Buying selenium: more µg is not a better deal
Futures Nutrition Editorial Team · 12 August 2026
Buying selenium: more µg is not a better deal
The short answer: with selenium, micrograms per euro is the wrong number to look at. With most nutrients you can work out how much you get per euro, and the larger amount is at least not a drawback. With selenium it is one. Between the recommended intake of 60 to 70 µg a day and the tolerable upper intake level of 255 µg lies a good factor of four — with hardly any other mineral is the range this narrow. A pack with 200 µg per tablet is therefore not the better bargain but a different decision, one that has to fit the diet.
The second figure, the one printed on no tin, is the more important: what already comes in through food. Only after that can you compare.
First your own intake, then the shopping basket
A supplement adds to an intake, it does not replace it. Germany sits in the European midfield for selenium supply, and a genuine deficiency is rare according to the German Nutrition Society (DGE, selected questions and answers on selenium, 2021). Even so, your own intake can hardly be pinned down: soils in Europe are low in selenium, and how much ends up in meat or grain depends on where the feed was grown.
In practice that means: anyone eating fish, meat, eggs and wholegrain regularly is filling a smaller gap than someone on a purely plant-based diet. And anyone eating Brazil nuts daily is working with a very uncertain quantity: depending on origin, a single nut supplies between 11 % and 288 % of an adult man's daily requirement (Silva Junior et al., Chemosphere 2017;188:650–658). That spread is the reason a high tablet dose cannot be justified with "it does no harm".
Why the high dose is not a bargain
At the top end, EFSA has since 2023 capped intake from all sources combined at 255 µg per day for adults (EFSA Journal 2023;21(1):7704). The German Federal Institute for Risk Assessment proposes a considerably lower maximum level for food supplements of 40 µg per recommended daily portion (opinion 010/2024). Neither is a maximum level in force — across the EU, maximum levels for minerals in food supplements have to this day not been set. Everything on the shelf moves between those two figures.
On top of that comes a point hardly anyone has on their radar: the figure on the pack is an average value, not a guaranteed individual value. For official controls, minerals in food supplements have a tolerance range of −20 % to +45 %, which already includes measurement uncertainty (European Commission guidance document on the setting of tolerances, December 2012, table 2). Work that through — the last column assumes 50 µg from the diet — and the picture shifts:
| Declared on the pack | Tolerance range (−20 %/+45 %) | Upper value plus 50 µg from food |
|---|---|---|
| 50 µg | 40–73 µg | 123 µg |
| 100 µg | 80–145 µg | 195 µg |
| 200 µg | 160–290 µg | 340 µg |
At 200 µg per tablet the upper edge of the tolerance already lies above the tolerable upper intake level — with the diet not yet counted at all. This is no accusation against any manufacturer: the tolerance range describes the point from which an authority objects to a deviation, not what a manufacturer aims for. For the purchase decision it still means that the number on the tin is not sharp at the upper end.
Price per day instead of price per microgram
Two packs become comparable through the number of days they cover: pack contents divided by the daily amount taken, then the price divided by those days. 180 tablets at one tablet a day is half a year, 365 tablets a year. Large packs almost always lower the price per day — but that only makes sense if the best-before date covers the intended period of use.
Four items that must appear on every label
The labelling of food supplements in Germany is governed by the food supplements regulation (Nahrungsergänzungsmittelverordnung, NemV). Under § 4 NemV the following are required, among others:
| Mandatory item | What it is good for when comparing |
|---|---|
| The designation "food supplement" | separates the product from a medicine |
| Amount of the nutrient, related to the daily amount to be consumed | the only figure you can calculate with |
| Percentage of the nutrient reference value | quick cross-check: 55 µg = 100 % |
| Recommended daily portion | without it the amount stated is worthless |
Added to that are the note that the stated daily amount must not be exceeded, the note that food supplements are no substitute for a balanced diet, and the note to store the product out of the reach of young children. The nutrient reference value for selenium is 55 µg (Regulation (EU) No 1169/2011, Annex XIII) — so a tablet with 100 µg stands at 182 %.
The most common comparison error arises when one pack states the amount per tablet and another per two tablets. Both are permitted as long as the statement refers to the recommended daily portion. Anyone who skims over the portion size is comparing two different things.
The form is in the ingredients list, not the nutrition table
The table states only "selenium" in micrograms. Which compound sits behind it is revealed by the ingredients list: a salt (sodium selenite, sodium selenate, sodium hydrogen selenite), "L-selenomethionine" or "selenium-enriched yeast". Only these sources are permitted under Annex II of Directive 2002/46/EC. The form changes less about the amount absorbed than advertising suggests — but it does change how long selenium stays in the body and how much a later blood value can tell you. The comparison in detail is in Selenium forms.
