The Sodium content of drinking water is generally of little concern to consumers except those on sodium restricted diets. The amount of sodium in drinking water is insignificant compared to the sodium normally consumed in the average diet. When it is necessary to know the precise amount of sodium present in a water supply due to dietary constraints, a laboratory analysis should be made. The usual low sodium diets allow for 20 mg/l sodium in the drinking water. When this limit is exceeded, persons on low sodium diets should seek a physician's advice on diet and sodium intake.

When water is softened by the ion exchange method, the amount of sodium is increased when sodium chloride is the regenerant. For this reason, water that has been softened should be analyzed for sodium if a precise record of an individual's sodium intake is recommended. High sodium levels can be reduced with reverse osmosis or electrodialysis units.