Exactly. And also the fact that taking it as supplement (tablet form) may result in it entering the bloodstream from the stomach, when the natural route of absorption of potassium from food is through the intestines where there may be a control mechanism for how much is uptaken.
It is my opinion that the differences in skin color and other physiological differences are caused by differences in mineral ratios in various regions, and that migration is the basis for evolutionary changes over tens of thousands of years. InfiniteLove also raised this point in her post earlier in the forum.
In the shorter span of our own lifetimes, I think that our own health issues may in some part result from being in (or moving to) a region where the mineral ratios do not match those that our own metabolism is designed for.