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Serum Selenium Concentration

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of selenium, a trace mineral important for immune function and antioxidant protection, in your blood serum.

Quick summary

["Helps assess selenium status and potential deficiencies or excesses."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
78696-2
Short code
Selenium Bld-sCnc
Synonyms
Selenium Bld-sCnc
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms like hair loss, fatigue, or weakened immunity, or if you have conditions like selenium deficiency or certain genetic disorders. It may also be part of routine screening in high-risk groups or when evaluating nutritional status.

What to Expect Before the Test

No special preparation is needed. You may fast before the test, but your provider will confirm if fasting is required. Bring any medications you’re currently taking, as some may affect results.

How the Test Works

A blood sample is drawn from a vein in your arm. The serum portion is separated and analyzed to determine selenium concentration using a specialized laboratory technique.

Possible Results and Interpretation

Results are compared to general reference ranges for selenium in blood. Low levels may indicate deficiency, while very high levels could suggest exposure to excessive selenium or certain medications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Selenium Blood Level

Frequently asked questions

What Does a Low Selenium Level Mean?
A low result may suggest insufficient dietary intake, malabsorption issues, or certain medical conditions. Your provider may recommend dietary changes, supplements, or further testing to identify the cause.
Can Diet Affect Selenium Test Results?
Dietary intake of selenium can influence results, but the test measures current blood levels rather than recent consumption. Avoiding selenium-rich foods (e.g., Brazil nuts) for a few days before testing may help standardize results.
Are There Common Medications That Affect Selenium Levels?
Some medications (e.g., certain antibiotics, diuretics, or chemotherapy drugs) may interact with selenium metabolism. Always inform your provider about all medications you’re taking before the test.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy