Selenium is a micronutrient vital for many processes in the body. This includes maintaining a healthy immune system and plays an important role in normal thryoid hormone metabolism. Selenium also helps maintain male fertility, by promoting sperm motility.

Most soils in the UK and Europe are deficient in selenium, which translates in low-selenium of farmed food and eventually, low selenium status of populations who consume local food.

Selenium is an essential component of the key antioxidant enzyme glutathione peroxidase which works with other antioxidants to protect the cells of the body.