Selenium

Selenium

Selenium is a trace element you need only in small amounts, but it punches above its weight — it’s a key part of your body’s antioxidant defences and helps your thyroid and immune system work well.

What does selenium do?

• Acts as a powerful antioxidant (through an enzyme called glutathione peroxidase), protecting your cells from damage — and it teams up with vitamins E, C and A, helping them do their antioxidant work too

• Supports thyroid function

• Helps the immune system work properly

Which foods are rich in selenium?

Brazil nuts are the famous source — so rich that just one or two a day covers most people’s needs. Other good sources include fish and seafood, eggs, meat and whole grains. As with iodine, how much a food contains depends partly on the soil it grew in (or the animal’s diet).

Can you have too little — or too much?

Deficiency is uncommon with a varied diet. Selenium is also a good example of “more isn’t better”: because Brazil nuts are so concentrated, a small handful every day (or high-dose supplements) can tip you into too much over time. A couple of nuts a day is plenty.

Common questions

How much selenium do I need? Very little — a Brazil nut or two a day will usually cover it.

Can you have too much selenium? Yes — regularly eating lots of Brazil nuts or taking supplements can provide more than you need, so moderation is key.

This is general information to help you eat well, not medical advice. If you have a specific concern, your doctor is the best person to help.