Earlier quoted context omitted.
Note that windows typically block the majority of the radiation that allows you to make vitamin D, so even if the sun hits you every day through your window, it's still not a good substitute for a sunny walk every once in a while. My doctor told me to go out at noon every day, but anything is better than nothing.
Walking doesn't help me for 8 months of the year: There simply isn't strong enough sun to help. December days are only 4-5 hours long anyway. So, I was told to take a supplement from September to May. 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…
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