Complaints & connections · borters.ch
Scarce in our soils — important for thyroid and defence, but the margin between too little and too much is small.
Also known as: low selenium · selenium deficiency
Open in the tool — with search and all the links →This compilation is for information and replaces neither medical diagnosis nor treatment. If you have symptoms, see a doctor.
Selenium is a trace element the body needs only in tiny amounts — but where it performs important tasks: it is part of enzymes that protect cells from oxidative stress, and plays a role for the thyroid and the immune system. How much selenium our food contains depends strongly on the selenium content of the soils; in parts of Europe these are rather selenium-poor, so intake can be lower than elsewhere. A marked selenium deficiency of clinical significance is, however, rare here and mostly affects special situations (such as a one-sided diet, artificial nutrition or certain bowel diseases). For most people with a balanced diet the supply is sufficient, and uncritical high-dose selenium intake is not sensible, since too much selenium can also harm. If suspected, the blood selenium level can be measured and intake adjusted in a targeted way.
Brazil nuts, fish, eggs and wholegrains provide selenium; usually enough.
Supplement only with proven deficiency or special situation.
The blood value helps judge intake correctly.
More is not better here — the right amount counts.
Selenium is built into the thyroid enzymes and the cell’s own protective systems; the blood value rises within weeks. In Hashimoto’s, selenium lowered antibodies over three to six months in studies — whether that changes the course is open. The gap between requirement and too much is narrower for selenium than for other trace elements: above about 400 micrograms a day over months, hair loss, brittle nails and a garlic smell on the breath appear.
The daily requirement is about 60 to 70 micrograms; the safe upper limit 300 to 400 a day. The gap between the two is smaller than for other trace elements. On intake the blood value rises within four to eight weeks. Swiss soils are low in selenium, so the content in local grain is lower than in imported. Two Brazil nuts cover the daily requirement — though the content varies a great deal.
Protects cells; important for thyroid & immune system.
In parts of Europe soils are selenium-poor — intake can be lower.
Mostly affects special situations here, not most people.
Too much selenium can also harm — supplement only targeted and with advice.
What a deficiency makes visible on the body — skin, nails, tongue, eyes and nerves. The signs are unspecific: they show where to look, they prove nothing.
The raw material of the thyroid hormones. In Switzerland it comes mainly from iodised salt, dairy and sea fish — too little and too much both cause problems, so the middle is the aim.
Needed to convert the storage hormone into the active form and protects the gland from oxidative stress. Brazil nuts, fish and eggs cover the need; not high doses over years without a reason.
The enzyme that builds iodine into the hormone needs iron. An empty iron store can therefore cause complaints that look like an underactive thyroid — and the two often occur together.
Involved in the conversion and in the action of the hormones inside the cell. A lack often shows first in hair and nails — exactly where the thyroid becomes visible too.
With a proven deficiency 100–200 µg a day. The gap between need and too much is narrower for selenium than for almost any other nutrient — above 400 µg a day over months counts as too much.
Clearly effective with proven deficiency, useless without. Take only with a documented deficiency — excess is harmful.
The enzymes that convert T4 into active T3 carry selenium at their core. With a deficiency T4 rises while T3 falls — the thyroid produces, but the conversion stalls.
The same enzyme decides whether T4 becomes active T3 or ineffective rT3. With selenium deficiency and with serious illness the balance shifts towards rT3.
One Brazil nut holds 20–90 µg selenium depending on origin; the daily need is 60–70 µg. Two nuts a day usually cover it, ten a day over months can become too much — brittle nails and garlic breath are the first signs.
European soils are low in selenium, so grain supplies less here than in North America. Fish, egg and offal are the more reliable sources.
Supplementation follows a proven deficiency. The gap between need and too much is narrower for selenium than for most nutrients — above 400 µg a day over months counts as too much.