Quick Facts
- Sample: Urine (24-hour timed collection)
- Fasting: No fasting required
- Turnaround: 2-4 days (may take longer based on weather, holiday, or lab delays)
What This Test Measures
This test measures iodine levels in a 24-hour urine collection, including both total iodine excreted over the 24-hour period and urine iodine concentration. It also measures urine creatinine, then uses these directly measured values to calculate an iodine to creatinine ratio.
The iodine and creatinine values are directly measured, while the iodine to creatinine ratio is a calculated result. This ratio helps account for variations in urine concentration across the collection period. Results reflect iodine status at the time of collection and do not represent a complete evaluation of thyroid function or overall health.
Benefits
- Measures iodine excretion over a full 24-hour period
- Provides a calculated iodine to creatinine ratio for context
- Supports monitoring of iodine intake over time
- Non-fasting urine collection you can do at home
- Results delivered securely online
Who Is This Test For?
- Adults who want to monitor their iodine intake over time
- People whose healthcare provider is monitoring iodine-induced hypothyroidism
- People whose provider is following autoimmune inflammation of the thyroid gland
- People whose provider is monitoring hyperthyroidism associated with high iodine intake
- Adults working with a healthcare provider to track iodine status over time
How It Works
- Order Your Test Online
- Visit a Local Lab
- Get Results Online
FAQ
1. What is the purpose of this test?
This test measures iodine in a 24-hour urine collection along with urine creatinine, and calculates an iodine-to-creatinine ratio. It may help a healthcare provider evaluate iodine status over the collection period. This test does not diagnose a specific thyroid condition on its own, and results should be reviewed with a healthcare provider alongside other clinical information.
2. Who would benefit from this test?
Adults interested in tracking their iodine intake, or those whose healthcare provider is monitoring iodine-related thyroid conditions such as iodine-induced hypothyroidism, autoimmune thyroid inflammation, or hyperthyroidism linked to high iodine intake, may benefit from this test. It is best used as part of a broader conversation with your healthcare provider.
3. When should I order this test?
You may consider this test if your healthcare provider is monitoring your iodine status or following a known iodine-related thyroid condition. It may also be used as part of ongoing evaluation of iodine intake over time. This test does not replace a full medical evaluation and should be interpreted within that broader context.
4. What does this test measure?
This test measures iodine in a 24-hour urine collection (both total 24-hour excretion and urine concentration) and urine creatinine, both of which are directly measured values. It then calculates an iodine-to-creatinine ratio, which is a derived result rather than a directly measured value. The specimen type is urine, collected over a timed 24-hour period rather than a single random sample.
5. Do I need to fast before this test?
No fasting is required for this test. You will need to obtain a proper specimen container from the lab before starting your 24-hour urine collection.
6. How quickly will I get results?
Results are typically available in 2-4 days, though this may take longer based on weather, holidays, or lab delays.
7. How do I interpret the results?
Interpreting your iodine, creatinine, and iodine-to-creatinine ratio results depends on your individual health history, symptoms, medications, supplements, and how accurately the 24-hour collection was performed. Directly measured iodine and creatinine values and the calculated ratio should not be interpreted interchangeably, since each reflects a different aspect of the result. An abnormal result does not automatically confirm a condition, and a normal result does not automatically rule one out. Discuss your results with a qualified healthcare provider for full interpretation.
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
8. What should I do if my results are abnormal?
If your results fall outside the expected range, review them with a qualified healthcare provider. They can help interpret your results in the context of your health history and determine whether additional evaluation or testing is appropriate. Do not start, stop, or change any medication based on this test result alone.
9. How often should I get tested?
There is no fixed testing schedule for this test. How often you are tested should be determined by your healthcare provider based on your individual situation and any condition being monitored.
Pre-test preparation
You must take your lab order to the lab to obtain a proper specimen container before collection. No fasting required. Urinate at 8am and discard the specimen. Then collect all urine in the 24-hour period, ending with final collection at 8am the next morning. Refrigerate the collected urine between all voidings or keep it in a cool place. Screw the lid on securely. Transport the specimen promptly to the laboratory. Container must be labeled with full name, date and time collection started, and date and time collection finished.
