What is sodium?
Sodium is a pure chemical element with the symbol Na on the periodic table. Sodium has the atomic number 11, meaning that each atom of calcium has 11 protons and 11 neutrons in its nucleus. Sodium is used by the body to regulate water and electrolyte balance. Sodium concentrations are crucial for proper muscle functioning and neural signal transmission.
What does sodium do?
Sodium’s single outer valence shell electron is easily lost in solution to form a single charge positive cation. Sodium is one of the major electrolytes of the body and is found as a component of table salt.
Sodium is crucial for regulating intracellular and extracellular fluid concentrations. Sodium helps to balance acidity and alkalinity in the body.
Sodium is pumped back and forth across the membranes of our cells to form an electrochemical gradient that sustains life and transmits neural impulses to and from different parts of the body. Proper sodium levels are required for correct muscle function.
Sodium is lost from the body in urine and sweat. On hot days, athletes who sweat profusely and do not replace sodium by ingesting more than just water run the risk of abnormal muscle function, or cramping. Sports drinks contain sodium and other electrolytes to counteract electrolyte loss from perspiration.
Excess sodium consumption is a health concern because an increase of sodium levels increases water retention, which raises blood pressure. Increased blood pressure, in turn, increases stresses on arterial walls, increasing one’s risk of developing arteriosclerosis.
Where does sodium come from?
Sodium can be found in salty foods like potato chips, soy sauce, and other processed foods. Only about 10% of our salt intake comes naturally from food. Most is added during food processing.
How much sodium do I need?
Although the body’s requirements for sodium is quite low, only a few hundred milligrams, the Food and Nutrition Board sets the AI for sodium for adults at 1,500 mg/day. Unfortunately, the typical American consumes as much as 3,000-6,000 mg/day.
1) Insel P, Turner RE, Ross D. Discovering Nutrition. 3rd ed. Jones and Bartlett, Sudbury Massachusetts. pp 411-412.