While vitamin D can help with sleep overall, I've read that vitamin D can temporarily interfere with melatonin production immediately after ingesting. So you sh

While vitamin D can help with sleep overall, I've read that vitamin D can temporarily interfere with melatonin production immediately after ingesting. So you shouldn't take it at night, too close to bedtime. Of course, I've also read many people take it at night with no negative effects – and that, as a hormone, it absorbs more efficiently overnight in a sleeping state. So, this is probably one of things that affects people differently, but it's just something to be cognizant of. If you take it a night and feel restless, try switching to the morning. I also have a close friend who gets severely constipated with most vitamin D. It took her a lot of trial and error to find a brand that did not constipate her, which I cannot remember right now.