There are specific medical conditions that respond well to uv exposure (perhaps through mechanisms like apoptosis and changes to the immune system) that don't b

There are specific medical conditions that respond well to uv exposure (perhaps through mechanisms like apoptosis and changes to the immune system) that don't benefit much from vitamin D supplementation. I would be wary about assuming those benefits can be generalized or outweigh the known risks of uv exposure. People who spend more time outdoors likely have more physically active lives, are less exposed to VOCs and infections and there could be many demographic differences that are hard to control.