Selenium is the mineral your food inherits from the dirt it grew in. That makes plant levels a lottery of geography, and it is why vegan intakes can run low, and why two Brazil nuts can flip the whole thing.
Vegan Brief·Evidence last reviewed July 15, 2026
This is a summary of the cited evidence, not medical advice.
RDA (adults)55 mcg/day
Brazil nuts544 mcg per ounce (average)
Plant levelsVary by soil
01
A mineral that comes from the soil
Selenium is unusual. A plant food's selenium is not a fixed property of the food; it is a property of the ground it grew in. The NIH fact sheet, a public-domain US government document, spells out both the rich sources and the catch.
Primary source 01 / 03
Foods that are high in protein, such as seafood, meat, and poultry, are rich sources of selenium. Brazil nuts contain particularly high amounts of selenium.
The selenium concentrations of plant-based foods vary by geographic location because the amount and form of selenium in the soil and other factors can influence the selenium content of these foods.
Animal products dodge that variability because livestock feed is topped up to a set level, so meat and dairy deliver a predictable dose. Plants pass the soil lottery straight to your plate, which is why a vegan diet is where the shortfall tends to appear.
Primary source 03 / 03
people who follow a vegetarian or vegan dietary pattern may have lower selenium intakes than others
The good news is how concentrated the best plant source is. USDA figures put the average Brazil nut ounce at 544 micrograms of selenium, against a daily target of 55 micrograms for adults. One or two nuts a few times a week covers most people. The caution is the flip side of that number: Brazil nuts vary enormously, and selenium has a real upper limit, so a fistful every day is too much. A couple of nuts, or a supplement at the RDA, is the sensible range.
Zinc on a vegan dietPlants have zinc; phytates make you absorb less of it. The fix is more intake plus a few kitchen tricks that free the zinc up.
Iodine on a vegan dietIodine is the quiet one: no drama, easy to miss, easy to fix. Iodized salt or a measured amount of seaweed does it, and kelp can overshoot hard.
Iron on a vegan dietPlants have iron, just the kind your body absorbs less easily. The government fact sheet quantifies exactly how much less, and what raises the odds in your favor.
Frequently asked
Do vegans get enough selenium?
Not always. Because plant selenium depends on the soil the crop grew in, the NIH notes that people on vegetarian or vegan diets may have lower selenium intakes than others. It is one of the trace minerals worth a deliberate source rather than assuming a varied diet covers it.
How many Brazil nuts a day for selenium?
Very few. USDA data give an average of 544 micrograms of selenium per ounce of Brazil nuts, roughly ten times an adult's 55-microgram daily target, and the levels swing widely nut to nut. One or two a few times a week is plenty, and a daily handful can push past the safe upper limit.
The primary sources
The documents this page quotes. Read them yourself.
