Blood draw
Selenium
Selenium; thyroid and antioxidant enzymes.
€ 35,00
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Vitamins, minerals and amino acids · Blood
Selenium
The selenium in your blood; the value mainly follows recent intake, and a deficiency is unusual in the Netherlands.
At a glance
- Measured in blood
- In 3 test panels
- No special preparation
Explanation
Selenium: what is measured?
Selenium is a trace element. It protects cells against damage (antioxidant) and is needed for the thyroid to work. In the blood, selenium is mostly found in proteins, especially selenoprotein P, which carries selenium to the tissues. This analysis measures the total selenium in the blood; this value mainly follows the intake from food and supplements in the preceding period.
What can it detect?
- A low selenium intake, for example with a very one-sided diet, long-term artificial nutrition or a severe bowel disease
- Too much selenium from supplements or a lot of Brazil nuts
Result
What does the result mean?
Selenium too high
A raised selenium is almost always caused by supplements or by regularly eating a lot of Brazil nuts. According to the Netherlands Nutrition Centre (Voedingscentrum), a handful of Brazil nuts already gives you more than the tolerable upper limit of 255 micrograms per day for adults. Going over that limit once causes no symptoms. With too much selenium over a long period, loss of hair, nails and teeth, skin damage and symptoms of the nervous system can develop.
Selenium too low
A low selenium can fit a low intake. According to the Netherlands Nutrition Centre (Voedingscentrum), it is not known how often this occurs in the Netherlands, and people who eat mainly plant-based or organic food are at greater risk of a low intake, because the amount of selenium in plant products depends on the soil. The value can also fall temporarily during inflammation or a serious illness, without there being a deficiency. Symptoms of a true deficiency, such as muscle pain, muscle weakness and heart disorders, are rare.
After an abnormal result
With a low selenium, the GP looks at your diet and at diseases that reduce absorption, and repeats the measurement if needed once there is no more inflammation. With a raised selenium, the GP asks about the use of supplements and Brazil nuts.
Reliability
How reliable is the test?
The test is mainly used in hospital for a specific question, such as long-term artificial nutrition. The blood value mainly follows recent intake and says little about the stores in the tissues. The Health Council of the Netherlands, following EFSA, uses selenoprotein P as the best measure of selenium status, and notes that its link with health has also not been studied enough.
What can affect the result?
- Supplements and Brazil nuts raise the value within a short time.
- Inflammation or a serious illness can temporarily lower the value.
- Laboratories measure in serum, plasma or whole blood with different reference values; this makes results hard to compare.
Who it is for
Who is the test useful for?
Useful for
Useful when a severe deficiency is suspected, for example with long-term artificial nutrition or a severe bowel disease, and with long-term use of selenium supplements. In healthy people, including those eating plant-based, the result says little, because the blood value mainly follows recent intake. The advice of the Netherlands Nutrition Centre (Voedingscentrum) to vary your diet with foods such as fish and different kinds of nuts applies regardless of the result.
How common is it?
According to the Netherlands Nutrition Centre (Voedingscentrum), selenium deficiency does not normally occur in the Netherlands, but it is not known how often a (too) low intake occurs. People who eat mainly plant-based or organic food are at greater risk of a low intake. Too much selenium occurs mainly with supplement use; according to the Health Council of the Netherlands, eating Brazil nuts can also exceed the upper limit.
Netherlands Nutrition Centre (Voedingscentrum) and the Health Council of the Netherlands (2023)
Drawbacks and risks
- A low result can lead to taking selenium supplements on your own; staying above the tolerable upper limit of 255 micrograms per day for a long time can be harmful.
- Because the meaning of a slightly abnormal value is unclear, the result can cause unnecessary worry.
Get tested
Selenium: test panels
Selenium is part of these test panels. You order online and have your blood drawn at a collection point or collect the sample at home.
Evidence
Sources
This explanation is based on Dutch guidelines and independent information. It is general information, not a diagnosis. Discuss an abnormal result with your GP.
More about risks and resultsMore explanations
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