I have a similar issue. I have had 4 back surgeries and after my last two the cramps were intolerable. I had all of my chemicals checked and they were normal. Exercising seems to bring them on more severely.
After trying quinine water and other things my doctor suggested Magnesium tablets. I take them now every night and they have helped.
From what I understand , magnesium regulates the calcium you intake. If you are taking calcium supplements or eat or drink anything that contains calcium you could get cramps. Keep an eye on your calcium intake and take magnesium tablets. See if that helps. The strength I take is 250 mg.View Thread