Selenium is an essential trace element with important functions throughout the body, including aiding the synthesis and metabolism of thyroid hormones, strengthening the immune system, and in DNA synthesis.

Selenium is found in many foods but has the highest quantities in Brazil nuts, seafood, kidney, and meat.

Selenium deficiency symptoms include weakness, dizziness, hair loss, and nausea. Although selenium is needed in your body, exposure to high levels can cause adverse health effects. Toxicity may occur following over-ingestion of supplements/foods or through occupational exposure.