Selenium is a trace element - these are minerals that are essential for the body to function properly but they are only required in extremely low quantities. Selenium is needed for good immunity.

Where do I find selenium?

Selenium is a mineral found in soil, water and some foods. Rich food sources include: brazil nuts, fish, meats, eggs, sunflower seeds and garlic. It is a good idea to take selenium and vitamin E together as they help each other to get absorbed and together works as a powerful antioxidant. According to NHS Choices men require just 0.075mg a day and women 0.06mg.

Why do I need selenium?

Selenium supports our immune system and helps to prevent cell and tissue damage. It’s an important antioxidant which means it helps protect our cells from damage from free radicals. Free radicals are thought to contribute to ageing and diseases such as cancer. In addition, selenium helps regulate thyroid function. Some experts also believe it reduces the risk of secondary cancers and may be protective against heart disease. Selenium plays a role in sperm production. Some studies believe selenium supplements might improve male fertility.

How will I know if I am lacking in selenium?

A selenium deficiency is rare in the West but it can affect people living in countries where the soil concentration of selenium is low. A deficiency has been associated with diseases of the thyroid. Symptoms of a deficiency include pain and muscle weakness. Most people can get enough selenium from their diet. You may have lower levels of selenium if you have Crohn’s disease or ulcerative colitis which impact on the body’s absorption of minerals.

Can too much selenium be harmful?

If you eat meat, fish or nuts you can probably get all your selenium needs met through your natural diet. The Department of Health advises that a dose of 0.35mg or less per day is unlikely to cause harm but in high doses selenium can be toxic. Too much selenium causes a condition called ‘selenosis’ which can lead to fatigue, hair and fingernail loss, a skin rash, irritability and weight loss.

Some studies also suggest a link between daily selenium intake and a higher risk of type 2 diabetes. More studies are needed in this area. Selenium supplements can also interfere with some therapeutic drugs so always consult your doctor if you are on medication and planning to take supplements.