Selenium
Se · last AI check: 2026-07-19
In short
A trace element with a narrow safety margin — needed in small amounts, harmful in large ones.
What it does in the body
The sentences below are officially authorised EU health claims.
Selenium contributes to the normal thyroid function EU health claim
Commission Regulation (EU) No 432/2012 of 16 May 2012, Annex — list of permitted health claims · register entry: 279, 282, 286 · EFSA opinion: 2009;7(9):1220; 2010;8(10):1727
Condition of use on a product: The product is at least a source of Selenium.
Selenium contributes to the normal function of the immune system EU health claim
Commission Regulation (EU) No 432/2012 of 16 May 2012, Annex — list of permitted health claims · register entry: 278, 1750 · EFSA opinion: 2009;7(9):1220; 2010;8(10):1727
Condition of use on a product: The product is at least a source of Selenium.
Selenium contributes to the protection of cells from oxidative stress EU health claim
Commission Regulation (EU) No 432/2012 of 16 May 2012, Annex — list of permitted health claims · register entry: 277, 283, 286 · EFSA opinion: 2009;7(9):1220; 2010;8(10):1727
Condition of use on a product: The product is at least a source of Selenium.
Selenium contributes to the maintenance of normal hair EU health claim
Commission Regulation (EU) No 432/2012 of 16 May 2012, Annex — list of permitted health claims · register entry: 281 · EFSA opinion: 2010;8(10):1727
Condition of use on a product: The product is at least a source of Selenium.
Selenium contributes to the maintenance of normal nails EU health claim
Commission Regulation (EU) No 432/2012 of 16 May 2012, Annex — list of permitted health claims · register entry: 281 · EFSA opinion: 2010;8(10):1727
Condition of use on a product: The product is at least a source of Selenium.
How much you need
| Country / organisation | Group | Value | Type |
|---|---|---|---|
| EFSA | adult men | AI Adequate intake — an approximate value used when data are insufficient to set an exact requirement (RDA). | |
| FAO | adult men | RNI Reference nutrient intake — the RDA equivalent in WHO/FAO, UK and Philippine terminology. | |
| NASEM (US/CA) | adults | RDA Recommended daily allowance — covers the needs of almost all healthy people in a group. | |
| NASEM (US/CA) | adults | UL Tolerable upper level — the highest safe intake; above it the risk of adverse effects rises. | |
| Philippines | adult men | RNI Reference nutrient intake — the RDA equivalent in WHO/FAO, UK and Philippine terminology. | |
| Poland | adults | RDA Recommended daily allowance — covers the needs of almost all healthy people in a group. | |
| Switzerland | adults | RDA Recommended daily allowance — covers the needs of almost all healthy people in a group. | |
| United Kingdom | adult men | RNI Reference nutrient intake — the RDA equivalent in WHO/FAO, UK and Philippine terminology. |
Reference values from different countries are not directly comparable — they differ in definition and age group. How to read reference values →
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.
Worth knowing
The selenium content of plants depends on how much was present in the soil they grew in — which is why its level in the diet varies markedly between regions of the world, regardless of dietary habits. Brazil nuts are an extreme case here: they come from soils exceptionally rich in selenium, and the spread in content between batches is so large that a handful of nuts from one packet can supply many times more selenium than the same handful from another. This is why they are hard to treat as a predictable source of this element.
Selenium has one of the narrowest safety margins among trace elements — the difference between the recommended dose and the upper limit is relatively small. This is a good example of why it's worth distinguishing the type of reference value in the atlas (RDA/AI vs UL) — for selenium, this distinction has greater practical significance than for nutrients with a wide margin, such as vitamin C.
Where to find it
Brazil nuts · fish and seafood · offal · eggs · wholegrain products (depending on soil)
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.