For most adults, the limit is 2,300 mg of sodium a day, the figure on U.S. food labels (FDA). The American Heart Association calls 1,500 mg an optimal goal for most adults, and the World Health Organization suggests under 2,000 mg (AHA; WHO). For potassium, the National Academies set 3,400 mg a day for men and 2,600 mg for women (NASEM, 2019).
Key takeaways
2,300 mg of sodium is a ceiling, not a target: the National Academies say people 14 and older should cut back if they eat more (NASEM, 2019).
In one U.S. study, about 71% of sodium was added before the food reached people (Harnack et al., 2017).
Cutting about 4.4 grams of salt a day lowered blood pressure by about 4.2/2.1 mm Hg on average (He et al., 2013).
Potassium salt substitutes aren't for everyone: kidney disease and some medicines make extra potassium risky (NIH).
How much sodium do you need?
Not much. The body needs less than 500 mg a day, and Americans average more than 3,100 mg (AHA).
The National Academies set an adequate intake of 1,500 mg a day for people 14 and older. It's based on the lowest intakes tested in trials that showed no sign of too little sodium. They set 2,300 mg as the point to cut back from, which they call the chronic disease risk reduction intake (NASEM, 2019). The report says cutting back to 2,300 mg or below helps whether or not your blood pressure is high.
Source | Sodium a day |
|---|---|
cut back if above 2,300 mg (ages 14 and up); adequate intake of 1,500 mg | |
no more than 2,300 mg; 1,500 mg optimal for most adults | |
under 2,000 mg (under 5 grams of salt) | |
Daily Value: less than 2,300 mg |
Children's limits are lower, from 1,200 to 1,800 mg depending on age (NASEM, 2019).
Why does sodium matter for blood pressure?
Cutting sodium lowers blood pressure, and the drop is bigger when blood pressure is high.
A review of 34 trials looked at people who cut about 4.4 grams of salt a day for at least four weeks. That's about 1,760 mg of sodium, since salt is about 40% sodium (AHA). On average, blood pressure fell by about 4.2/2.1 mm Hg, meaning the top number fell about 4 points and the bottom about 2. For people with high blood pressure, it fell about 5.4/2.8 mm Hg, and for people without, about 2.4/1.0 (He et al., 2013).
Cutting sodium also adds to what the DASH eating pattern does on its own (Sacks et al., 2001), and blood pressure numbers has the details. A larger pooled analysis, covered in the habits that move blood pressure, found the drop grows with the size of the cut. If your readings run higher at the doctor's office than at home, the white coat effect explains why.
Where does sodium come from?
Mostly packaged and restaurant food, not the salt shaker. Researchers tracked the sodium of 450 adults in three U.S. cities. About 71% was added before the food reached them. About 14% was natural in food, and 10.5% came from home cooking and the table (Harnack et al., 2017).
In U.S. survey data from 2003 to 2008, the top sources were everyday foods: bread, pizza, pasta, chicken dishes, processed meats, cheese and cold cuts. That analysis was funded by the National Restaurant Association (Drewnowski and Rehm, 2013).
A teaspoon of table salt has about 2,400 mg of sodium, and some medicines contain sodium too (AHA).
Logged sodium can be off. One study found a popular app's sodium figures didn't match a reference database, though its calories did (Evenepoel et al., 2020). There's more in how accurate calorie tracking is.
How much potassium do you need?
The National Academies set adequate intakes of 3,400 mg a day for men and 2,600 mg for women. They didn't set a risk-reduction level for potassium, because the evidence was inconsistent (NASEM, 2019).
The World Health Organization suggests at least 3,510 mg a day from food (WHO). U.S. food labels use 4,700 mg as the Daily Value (FDA).
U.S. adults get about 3,016 mg (men) and 2,320 mg (women) from food on average (NIH).
Does potassium lower blood pressure?
In people with high blood pressure, yes. A review of 22 trials found that more potassium lowered blood pressure by about 3.5/2.0 mm Hg in adults. The drop showed up in people with high blood pressure, not in people without it. Most of those trials used potassium supplements (Aburto et al., 2013). The World Health Organization advises getting more potassium from food (WHO).
In the long-term studies in the same review, more potassium was linked to 24% lower stroke risk (Aburto et al., 2013). Those studies show a link, not proof.
Good food sources include a medium baked potato without the skin, at about 610 mg. A cup of lentils has 731 mg, a cup of canned kidney beans 607 mg and a banana 422 mg (NIH).
What about salt substitutes?
They can lower blood pressure, but they aren't safe for everyone, so ask your doctor first.
Some salt substitutes swap part of the sodium for potassium. A trial of 20,995 adults in 600 villages in rural China tested a blend of 75% regular salt and 25% potassium chloride. Everyone had a past stroke, or was 60 or older with high blood pressure. Over almost five years, the substitute lowered stroke by 14%, major heart events by 13% and deaths by 12%. Serious high potassium wasn't clearly more common (Neal et al., 2021).
The trial left out anyone whose household included someone with serious kidney disease, or someone taking a potassium-sparing diuretic or potassium supplement. In China, most salt is added at home. In Western countries, most already comes in packaged and restaurant food, so swapping the salt shaker may do less (WHO, 2025).
A Cochrane review of 26 trials found that these substitutes lowered blood pressure by about 4.8/2.4 mm Hg in adults, with limited evidence for people without high blood pressure. Every trial left out people for whom extra potassium could be harmful (Brand et al., 2022).
In 2025, the World Health Organization suggested that adults who use table salt switch to a lower-sodium substitute with potassium. It's a conditional recommendation, and it isn't meant for pregnant women, children, or people with kidney problems or other conditions that limit how the body clears potassium. WHO also says these substitutes shouldn't go in shared meals eaten by anyone at risk of high potassium (WHO, 2025).
Who should be careful?
Kidney disease, or medicines that raise potassium: ACE inhibitors, ARBs (common blood pressure medicines) and potassium-sparing diuretics can let potassium build up, even from food. Salt substitutes can carry 440 to 2,800 mg of potassium per teaspoon (NIH).
Other conditions: type 1 diabetes, adrenal insufficiency and liver disease can raise the risk of high potassium (NIH).
Heart failure: it can raise the risk of high potassium (NIH). Your provider may also set a sodium limit of 1,500 to 2,300 mg and change how much fluid you drink (MedlinePlus).
Heavy sweating: the AHA says its 1,500 mg goal may not fit competitive athletes or people who work in heavy heat (AHA).
If your doctor has given you your own sodium or potassium numbers, those come first.
Frequently asked questions
Should I aim for 1,500 mg? The AHA calls it an optimal goal for most adults. It says the goal may not fit people who sweat heavily, and your doctor's number comes first (AHA).
Is 2,300 mg about a teaspoon of salt? Roughly. A teaspoon of table salt has about 2,400 mg of sodium, and sea, kosher and pink salt have about the same (AHA).
What does "low sodium" mean on a label? 140 mg or less per serving. "Very low sodium" is 35 mg or less, and "sodium-free" is under 5 mg (FDA).
How Knit shows your sodium
When you log food in an app connected to Apple Health, Knit shows your daily sodium in the Record tab, under Nutrition. The chart draws a line at 2,300 mg, the label's Daily Value, as a ceiling to stay under rather than a goal. If you also track your blood pressure, it sits under Heart & vitals, so you can look at the two together.
