I have had a great improvement from a magnesium supplement with potassium and calcium. As the cramps are usually during the night I take the tablets when I retire for the evening. I ran out of them some time ago and just kept forgetting to order them in from my health shop and it wasn't very long before the cramping started again. I even feel it helps with the rigidity I get in my legs. I do suggest you seek the advice of a nutritionist or a naturapath because some forms are better than others and also it shouldn't be taken after certain foods. I think it was some-thing to do with stopping a certain food from absorbtion. Regards Mary from Oz.