I read quite a few comment of people people taking vitamin D in the morning because of my comment, so I bothered to look up some sources.

https://www.healthline.com/nutrition/best-time-to-take-vitam... (a few good sources are in that link)

https://www.lesswrong.com/posts/c5aycbSsSc38XWPEc/taking-vit... (this reports that the morning evidence is only anecdotal)