What is selenium?
Discover why we need selenium in our diets, how much we require, which foods are good sources and our top recipe suggestions
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.
The health benefits of selenium include:
- Metabolises iodine
- Provides antioxidant defence in the thyroid
- Aids the immune system
- May be an effective antioxidant against the risk of cancers
- May reduce effects of male infertility
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, those containing selenium yeast
- Meat, such as beef steak, beef liver, turkey, chicken
- Fish, specifically yellowfin tuna
- Baked beans
- Brazil nuts
In the UK, selenium levels in soil are relatively low, therefore foods grown or raised here are lower in selenium than their international counterparts. Just two Brazil nuts daily will provide you with your daily requirement of selenium.
Recipes that are high in selenium
Tofu & spinach cannelloni
Chilli salmon & teriyaki noodles
Jacket potato with home-baked beans
Smoked mackerel risotto
Brazil nut refried beans
Chicken with pomegranate & Brazil nuts
Sweet & spicy nuts
Healthy baked beans
Saucy bean baked eggs
Crispy chilli beef
Turkey breast fingers with avocado dip
More on vitamins and minerals
This content was updated on 20 October 2023.
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.
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