Iodine in urine
urine iodine test · urinary iodine · iodine level test · iodine deficiency test
This urine test shows how much iodine your body gets from food.
To check for too little or too much iodine: with thyroid conditions, in pregnancy, and before radioactive iodine treatment.
⏱ Duration: urine collection takes a few minutes or 24 hours; results usually come in a few days
Be sure to tell your doctor
How to prepare
- Contrast dye. After a CT scan with contrast, urine iodine stays high for several weeks. Tell your doctor. The test may be moved.
- Food. Eat as usual, without large servings of seaweed or seafood the day before.
- Supplements. Do not stop them on your own. Ask your doctor if you should pause iodine.
- Collection. Usually the first morning urine is tested. Sometimes the doctor asks for a 24-hour collection. Check which one.
What to bring
- Your referral
- The urine container
- Your ID
How it goes
- Get a sterile container from a pharmacy or the lab
- In the morning, wash your hands and wash your genitals with water, without iodine soap
- Pee into the container without touching its rim
- Close the lid tightly
- Take the urine to the lab within a few hours
What you'll feel
- Nothing unpleasant. It is a normal urine sample
- It can be a little awkward to aim. Hold the container by the outside
Afterwards
- You can eat and drink as usual right away
- One result can change from day to day. The doctor sometimes repeats the test
Common questions
Can I eat iodized salt before the test?
Yes, eat as usual. The test should reflect your normal diet.
Does a CT scan with contrast affect the result?
Yes, a lot. Tell your doctor if you had a CT scan in the last few weeks.