Brazil nuts contain 659 kcal per 100g — the highest calorie count of any common tree nut. A small handful of about 30g (roughly 6 nuts) contains approximately 198 kcal — 10% of the adult 2,000 kcal daily reference intake. A single brazil nut weighs approximately 5g and contains around 33 kcal. The high calorie density comes from the very high fat content at 67g per 100g. Portion control is particularly important with brazil nuts — both for calorie management and, more critically, for selenium intake.

Brazil nuts contain approximately 1917ug of selenium per 100g — by a very large margin the richest dietary source of selenium available. A 30g handful provides approximately 575ug of selenium — 767% of the adult daily requirement of 75ug. A single brazil nut provides approximately 96ug — already 128% of the adult daily requirement. The NHS upper safe limit for selenium is 350ug per day for adults. Eating just 4 brazil nuts in a day (approximately 20g) provides roughly 383ug — above the safe upper limit. Brazil nuts are the only common food where a single small serving can exceed safe micronutrient limits. They should not be eaten in large quantities or daily.

The NHS advises eating no more than a small handful (about 30g, roughly 6 nuts) of brazil nuts occasionally — not every day. The NHS upper safe limit for selenium is 350ug per day for adults. Given that a single brazil nut provides approximately 96ug of selenium, the safe daily maximum is approximately 3 to 4 nuts per day when accounting for selenium from other dietary sources such as meat, fish, eggs and dairy. Eating a 30g handful (575ug selenium) regularly over time poses a risk of selenium toxicity. One to two brazil nuts per day, a few times a week, is widely considered a safe and nutritionally useful intake for maintaining selenium levels.

Selenium is an essential trace mineral that the body needs in very small amounts. It forms part of selenoproteins — enzymes that protect cells from oxidative damage, regulate thyroid hormone metabolism and support immune function. Selenium deficiency is rare in the UK but more common in parts of Europe where soils are selenium-poor. The adult RNI for selenium is 75ug per day for men and 60ug per day for women. Just one or two brazil nuts per day is sufficient to meet or exceed this requirement, making brazil nuts one of the most practical ways to ensure selenium adequacy without supplements.

Selenium toxicity (selenosis) can occur from regularly eating large quantities of brazil nuts. Early symptoms include a garlic-like odour on the breath, a metallic taste in the mouth, nausea and diarrhoea. Chronic excessive intake can cause hair loss, brittle nails, skin rashes, fatigue and in severe cases neurological damage. Selenosis is unlikely from occasional consumption of a small handful, but can develop from eating brazil nuts daily in quantities of 5 or more. Children are at higher risk due to lower body weight and lower upper safe limits — a single brazil nut can provide several times a child's daily selenium requirement. If you eat brazil nuts regularly, limiting intake to 1-2 nuts per day is a sensible precaution.

Brazil nuts contain 67g of fat per 100g — the highest fat content of any common tree nut. A 30g handful provides approximately 20.1g of fat. Unlike almonds and peanuts, a significant proportion is saturated fat — 15.1g per 100g (4.5g per 30g handful), representing 19% of the adult daily saturated fat guideline of 24g in a single handful. The remaining fat is predominantly oleic acid (monounsaturated) and linoleic acid (polyunsaturated). The high saturated fat content makes brazil nuts nutritionally distinct from most other nuts, where unsaturated fat is dominant.

Brazil nuts contain 2.3g of sugar per 100g — approximately 0.7g per 30g handful, or less than a quarter of a teaspoon. This is among the lowest natural sugar content of any tree nut. All of it is intrinsic sugar, naturally occurring within the nut, with 0g of added or free sugar. Brazil nuts contribute 0g to the NHS daily free sugar limits of 30g for adults, 24g for children aged 7 to 10, and 19g for children aged 4 to 6. For those specifically managing sugar intake, brazil nuts are one of the lowest sugar nut options available.

