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26444 Iodine/Creatinine Ratio, Random, Urine (IODCU)

Iodine/Creatinine Ratio, Random, Urine (IODCU)
Test Code: ICRUSO
Synonyms/Keywords

​Iodine/Creatinine Ratio, Random, Urine, ICRUSO, U ICRUSO, Iodine Creatinine Ratio, Random Urine (ICRU), Iodine Excretion, Urinary Free Iodine, Urinary Iodine, IODCU

Useful For

​Assessment of iodine toxicity or recent iodine exposure in a random urine collection

Monitoring iodine excretion reate as index of replacement therapy

Specimen Requirements
Fasting RequiredSpecimen TypePreferred Container/TubeAcceptable Container/TubeSpecimen VolumeSpecimen Minimum Volume
(allows for 1 repeat)		Pediatric Minimum Volume
(no repeat)
​​Urine​Urine Tube​Clean, plastic aliquot container with no metal cap or glued insert​3 mL​2 mL​
Collection Processing Instructions

​Patient Preparation: High concentrations of gadolinium and iodine are known to interfere with most metal tests. If either gadolinium- or iodine-containing contrast media has been administered, wait a minimum of 96 hours before starting collection.

Specimen Stability Information
Specimen TypeTemperatureTime
​Urine ​ ​​Refrigerated (Preferred)​30 Days
​Frozen​30 Days
​Ambient​14 Days
Rejection Criteria

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

Interference

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

Performing Laboratory Information
Performing LocationDay(s) Test PerformedAnalytical TimeMethodology/Instrumentation
​Mayo Clinic Laboratories​Monday, Wednesday, Friday​1-3 Days

​IODC: Iductively Coupled Plasma Mass Spectrometry (ICP-MS)

CRETR: Enzymatic Colorimetric Assay

Reference Lab
Mayo Clinic Laboratories
Test Information

​Iodine is an essential element for thyroid hormone production.

The measurement of urinary iodine is preferred for assessment of toxicity, recent exposure, and monitoring iodine excretion rate as an index of replacement therapy.

Reference Range Information
Performing LocationReference Range
​Mayo Clinic Laboratories

​0-17 Years: not established

> or = 18 Years: <584 mcg/g creatinine

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 deficiency, 10 repeat random urines are recommended.

 

World Healthcare Organization (WHO) Criteria for Assessing Iodine Status(1)

Children >6 years old and adults:

Median urinary iodine (mcg/L)Iodine intakeIodine status
<20InsufficientSevere deficiency
20-49InsufficientModerate deficiency
50-99Insufficient Mild deficiency
100-199AdequateAdequate nutrition
200-299Above requirementsMay pose a slight risk of more than adequate
>299ExcessiveRisk of adverse health consequences

 

Pregnant Women:

Median urinary iodine (mcg/L)Iodine intake
<150Insufficient
150-249Adequate
250-499

Above

requirements

>499Excessive

 

Lactating women and children <2 years old:

Median urinary iodine (mcg/L)Iodine intake
<100Insufficient
>99Adequate
Outreach CPTs
CPTModifier
(if needed)		QuantityDescriptionComments
​83789​​1​​
​82570​​1​​
Synonyms/Keywords

​Iodine/Creatinine Ratio, Random, Urine, ICRUSO, U ICRUSO, Iodine Creatinine Ratio, Random Urine (ICRU), Iodine Excretion, Urinary Free Iodine, Urinary Iodine, IODCU

Ordering Applications
Ordering ApplicationDescription
COM​​Iodine Creatinine Ratio, Random Urine (ICRU)
​Cerner​Iodine Creatinine Ratio, Random Urine (ICRU)
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Fasting RequiredSpecimen TypePreferred Container/TubeAcceptable Container/TubeSpecimen VolumeSpecimen Minimum Volume
(allows for 1 repeat)		Pediatric Minimum Volume
(no repeat)
​​Urine​Urine Tube​Clean, plastic aliquot container with no metal cap or glued insert​3 mL​2 mL​
Collection Processing

​Patient Preparation: High concentrations of gadolinium and iodine are known to interfere with most metal tests. If either gadolinium- or iodine-containing contrast media has been administered, wait a minimum of 96 hours before starting collection.

Specimen Stability Information
Specimen TypeTemperatureTime
​Urine ​ ​​Refrigerated (Preferred)​30 Days
​Frozen​30 Days
​Ambient​14 Days
Rejection Criteria

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

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 iodine exposure in a random urine collection

Monitoring iodine excretion reate as index of replacement therapy

Reference Range Information
Performing LocationReference Range
​Mayo Clinic Laboratories

​0-17 Years: not established

> or = 18 Years: <584 mcg/g creatinine

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 deficiency, 10 repeat random urines are recommended.

 

World Healthcare Organization (WHO) Criteria for Assessing Iodine Status(1)

Children >6 years old and adults:

Median urinary iodine (mcg/L)Iodine intakeIodine status
<20InsufficientSevere deficiency
20-49InsufficientModerate deficiency
50-99Insufficient Mild deficiency
100-199AdequateAdequate nutrition
200-299Above requirementsMay pose a slight risk of more than adequate
>299ExcessiveRisk of adverse health consequences

 

Pregnant Women:

Median urinary iodine (mcg/L)Iodine intake
<150Insufficient
150-249Adequate
250-499

Above

requirements

>499Excessive

 

Lactating women and children <2 years old:

Median urinary iodine (mcg/L)Iodine intake
<100Insufficient
>99Adequate
For more information visit:
Performing Laboratory Information
Performing LocationDay(s) Test PerformedAnalytical TimeMethodology/Instrumentation
​Mayo Clinic Laboratories​Monday, Wednesday, Friday​1-3 Days

​IODC: Iductively Coupled Plasma Mass Spectrometry (ICP-MS)

CRETR: Enzymatic Colorimetric Assay

Reference Lab
Mayo Clinic Laboratories
For billing questions, see Contacts
Outreach CPTs
CPTModifier
(if needed)		QuantityDescriptionComments
​83789​​1​​
​82570​​1​​
For most current information refer to the Marshfield Laboratory online reference manual.