My DH surely must have had this. Since going LC it has gotten much better but I can tell if he has eaten carbs because it pops up again. Strange how it's only when sleeping...When he was at his worse I could time it every 30 seconds.
I've read to take Magnesium with calcium which he does now.
Be sure that you are taking 2 mag which is the daily dose on the bottle, maybe yours too. My DH was only taking one when I pointed that out to him.