I found this piece in Scientific American interesting.
This idea is intriguing, but the whole article is interesting:
>>The idea is similar to recent research showing that early exposure to small amounts of allergens can condition the immune system and prevent a hyperactive response later on. “You get this rebalancing,” Hart says. “UV light calms inflammation in the skin. But it also then calms inflammation in the central nervous system. It’ll calm inflammation in the pancreas and the gut. So I think it’s not fully realized the potential it has to be a controller of body homeostasis.”<<