Toss a bit of good salt in the broth, while you're at it.

There is also, which may help even more, a salt that is half salt, half potassium. It's by the regular salt at the grocery store. I know they have it at SuperTarget and Cub. Instead of the dark blue canister, it's in a pale blue one.

When you don't get enough sodium, you can be low on potassium, too, and that can make for achy muscles.