Low blood sugar will do it also... cause various muscle sensations and twitching. (I get this), and I read in one book a while ago that up to 70% of people with low blood sugar experience twitching.

I'd consider acetyl carnitine for you, and CoQ-10. Muscle issues may reflect a mito problem and these two nutrients support the mitochondria. Some researchers now think many more people have mild mito disease and are never diagnosed properly.

Start at 500mg a day of the carnitine and work up to 2 grams a day if necessary. Take in divided doses as carnitine is not absorbed well, and take on an empty stomach too. The CoQ-10 --start at 100mg a day of a quality type that states it has absorption enhancement. (like Q-sorb or Bioperine). However, the Bioperine additive may interact with any drugs you use, so unless you don't take prescription drugs, it should be avoided.
This website has a very good CoQ-10... and information that explains why enhancement is so important:
epic4health.com
But there are other types with Q-sorb around as well.

I get alot of muscle pain when I excercise and find carnitine extremely useful.