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24847 Iodine, 24 Hour Urine (UIOD)

Iodine, 24 Hour Urine (UIOD)
Test Code: IOD24SO
Synonyms/Keywords
Urinary Free Iodine, Urinary Iodine
Useful For

Assessment of iodine toxicity or recent exposure in a 24-hour urine collection

Monitoring iodine excretion rate as index of replacement therapy

Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
​Urine 24 Hour Urine Container  ​10 mL 0.3 mL​
Collection Processing Instructions
1. Collect urine for 24 hours.
2. No preservative.
3. Plastic, 10-mL urine tube or clean, plastic aliquot container with no metal cap or glued insert.
4. Refrigerate specimen within 4 hours of completion of 24-hour collection.
 
Additional Information:
1. 24-Hour volume is required.
2. If this test is used in conjunction with the (131)I uptake test, then specimen collection should begin immediately after the dose of (131)I is given (ie, the patient should void and discard urine just prior to the (131)I, and all subsequent urine should be collected for the next 24 hours). The last void should be included in the collection.
3. High concentrations of gadolinium and iodine are known to interfere with most metals tests. If gadolinium- or iodine-containing contrast media has been administered, a specimen should not be collected for 96 hours.
Specimen Stability Information
Specimen Type Temperature Time
​Urine ​ ​ ​Refrigerated (preferred) ​146 days
Ambient​ ​146 days
​Frozen ​146 days
Interference

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

Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Mayo Clinic Laboratories Monday, Wednesday, Friday​ ​1-3 days
Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)​
Reference Lab
Test Information
Iodine is an essential element for thyroid hormone production. The measurement of urinary iodine serves as an index of adequate dietary iodine intake. ​
Reference Range Information
0-17 years: not established
 
> or = 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.
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
​83789
Synonyms/Keywords
Urinary Free Iodine, Urinary Iodine
Ordering Applications
Ordering Application Description
​Centricity ​Iodine, 24Hr
​Cerner Iodine, 24Hr Urine (9549)​
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
​Urine 24 Hour Urine Container  ​10 mL 0.3 mL​
Collection Processing
1. Collect urine for 24 hours.
2. No preservative.
3. Plastic, 10-mL urine tube or clean, plastic aliquot container with no metal cap or glued insert.
4. Refrigerate specimen within 4 hours of completion of 24-hour collection.
 
Additional Information:
1. 24-Hour volume is required.
2. If this test is used in conjunction with the (131)I uptake test, then specimen collection should begin immediately after the dose of (131)I is given (ie, the patient should void and discard urine just prior to the (131)I, and all subsequent urine should be collected for the next 24 hours). The last void should be included in the collection.
3. High concentrations of gadolinium and iodine are known to interfere with most metals tests. If gadolinium- or iodine-containing contrast media has been administered, a specimen should not be collected for 96 hours.
Specimen Stability Information
Specimen Type Temperature Time
​Urine ​ ​ ​Refrigerated (preferred) ​146 days
Ambient​ ​146 days
​Frozen ​146 days
Interference

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

Useful For

Assessment of iodine toxicity or recent exposure in a 24-hour urine collection

Monitoring iodine excretion rate as index of replacement therapy

Reference Range Information
0-17 years: not established
 
> or = 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.
For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Mayo Clinic Laboratories Monday, Wednesday, Friday​ ​1-3 days
Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)​
Reference Lab
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
​83789
For most current information refer to the Marshfield Laboratory online reference manual.