Selenium is a trace element that works as an antioxidant in the body by preventing damage to your cells that some particles from the environment can cause. The selenium content of foods can vary considerably depending on the selenium content of the geographic sources where the animal was raised or the plant was grown. It is mainly absorbed in the small bowel, specifically the duodenum.


Always speak to your GP or healthcare provider before taking a new supplement or if you are concerned about nutritional deficiencies.

Why do we need selenium?

Selenium plays a role in iodine metabolism and thyroid function, protects against oxidative stress and aids the immune system. Some studies provide evidence that adequate selenium levels may reduce the risk of some cancers.

There is also some evidence that a higher selenium status has been linked to enhanced immune competence, male infertility, mood disorders and cardiovascular disease, however more studies are needed in these areas.

Pile of Brazil nuts

How much selenium do we need and what are the effects of consuming too much?

Daily recommendations of selenium in the UK are 75mcg for men and lactating women and 60mcg for women. As selenium is largely excreted in the urine with some metabolites being excreted in the breath, it is very difficult to consume too much from diet alone.

Large doses of selenium supplements may cause toxicity, however that depends on the nature of the compound and its solubility. Insoluble selenium sulphide is much less toxic than selenite, selenate and selenomethionine – different forms of selenium. It is advised not to exceed daily levels above 400mcg.

Which foods are good sources of selenium?

The main food sources of selenium are bread, meat, poultry, fish, tofu, baked beans, eggs, Brazil nuts and milk. In the UK, selenium levels in soil are relatively low, therefore foods grown or raised here are lower in selenium then their international counterparts. Just two Brazil nuts daily will provide you with your daily requirement of selenium.

Tofu and spinach cannelloni

Recipes that are high in selenium

Tofu & spinach cannelloni
Chilli salmon & teriyaki noodles
Jacket potato with home-baked beans
Smoked mackerel risotto

More on vitamins and minerals

Five nutrients every woman needs
Vital vitamins
What is vitamin B12?
The best sources of vitamin C
Am I getting enough vitamin D?

This article was published on 18th June 2019.

Emer Delaney BSc (Hons), RD has an honours degree in Human Nutrition and Dietetics from the University of Ulster. She has worked as a dietitian in some of London's top teaching hospitals and is currently based in Chelsea.


All health content on is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other health care professional. If you have any concerns about your general health, you should contact your local health care provider. See our website terms and conditions for more information.

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