Why Do You Need Iodine and Iodine Supplements In Pregnancy?

Why Do You Need Iodine and Iodine Supplements In Pregnancy

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Globally, 18 billion babies are born with a mental impairment due to iodine deficiency in mothers. Around 38 million are born with a risk of iodine deficiency (1).

Alarming, isn’t it? Iodine is a key nutrient that your body needs to produce enough thyroid hormones during pregnancy. This hormone is essential for the healthy development and functioning of the brain, bones, muscles, heart, immunity, and metabolism of both the mother and the baby.

In this article, MomJunction reveals the need for iodine, its recommended dosage, and the risks of deficiency during pregnancy.

Why Do You Need Iodine During Pregnancy?

Here is why you need iodine in pregnancy:

  • It is essential for the development of your baby’s brain and nervous system, and a deficiency might impair their development.
  • Iodine helps in regulating the baby’s metabolism.
  • Your body should be producing around 50% more of the thyroid hormone to help the baby develop a normal and healthy thyroid. Otherwise, it can lead to maternal and fetal goiter (abnormal enlargement of the thyroid gland), or hypothyroidism (underactive thyroid gland) (2).
  • Also, if the fetus has an underdeveloped thyroid, it could cause low IQ, and your baby could have developmental problems or learning disabilities. (3).
  • Insufficient iodine intake can increase the chances of preterm labor, miscarriage, stillbirth, and even death of the infant (4).
  • Extremely low levels of iodine will affect the physical and mental development of the baby (cretinism) (5).
  • According to a study, insufficient iodine intake during pregnancy is associated with an increased risk of ADHD (attention deficit hyperactivity disorder) in children. ADHD is linked with conduct disorder, oppositional defiant disorder, anxiety, depression, autism spectrum disorders, and substance use disorders (6).

While iodine is necessary, it must be taken no more or less than the recommended amount.

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[ Read: Reasons To Eat Paneer In Pregnancy ]

How Much Iodine Is Recommended In Pregnancy?

According to the US National Institute of Health, the recommended daily allowance of iodine for pregnant women is 220mcg (7).

Even if you cannot get the recommended amount every day, you might want to make up to obtain the average amount over a week or a few days by including iodine-rich foods in your diet. You may also take iodine supplements, but only if suggested by the doctor.

According to the US Institute of Medicine, you can consume up to 1,100mcg of iodine per day. But you should avoid iodine overdose.

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What Happens If You Take Too Much Iodine In Pregnancy?

A study shows that women who have taken above this safe upper limit had babies with congenital hypothyroidism, which is a thyroid deficiency.

When left untreated, hypothyroidism will lead to neurocognitive impairments in infants and children (8).

Too much iodine will also cause some symptoms similar to iodine deficiency, including:

  • Goiter (abnormal enlargement of thyroid gland)
  • Thyroid gland inflammation and thyroid cancer
  • Burning sensation in the throat, mouth, and stomach
  • Fever, diarrhea, and stomach pain
  • Nausea and vomiting
  • Weak pulse, and coma in rare cases (7)

To stay safe, limit your iodine intake by relying on dietary sources that are naturally rich in the nutrient.

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What Are The Best Food Sources Of Iodine?

Iodine is present in dairy products, vegetables, seafood, and eggs among other foods. The amount of iodine in these sources may depend on the iodine present in that particular region’s soil or water.

[ Read: Seafood During Pregnancy ]

Following is the list of iodine-rich foods you can include in your pregnancy diet (9).

FoodServingIodine (mcg)
Iodized salt1g77
Cow milk1 cup/ 8oz99
Yogurt (plain and low-fat)1 cup75
Navy beans (cooked)½ cup32
Potato with peel (baked)1 medium-sized60
Egg (boiled)1 large12
Tuna (canned in oil)½ can/ 3oz17
Fish sticks3oz54
Turkey breast (baked)3oz34
Enriched bread2 slices45
Enriched macaroni (boiled)1 cup27
Cheddar cheese1oz12
Apple juice1 cup7

Be cautious about the presence of nitrates in certain foods, as they affect your ability to absorb iodine. Avoid processed foods and meats including deli meat, hot dogs, and sausages that contain nitrates (10).

