I'm vitamin D deprived, blood work says so. Not surprising because I am a recluse and can get away with it now. Doc said get some, so I did. It was like taking LSD or something akin to it. The dreams were horrible. Living color nightmares. He never mentioned such a thing. Over the course of time I stopped taking it and then it was suggested, through a conversation, I take it in the morning and not at night. That has helped, but the dreams are still more pronounced, but easier to handle. I'm doing a smaller dose too.
In hind sight, I wonder. If part of my diet and my habit of not liking to go outside is part of a "the body is telling me". I hope that makes sense. There are some real pros and cons to that statement, I think, and vitamin D, perhaps others.
I've never been able to do it, but my Father had PTSD from the war (WW2, B-17 gunner) and he had a habit of sleeping with one foot out from under the covers and I know why he did it. Heat brings it on. Point is, you don't have to have been in combat to have PTSD.
Sleep sometimes is my enemy and sometimes the only thing that saves me. One little trick I learned in the Army is the cat nap and it will get you through a lot for a little while. Naps are your friend and it sometimes is just that moment you catch before real sleep and the wake that can get you through more. I hope that makes sense too.