Vitamin B12 cured my insomnia but I don't remember having extra vivid or disturbing dreams. Well, I take that back. I did start to remember my dreams... which I hadn't in many years. I thought I just didn't dream. While some dreams are entertaining, I guess I actually prefer NOT to remember my dreams.

I suspect I was B6 deficient as well, and I did start supplementing with a B-complex at the same time I started correcting my B12 deficiency.

I know that vitamin B6 deficiency is associated with lack of dream recall, and some suggest increasing your B6 intake until you can remember your dreams.

My daughter's experience seemed to be somewhat opposite. She actually had sleep disturbances, sleep walking (and sleep punching walls.. that might qualify as disturbing.. it was disturbing for ME) when she was B6 deficient... and that all calmed down when we fixed her B6 deficiency.

So.... it seems to me that B vitamins can affect sleep and dreaming... but it seems somewhat variable depending upon the individual.

I have heard not to take B's close to bedtime... because they can keep you from falling asleep. And, I'd recommend doing a B-complex along with mega dose B12, because they need each other in somewhat balanced amounts. I think a B-50ish dose is adequate for B-complex no matter how high you go with B12.