Selenium is an essential mineral that may support the immune system, fertility, and cognitive function. It exists mostly in the skeletal muscles. Learn more.

Selenium deficiency refers to not having enough selenium in your system. Symptoms may include fatigue, muscle weakness, and infertility, among others.

Keep reading to learn more about selenium and why we need it, as well as 15 foods that contain this important nutrient.

You need only trace amounts of selenium to survive. Falling outside of this narrow therapeutic window can have significant health consequences.

Here's what selenium is, what benefits it provides and the dangers of taking too much.

Selenium – a mineral found in many foods – could reverse the cognitive impact of stroke and boost learning and memory in aging brains, according to University of Queensland research.

Taking high doses of selenium or vitamin E can increase the risk of prostate cancer, a new study found. Vitamin E supplements can raise the risk of prostate cancer by as much as 63 percent in certain ...

Selenium supplementation is associated with improvements in key thyroid measures in patients with Hashimoto thyroiditis who are not treated with thyroid hormone replacement therapy, research from ...