Sodium

Your intake

What each level of sodium does

Approximate dose-response bands. Individual response varies — these are starting points, not prescriptions.

1. Severely lowYOU ARE HERE

   0 mg – 759 mg

   Well below target. Risk of deficiency symptoms tied to electrolyte.

2. Insufficient

   759 mg – 2300 mg

   Below the recommended daily target. Long-term adequacy not assured.

3. Adequate

   2300 mg – 3450 mg

   Daily target met. Standard nutritional support for electrolyte.

4. Over upper limit

   2300 mg – +

   Above the tolerable upper limit. Risk of adverse effects — back off or consult a clinician.

Overview

Principal extracellular cation. Required for fluid balance, nerve conduction, and nutrient transport — but median US intake (~3,400 mg/day) is roughly 50% above the upper bound for most adults (2,300 mg). The intake-to-target ratio is the opposite of potassium's: too much, not too little.

Functions

• ●Maintains extracellular fluid volume and blood pressure
• ●Generates action potentials (nerve impulses)
• ●Drives co-transport of glucose, amino acids in gut and kidney
• ●Maintains pH balance with bicarbonate buffer

Mechanism

Na+ enters cells via voltage-gated channels and is pumped out by Na/K ATPase. The resulting gradient powers nutrient co-transport, action potentials, and renal water reabsorption. Chronic high intake expands plasma volume and stiffens arteries (especially in salt-sensitive individuals — ~50% of hypertensives), driving blood pressure independent of weight or activity.

Benefits

• ●Essential for life — true deficiency is rapidly fatal
• ●Required for endurance exercise in heat (sweat losses)
• ●Treatment for orthostatic hypotension (Addison's, POTS)
• ●Iodised salt programs prevented widespread iodine deficiency

Deficiency

Frank hyponatremia is acutely dangerous but rarely caused by inadequate intake — most cases are dilutional (SIADH, excess water intake, MDMA, marathon overhydration).

Excess

Chronic high intake elevates blood pressure in roughly half of hypertensives and ~25% of normotensives. The cardiovascular cost is the dominant public-health concern.

Forms

• Sodium chloride (table salt)
  The dominant dietary form
• Sodium bicarbonate
  Antacid, baking soda, ergogenic aid (1–3 g/kg before exercise)
• Sodium citrate
  Less acidic; some sports drinks; clinical use in metabolic acidosis
• Disodium phosphate / glutamate
  Food additives that contribute meaningful sodium

Food sources

• Restaurant entrees (most) · 1 serving1,000–2,500 mg
• Bread (most commercial) · 1 slice150 mg
• Soy sauce · 1 tbsp900 mg
• Canned soup · 1 cup700 mg
• Cottage cheese · 1/2 cup400 mg
• Salted nuts · 1 oz100–200 mg

Supplement forms

Most readers should be reducing sodium, not supplementing it. Read labels — 'low sodium' = ≤140 mg/serving, 'reduced sodium' = at least 25% less than the original. Total sodium targets matter more than salt-shaker behavior; ~75% of dietary sodium comes from packaged and restaurant food.

Bioavailability

Near-100% absorption; renal regulation handles excretion. Sweat losses can reach 1–2 g sodium per hour in heat-acclimatised endurance athletes — the only routine context where supplementation matters.

Longevity relevance

U-shaped relationship: extreme restriction (<1,500 mg) and excess (>5,000 mg) both associate with higher mortality in some cohorts. For most adults, moving toward 2,300 mg/day (or 1,500 mg/day for hypertensives, older adults, African Americans) lowers blood pressure and stroke risk — among the highest-leverage dietary changes available.

Relationships

References

• NIH ODS — Sodiumguideline
• Linus Pauling Institute — Sodiumreview
• PURE — sodium intake and CV events (NEJM 2014)study
• He — sodium reduction meta-analysis (BMJ 2013)review

About Sodium

Extracellular fluid balance, nerve impulse conduction.

Role

Electrolyte

Daily target

2300 mg (DV)

Upper limit

2300 mg

Also called

sodium, sodium chloride, salt