Two points are enough for the purchase decision: if the pack says "selenium yeast", an additional statement of the selenomethionine content is a good sign — it is not required. And anyone choosing a product with sodium selenite is better off not taking it together with a high-dose vitamin C product; details on that in Taking selenium.
Count combination products in
Selenium is in many multivitamin products, in thyroid combinations with iodine and in products for hair and nails. Anyone taking two of them in parallel adds the amounts together — and ends up in the upper range faster than the single pack suggests. With iodine combinations it is also worth looking at the order of the two trace elements.
The other way round: a combination product with 15 µg selenium next to twelve other substances closes no gap, it decorates the ingredients list. If selenium is the reason for the purchase, it belongs in there in an amount that matches your own intake.
How to recognise a careful supplier
A few details cost nothing and say a lot:
- Batch number and best-before date on the tin — without them traceability is impossible.
- Name and address of the food business operator in the EU (Regulation (EU) No 1169/2011, Article 9). No address, no one to talk to.
- Notification to the Federal Office of Consumer Protection and Food Safety: under § 5 NemV every food supplement must be notified there with a specimen of the label at the latest when it is first placed on the market. That is not an authorisation and not a check of the contents — but a product without notification may not be marketed in Germany.
- Comprehensible additives. Fillers such as microcrystalline cellulose and anti-caking agents such as silicon dioxide belong to every pressed tablet and are not a quality defect. With capsules the shell decides whether the product suits a plant-based diet: hydroxypropyl methylcellulose is plant-based, gelatine is not.
What a supplement cannot do is answer the question of whether there is a gap at all. Selenium is not part of a standard blood panel, and the available markers have their limits.
What is on our label
Our Selenium 100 µg is an example of the calculation above: one tablet daily, 180 per tin, so half a year's supply.
| Per tablet (recommended daily dose) | Amount | % NRV* |
|---|---|---|
| Selenium (from selenium-enriched yeast) | 100 µg | 182 % |
* Nutrient reference value under Regulation (EU) No 1169/2011, Annex XIII.
The 100 µg lie below the tolerable upper intake level of 255 µg and above the BfR proposal of 40 µg per daily dose — in the range, then, in which the market moves as long as no binding maximum level applies. Anyone additionally taking a multivitamin product counts its selenium share in. What else stands in the Selenium category, and how the remaining trace elements line up beside it, is shown by Minerals.
The following claims are authorised for selenium (Regulation (EU) No 432/2012): Selenium contributes to the normal function of the immune system. Selenium contributes to normal thyroid function. Selenium contributes to the protection of cells from oxidative stress. Selenium contributes to the maintenance of normal hair and nails. Food supplements are not a substitute for a balanced and varied diet and a healthy lifestyle.
Frequently asked questions
Which strength is the right one? That depends on the diet, not on the price. Anyone eating fish, meat and eggs regularly anyway gets by with a smaller amount than someone eating plant-based. Common strengths on the market are 50, 100 and 200 µg; total intake from diet and supplement should not exceed 255 µg per day.
Is a high-dose product more economical? Not with selenium. Micrograms beyond the requirement are not value for money, and the distance to the tolerable upper intake level is small. A high strength only makes sense if the tablet is expressly divisible or a medically established situation lies behind it.
How do I tell whether a pack states 100 µg per tablet or per daily portion? From the line above the nutrition table and from the recommended daily amount. If it says "per 2 tablets", the content per piece is halved — and the tin lasts only half as long. Both statements are mandatory on the pack under § 4 NemV.
Why do some products state a selenium amount that the analysis does not hit exactly? Because the statement is an average value. For official controls, minerals in food supplements have a tolerance range of −20 % to +45 % around the declared value. With selenium that is the reason not to read the number on the tin as a sharp upper limit.
Sources: German food supplements regulation (NemV), §§ 4 and 5 · Directive 2002/46/EC, Annex II, in conjunction with Regulation (EC) No 1170/2009 · Regulation (EU) No 1169/2011, Article 9 and Annex XIII · DGE, selected questions and answers on selenium (2021) · European Commission, guidance document for competent authorities on the setting of tolerances for nutrient values declared on a label, December 2012, table 2 · EFSA, Scientific opinion on the tolerable upper intake level for selenium, EFSA Journal 2023;21(1):7704 · BfR, proposed maximum levels for selenium in foods including food supplements, opinion No. 010/2024 · Silva Junior et al., Natural variation of selenium in Brazil nuts and soils from the Amazon region, Chemosphere 2017;188:650–658 · Regulation (EU) No 432/2012.
