Well unfortunately (almost) all magnesium supplements here has vitamin b6 for better absorpion. I took 6mb vitamin b6 (300%) magnesium supplement almost daily for a long time.
I had been interested about that overdose and from what I know ~12mb for a longer time might be toxic.
I'm said to take magnesium and potassium (I'm drinking tomato) by a doctor btw. Maybe I should also try to take more magnesium naturally instead of supplement..
It takes hundreds of milligrams per day to poison yourself.
http://www.nap.edu/o...d=6015&page=184
I believe symptoms have been noted at lower doses in some individuals. Biochemical individuality.