Sodium and Chloride: Nutrition and Electrolyte Basics (Not Routine Supplements)

Overview: a food topic, not a supplement

Salt is sodium chloride. The NHS says sodium and chloride are minerals needed in small amounts to keep body fluids balanced, and chloride also helps digestion. [2] MedlinePlus adds that the body uses sodium to control blood pressure and blood volume and for muscles and nerves. [3] These are established nutritional roles. Sodium occurs naturally in most foods. [3]

Most people eat more sodium than they need, not less. WHO says almost all populations consume too much, with a global adult average of 4,278 mg of sodium a day (11 g of salt) in 2021. [4] The UK Department of Health and Social Care says sodium chloride should not be used in supplements. [2] This page explains salt in food and the body. It is not advice to take salt products.

Salt versus sodium: the units

Salt (sodium chloride) and sodium are not the same number. The NHS gives 6 g of salt as 2.4 g of sodium. [2] MedlinePlus says table salt is 40% sodium and a teaspoon holds 2,300 mg of sodium. [3] Labels may show either, so check which one before comparing.

Official intake levels (healthy adults)

All figures are for sodium unless stated.

EFSA treated chloride the same way as sodium. It found no appropriate biomarker of chloride status and set 3.1 g of chloride a day for adults, including pregnant and lactating women. [7] MedlinePlus lists adequate intakes for children by age, such as 800 mg of sodium for ages 1 to 3 and 1,500 mg for ages 14 to 18. [3] People with heart failure, liver cirrhosis or kidney disease may need to consume even lower amounts, so ask a clinician for a personal limit. [3] Country-by-country detail is on Sodium intake guidelines by country and where salt hides.

Where the sodium comes from

Salt is added to many processed foods such as ready meals, bacon, cheese, some bread and savory snacks. [2] NIDDK says much US sodium comes from packaged, prepared and restaurant foods, not the saltshaker. [8] Processed meats and canned soups and vegetables are examples. [3] On the Daily Value scale, 20% or more per serving is high. [6]

Evidence by use

Labels: established means a standard nutritional or public-health finding; evidence in a specific group means the result may not apply elsewhere.

Too little sodium

WHO says sodium deficiency is extremely unlikely in healthy individuals. [4] Low blood sodium (hyponatremia) is a water and sodium balance problem. Causes listed by MedlinePlus include diuretics (water pills), diarrhea, vomiting, sweating, heart failure, kidney disease and cirrhosis. [1] Medicine questions go to a pharmacist; see Medication interactions. For exercise and heat, see Electrolytes and electrolyte supplements. MedlinePlus gives a usual blood range of 136 to 144 mEq/L, and ranges vary by lab. [1]

Practical ways to eat less salt

The NHS suggests checking labels, choosing tinned vegetables and pulses with no added salt, and tasting food before adding salt. [2] Children: MedlinePlus says there are no specific sodium restrictions for infants, children and teens, but it suggests avoiding too much sodium. [3] Pregnancy-specific sodium advice was not covered in the sources we read; ask your clinician. Salt substitutes raise potassium and need care with kidney disease; see Potassium.

Related

Understanding minerals, Reading supplement labels.