I bumped into this. It's about how sunlight and different frequencies of light affect the body and those mechanics. It is interesting after about the first hour of the lecture.
It talks about how green spaces improve health physical and mental. NIR light and Diabetes II, cardio improvement, premature birth, lower blood pressure, heart rate and stress.
He doesn't advocate nudity, he mentions that good stuff penetrates clothing, like a shirt anyway, but less so more clothing.
There's stuff on SAD and the need for full spectrum light. He's an MD, but I don't know much about what he does with that, or sponsorship.
Anyway, sunlight good, covering bad to not so bad, skin likes it. Mid-day more Vit D, morning and evening are good too. So my take away is sunlight is good all day.
https://www.youtube.com/watch?v=5YV_iKnzDRgJbee