Beyond selenium, brazil nuts are high in copper (170% NRV per 100g), phosphorus (104%), magnesium (100%), manganese (60%) and zinc (41%). A 30g handful provides 113mg of magnesium — 38% of the adult daily requirement — and 218mg of phosphorus — 40% of the adult daily requirement. Magnesium supports muscle and nerve function; phosphorus works with calcium for bone health. The combination of magnesium, phosphorus and zinc makes brazil nuts a genuinely broad micronutrient source, even before the extraordinary selenium content is considered.

Yes, in small amounts. Brazil nuts are a NOVA group 1 whole food with 0g of added sugar, 0g of salt and no additives. They are the single most efficient dietary source of selenium available — 1 to 2 nuts provides the entire adult daily selenium requirement. They also provide meaningful amounts of magnesium, phosphorus, copper and zinc. The caveats are significant: very high in calories at 659 kcal/100g, highest saturated fat of any common nut at 15.1g/100g, and a very real selenium toxicity risk if eaten in large quantities regularly. Brazil nuts are best thought of as a micronutrient supplement food rather than a snacking nut — 1 to 2 per day, a few times a week, is the nutritionally optimal approach.

Whole brazil nuts are a choking hazard for children under 5 and must not be given to this age group. From age 5 upwards they can be introduced carefully. The selenium content requires particular attention with children: the upper safe limit for selenium in children aged 4 to 6 is 60ug per day. A single brazil nut provides approximately 96ug — already above the safe upper limit for this age group. Children aged 4 to 6 should not be given whole brazil nuts. Older children (7 to 10) have an upper limit of approximately 150ug — meaning at most 1 to 2 small nuts occasionally. Brazil nuts are a tree nut and one of the 14 major allergens — introduce with care and watch for any allergic reaction.

Yes. Brazil nuts are a tree nut and one of the 14 major allergens regulated under UK food law. Tree nut allergy can cause reactions ranging from mild hives and itching to severe anaphylaxis. Brazil nut allergy is one of the more common tree nut allergies. Cross-reactivity with other tree nuts is possible — someone allergic to one tree nut may also react to others, though this is not always the case. Anyone with a known or suspected tree nut allergy should seek medical advice before consuming brazil nuts. They should not be given to children with a family history of tree nut allergy without GP or allergy specialist guidance.

Yes. Brazil nuts are suitable for vegans and vegetarians. They contain no animal-derived ingredients. For vegans, brazil nuts are particularly valuable as a selenium source — selenium is found mainly in meat, fish and eggs in most diets, making it a nutrient that plant-based eaters can struggle to obtain. One to two brazil nuts per day is sufficient to meet the adult daily selenium requirement without animal products. They are naturally gluten-free, though those with coeliac disease should check for cross-contamination on packaged products.

Brazil nuts are the most calorie-dense common nut at 659 kcal/100g, ahead of almonds at 579 kcal and peanuts at 567 kcal. They have the highest fat content at 67g/100g and the highest saturated fat at 15.1g/100g — significantly more than almonds at 3.8g/100g. Protein at 14g/100g is moderate — less than almonds (21.2g) and peanuts (26g) but more than tiger nuts (4g). Fibre at 7.5g/100g is reasonable but lower than almonds (12.5g) and tiger nuts (33g). The selenium content at 1917ug/100g is without comparison in the food world — no other commonly eaten food comes close. Brazil nuts are best consumed for selenium rather than as a general-purpose snack nut.

Brazil nuts fit best into a balanced diet as an occasional selenium source rather than a regular snacking nut. One to two nuts per day, a few times a week, is the approach that captures the selenium benefit without risking toxicity. At this quantity the calorie and saturated fat contribution is minimal — 1 nut provides approximately 33 kcal and 0.75g of saturated fat. A 30g handful eaten regularly would provide excessive selenium, significant saturated fat and nearly 200 kcal — not appropriate as a daily snack in that quantity. The NHS recommends eating a variety of nuts rather than large amounts of any single type, and this advice applies with particular force to brazil nuts given the selenium upper limit.