Phyl,
I've forgotten where I read that sardines is very good, coz of the oil and the soft bones, those canned type can retain the good oil and calcium coz of the preparation for the canning is very stringent . Calcium is very important, not tat there's evidence it affects cramps anot. U need xtra calcium for the bb growth.
Agree with LuthAdel, Do some stretching exercise on ur legs , calf can help. I usually will stretch my legs and rotate my feet b4 I go to sleep.