BiomarkersUrinary iodine
Minerals
Urinary iodine
Iodine in urine, a measure of recent intake
On your report it may say: UIC, Urinary iodine concentration
Most iodine you eat leaves in urine, so urinary iodine reflects recent intake. It's best for checking populations; a single result for one person varies from day to day.
Typical ranges · µg/L
Adults (not pregnant)
Targets are higher in pregnancy (150–249 µg/L adequate).
Ranges vary by lab, age and sex. The range printed on your report applies.
If it's low
Recent iodine intake may be low.
Common causes
- No iodised salt
- Low dairy and seafood
What you might notice
- Usually none short term
If it's high
Recent intake is high, often from supplements or seaweed.
Common causes
- Kelp or seaweed
- Iodine supplements
- Contrast scans
What you might notice
- Thyroid changes in sensitive people
Testing
- Who should test
- When a doctor wants to check iodine intake.
- How to prepare
- Spot or 24-hour urine sample as your lab instructs.
- When to retest
- As your doctor advises.
What can help
Food sources
Discuss results with your doctor, especially in pregnancy.
Common questions
Why does one result vary so much?
It changes with what you ate in the last day or two.
Is it useful in pregnancy?
Yes, as needs rise; your doctor will interpret it.
Explore further
Related markers
When to take them
Sources
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Build My Nutrition PlanFor general education only, not medical advice. Ranges shown are typical for adults; the range printed on your lab report applies. Talk to a qualified doctor about your results.