Evidence Based

Iodine: Health Benefits in Pregnancy, Childhood & Diet

Written by Joe Cohen, BS | Last updated:

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It is difficult to overpraise Iodine. It is an element that our bodies simply cannot do without. And it has to come with diet in appropriate quantities so our life and development throughout life may not be affected. Here is a short list of some proven health benefits of iodine.

What is Iodine?

Iodine is a chemical element which is the heaviest and the least available of the stable “halogens”. It occurs in many oxidation states, including iodide (I) and iodate (IO3) and is found in the thyroid hormones.

Iodine deficiency affects about two million people and is the leading preventable cause of intellectual disabilities.

Health Benefits of Iodine

  • Regulates metabolism through thyroid hormones;
  • Influences brain development;
  • Protects from certain types of cancer (thyroid, breast, stomach cancer);
  • Is a known and widely used disinfectant;
  • Used for radiation cancer treatment;
  • A known measure for radiation damage prophylaxis;

1) Extremely Important For Thyroid Gland

The synthesis of hormones in the thyroid gland – a small butterfly structure on the base of the neck – is completely dependent on iodine. They are called triiodothyronine (T3) and thyroxine (T4).

At present, it was established that thyroid hormones influence the development of the skeleton, brain and reproductive ability in many species [1, 2, 3, 4].

2) Important For Health Of Children

The lack of iodine in the diet of pregnant mothers and small children leads to devastating consequences [5].

In young children, iodine deficiency results in low stature and a form of intellectual disability called cretinism [5].

In the 19th century, the condition of such children was improved by the addition of thyroid extracts in the diet, but it never improved the development of their intellect, only the body [5].

The other consequence of iodine deficiency is the enlargement of the thyroid gland goiter [6].

At present, the main method of preventing cretinism and goiter development in children is the introduction of iodized salt into the everyday diet [5].

Several studies have shown that the introduction of iodized supplements, mostly iodized salt in the poor areas of Asia and Africa consistently improves the physical and mental condition of children [5].

For instance, a study focused on the effects of introduction of iodized salt and other types of iodine supplements in villages of Benin, Africa has shown that children that had an increase of iodine content in urine due to supplementation were doing much better with school tasks and tests compared to the children that had low iodine content [7].

A similar study that was carried out in eastern China has shown that the introduction of iodized salt in the region led to a decrease in goiter incidence among local children [8].

The same effects were observed after the introduction of iodized poppy seed oil in village children in western Cote d’Ivoire [9].

In the group that was studied, all children had a goiter and besides had selenium deficiency as well [9].

Selenium is equally important in health and is connected to iodine influence on body condition, as they participate in the production of thyroid hormones [10].

The Introduction of iodized oil into the children’s diet made thyroid glands of affected children smaller and lessened the goiter symptoms [9].

It was also noted that severe selenium deficiency made the children significantly less responsive to iodine supplements [9].

During further studies in the same area, it was also shown that iodine supplementation works better if coupled with iron and selenium supplements [11].

The importance of iron supplementation in children with goiter was corroborated by an independent study in Iran [12].

3) It Is Important To Take During Pregnancy

In pregnancy, the mother requires a lot of iodine (especially in early stages) as there is an increased hormone production [13].

Iodine has to be transferred to the developing baby and there is a significant loss in the urine [13].

There is some iodine stored in the placenta during pregnancy, but it is only 3% of the concentration in the thyroid and is more of emergency storage [14].

Severe iodine deficiency in the mother affects the child`s brain development greatly and can lead to cretinism [5].

Mild iodine deficiency causes abnormalities in movement and intellectual development of the future child [13].

Pregnant women require about 250 μg of iodine daily [15] and several studies have shown that supplementation during early pregnancy has many benefits [16].

For instance, it leads to an increase in the body weight of the newborns, the possibility of newborn mortality is lower the rate of development in young children is improved by approximately 20% [16].

4) Helps Fight The Adverse Effects Of Excess Weight

Recently, a study has shown that there is a high risk of iodine deficiency in women with high-level obesity [17].

Also, in the case of pregnant women, excess weight can be an additional risk of developing a deficiency in early pregnancy, which affects both the mother and the child [18].

Moreover, it was shown that in women with both excess weight and iodine deficiency that intake of 200 μg of iodine lowered cholesterol concentrations in their blood [19].

High levels of cholesterol can lead to blood vessel blockage and heart disease, so iodine supplementation seems to prevent such developments in the case of excess weight [19].

