The reason water helps with RL is because the nerves are controlled by HYDRO electricity.
Magnesium (MG)is a chemical gate blocker- it relaxes the nerves. Usually people get way too much calcium and not enough MG, especially if you eat milk products which are 8 times the calcium to magnesium. To much dairy and added calcium tabs in the diet will contribute to even more MG deficiceny.
Cacium deficicncy will cause cramps in one side of the body/leg, MG deficieicny will cause cramps in the other side. Too much calcium in ratio to MG will pull magnesium out of the body parts in order to assimilate the calcium. I would take Magnesium Malate or magnesium citrate ...and also rub Magnesium oil on your skin into the legs. You can find Magnesium oil (magnesium chloride) online.
Other nerve helpers are vitamin liquid b complex (under the tounge), vit b6, and vit b12,manganese, and potassium...which is an electroyte which conducts electricity. I would consider eating a banana or romaine salads before I drank pedialyte. But that's just me.
Iron supplementation can deplete MG so if you have been given Iron like Slowfe, which is popular for pregnant women,you should be taking MG as well.
Of course you should use this info for your own research, and consult your doctor.
http://www.zhealthinfo.com/calm.htm
http://www.thewayup.com/newsletters/081501.htm