Selenium (SE) | LabsVault

What is Selenium?

Selenium is an essential trace mineral with powerful antioxidant properties. It’s a key component of selenoproteins, including glutathione peroxidase, which protects cells from oxidative damage. Selenium also supports thyroid hormone metabolism and immune function.

Why is it Tested?

Doctors order selenium levels to evaluate deficiency in areas with selenium-poor soil, assess antioxidant status, or investigate unexplained muscle weakness or thyroid dysfunction. It’s also monitored in patients receiving long-term parenteral nutrition or those with malabsorption conditions.

Normal Ranges

Reference ranges vary by lab. General adult guidelines:

Adults: 70–150 μg/L

Selenium levels reflect both dietary intake and geographic location, as soil selenium content varies significantly worldwide. Brazil nuts, seafood, and organ meats are rich sources.

Reference ranges vary by authority. Track yours across multiple standards with automatic unit conversions in LabsVault.

What do Abnormal Results Mean?

Abnormal results are not a diagnosis. Always discuss your results with a qualified healthcare provider before making any medical decisions.

Low Selenium

Deficiency may indicate:

Inadequate dietary intake
Living in selenium-deficient regions
Malabsorption disorders
Chronic kidney disease
Keshan disease (selenium-deficient cardiomyopathy)

High Selenium

Excess selenium may result from:

Excessive supplementation
Industrial exposure
High intake of Brazil nuts or selenized supplements
Living in areas with high soil selenium

How to Track Over Time

Selenium levels change slowly, reflecting long-term intake patterns rather than recent dietary changes. Monitoring helps ensure adequate antioxidant protection while avoiding toxicity from over-supplementation, particularly important for those taking multiple vitamin supplements.

Selenium