Iodine, 24 Hr Urine (Sendout)

General Information

Lab Name

Lab Code

650

External Test Id

UIOD

Description

Useful For:

Assessment of iodine toxicity or recent exposure in a 24-hour urine collection
Monitoring iodine excretion rate as index of replacement therapy

Patient Preparation:

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.

Ordering Note: This test is for timed urine collections only. For random collections, see test Iodine/Creatinine Ratio, Random Urine (Sendout). Due to the significant variation in the rate of secretion over the course of a day, a 24-hour collection is preferred.

References

Mayo Clinical & Interpretive Information: Iodine, 24 Hour, Urine

Synonyms

UIOD, Urinary Free Iodine, Urinary Iodine

Components

Interpretation

Method

Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)

Reference Range

Ref. Range Notes

Reference Values:

0-17 years:	Not Established
>/= 18 years:	75-851 mcg/24 hour

Interpretation: Measurement of urinary iodine excretion provides the best index of dietary iodine intake and deficiency is generally indicated when the concentrations are below 100 mcg/L.

See also: World Healthcare Organization (WHO) Criteria for Assessing Iodine Status.¹

Interferences and Limitations

Cautions: Administration of iodine-based contrast media and drugs containing iodine, such as amiodarone, will yield elevated results.

References

Mayo Clinical & Interpretive Information: Iodine, 24 Hour, Urine

Ordering & Collection

Specimen Type

Urine

Collection

Collection:

Collect urine for 24 hours in a preservative-free amber polyethylene 24-hr urine collection container (with no metal caps or glued inserts).
Refer to Mayo Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for additional information on acceptable collection conditions.
Refrigerate urine within 4 hours of completion of collection.

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Handling Instructions

Outside Laboratories:

Mix specimen well. Measure and record total volume. Document total volume and collection interval on the requisition.
Transfer 10 mL urine to a screw-cap, plastic aliquot container with no metal cap or glued insert. Refrigerate urine while awaiting shipment. Transport with a cold pack.

Stability: Refrigerated (preferred): 28 days; Frozen 28 days; Ambient: 14 days.

Quantity

Requested: 10 mL urine
Minimum: 0.3 mL urine

Processing

Receiving Instructions

SPS: Specimen should be refrigerated within 4 hours of completion of 24-hour collection.

Mix specimen well.
Measure and record the total volume. Document the total volume and collection interval on the requisition and forward a copy to Sendouts.
Transfer 10 mL urine to a screw-cap, plastic aliquot container with no metal cap or glued insert. Refrigerate urine.

Login: SEND1-;REFRIG

RSNDT1: MAYOSD
RSTYP1: URN-;24 hr, TV (<volume>)
RTSRQ1: ;Iodine, Urine (Mayo Test UIOD)

Sendouts,

Order Mayo Test: UIOD
Enter the Collection Duration and Total Volume at the corresponding Order Questions in MayoAccess.

Stability: Refrigerated (preferred): 28 days; Frozen 28 days; Ambient: 14 days.

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Misc Sendout

Performance

Lab Department

Frequency

Performed: Tuesday, Friday. Reported: 1-5 days from sample receipt at Mayo Clinic Labs.

Available STAT?

Performing Location(s)

Sendout	Mayo Clinic Laboratories (Superior Drive) 800-533-1710 3050 Superior Drive NW Rochester, MN 55901

Billing & Coding

Billing Comments: CPT: 83789