Test Code LAB1413 Iodine, 24 Hour, Urine
Additional Codes
Mayo Test ID |
UIOD |
Performing Laboratory

Useful For
Assessing iodine toxicity or recent exposure in a 24-hour urine collection
Monitoring iodine excretion rate as index of replacement therapy
Special Instructions
Method Name
Inductively Coupled Plasma Mass Spectrometry (ICP-MS)
Reporting Name
Iodine, 24 Hr, USpecimen Type
UrineNecessary Information
24-Hour volume (in milliliters) is required.
Specimen Required
Patient Preparation:
1. High concentrations of gadolinium and iodine are known to potentially interfere with most inductively coupled plasma mass spectrometry-based metal tests. If either gadolinium- or iodine-containing contrast media has been administered, a specimen should not be collected for 96 hours.
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 dose, and all subsequent urine should be collected for the next 24 hours). The last void should be included in the collection.
Supplies: Urine Tubes, 10 mL (T068)
Collection Container/Tube: Clean, plastic aliquot container with no metal cap or glued insert
Submission Container/Tube: Plastic, 10-mL urine tube
Specimen Volume: 10 mL
Collection Instructions:
1. Collect urine for 24 hours.
2. Refrigerate specimen within 4 hours of completion of 24-hour collection.
3. See Metals Analysis Specimen Collection and Transport for complete instructions.
Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.
Specimen Minimum Volume
0.3 mL
Specimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
Urine | Refrigerated (preferred) | 146 days |
Ambient | 146 days | |
Frozen | 146 days |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.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.
World Healthcare Organization (WHO) Criteria for Assessing Iodine Status
Children older than 6 years and adults(1)
Median urinary iodine (mcg/L) |
Iodine intake |
Iodine status |
<20 |
Insufficient |
Severe deficiency |
20-49 |
Insufficient |
Moderate deficiency |
50-99 |
Insufficient |
Mild deficiency |
100-199 |
Adequate |
Adequate nutrition |
200-299 |
Above requirements |
May pose a slight risk of more than adequate |
>299 |
Excessive |
Risk of adverse health consequences |
Pregnant women(1)
Median urinary iodine (mcg/L) |
Iodine intake |
<150 |
Insufficient |
150-249 |
Adequate |
250-499 |
Above requirements |
>499 |
Excessive |
Lactating women and children younger than 2 years(1)
Median urinary iodine (mcg/L) |
Iodine intake |
<100 |
Insufficient |
>99 |
Adequate |
Day(s) Performed
Tuesday, Friday
Report Available
1 to 5 daysSpecimen Retention Time
14 daysTest 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 |
---|---|---|
UIOD | Iodine, 24 Hr, U | 2492-7 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
9549 | Iodine, 24 Hr, U | 2492-7 |
614369 | Iodine Concentration | 26842-5 |
614423 | Iodine Concentration Interpretation | 77202-0 |
TIME5 | Collection Duration (h) | 13362-9 |
VL23 | Volume (mL) | 3167-4 |