As always, Naxis is right on target! Yeah, those toe cramps are nasty -- especially when one of 'em gets "stuck". I always tend to run low on potassium so bananas are a staple as are potassium supplements. All the supplements I've looked at only supply 3% of the RDA, but use care when taking them. Electrolyte balance is a delicate thing as it can have drastic effects on your heart (when running low). I suppose that is why the supplements only have 3% RDA. I only take enough to keep cramping in check.
Good luck to ya and enjoy your Pilates!