🧬 Family & Essentiality

🌿 Plain-Language Summary

Sodium is best known as part of table salt (NaCl). It balances body fluids, enables nerve signals, and supports muscle contractions. Australians typically consume well above recommended levels, mostly from processed foods — raising blood pressure and long-term disease risk.

⚗️ Molecular & Chemical IDs

• Element: Na (Sodium)
• Atomic number: 11
• Common dietary form: Sodium chloride (table salt)
• Other forms: Sodium bicarbonate, sodium phosphate (additives/medications)

⚡ Functions

• Maintains extracellular fluid volume and osmolarity
• Nerve impulse transmission and muscle contraction
• Helps regulate acid–base balance

🍽️ Absorption & Bioavailability

🥗 Food Sources

• Processed meats, breads, sauces, snack foods
• Restaurant and fast foods
• Added table salt, stock cubes, seasonings
• Fresh fruits/vegetables are naturally low in sodium

🇦🇺 Australian NRVs (NHMRC)

• AI (Adults): 460–920 mg/day sodium (~1.2–2.3 g salt)
• SDT: ≤2000 mg/day sodium (~5 g salt) to reduce chronic disease risk
• Population intakes average ~3500 mg/day — above safe limits

🚨 Deficiency & Excess

Deficiency / Hyponatraemia

Usually due to fluid imbalance, illness, or medications — not diet alone. Symptoms: headache, nausea, confusion, seizures, coma (severe).

Excess Intake

Common in Australia. Raises blood pressure, increases fluid retention, and heightens risk of stroke, kidney disease, and heart disease.

🧪 Testing & Monitoring

• Serum sodium: reflects water balance (normal: ~135–145 mmol/L)
• 24-hour urinary sodium: best intake estimate in research
• Blood pressure: practical clinical marker influenced by sodium intake

🔄 Interactions

• Diuretics and SSRIs/antidepressants can disturb sodium balance
• High sodium increases calcium excretion (bone health risk if calcium is low)
• Adequate potassium intake helps counteract sodium’s blood pressure effects

📊 Evidence Snapshot

• 🔬✅ Well-established: Reducing high sodium lowers blood pressure in many individuals
• 🧪⚖️ Individual variation: Salt sensitivity differs by age, health conditions, and potassium intake
• ⚠️❌ Unproven/hype: Extreme sodium restriction or “detox” claims — can be harmful

🧂 Misconceptions About Salt

It is a common misconception that switching from commercial table salt to “organic” or “sea salt” provides major health benefits. While sea salt may contain trace minerals, both are chemically ~98–99% sodium chloride. The health risk comes from total sodium intake, not the source. For blood pressure and heart health, lowering all salt is what matters most.