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Selenium in your blood: what your level tells you

For adults aged 18 and over, the adequate intake of selenium is 70 micrograms a day. According to the Voedingscentrum, that is more than most people need.[1]

On this page you can read what selenium is, what the guidelines say about a level that is too low or too high, what affects your level and which other levels are best to look at alongside it.

Also called: seleen. At the lab: SE.

In short

What is selenium?

Selenium is a trace element: a mineral your body needs only in very small amounts. It works as an antioxidant and protects red blood cells and other cells from damage. It is also important for your thyroid to work properly. On top of that, selenium makes heavy metals that sometimes end up in food less toxic.[1]

Selenium is found in many foods, especially fish and certain kinds of nuts. In plant foods, the amount depends on how much selenium is in the soil. In the Netherlands, you would not normally see a deficiency. People who mainly eat plant-based or organic food are, however, more likely to have too low an intake.[1]

A selenium deficiency can go together with heart problems, muscle pain and muscle weakness. It is not easy to get too much selenium from your food, but it can happen with supplements. Taking in too much selenium over a long period can lead to loss of hair, nails and teeth, skin damage and disorders of the nervous system.[1]

Why selenium matters

With selenium, both too little and too much matter. That is why the Voedingscentrum sets a limit on both sides: an adequate intake and a tolerable upper intake level.[1]

Brazil nuts contain so much selenium that a handful already goes over the tolerable upper intake level. That is why the Voedingscentrum advises you to vary them with other unsalted nuts, for example a handful of unsalted mixed nuts.[1]

What your selenium level tells you

The lab's reference range

Labplusarts, the lab BioProfile works with, uses a reference range for selenium of 0.64 to 1.91 umol/l. The lab calls a level between those limits normal.[2]

The Voedingscentrum guideline: intake per day

Intake per dayWhat it meansWho it is for
Less than 70 micrograms[1]Below the adequate intake; that does not straight away mean a deficiency18 years and over
70 micrograms[1]Adequate intake; for most people, more than they need18 years and over
70 micrograms[1]Adequate intakePregnant
65 micrograms[1]Adequate intake15 to 17 years
255 micrograms[1]Tolerable upper intake level: the amount you can take in over a long period without negative health effects18 years and over
230 micrograms[1]Tolerable upper limit15 to 17 years

Source: Voedingscentrum. These are amounts of selenium per day from your diet, not blood levels. The tolerable upper intake level was set by the European Food Safety Authority (EFSA).[1]

Selenium too low

The Voedingscentrum gives limits for intake, not for your blood level. If you take in less than the adequate intake, the Voedingscentrum says that does not straight away mean you have a deficiency. Low intakes are, however, linked to a higher risk of heart and blood vessel disease. It is not known whether, or how often, too low an intake occurs in the Netherlands.[1]

Selenium too high

Taking in too much selenium over a long period can be harmful to your health. That is why EFSA has set a tolerable upper intake level. This limit includes a safety margin. If you go over it once, you will not get symptoms straight away.[1]

BioProfile is working on its own zones for each value, from risk to optimal. A doctor reviews those zones before they appear in your result.

What affects your selenium

What you eat

Meat also contains selenium, because selenium is added to almost all animal feed. In wholegrain products and vegetables, the amount depends on the selenium content of the soil. Brazil nuts contain a lot of selenium.[1]

Supplements

You are unlikely to get too much selenium from your food. If you take supplements, there is a chance you get too much.[1]

How your body absorbs it

On average, your body absorbs about 70% of the selenium in your food. Selenomethionine and selenocysteine are the most common forms in food. Your body absorbs these forms better than selenite or selenate.[1]

Which BioProfile packages measure selenium

Selenium is included in BioProfile 150.[3]

Values that go with it

How this page was made

The BioProfile editorial team wrote this page on 10 October 2026 from the sources below, which we read on 10 October 2026. Every number on this page appears in one of those sources, with that source's number next to it. An expert has yet to check this page; after that check, the expert's name and the date of the check will appear at the top. This page offers explanation, not a diagnosis. Discuss a value outside the range with your GP.

Sources

  1. Voedingscentrum. Selenium (seleen). Accessed on 9 November 2026. https://www.voedingscentrum.nl/encyclopedie/seleen.aspx
  2. Labplusarts, the laboratory BioProfile works with: reference range for the selenium (SE) test, 0.64 to 1.91 umol/l. List dated 24 September 2026.
  3. BioProfile, the blood test packages and the values in each package. https://bioprofile.com/en/blood-testing/