Sodium is the primary cation (positive ion) in extracellular fluids in humans. Sodium is necessary for regulating the water content of blood and other bodily fluids and is transported across cell membranes to regulate the transmission of nerve impulses and heart activity. Salt (sodium chloride) is the primary form of sodium in the diet. Other forms of sodium found in food include monosodium glutamate, sodium benzoate, sodium nitrite, sodium bicarbonate and sodium citrate. The amount of dietary sodium that is absorbed through the intestine is approximately 98%.
The U.S. Food and Drug Administration (FDA) has established a Daily Reference Value (DRV) of 2,400 mg sodium for adults and children 4 or more years of age (21CFR101.9). DRVs are a set of dietary references for energy-producing nutrients, cholesterol, sodium and potassium that are considered amounts sufficient to meet the daily requirements of healthy individuals. DRVs serve as the basis for calculating the percent daily value (%DV) amounts found on dietary supplement and food labels.
It is well-recognized that the current intake of sodium for most individuals in the United States exceeds recommended doses. The most common adverse effect seen with high sodium intake is an increase in blood pressure 1.