I was also tested for Vitamin D deficiency and my doctor prescribed 50,000 ICU a week, followed by a much smaller amount per day afterwards. I noticed an improv

I was also tested for Vitamin D deficiency and my doctor prescribed 50,000 ICU a week, followed by a much smaller amount per day afterwards. I noticed an improvement in my well-being as well (could have been psychological). My armchair hypothesis is that modern humans tend to be indoor creatures, yet our bodies evolved as if we were outdoor creatures, therefore we're supposed to be getting more sunlight and Vitamin D than we actually are.