Test Catalog

Test ID: SEWB    
Selenium, Blood

Useful For Suggests clinical disorders or settings where the test may be helpful

Assessment of tissue stores of selenium

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Selenium is a naturally occurring, solid substance that is widely but unevenly distributed in the earth's crust. Selenium and its compounds are used in some photographic devices, gun bluing, plastics, paints, anti-dandruff shampoos, vitamin and mineral supplements, fungicides, and certain types of glass. Selenium is also used to prepare drugs and as a nutritional feed supplement for poultry and livestock. It is an essential element for humans and animals.


People are exposed to low levels of selenium daily through food, water, and air. Plasma and serum typically contain approximately 75% of the selenium measured in whole blood. Selenium whole blood concentrations can be used to assess tissue stores. For routine assessment of selenium deficiency or toxicity, the preferred test is selenium urine.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

0-17 years: not established

> or =18 years: 150-241 ng/mL

Interpretation Provides information to assist in interpretation of the test results

Ultimately, any metal ion concentration value needs to be interpreted in relation to the overall clinical scenario including symptoms, physical findings, and other diagnostic results when determining further actions.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

No significant cautionary statements

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. US Department of Health and Human Services: Toxicological profile for selenium. HHS: Agency for Toxic Substances and Disease Registry; 2003. Accessed July 30, 2021. Available at www.atsdr.cdc.gov/toxprofiles/tp92.pdf

2. Rifai N, Horwath AR, Wittwer CT: Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018

Special Instructions Library of PDFs including pertinent information and forms related to the test