I love calcium citrate from Doublewood. Have been taking it for years for other issues. This may sound weird but if you find no reason for cramps, try taking a slug of pickle juice , apple cider vinegar or mustard when you get the cramps.. I swear by it only once it didn't work. I also use it for leg cramps.I have PsA and my hands cramp from holding a book while I read or struggle to open jars. Old age . It's beautifal isn't it?