Folic acid gets the headlines, but iodine is the nutrient many women trying to conceive overlook — and many prenatal vitamins leave it out. If you are comparing a TTC supplement or prenatal, here is what to check.
This is educational, not medical advice. For the full buying overview, see fertility supplements to get pregnant.
1. Why iodine matters before and during pregnancy
Iodine is needed to make thyroid hormones, which support normal growth and brain development in a baby. Needs rise in pregnancy because the thyroid works harder and the baby depends on the mother’s supply. Thyroid hormone also plays a role in cycle regularity, so it is worth reviewing alongside your doctor — see thyroid health and conception.
2. How much: NIH intake levels
| Group | Per day |
|---|---|
| Adults 19+ (RDA) | 150 mcg |
| Pregnancy (RDA) | 220 mcg |
| Breastfeeding (RDA) | 290 mcg |
| Upper level, adults (UL) | 1,100 mcg |
Source: NIH Office of Dietary Supplements. Check current figures on the NIH ODS site. The American Thyroid Association has recommended that women who are pregnant, breastfeeding or planning pregnancy take a daily supplement with about 150 mcg of iodine — confirm what applies to you with your doctor.
3. Food first: where iodine comes from
- Iodized salt — check the label; sea salt, kosher salt and many specialty salts are often not iodized.
- Dairy, eggs and seafood — milk, yogurt, eggs, cod and shrimp contribute meaningful amounts.
- Seaweed — very variable. Some kelp products contain far more than the upper level in a single serving, so do not rely on them without checking the label.
If you avoid dairy, eggs and fish, or use non-iodized salt, it is easier to fall short. See vegan and vegetarian fertility supplements for the other nutrients to watch.
4. Prenatal or TTC supplement: 5 label checks for iodine
- Is iodine listed? Not every prenatal contains it. Look for a line such as “iodine (as potassium iodide)” with an amount in mcg.
- Source of the iodine: potassium iodide is a defined amount; kelp or seaweed blends can vary from batch to batch, so ask for the form.
- Add up your total from food, prenatal and any extra product. The upper level is 1,100 mcg per day — kelp tablets plus a prenatal can add up quickly.
- Thyroid condition or thyroid medication? Talk to your doctor before adding iodine. Too much or too little can matter, and timing with medication matters too — see fertility supplements and levothyroxine timing.
- Third-party testing (USP, NSF or a certificate of analysis); in Canada, look for an NPN. For any AGO product, ask the care team for the full label — they share it on request.
5. Where AGO fits in your TTC routine
- Keep your prenatal for folic acid, iodine and the other basics your doctor recommends. AGO formulas are designed to support reproductive wellness alongside it — see AGO Mom vs prenatal vitamins.
- Avoid doubling up: review every label together so iodine and other nutrients are not duplicated — see what to take and what’s redundant.
- Include him: sperm takes about 2–3 months to develop, so start together. See fertility supplements for couples.
- After a positive test, review everything with your OB — see what to keep and what to stop.
Results vary and no supplement guarantees pregnancy. Get a free personalized plan and our care team will help you build a simple routine to review with your doctor.
FAQ
How much iodine do I need while trying to conceive?
The NIH recommended intake is 150 mcg per day for adults and 220 mcg per day during pregnancy, from food and supplements combined. Ask your doctor what is right for you.
Does my prenatal vitamin contain iodine?
Not always. Check the Supplement Facts panel for iodine and its amount in mcg, and whether it comes from potassium iodide or from kelp.
Can you take too much iodine?
The adult upper level is 1,100 mcg per day. Very high intake from kelp or seaweed products can affect thyroid function, so check labels and ask your doctor if you have a thyroid condition.
Is sea salt a good source of iodine?
Often not. Many sea salts and specialty salts are not iodized, so check the label for the word iodized.
Can I take AGO Mom with a prenatal that has iodine?
Ask the AGO care team for the AGO Mom label and review it with your doctor so you can check totals and avoid doubling up.