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Test Code IOD Iodine, Serum

Important Note

  • Must be drawn at Outpatient Lab at the Main Campus
  • Collect in Royal Blue Tube with RED label

Reporting Name

Iodine, S

Useful For

Determining iodine overload using serum specimens

 

Monitoring iodine levels in individuals taking iodine-containing drugs

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Serum


Specimen Required


Patient Preparation:

1. Disinfectants (such as Betadine) that contain iodine should not be used during venipuncture.

2. High concentrations of gadolinium and iodine may interfere with inductively coupled plasma mass spectrometry-based metal tests. If either gadolinium- or iodine-containing contrast media has been administered, the specimen should not be collected for at least 96 hours.

Supplies:

-Metal Free B-D Tube (No Additive), 6 mL (T184)

-Metal Free Specimen Vial (T173)

Collection Container/Tube: Plain, royal blue-top Vacutainer plastic trace element blood collection tube

Submission Container/Tube:  Mayo metal-free, screw-capped, polypropylene vial

Specimen Volume: 1 mL

Collection Instructions:

1. Allow specimen to clot for 30 minutes; then centrifuge the specimen to separate serum from the cellular fraction.

2. Remove the stopper. Carefully pour specimen into Mayo metal-free, polypropylene vial, avoiding transfer of the cellular components of blood. Do not insert a pipet into the serum to accomplish transfer, and do not ream the specimen with a wooden stick to assist with serum transfer.

3. See Trace Metals Analysis Specimen Collection and Transport for complete instructions.


Specimen Minimum Volume

0.3 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 21 days
  Ambient  21 days
  Frozen  21 days

Reference Values

40-92 ng/mL

Day(s) Performed

Tuesday, Friday

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

83789

LOINC Code Information

Test ID Test Order Name Order LOINC Value
IOD Iodine, S 2494-3

 

Result ID Test Result Name Result LOINC Value
81574 Iodine, S 2494-3

Interpretation

Values between 80 ng/mL and 250 ng/mL have been reported to indicate hyperthyroidism.

 

Values above 250 ng/mL may indicate iodine overload.

Clinical Reference

1. Allain P, Berre S, Krari N, et al. Use of plasma iodine assay for diagnosing thyroid disorders. J Clin Pathol. 1993;46(5):453-455

2. Rifai N, Chiu RWK, Young I, Burnham CAD, Wittwer CT, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier; 2023

3. Leung AM, Braverman LE. Consequences of excess iodine. Nat Rev Endocrinol. 2014;10(3):136-142. doi: 10.1038/nrendo.2013.251

4. U.S. Department of Health and Human Services, Agency for Toxic Substances and Disease Registry: Toxicological Profile for Iodine. HHS; 2004. Accessed March 20, 2025. Available at www.atsdr.cdc.gov/ToxProfiles/tp158.pdf

Report Available

2 to 4 days

Method Name

Inductively Coupled Plasma Mass Spectrometry (ICP-MS)