Selenium
Selenium measures the level of this essential trace mineral in your blood. Selenium plays a key role in thyroid hormone metabolism, antioxidant defense, and immune system function.
Category: Vitamins & Minerals
Also known as: selenium, se, serum selenium, selen
Reference range: 70–150 µg/L (Source: ABIM)
Standard unit: µg/L
High values may indicate
High selenium levels may indicate selenium toxicity (selenosis) from excessive supplementation, which can cause garlic breath odor, hair loss, nail brittleness, nausea, and nerve damage.
Low values may indicate
Low selenium levels may indicate poor dietary intake, malabsorption, or living in selenium-depleted soil regions, and can contribute to weakened immune function, thyroid dysfunction, and Keshan disease (a cardiomyopathy).
Frequently asked questions
- What is a normal Selenium level?
- A typical reference range for Selenium is 70–150 µg/L (source: ABIM). Reference ranges vary by laboratory, age, and sex, so always compare against the range on your own lab report.
- What units is Selenium measured in?
- Selenium is most commonly reported in µg/L. Labs in different countries may use other units — you can convert between them with BloodId's blood test unit converter.
- Where do Selenium reference ranges come from?
- BloodId uses ABIM standard reference ranges and educational information from MedlinePlus (see our methodology). Reference ranges still vary by lab, age, and sex, so always compare against your own report.
- Can I track Selenium over time?
- Yes. Upload results from any lab and BloodId charts your Selenium over time against its reference range, so you can see whether the trend is rising, falling, or stable.