It was also shown that in children with a mild form of iodine deficiency iodine supplementation lowers both markers of inflammation and cholesterol, which helps prevent heart disease [20].


At present, the recommended intake of iodine in the USA and Canada is 220 μg in pregnant and lactating women and 150 μg in nonpregnant women and males [21].

In the case of countries with low income and low iodized salt coverage 250 μg daily or 400 μg once per year or 27 μg in emergency cases [21].

A recent review also postulated that women living in a population with a median urinary iodine concentration (UIC) at or above 100 µg/l are not in need of iodine supplementation in pregnancy [22].

On the other hand, if the population median UIC is below 100 µg/l pregnant women should take iodine-containing supplements until the population in general, has been iodine sufficient for at least 2 years [22].

It was also shown that in regions of moderate-to-severe iodine deficiency where no iodized salt is available it is sufficient to give lactating women one dose of 400 mg iodine in form of iodized oil soon after delivery so they can give their infants sufficient iodine for at least 6 months [23].

Giving some form of supplementation to newborns low on iodine was not considered effective [23].

Surprisingly, iodine deficiency can be present even in developed countries. For example, the United Kingdom is ranked among the top ten iodine-deficient countries in the world [24].

So it is important to monitor such statistics while deciding whether or not to take additional supplements (besides iodized salt).

Iodine Overdose Can Be Dangerous

It is crucially important not to take too much iodine as well. In a population, a study carried out in Liaoning Province, China it was shown that intake of iodine that exceeded 250 – 499 μg/L led to iodine deficiency disorder (hypothyroidism) [25].

This is due to the so-called Wolff–Chaikoff effect when an excess of iodine leads to a decrease in hormone production by the thyroid gland [25].

The thyroid gland in the baby develops on 10 – 12 weeks of pregnancy and in a case of excess iodine intake by the pregnant mother hypothyroidism can develop in the children as well [25].

There was a report on mothers that overdosed on iodine during pregnancy. The children of those three mothers were diagnosed with hypothyroidism [26].

The correction of the condition was achieved by stopping this overdose coming from supplements [26].

The same condition was reported in children born to Japanese mothers that ate a lot of seaweed during pregnancy [27].

Diets That Can Cause Iodine Deficiency

Besides such factors as the content of iodine in food and water, some diets can directly cause iodine deficiency. For example, it was noted in one recent study that exclusion of salt that is recommended for hypertension can cause its deficiency [28].

Among patients with hypertension on a no-salt diet, 24% of men and 40% of women with hypertension had low iodine concentrations in their urine [28]. So it is important to seek alternative products in such cases.

Also one should remember that some components in soy especially isoflavones may cause goiter [29].

There are several studies showing that a diet containing soy may lead to goiter development [29].

For example, infants fed soy milk are at risk [29].

The abundance of soy in a diet can even cause autoimmune thyroid disorders [29].

On the other hand, a study carried out on monkeys has shown that soy protein may not be dangerous for thyroid function and can even support it in women after menopause [30].

Buy Iodine-Rich Kelp Powder Supplement

Is Iodine Right For You?

If you’re unsure about which vitamins you need more or less of, check out our Vitamin DNA Wellness Report. This report tells you if you’re genetically more or less predisposed to have a vitamin deficiency. We also give personalized recommendations to fix the deficiency when they occur.

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About the Author

Joe Cohen, BS

Joe Cohen won the genetic lottery of bad genes. As a kid, he suffered from inflammation, brain fog, fatigue, digestive problems, anxiety, depression, and other issues that were poorly understood in both conventional and alternative medicine.Frustrated by the lack of good information and tools, Joe decided to embark on a journey of self-experimentation and self-learning to improve his health--something that has since become known as “biohacking”. With thousands of experiments and pubmed articles under his belt, Joe founded SelfHacked, the resource that was missing when he needed it. SelfHacked now gets millions of monthly readers.Joe is a thriving entrepreneur, author and speaker. He is the CEO of SelfHacked, SelfDecode and LabTestAnalyzer.His mission is to help people gain access to the most up-to-date, unbiased, and science-based ways to optimize their health.
Joe has been studying health sciences for 17 years and has read over 30,000 PubMed articles. He's given consultations to over 1000 people who have sought his health advice. After completing the pre-med requirements at university, he founded SelfHacked because he wanted to make a big impact in improving global health. He's written hundreds of science posts, multiple books on improving health, and speaks at various health conferences. He's keen on building a brain-trust of top scientists who will improve the level of accuracy of health content on the web. He's also founded SelfDecode and LabTestAnalyzer, popular genetic and lab software tools to improve health.

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