About
What it is and where it shows up.
Selenium is an essential trace mineral incorporated into selenoproteins that support antioxidant defence, thyroid hormone metabolism, and immune function. It is added to infant formula, fortified foods, and dietary supplements to prevent or correct deficiency, and occurs naturally in Brazil nuts, seafood, grains, and meats.
Safety summary
The regulatory and scientific consensus.
Selenium has a narrow margin between the nutritional requirement (~55 µg/day adult RDA in the US) and the Tolerable Upper Intake Level (255 µg/day for adults per EFSA 2023; 400 µg/day per the US Food and Nutrition Board). Chronic excess causes selenosis, characterised by hair and nail loss, neurological symptoms, and gastrointestinal disturbance. Acute high-dose toxicity — most often from misformulated supplements — can cause respiratory distress syndrome, myocardial infarction, kidney failure, cardiac failure, and, rarely, death.
Regulatory landscape
What food-safety regulators have decided.
| Jurisdiction | Status | Note |
|---|---|---|
| EFSA (European Food Safety Authority) (European Union) | Approved | EFSA NDA Panel (November 2022, published EFSA Journal 2023, 21(1)) set a Tolerable Upper Intake Level (UL) of 255 µg Se/day as safe for adult men and women, including pregnant and lactating women, superseding the previous EC SCF value of 300 µg/day. Selenium is approved as a nutrient source for food supplements under EU Regulation (EC) No 1170/2009 in multiple forms including sodium selenate, sodium hydrogen selenite, sodium selenite, L-selenomethionine, and selenium-enriched yeast.source |
| FSSAI (Food Safety and Standards Authority of India) (India) | Approved | Elemental selenium from L-Selenomethionine approved as a health supplement ingredient at a recommended dosage of 200 µg/day (FSSAI Application No. 86/Std/PA/FSSAI/2020, approved 12 July 2021). FSS (Food Product Standards and Food Additives) Regulations 2011 set selenium in infant nutrition products at 5.0–17.0 µg per 100 g. FSSAI's 2018 Nutraceutical Regulations order prohibited selenium dioxide specifically in nutraceutical products, with immediate withdrawal required; other approved selenium forms remain permitted.source |
| FDA (Food and Drug Administration) (United States) | Approved | FDA Daily Value (DV) for adults and children ≥4 years is 55 µg/day. The FNB-established UL is 400 µg/day (adults 19+), based on prevention of hair and nail brittleness. Selenium is a required nutrient in infant formula (minimum 2.0 µg/100 kcal per 21 CFR Part 107). FDA allows a qualified health claim associating selenium intake with possible reduction of certain cancer risks, noting evidence is limited and not conclusive. Supplement forms include selenomethionine, selenium-enriched yeast, sodium selenite, and sodium selenate.source |
Who should approach with care
Whose guidance would steer them away.
Kidney Disease — Impaired renal clearance reduces selenium excretion and increases the risk of accumulation and selenosis, particularly with dietary supplement use above normal food intake.
Liver Disease — Selenium metabolism is partly hepatic and selenoprotein synthesis can be disrupted by liver dysfunction, warranting medical supervision before selenium supplementation.
Pregnancy — Although the EFSA 2023 UL of 255 µg/day applies equally to pregnant women, supplemental selenium intake should remain within established Dietary Reference Values to avoid embryotoxic effects associated with excessive intake.
Infants — FSSAI and FDA mandate specific selenium ranges in infant formula (5.0–17.0 µg/100 g; minimum 2.0 µg/100 kcal respectively); doses outside these narrow limits in infant nutrition require clinical supervision due to the small margin between sufficiency and toxicity in this age group.
Thyroid Disease — Selenium and iodine interact in thyroid hormone synthesis; selenium supplementation in individuals with pre-existing thyroid conditions (particularly iodine deficiency) may exacerbate thyroid dysfunction and should be medically supervised.
Research citations
The sources behind this verdict.
- 1FDA. Selenium — Health Professional Fact Sheet. ods.od.nih.gov
- 2FSSAI. Status of Applications under Food Safety and Standards (Approval for Non-Specified Food and Food Ingredients) Regulations, 2017 — as on 2 May 2025, 2025. fssai.gov.in
- 3EFSA. Consumer safety of feed additives containing selenium (EFSA FEEDAP Panel Opinion), 2024. efsa.europa.eu
- 4EFSA. Scientific opinion on the tolerable upper intake level for selenium, 2023. doi.org
- 5EFSA. Scientific Opinion on Dietary Reference Values for selenium, 2014. efsa.europa.eu
Independently researched5 citations