How Much Sodium Should You Eat, and Why Does Potassium Matter Too?

Most adults eat far more sodium than they need, and cutting it lowers blood pressure. The US and Canadian National Academies advise reducing intake if it’s above 2,300 mg of sodium a day, and the World Health Organization (WHO) recommends under 2,000 mg. Potassium works the other way: eating more of it, from fruit, vegetables, and legumes, also lowers blood pressure.

This article is general information, not medical advice.

The Recommendations

• National Academies (2019). In its Dietary Reference Intakes for sodium and potassium, the committee set a Chronic Disease Risk Reduction Intake (CDRR) for sodium of 2,300 mg a day for adults: reducing intake above that is expected to lower the risk of chronic disease. It set an Adequate Intake (AI) of 1,500 mg, enough for nearly everyone’s needs. For potassium, it set AIs of 3,400 mg a day for men and 2,600 mg for women.
• WHO (2012). Adults should eat less than 2,000 mg of sodium a day (5 g of salt), and at least 3,510 mg of potassium.

Salt Versus Sodium

Table salt is sodium chloride, about 40% sodium by weight. So 1 g of salt holds about 400 mg of sodium, and the WHO’s 5 g of salt is 2,000 mg of sodium. Food labels in some countries list salt, others sodium; check which before comparing with a target.

Where Sodium Comes From

In many countries, the salt shaker isn’t the main source: much of the sodium people eat comes from processed and restaurant food, such as bread, cured meats, cheese, soups, sauces, and ready meals. The quickest way to see your own sources is to log a few typical days and look at which foods carry the most.

Potassium’s Part

The WHO’s potassium guideline found that higher potassium intake lowers blood pressure in adults. People with kidney disease, or who take some blood pressure medicines, may need to limit potassium, so ask your doctor before taking supplements.

Following It in Kaizora

Dietary Sodium and Dietary Potassium come from the foods you log on Food Log, Cronometer’s import, or Apple Health’s export. Default reference ranges come from the Dietary Reference Intakes: sodium above the CDRR of 2,300 mg, or below the AI, and potassium below its AI for your sex. Since they’re average daily intakes, each day is judged on the total of the 7 days ending it, so one salty meal doesn’t flag. Break a day’s sodium down by food from its chart to find your main sources. On Correlations, put sodium beside Systolic Blood Pressure by week.

The Short Version

• Keep sodium under 2,300 mg a day (National Academies) or 2,000 mg (WHO).
• 1 g of salt holds about 400 mg of sodium.
• Aim for 3,400 mg of potassium a day for men and 2,600 mg for women.
• Much of it comes from processed and restaurant food.

Sources

• National Academies of Sciences, Engineering, and Medicine, Dietary Reference Intakes for Sodium and Potassium (2019).
• World Health Organization, Guideline: sodium intake for adults and children (2012).
• World Health Organization, Guideline: potassium intake for adults and children (2012).