Is it safe? · Pregnancy Smart
Is iodine safe during pregnancy?
What does the evidence say about iodine during pregnancy?
- 220 mcg a day is the recommended dietary allowance for iodine in pregnancy across all age bands, up from 150 mcg for non-pregnant adults, and it rises again to 290 mcg while breastfeeding. 1
- The tolerable upper intake level in pregnancy is 1,100 mcg a day for ages 19 and up and 900 mcg for ages 14 to 18, counting all sources. 1
- The World Health Organization, UNICEF, and the International Council for the Control of Iodine Deficiency Disorders recommend a somewhat higher intake in pregnancy of 250 mcg a day. 1
- A prenatal vitamin with at least 150 mcg of iodine is advised for anyone pregnant or planning pregnancy, since the body needs iodine to make thyroid hormones and the thyroid cannot work properly without it. 2
- Very high iodine levels can push thyroid hormone too high, and that can leave the fetus with an underactive thyroid or a goiter large enough to affect breathing or swallowing. 2
Is iodine safe in each trimester?
- First trimester. Your thyroid is doing extra work from very early on, and fetal thyroid development depends on your supply. Check whether your prenatal actually lists iodine, because roughly a quarter of prenatal products leave it out.
- Second trimester. The target stays at 220 mcg. Dairy, seafood, eggs, and iodized salt are the everyday sources. Note that most specialty salts, including sea salt and kosher salt, are not iodized.
- Third trimester. No change to the number. Too much iodine is its own problem, so this is not a nutrient where doubling up on supplements is a safe default.
Frequently asked questions
Do all prenatal vitamins contain iodine?
No. Around 76 percent of prenatal products contain it, which leaves a meaningful share without any. Iodine is one of the nutrients most worth confirming on the label rather than assuming, since it is not universally included.
Is kelp or seaweed a good iodine source during pregnancy?
Seaweed is a food source of iodine, but kelp supplements are notorious for delivering unpredictable and sometimes very large amounts. Given that too much iodine carries its own thyroid risk, this is one to raise with your provider before starting.
Does sea salt have iodine?
Generally not. Iodized table salt is fortified deliberately, while sea salt, kosher salt, and most specialty salts are not. If you have swapped to one of those, you may have quietly removed a routine iodine source.
What happens if I do not get enough iodine while pregnant?
Severe iodine deficiency in pregnancy can raise the chance of serious learning problems in the child. That is why the recommendation rises in pregnancy and why a prenatal with iodine is standard advice rather than optional.
Related in the library
References
Iodine: Health Professional Fact Sheet, NIH ODS
ODS · https://ods.od.nih.gov/factsheets/Iodine-HealthProfessional/
Iodine: MotherToBaby Fact Sheet
MotherToBaby · https://mothertobaby.org/fact-sheets/iodine-pregnancy/
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.