What are the mechanisms for maintaining the internal potassium balance?
A typical Western diet ingests approximately 70 to 80 mEq of K + per day. Almost all the ingested potassium is absorbed by the intestine. Adjustments in the kidney potassium excretion to match potassium intake is the principal mechanism for maintaining potassium balance. Because the changes in the kidney excretion of potassium occur over several hours, the initial buffering of an increase in ECF potassium occurs by movement of potassium into skeletal muscle. With intact kidney function, only about 10% of dietary potassium is excreted in the feces.