mineral
Selenium: Daily Needs, Brazil Nuts and Upper Limit
Also known as selenomethionine, selenium yeast, sodium selenite, sodium selenate, Brazil nuts selenium
Short answer
Selenium is a trace mineral the body builds into about 25 selenoproteins used in thyroid hormone metabolism, DNA synthesis and protection from oxidative damage [1]. The adult RDA is 55 mcg, and most Americans get enough from food [1]. One Brazil nut can hold 68 to 91 mcg; the adult upper limit is 400 mcg a day [1].
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What is Selenium?
Selenium is an essential mineral that is part of 25 selenoproteins, including glutathione peroxidases and thioredoxin reductases [1]. Selenoproteins have roles in thyroid hormone metabolism, DNA synthesis, reproduction and protection from oxidative damage and infection [1]. In food, selenium is mostly present as selenomethionine and selenocysteine [1].
Forms of Selenium you'll see on labels
Selenomethionine
The main form in food and a common supplement form [1]. Up to about 90% is absorbed [1].
Selenium-enriched yeast
Yeast grown in a high-selenium medium; mostly selenomethionine [1].
Sodium selenite or sodium selenate
Inorganic forms; also up to about 90% absorbed [1]. NIH says chronic high intakes of organic and inorganic forms have similar effects [1].
How much Selenium do adults need?
NIH lists these Recommended Dietary Allowances (RDA) for adults 19+ in micrograms (mcg). Reference values, not a personal recommendation.
| Group | Amount per day |
|---|---|
| Men 19+ | 55 mcg |
| Women 19+ | 55 mcg |
| Pregnancy | 60 mcg |
| Breastfeeding | 70 mcg |
Upper limit: 400 mcg/day for adults 19+, including pregnancy and breastfeeding, from food and supplements [1]
How Selenium appears on a label
Selenium is listed in mcg, and the Daily Value is 55 mcg [1]. Many multivitamins contain 55 mcg [1]. Products that pair selenium with vitamin E or other ingredients often contain 50 to 200 mcg, and selenium-only supplements typically contain 100 to 400 mcg [1].
When to take Selenium
No source we checked names a best time of day or says whether to take selenium with food.
What to keep apart from Selenium
Brazil nuts
They contain 68 to 91 mcg per nut and could cause selenium toxicity if eaten regularly [1]. Count them alongside any supplement.
Cisplatin (chemotherapy)
Cisplatin can lower selenium levels; whether this matters clinically is not known, and evidence that selenium eases chemotherapy side effects is insufficient [1]. Ask your cancer care team.
Vitamin E combination products
Supplements that combine selenium with vitamin E generally contain 50 to 200 mcg selenium [1]. Check the total against other products you take.
Foods that contain Selenium
- Brazil nuts
- Tuna, sardines, cod and shrimp
- Pork, beef and ham
- Turkey and chicken
- Beef liver
- Eggs
- Cottage cheese
- Pasta, bread and other grains
- Baked beans
Who should ask a doctor or pharmacist first
Talk to your doctor before taking selenium if you are pregnant and have thyroid autoimmunity; the American Thyroid Association recommends against selenium supplements for pregnant women who are TPO antibody positive [1]. Ask first if you are having cisplatin chemotherapy [1]. Selenium-only supplements can contain up to 400 mcg, the adult upper limit, so check the total from all products and foods [1].
Keep Selenium in a routine that fits
Supin schedules what you take by time of day, reminds you, and tells you when a bottle runs low.
Selenium: questions people ask
Sources
- Selenium - Health Professional Fact Sheet — NIH Office of Dietary Supplements
- Vitamins and minerals: Others — NHS
Educational information, not medical advice. The amounts above are official reference values, not a recommendation for you. Check with your doctor or pharmacist before starting or changing supplements, especially if you take medication, are pregnant or have a health condition. Supin sells a subscription, not supplements. Last reviewed .