Sodium is a macro (major) mineral.
Salt (sodium chloride) is essential for life. The tight regulation of the body's sodium and chloride concentrations is so important that multiple mechanisms work in concert to control them. Although scientists agree that a minimal amount of salt is required for survival, the health implications of excess salt intake represent an area of considerable controversy among scientists, clinicians, and public health experts.
Sodium is absorbed in the small intestine where it is carried via the bloodstream to the kidney. The kidneys then filter out the necessary sodium the body needs to maintain blood sodium levels and then releases this amount into the bloodstream. The excess is then excreted in the urine.
Why is Sodium important?
Sodium is essential for maintaining blood pH and proper water balance. With potassium, sodium helps regulate the distribution of fluids on either side of the cell walls. Sodium and potassium are also intricately involved in muscle contraction and expansion as well as nerve stimulation.
Sodium (and chloride) deficiency does not generally result from inadequate dietary intake, even in those on very low-salt diets.
How much Sodium is enough?
Adequate intake (AI) for sodium and sodium chloride (salt)
Intake:
Adequate Intake (AI) for Sodium |
Life Stage, Age |
Males and Females
Sodium (g/day) |
Males and Females
Salt (g/day) |
Babies 0-6 months |
0.12 g/day |
0.30 g/day |
Babies 7-12 months |
0.37 g/day |
0.93 g/day |
Children 1 to 3 years |
1.0 g/day |
2.5 g/day |
Children 4 to 8 years |
1.2 g/day |
3.0 g/day |
Children 9 to 13 years |
1.5 g/day |
3.8 g/day |
Teenagers 14 to 18 |
1.5 g/day |
3.8 g/day |
Adults |
1.5 g/day |
3.8 g/day |
Adults 51 years and older |
1.2 g/day |
3.0 g/day |
Pregnant women |
1.5 g/day |
3.8 g/day |
Breastfeeding |
1.5 g/day |
3.8 g/day |
Function:
Sodium (Na+) and chloride (Cl-) are the principal ions in the fluid outside of cells (extracellular fluid), which includes blood plasma.
Sodium and chloride are electrolytes that contribute to the maintenance of concentration and charge differences across cell membranes. Potassium is the principal positively charged ion (cation) inside of cells, while sodium is the principal cation in extracellular fluid. Potassium concentrations are about 30 times higher inside than outside cells, while sodium concentrations are more than 10 times lower inside than outside cells. The concentration differences between potassium and sodium across cell membranes create an electrochemical gradient known as the membrane potential.
Sodium also acts with chlorine to improve blood and lymph health and aids in eliminating carbon dioxide from the body.
Sources:
Most of the sodium and chloride in the diet comes from salt. It has been estimated that 75% of the salt intake in the U.S. is derived from salt added during food processing or manufacturing, rather than from salt added at the table or during cooking. The lowest salt intakes are associated with diets that emphasize unprocessed foods, especially fruits, vegetables, and legumes.