Sodium is the chief cation found in extracellular fluid and plays important roles in blood pressure, acid-base balance, and cell permeability. The recommended daily intake is 5-10g, though hypertensive patients should aim for 1g. Sources include salt, foods, and some vegetables. Sodium is readily absorbed in the gut and excreted primarily in urine. Normal plasma levels are 135-145 mEq/L. Imbalances can cause hyponatremia or hypernatremia. Potassium is found intracellularly and is important for nerve impulse transmission and protein synthesis. Sources include bananas and potatoes. It is highly absorbed and excreted in urine. Normal plasma levels are 3.4-5