Sodium selenite

Sodium selenite is a chemical compound with the formula Na2SeO3. This salt is a source of selenium in many food supplements.

Sodium selenite is listed in the material safety data sheets from U.S. Environmental Health and Safety as a dangerous poison in large amounts. Its toxicity is similar to that for arsenic. It attacks sulfhydryl enzymes.

Although selenium is poisonous, it should be noted that selenium is an essential element, albeit in small amounts. Animals require selenium for selenium-dependent enzymes (selenoproteins) such as glutathione peroxidase. .

Sodium selenite can be found as a listed ingredient in various foods such as dog biscuits and multivitamins.