hi there, welcome to the forum. your description (spasm) makes me think magnesium may be in order..
spinach and chard are excellent dietary sources of magnesium. more magnesium-rich healthy foods: http://www.whfoods.com/genpage.php?tnam ... oodsources
supplementing magnesium is tricky, you have to be specific with the form. magnesium citrate is okay, magnesium glycinate is really good for absorption.
you can also try taking an epsom salts bath. the salts are magnesium sulfate. they'll absorb into your bloodstream to a degree, through the skin.
if you can get bloodwork, ensure your serum level is 0.90 mmol/L minimum.
if you have any questions feel free to ask