I’ve wondered whether vitamin D is a real time signal within the circadian rhythm regulation system. Perhaps it is released in response to sunlight in order to let other parts of the system know it is daytime.

If it were like this, bulk dosing would be expected to be better than nothing (“maximum daytime!!!! Followed immediately by a very long slow sunset at whatever curve it is cleaned up in the body), but it would be better to dose continuously in real time at a level and body location(s) that would simulate the range of sunlight throughout the day.

Can anyone professionally familiar with the research in this area comment?