TempoLife › Features › Reference intakes by nutrient, age and sex › selenium
Selenium: the daily reference intake
The selenium adequate intake is 70 micrograms a day for adults. Selenium is the clearest example of a nutrient whose supply depends on geology rather than diet: the amount in bread and meat reflects the selenium in the soil the grain grew in, and Finland changed its national supply by changing its fertiliser.
These are published population reference values, not a diagnosis and not a prescription. A reference intake describes what covers a healthy group; it cannot tell you your own status, and no page can. Pregnancy, chronic illness, medicines and malabsorption all change the picture — take those questions to a doctor, midwife, pharmacist or dietitian.
Selenium by age, sex and life stage
This page carries the adult values. EFSA also publishes lower adequate intakes for each child band; they are not reproduced here.
| Group | Reference value | Type | Note |
|---|---|---|---|
| Men 19-50 | 70 µg | AI | |
| Women 19-50 | 70 µg | AI | |
| Men 51 and over | 70 µg | AI | |
| Women 51 and over | 70 µg | AI | |
| Adults 65 and over | 70 µg | AI | |
| Pregnancy | 70 µg | AI | no increase in pregnancy |
| Breastfeeding | 85 µg | AI | raised to cover what leaves in the milk |
Soil, not diet, sets the supply
Selenium enters the food chain through plants, and plants take up what the soil holds. Soils across large parts of northern Europe are naturally low in it, and that carries through into grain, and then into the meat, milk and eggs of animals fed on that grain. Two chemically identical loaves of bread can differ several-fold in selenium depending on where the wheat was grown.
This makes selenium unusual: the composition figures below are American, and the same food grown in Baltic or Nordic soil may hold less. It is one of the few places where a USDA number should be read as an order of magnitude rather than a measurement.
The Finnish fertiliser decision
Finland responded to naturally selenium-poor soils by adding selenium to agricultural fertilisers nationally from the mid-1980s, deliberately raising the selenium content of domestically produced food. It remains one of the clearest examples anywhere of a country correcting a micronutrient shortfall through the agricultural system rather than through supplements, and it is the reason Finnish and neighbouring food-composition figures for selenium changed over that period.
A narrow window
Selenium has one of the tightest ratios between the reference intake and the upper level of any nutrient: 70 micrograms against a ceiling of 300. Most nutrients allow a tenfold margin or more. That is why casual high-dose selenium supplementation is a poor idea, and why Brazil nuts deserve a specific warning — their selenium content varies by more than an order of magnitude with the soil they grew in, so "a few a day" is not a controlled dose.
Where it comes from here
Fish and seafood, offal, eggs, meat and wholegrain are the practical carriers. Wheat products contribute a large share of the total in most European diets simply because bread is eaten in quantity, which is exactly why the fertiliser route worked.
The upper level
The tolerable upper intake level for selenium in adults is 300 micrograms a day. The margin between the 70 microgram reference intake and that ceiling is narrower than for almost any other nutrient, and chronic excess causes selenosis: brittle hair and nails, hair loss, a garlic breath odour and nerve symptoms. Brazil nuts vary enormously in selenium content and a daily habit of several can pass the limit.
Ordinary food against the 70 microgram adult adequate intake
Top of this list: Whole-wheat pasta, 72.6 µg in a 200 g serving (a portion, cooked) — 104% of the 70 microgram adult adequate intake. One serving covers the whole day on its own.
| Food | Ordinary portion | Per portion | Share of the day |
|---|---|---|---|
| Whole-wheat pasta | a portion, cooked, 200 g | 72.6 µg | 104% |
| Canned tuna | a small tin, drained, 100 g | 70.6 µg | 101% |
| Mackerel | a fillet, 120 g | 61.9 µg | 88% |
| Salmon | a fillet, 120 g | 56.2 µg | 80% |
| Boneless pork chop | a chop, 120 g | 53.5 µg | 76% |
| Cod | a fillet, 130 g | 48.9 µg | 70% |
| Canned sockeye salmon | half a tin, 100 g | 34.3 µg | 49% |
| Trout | a fillet, 120 g | 33.7 µg | 48% |
| Chicken breast | a breast, 120 g | 33.1 µg | 47% |
| Chicken thigh | a thigh, 120 g | 32.5 µg | 46% |
| Sardines | half a tin, 60 g | 31.6 µg | 45% |
| Ground beef | a portion, 120 g | 24.6 µg | 35% |
Portion sizes are ordinary household servings chosen for this table, not official reference portions, and the shortlist is an editorial one: everyday foods eaten in this region rather than the highest per-100 g entries in the database. A raw per-100 g ranking would be topped by dried herbs, drink powders and fortified breakfast cereals, which answers a different question. The composition data is American, so where US fortification practice differs from European practice the row carries a dagger and the reason. For the full per-100 g ranking of a nutrient, the food-data section of this site publishes one.
For the full ranking of every food in the database by selenium per 100 g, see foods highest in selenium.
Sources: EFSA Dietary Reference Values · Regulation (EU) No 1169/2011, Annex XIII · USDA FoodData Central SR Legacy (food composition) · EFSA scientific opinion on dietary reference values for selenium (2014) · USDA FoodData Central SR Legacy composition data · checked 2026-09-06
Frequently asked questions
How much selenium a day?
EFSA adequate intake for adults is 70 micrograms a day, rising to 85 micrograms while breastfeeding.
Can you get too much selenium?
Yes, more easily than with most nutrients. The upper level is 300 micrograms a day for adults, and chronic excess causes hair and nail loss, garlic-smelling breath and nerve symptoms.
Why do selenium values vary so much between countries?
Because plants take selenium from the soil, and soil selenium varies geographically. Finland has added selenium to fertilisers since the mid-1980s specifically to raise the selenium content of its food supply.
See your own numbers, not the population average
TempoLife logs what you eat and adds it up, so you can compare a real week against the reference intake on this page instead of guessing.