Blood test show 2.1mg/l magnesium. was wakeup at night with palpitations&choking,&also high bp,leg arm cramps. now i feel gd on mag supplement. does this mean that i have mag inadequacy?or could the mag supplement mask the symptoms of other problems?

Magnesium of 2.1 is normal, less likely the cause of your symptoms. However, if your kidney function is normal, taking Mg supplement will not mask the symptoms because your kidneys will excrete the extra amount of magnesium in your body. Then if symptoms recur even with Mg supplement, you know Mg is not the culprit. However, Mg supplement is not recommended in advanced chronic kidney disease.

Need normal values for your lab. One possibility is that with HB, leg cramps, palpations and awakening at night (maybe to pee?) you have Primary Aldosteronism. Esp if you K has ever been low. Go to hyperaldosteronism@groups.io to learn more.