For about two months, I have been following the supplement protocol recommended on this site. Besides AFib, I exhibited other symptoms of magnesium deficiency such as leg cramps at night, eye twitching, and constipation. As part of that protocol, I have been taking quite a bit of magnesium--probably close to, if not above, the recommended 800 mg per day. A blood test I took last month showed my magnesium level had maxed out at 2.3 mg/dL (the upper reference limit listed on the report; I assume that any excess would be excreted by the body). I realize that there may be quite a lag before the magnesium works its way into the tissues; someone on this forum mentioned 20 weeks to see an effect. However, I was quite surprised to wake up this morning with severe cramping in my calves. (My AFib episodes have not magically stopped happening yet either.) How is it that someone can be taking so much magnesium and still experience cramping? Could there be something else going on?

Maybe peripheral vascular disease, maybe any of the other electrolytes is deficient....hard to know without expert analysis of blood, urine, stool, and maybe an MRI.