General Fitness & Nutrition: leg cramps

Tried to respond to previous question about leg cramps but somehow...can't figure out how to respond directly so hopefully the individual will get this response.  As a Nurse Practitioner I have many patients who complain of leg (and muscle) cramps.  One product that seems to work well is Magnesium Oxide 400 mg.  There is a product called "SloMag" that can be used or for less $$, the generic,  Magnesium Oxide 400 mg is effective.  The problem with generics is that one never can be sure of the bioavailability or the production process etc. (generics are not FDA regulated -hence the cost is less but one has to realize the possibility of unknown fillers etc.)-all of that being said, I have  used a generic with good results (yes I also have a problem with bothersome cramps that would often wake me-and my husband up in the middle of the night....).

I do not use the MagOx daily but do use it after a long mileage session or when I have "pounded" a trail or concrete....etc.