Selenium is a trace element found widely in the environment. Good food sources include brazil nuts, bread, fish, meat and eggs.

How much do I need?

If you eat meat, fish or nuts, you should be able to get all the selenium you need from your daily diet. This is:

  • 0.075 mg a day for men
  • 0.06 mg a day for women

What does it do?

Selenium plays an important role in our immune system's function, in thyroid hormone metabolism and in reproduction. It is also part of the body's antioxidant defence system, preventing damage to cells and tissues.

What happens if I take too much?

Too much selenium causes selenosis, a condition that in its mildest form can lead to loss of hair, skin and nails.

What is our advice?

You should be able to get all the selenium you need by eating a varied and balanced diet that includes meat, fish or nuts. But if you decide to take selenium supplements it's important not to take too much because this could be harmful.

Taking 0.35 mg or less a day of selenium supplements is unlikely to cause any harm.