Approximate dose-response bands. Individual response varies — these are starting points, not prescriptions.
Well below target. Risk of deficiency symptoms tied to thyroid · antioxidant.
Below the recommended daily target. Long-term adequacy not assured.
Daily target met. Standard nutritional support for thyroid · antioxidant.
Common for specific health goals. Check the evidence for your situation before sustaining this level.
Approaching the tolerable upper limit. Monitor and consider clinical guidance.
Above the tolerable upper limit. Risk of adverse effects — back off or consult a clinician.
You're at 0% of your selenium target. The biggest single-serving sources to top it off:
Trace mineral incorporated as selenocysteine into ~25 selenoproteins (glutathione peroxidases, thioredoxin reductases, iodothyronine deiodinases). Soil content varies enormously by region — Brazil nuts are the highest food source by far. The therapeutic window is narrow: deficiency drives Keshan cardiomyopathy; excess drives selenosis.
Glutathione peroxidase uses GSH to reduce hydrogen peroxide and lipid peroxides — the second major antioxidant system after vitamin E. Iodothyronine deiodinases (DIO1, DIO2, DIO3) remove iodine atoms from thyroid hormones, converting T4 to active T3 in peripheral tissues. Selenium and iodine deficiency together cause especially severe cretinism (myxedematous form).
Region-specific. Common in low-selenium soil belts (parts of China, Tibet, Russia). Rare in the US except in TPN without selenium or severe GI disease.
Selenosis from chronic intake >400 mcg/day. Single doses of contaminated supplements have caused acute toxicity. Brazil nut over-consumption is the realistic everyday risk.
Selenomethionine (organic, well-absorbed, builds tissue stores) is preferred over sodium selenite or sodium selenate. Two Brazil nuts most days will hit the RDA without a supplement. Don't stack multiple selenium-containing supplements with daily Brazil-nut intake — selenosis is real.
~80–90% of dietary selenium is absorbed regardless of form, but selenomethionine is incorporated into general protein pools (long-term stores) while inorganic selenite goes directly to selenoprotein synthesis.
U-shaped: deficiency drives cardiomyopathy and thyroid dysfunction; excess associates with type 2 diabetes and (in SELECT) possibly cancer. Aim for adequacy through food; routine supplementation is unnecessary outside specific clinical contexts (Hashimoto's protocols, low-selenium regions).
Glutathione peroxidase, thyroid hormone metabolism.
The mechanisms and systems this nutrient feeds. Click any to drill into what runs on it.
★ = load-bearing / primary cofactor. Track these in My Journey.
Whole foods that contribute meaningfully (≥10% DV per 100 g serving). Click any food to see its full nutrient profile and what else it brings to the table.
See all foods high in Selenium, ranked →