Water, Potassium, Sodium, and Chloride in Nutrition

Water, potassium, sodium, and chloride play key roles in health. Each nutrient has a physiologic role, homeostatic balance, and relationship to disease when ingested in inappropriate amounts. Adequate intake of water helps maintain circulating volume and prevent impairments in cognition and exercise capacity due to dehydration. Potassium is needed to maintain electrochemical gradients across cellular membranes; adequate intake from dietary sources can reduce blood pressure, bone demineralization, and formation of kidney stones. Sodium and chloride also impact membrane potential as the principal extracellular ions. When taken in excess, sodium increases blood pressure and cardiovascular risk in salt-sensitive populations such as older persons and African Americans. Education and policy measures to promote appropriate intakes of water, potassium, and sodium can translate into population-wide health benefits.