In some cases, when your diet is not as rich in iodine, your doctor may recommend supplementation.

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Is It Safe To Take Iodine Supplement During Pregnancy?

Yes. Most doctors recommend taking iodine supplements during pregnancy since it is not easy to obtain the necessary iodine from diet alone.

  • Women who are trying to conceive, or pregnant or lactating can take around 150mcg of iodine supplements every day, especially if they are unable to get the recommended dosage from dietary sources (7).
  • If you are already on iodine supplements due to a pre-existing thyroid issue, tell your doctor about it.
  • Most prenatal vitamins contain iodine. Otherwise, you can get supplements that are a combination of iodine and folate.
  • Do not include seaweed or kelp-based iodine supplements since they contain varying amounts of iodine, and might also have mercury, which is dangerous for the baby (11) (12).

Keep reading for more on the common queries about iodine during pregnancy.

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Frequently Asked Questions

1. For how long should I take iodine supplements during pregnancy?

You can take one 150mcg iodine tablet every day, from the time of conception to the time you stop breastfeeding. These tablets should only be supplemental to iodine-rich foods such as eggs, fish, vegetables and such (13).

2. Is it safe to take potassium iodide during pregnancy?

Yes, you can safely take potassium iodide (KI), which is an inorganic iodine supplement used for managing iodine deficiency and thyroid disorders. Research shows that infants born to mothers on potassium iodide supplementation in their first trimester had higher neuropsychological assessment scores compared to babies born to mothers who didn’t receive any iodine supplementation (10).

[ Read: Eating Tuna During Pregnancy ]

3. Can you use iodine tincture during pregnancy?

Iodine tincture is a topical antiseptic and disinfectant used for treating minor wounds. It is a combination of 2% iodine and 2% sodium iodide in 50% alcohol. It should not be used during pregnancy unless suggested by your doctor. Accidental ingestion of this compound can lead to death (14).

If you are planning to conceive or are pregnant but worried about your iodine levels, check with your healthcare provider. Your doctor may suggest a specialized 24-hour urine test to detect iodine levels in the body, based on which you may be asked to take iodine supplements.

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Have you taken iodine supplements during pregnancy? What dietary sources did you rely on for iodine? Share your thoughts and suggestions in the comments section.


1. Micronutrient Malnutrition:Reducing Nutritional Deficiencies Globally; CDC
2. M B Zimmermann; The Effects of Iodine Deficiency in Pregnancy and Infancy; Wiley Online Library (2012)
3. C Yarrington, E N Pearce; Iodine and Pregnancy; J Thyroid Res. (2011)
4. Assessment of iodine deficiency disorders and monitoring their elimination; WHO
5. S A Skeaff; Iodine Deficiency in Pregnancy: The Effect on Neurodevelopment in the Child; Nutrients (2011)
6. M H Abel, E Ystrom et al.; Maternal Iodine Intake and Offspring Attention-Deficit/Hyperactivity Disorder: Results from a Large Prospective Cohort Study; Nutrients (2017)
7. Iodine Fact Sheet; National Institutes of Health
8. New Study Associates Excess Maternal Iodine Supplementation with Congenital Hypothyroidism in Newborns; The Journal of Pediatrics (2012)
9. Iodine; Oregon State University
10. A M Leung; Iodine Nutrition in Pregnancy and Lactation; Endocrinol Metab Clin North Am. (2012)
11. M Zimmermann, F Delange; Iodine supplementation of pregnant women in Europe: a review and recommendations; European Journal of Clinical Nutrition (2004)
12. J Barone; 6 Things to Know About Seaweed; Berkley Wellness
13. Iodine tablets for healthy pregnant and breastfeeding women; Medsafe NZ (2010)
14. Reviewed by B Poulson, J Wilkins; Iodine; University of Rochester

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