Therefore this amount has to be added to the 2 grams above to get the minimum daily requirement. Potassium is primarily absorbed in the large intestine. The intestines thus assist the kidneys in preventing surges of potassium in the blood serum. It follows that your potassium requirements are higher in the summer than in the winter. The one nutrient which most affects the potassium excretion is sodium.
Sodium is one of the most serious limiting minerals in nature for mammals.
In the moist tropics where the distant ancestors of man probably evolved, I suspect that it is possible that almost all the sodium is present in the blood streams of vertebrates in some places, because the iron and aluminum hydroxides of tropical soils do not bind it very well, and plants do not concentrate it. Such ripples from the past must seem bizarre and dreamlike to you who read this and are wrestling with the opposite problem. Huge front end loaders, enormous pumps, and excellent transportation have made salt so cheap that it is used in snow melting salt, water softeners, pickling fluids, and is sprinkled liberally on almost every processed food sold. It would seem that a very low or a very high sodium intake would increase the potassium requirement from the 2.2 plus or so minimum established so far. Please keep in mind that this is a bare minimum and makes no allowance for disease, perspiration, emotional storms, mild genetic defects, poisons, and odd intakes of other nutrients.