Salt and blood pressure: why it isn't just sodium that counts, but potassium too
Modern recommendations look not only at how much salt we eat, but at the ratio of sodium to potassium. Both elements act in opposite directions in fluid and electrolyte balance, so a diet low in potassium deepens the effects of excess sodium — even when sodium itself stays within the limit.
The WHO thresholds for both nutrients are given at the end of the text, together with the document they come from. In practice, most of the population with a Western dietary pattern exceeds the sodium limit while also falling short of the recommended potassium level — a double discrepancy, not a single one.
A caution about comparing these figures
The WHO limit and the EFSA value aren’t two estimates of the same quantity. The WHO sets an upper limit from a public-health perspective: a threshold the whole population is advised to get below. EFSA, in its 2019 opinion, instead gave a safe and adequate intake — and explicitly noted that the available data didn’t allow it to establish, for sodium, an average requirement, a recommended intake, or a tolerable upper level. These are values of a different kind, and subtracting one from the other makes no sense. More on this distinction in Reading reference values correctly.
What this means in practice
The main source of sodium in the diet isn’t the salt cellar, but the salt present in processed products — bread, cold cuts, cheese and ready meals. That’s why simply cutting out adding salt at the table changes less than it seems, and reading labels achieves more.
On the potassium side, the direction is simpler: its main sources are vegetables, fruit and legume seeds, and consumption of these in many countries falls below recommendations.
If you have diagnosed high blood pressure or kidney disease, or take medication that affects potassium balance, don’t plan such changes on your own — with some conditions and medications, increasing potassium intake can be contraindicated. This is a topic for a conversation with your treating doctor, not a decision made on the basis of a reference table.
Figures cited in this text
Each shows its source document — click a value to see the evidence.
- Upper limit for sodium in adults according to the WHO — converted, less than a teaspoon of salt a day.
- Preventive minimum for potassium in adults according to the WHO.
- Safe and adequate sodium intake according to EFSA (2019) — a different type of value from the WHO limit.
Every value states its source — click it to see the document, location and link.Data and content are prepared and cross-checked against source documents by several independent AI models. They have not been audited by a human editor.Before citing a value, check it in the source document — verification is automated (AI), not editorial.
Health claims in this article
The sentences below are officially authorised EU health claims.
Potassium contributes to the maintenance of normal blood pressure EU health claim
Commission Regulation (EU) No 432/2012 of 16 May 2012, Annex — list of permitted health claims · register entry: 321 · EFSA opinion: 2010;8(2):1469
Condition of use on a product: The product is at least a source of Potassium.
This material is for information and education. It does not replace advice from a doctor or dietitian. For health matters, consult a qualified medical professional.