Selenium is a mineral found in the soil. Selenium naturally appears in water and some foods. While people only need a very small amount, selenium plays a key role in the metabolism.
Selenium helps the body with:
- Making special proteins, called antioxidant enzymes, which play a role in preventing cell damage
- Helping your body protect you after a vaccination
Some medical studies suggest that selenium may help with the following conditions, but more studies are needed:
- Prevent certain cancers
- Prevent cardiovascular disease
- Help protect the body from the poisonous effects of heavy metals and other harmful substances
- Taken at normal doses, selenium does not usually have side effects.
- An overdose of selenium may cause bad breath, fever, nausea, and liver, kidney and heart problems. At high enough levels, selenium could cause death.
- Skin cancer: Selenium supplements are associated with a risk of skin cancer (squamous cell carcinoma), so people at high risk of skin cancer should not take these supplements.
- Diabetes: One study found that people who took 200 micrograms a day of selenium were 50% more likely to develop type 2 diabetes. So far, it’s unknown if the selenium actually caused the disease. Discuss the risk with your doctor.
- Selenium may also interact with other medicines and supplements, such as antacids, chemotherapy drugs, corticosteroids, niacin, cholesterol-lowering statin drugs, and birth control pills.
Source: WebMD, “Selenium”, www.webmd.com/vitamins-and-supplements/