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Iodine Mass Concentration in Serum or Plasma

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

This test measures the amount of iodine present in your blood, which is important for thyroid hormone production.

Quick summary

["Iodine levels help ensure your thyroid is functioning properly."]

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

Key facts at a glance

LOINC
20864-5
Short code
Iodine Mlk-mCnc
Synonyms
Iodine Mlk-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your healthcare provider may order this test if you have symptoms of thyroid issues, such as fatigue, weight changes, or unexplained goiter. It can also be used to monitor iodine intake or thyroid replacement therapy.

What Does an Abnormal Result Mean?

Low iodine levels may indicate thyroid dysfunction, dietary deficiencies, or certain medical conditions. High levels could suggest overconsumption of iodine-containing supplements or medications.

How Is the Test Performed?

A blood sample is drawn from a vein, usually in your arm. The sample is then sent to a lab for analysis using a specialized method to measure iodine concentration.

What Should You Expect Before the Test?

No special preparation is typically required, but you may be asked to avoid certain supplements or medications that could affect results. Always follow your provider’s instructions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Iodine Level

Frequently asked questions

How long does it take to get results from this test?
Results are usually available within 1 to 3 business days, depending on your lab’s processing time.
Can dietary iodine supplements affect this test?
Yes, excessive iodine intake from supplements or certain foods (like seaweed) may temporarily alter results. Your provider may advise limiting intake before testing if instructed.
What are common symptoms linked to low or high iodine levels?
Low iodine levels may cause fatigue, weight changes, or goiter, while high levels could lead to nausea, hair loss, or skin rashes. Symptoms vary by individual and underlying cause.
  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