Selenium in Serum or Plasma (Mass Concentration)

Why Is This Test Done?

Your healthcare provider may order this test to check for selenium deficiency, monitor selenium levels in conditions like autoimmune diseases, or evaluate selenium toxicity. It can also be part of a broader nutritional assessment or screening for certain health concerns.

What Does a Low or High Level Mean?

Low selenium levels may indicate poor absorption, dietary deficiencies, or underlying health conditions affecting nutrient uptake. High levels could result from excessive supplementation or rare genetic disorders. Interpretation depends on clinical context and your overall health.

How Is This Test Performed?

A blood sample is drawn from a vein, usually in your arm. The sample is sent to a lab where selenium is measured using a specialized analytical technique (often high-performance liquid chromatography or immunoassay). Results are reported as mass concentration in micrograms per deciliter (µg/dL).

What Should You Expect Before or After the Test?

No special preparation is usually needed, but inform your provider about any medications or supplements you take, as they may affect results. After the blood draw, you may experience mild discomfort or bruising at the site. Results are typically available within 1–3 business days.