Just a random source here because I'm too lazy:
https://www.balancedwellbeinghealthcare.com/are-you-taking-v...
> Because vitamin D is so good at improving calcium levels, by taking it alone you could be working to increase the calcification of your arteries instead of strengthening your bones so make sure to include K2 in your vitamin D supplement regimen!
Vitamin K2 is what essentially takes calcium out of your blood and puts it in your bones (and teeth). It's something that's rather lacking in western diets and could be a big reason why people in western countries suffer so many bones injuries in old age (and why our teeth suck).
https://www.amazon.com/Sports-Research-Plant-Based-Verified-...
But if you can be in the sun your skin can make vitamin D.
My doctor told me to get 15 minutes a day from May through the end of August - and these should be walks with at least the arms exposed (Am in Norway, so this isn't always possible for me, the immigrant). Walking alone isn't always enough.
I'd go to sleep under them, just dont have them too close to you though otherwise you will burn but never tan.
https://www.reptilecentre.com/collections/t5-uvb-fluorescent...
I'd also read this website entirely, its got loads of useful info. http://www.uvguide.co.uk/lightingsurveyintro.htm
There is a corrugated plastic sheet (2mx1m) which allows UV-B through, but it needs replacing every few years as it breaks down and its expensive!
Needs to be balanced with calcium. I wouldn't recommend supplements until you have blood work done.
You should take vitamin K2 with D3 though.
>But if you can be in the sun your skin can make vitamin D.
This is harder than people say. You need UVB light to hit your uncovered skin (glass blocks it entirely). The sun needs to be above 35-50 degrees in the sky. If it's below that (like in winter or evenings) then you won't get vitamin D from it.