--that is 400mg, but I know that all of that is not elemental, and that I only absorb a fraction of that. Nevertheless, it does seem to make a difference as to how often and severely I cramp (which I still tend to do during certain types of isometric stretches recommended for my hip and spine).

I also notice that if I go heavy on the beans (I love black, pinto, white, navy) this is improved as well (although there are the usual, musical side effects).