Sodium (Elemental Na)

Direct Answer

Sodium is the principal extracellular cation (135–145 mEq/L extracellular), maintaining extracellular fluid volume, plasma osmolality, and driving secondary active transport. Adequate Intake (AI) is 1,500 mg/day, with a Chronic Disease Risk Reduction (CDRR) limit of 2,300 mg/day.

Source: NASEM / Dietary Guidelines for Americans (2020–2025) / WHO · Last reviewed Aug 28, 2026

Specs

Nutrient Type	Essential Macromineral / Major Extracellular Electrolyte
Adult Adequate Intake (AI)	1,500 mg / day (Equal to 3.8 g table salt NaCl)
Chronic Disease Limit (CDRR)	2,300 mg / day (Equal to 5.8 g table salt / 1 level teaspoon)
Chemical Forms	Sodium Chloride (NaCl, 39.3% Na by weight), Monosodium Glutamate (MSG, 12.3% Na), Sodium Bicarbonate (27.4% Na)
Primary Biological Function	Extracellular fluid osmolality maintenance, Blood pressure / volume homeostasis, Action potential depolarization (voltage-gated Na+ channels), SGLT1 glucose cotransport
Deficiency Condition	Hyponatremia (Serum Na+ < 135 mmol/L): Cerebral edema, Nausea, Muscle cramps, Seizures, Coma (often exercise-associated from over-hydration)
Top Whole Food Sources	Table Salt (NaCl), Cured Bacon, Soy Sauce, Parmigiano-Reggiano, Pickles, Olives, Bread (Processed food accounts for 70% of intake)
Renal Renin-Angiotensin System	Juxtaglomerular apparatus senses low tubular sodium/pressure, secreting renin to stimulate aldosterone and renal Na+ reabsorption