What could cause a recent increase in incredibly vivid and sometimes lucid dreams?

I've been having dreams recently that put movies to shame over the last week. Two or three dreams per night that I remember almost every detail of, can sometimes influence and have pulled people from my memories that I haven't seen in over a decade. Nothing much has changed in my life or diet except that I started taking GNC's Mega Men Sport dietary supplements (2 per day), but I can't see how that would affect my dreams. Any ideas?