgotten.
Protocols typically start out with just 30-45 seconds, and increase from there to a max of 5-7 minutes in front of the lamps. A lot depends however on the type of skin you have, which you should figure out before starting any of this. Even though it's UVB and not UVA like at tanning salons, you can still burn yourself very badly.
Snark aside, that's obviously not practical advice at higher latitudes or during darker or rainier months.
You can find the same type of devices on eBay and Alibaba for even cheaper, but those are the same "quality".
https://www.amazon.com/Alaska-Northern-Lights-Sperti-Sunlamp...
It has a 5 minute timer and the instructions say to use it twice a week maximum, unless directed to do otherwise by a doctor. It has four flourescent tubes tuned to optimally emit UVB for vitamin D creation. It comes with safety goggles that have to be worn when using it. You have to stay 17" away from the lamp when it is on. Sperti says it is the only FDA approved vitamin D lamp in the USA. It's expensive but apparently the only one of its kind at the moment, until the UVB LED's take over the market.
https://duckduckgo.com/?q=soviet+uv+lamp&t=brave&iar=images&...
I know it can be a struggle, but there are a lot of activities you can combine with getting outside and collect health benefits from both.
I remember 2 years ago, it was so bad, that local newspapers were celebrating when we finally got our first glimpse of sun (for a couple of hours) for that year on some day in late January (like 24th or 25th). It literally took almost an entire month to see the sun for the first time that year.
I can believe it. Two years ago we had measurable rain every single day from December until May. I still managed to get outside and ride my bike nearly 4-5 days a week.
Maybe somebody could push a patch to turn down the average fall-winter-spring rainfall in my area?
I seem to remember reading that you don't get much UV light when the sun is below 40 degrees. You don't have to go far north for the sun to be kind of useless in winter.
An interesting side-note, there's a theory that Europeans are so white because the gulf-stream makes it warm enough for farming grains despite being quite far north.. and so you don't get much Vitamin D from the sun all of winter, and you don't get it from your food (like the Inuits do, from eating a lot of fish), so white skin is a "hack" to try to maxize vitamin D production, despite the obvious downsides.