What is Iodine? – Sources, Foods, Deficiency Causes

Our body needs different minerals for everyday functioning. Iodine is one such essential mineral that the body needs to make thyroid hormones. These hormones are very important for controlling the body’s metabolism and several other functions. Iodine requirement in childhood is increased due to the growth spurt. Iodine deficiency in children can not only lead to delayed growth but also impair brain function. However, our body does not make iodine and hence iodine rich foods have to be taken through diet.

Table of Contents

• What is Iodine?
• Sources of Iodine
• Iodine Rich Foods
• Iodine Deficiency Causes
• Iodine Deficiency in Children
• Preventing and Managing Iodine Deficiency
• Conclusion

Read along to know more about what iodine is, best sources of iodine, and iodine deficiency causes.

What is Iodine?

Iodine is an essential micronutrient that becomes a key structural component of thyroid hormones. Thyroid hormones are responsible for:

1. Regulating metabolism
2. Controlling body temperature
3. Promoting growth and development, especially during pregnancy and childhood
4. Supporting reproductive health

It is necessary to include iodine rich foods in the daily diet as our bodies are not capable of making iodine.

According to Indian Council of Medical Research (2024), recommended daily allowance of iodine for children aged 1 to 9 years old is 90 mcg/day.

• Did You Know?

Approximately 70-80% of the body’s iodine is stored in the thyroid gland.

Sources of Iodine

Sources of iodine can differ vastly based on geographic location, and food processing. Additionally, the amount of iodine present in crops and livestock depends on the concentration of iodine in the soil and water of the region they are grown in.

A large part of the iodine on earth is found in the oceans, and the iodine concentration of the soil depends on how old it is. The older the soil (like in mountainous regions), the higher the chances of iodine being leached away due to erosion. Hence, coastal regions usually have more iodine rich soil and water compared to the inland regions.

• Did You Know?

Due to widespread iodine deficiency in children and adults, Government of India decided to iodize salt in 1984 and later banned the sale of non-iodized edible salt in 1997. Replacing iodized salt completely with other non-iodized gourmet salts is the number one iodine deficiency cause.

Iodine Rich Foods

Incorporating iodine rich foods in the daily diet can be an effective strategy to meet nutritional requirements and prevent iodine deficiency in children.

Top natural sources of iodine are:

1. Seafood: Fish, shellfish, seaweed
2. Eggs (especially egg yolks)
3. Milk and Milk Products (paneer, curd)
4. Grains: iodine content is based on the soil that they are grown in.

Fact Check: Iodized salt is the most common source of iodine worldwide.

Iodine Deficiency Causes

Apart from excluding iodized salt being the number one cause, other iodine deficiency causes are:

1. Not focusing on including different iodine rich foods in adequate quantities in the diet.
2. Following a vegetarian or vegan diet as it excludes major sources of iodine like dairy products, seafood, and eggs.
3. Unavailability of iodized salt
4. Increased iodine requirements. For example: during pregnancy.
5. Reduced concentration of iodine in soil (especially in hilly areas due to soil erosion)
6. Excessive intake of goitrogens can be found in raw cruciferous vegetables like cabbage, cauliflower, and broccoli. They can hinder the absorption of iodine. However, cooking can destroy the goitrogens present in these foods, and they should be taken in the cooked form.

Iodine Deficiency in Children

Iodine is used by the thyroid gland in our body to make thyroid hormones. Normally, the body tightly controls the production of thyroid hormones through the release of Thyroid Stimulating Hormone (TSH). However, when dietary iodine intake is low, TSH levels elevate to stimulate more iodine uptake to make hormones. In case of insufficient iodine, thyroid hormone production decreases despite high TSH levels, which leads to undesired consequences.

Iodine deficiency in children is a serious health concern as it can hamper growth, development, and cognitive function.

Consequences of iodine deficiency in children:

1. Hampered mental development and academic performance
2. Stunting of growth
3. Increased chances of developing attention deficit hyperactivity disorder (ADHD)
4. Enlarged thyroid gland (goiter) and hypothyroidism if the iodine intake falls below 10-20 mcg/ day

• Did You Know?

Even moderate iodine deficiency in children can reduce the Intelligence Quotient (IQ) by up to 3-5 points. It has also been mentioned as the most common cause of preventable cognitive impairment in the world.

Preventing and Managing Iodine Deficiency

Iodine deficiency in children is both preventable and reversible if addressed early.

How to prevent iodine deficiency in children?

1. Do not replace regular iodized salt with other gourmet salts. Check the food labels to know whether a particular salt is iodized or not.
2. Secure access to iodized salt especially if you live in areas with iodine deficient soils like the mountainous regions.
3. Include iodine rich foods in my daily routine.
4. Encourage consumption of milk and products if you are a vegetarian.
5. If you are a vegan, then you can take the help of supplements if required.

Hence, iodine deficiency in children can be avoided by keeping these things in mind. If your child already has iodine deficiency, then it is a wise choice to visit your doctor and start proper treatment.

Conclusion

Knowing about what iodine and its function plays an important role in the prevention of iodine deficiency in children. Hence, make sure your kid is getting enough iodine. It’s important to choose the right salt, opt for iodized salt, and try to avoid pink or low-sodium varieties of salt that may not provide enough iodine. Including diverse sources of iodine in a balanced diet and incorporating iodine rich foods is an effective strategy to meet optimal iodine intake. Complan a nutritional drink not only has 63% more protein than a leading malt based nutritional drink but also contains iodine along with other vitamins and minerals essential for a child’s growth and development.

References

1. National Institute of Nutrition. (2024). Short Summary of Recommended Dietary Allowances (RDA) and Estimated Average Requirements (EAR) – 2020. ICMR-NIN Expert Group on Nutrient Requirement for Indians. https://www.nin.res.in/RDA_short_Report_2024.html

2. National Institutes of Health, Office of Dietary Supplements. (2022, March 29). Iodine: Fact sheet for health professionals. U.S. Department of Health and Human Services. https://ods.od.nih.gov/factsheets/Iodine-HealthProfessional/#en41

3. Linus Pauling Institute. (n.d.). Iodine. Oregon State University. Retrieved April 8, 2025, from https://lpi.oregonstate.edu/mic/minerals/iodine#goitrogens

4. Bougma, K., Aboud, F. E., Harding, K. B., & Marquis, G. S. (2013). Iodine and mental development of children 5 years old and under: a systematic review and meta-analysis. Nutrients, 5(4), 1384–1416. https://doi.org/10.3390/nu5041384