Cool, for me it is still weekly injections as my magnesium deficency was rediculous. They couldn't believe I was still functioning. They did a 'load test'. Its basically collecting urine for 24 hours prior to the magnesium IV, then collecting it in a seperate container for another 24 hours after the IV. Then can then determine how much magnesium the body kept and how much it discarded. If you have a healthy magnesium level then the amount retained will be below 20%. A difficency is anything above 20%.. Severe is 40% or more... Mine was 97%... even after 15 IV's of large amounts of magnesium, I am still at 57%... I am noticing a slight difference since starting the IV's but it has taken a long time, and I have a long ways to go to get that part of me in balance. I also get B complex in the IV.
Once I get to a 'normal' level, then I can try supplements and get checked a couple months later... I will probably require IV's in 10 week intervals a couple times per year.
Anyway, thats the scoop for me and my magnesium... I was tested for the defficency because of the Chronic Fatigue (common for those with CF), but later learned that it can help with AF too.