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The magnesium supplementation isn't a problem but potassium supplementation CAN be unwise if on and ARB...
To be honest I can run a potassium defeciency even with Cozaar (and a low dose thiazide). Last hospital visit they gave me 40 meq. potassium on each of two days in spite of the ARB use.
It takes a LOT of potassium to OD and I personally think it's almost impossible to do with food alone...as for magnesium. I've NEVER seen any reference to problems with supplementation.
Just for grins, compute the amount of magnesium in a couple tablespoons of Epsom salts (MgSo4 heptahydrate)... all an O.D. like that causes is a "laxative" effect. Something like 250 mg has just got to always be safe.
And think of all the Mg consumed in Maalox (MgOH)...nobody ever found dead with a white ring around his mouth


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