- Potassium activates many enzymatic reactions and is essential to a number of physiologic processes, including transmission of nerve impulses, muscle contraction, gastric secretions, renal function, tissue synthesis, and carbohydrate metabolism. Potassium is the major cation of intracellular fluid and is essential for maintenance of acid-alkaline balance, isotonicity, and electrodynamic characteristics of the cell. In addition, it works with sodium to maintain healthy water balance, heart rhythm, and nerve and muscle function. Research suggests that adequate potassium intake may support healthy blood flow and cardiovascular health