How to get enough iodine each day? A practical guide

October 23, 2025 •

5 min read

Globally, iodine deficiency is one of the most common and preventable causes of intellectual disability, affecting millions. Understanding how to get enough iodine each day is crucial, as this essential mineral is vital for producing thyroid hormones that regulate metabolism and support overall health.

Quick Summary

This guide outlines how to meet daily iodine requirements through various dietary sources, including seafood, dairy, and iodized salt. It explains the importance of iodine for thyroid function and highlights signs of deficiency to ensure a balanced nutritional intake.

Key Points

Daily Requirements: Adult RDA for iodine is 150 mcg, but increases significantly during pregnancy (220 mcg) and lactation (290 mcg).
Rich Food Sources: Seafood like cod and shrimp, dairy products such as milk and yogurt, eggs, and seaweed are excellent dietary sources of iodine.
Iodized Salt Use: Iodized table salt is a common and effective source of iodine, but processed foods often use non-iodized salt, so it is not a reliable source.
Watch Seaweed Intake: Kelp and other seaweeds are very high in iodine and should be consumed in moderation to avoid excessive intake, especially during pregnancy.
Signs of Deficiency: Fatigue, weight gain, sensitivity to cold, dry skin, and goiter (an enlarged thyroid gland) can indicate an iodine deficiency.
Supplementation: Supplements can help high-risk groups, but it's crucial to consult a doctor before starting to avoid excessive intake, which can cause thyroid issues.
Monitor High-Risk Groups: Pregnant women and vegans should pay special attention to their iodine intake, as their dietary needs can be more difficult to meet from food alone.

The Importance of Iodine for Your Body

Iodine is a trace mineral that the human body cannot produce on its own, making dietary intake essential. Its primary function is to enable the thyroid gland to produce hormones, specifically thyroxine (T4) and triiodothyronine (T3). These hormones are crucial for a wide range of bodily processes, including:

Metabolism: Regulating the conversion of food into energy.
Growth and development: Supporting skeletal and central nervous system development, particularly in infants and children.
Brain health: Ensuring proper neurological development and cognitive function.

Without sufficient iodine, these vital functions can be impaired, leading to a spectrum of health issues known as iodine deficiency disorders.

Identifying and Addressing Iodine Deficiency

In developed nations, severe iodine deficiency is rare due to public health initiatives like salt iodization programs. However, certain populations remain at risk, and mild to moderate deficiencies can still occur. Some of the first signs of low iodine status often relate to the thyroid gland's function and include:

Goiter: The most well-known symptom, where the thyroid gland enlarges and causes a visible swelling in the neck.
Fatigue and weakness: A sluggish thyroid can slow down metabolism, leading to low energy levels.
Weight gain: A slower metabolic rate can make it easier to gain weight.
Hypothyroidism: An underactive thyroid gland that cannot produce enough hormones.

Pregnant women, breastfeeding women, and individuals following a vegan or dairy-free diet are among the most vulnerable groups. For these individuals, a more focused effort on dietary intake or supplementation is often necessary.

Top Dietary Sources of Iodine

Fortunately, a variety of readily available foods are excellent sources of iodine, making it easy to incorporate into a daily diet.

Seafood

Seafood is naturally rich in iodine due to its concentration in ocean water. Some of the best options include:

Cod: A three-ounce serving of baked cod can provide 97% of the Daily Value for iodine.
Shrimp: A three-ounce portion contains a notable amount of iodine.
Tuna: While lower in concentration than cod, canned tuna still contributes to your daily intake.

Dairy Products

Dairy is a significant source of iodine for many people, though amounts can vary based on factors like cow feed and sanitizing agents used in processing. Good sources include:

Yogurt: One cup of plain, nonfat Greek yogurt provides over half of the Daily Value.
Milk: A cup of nonfat milk contains a healthy dose of iodine.
Cheese: An ounce of cheddar cheese also contributes to your intake.

Iodized Salt

Since the 1920s, the fortification of salt with iodine has been a cornerstone of public health, dramatically reducing deficiency rates. Just one-quarter teaspoon of iodized table salt provides a significant portion of the recommended daily amount. However, it is important to note that most salt used in processed foods is not iodized, so relying solely on packaged goods is not an effective strategy.

Seaweed

As a vegetable harvested from the sea, seaweed is an extremely concentrated source of iodine. Varieties like kelp, nori, and wakame are potent sources, with iodine levels varying by species. Due to the high potency of certain seaweeds, eating it in moderation is recommended to avoid excessive intake, especially with kelp.

Eggs

Eggs are an easy and accessible source of iodine, with most of the mineral concentrated in the yolk. One large hard-boiled egg can provide 21% of the Daily Value.

Iodine Content Comparison: Key Food Sources


Food Source	Serving Size	Approximate Iodine (mcg)	Percent DV*	Notes
Dried Kelp	1 gram	Up to 2,984	1,989%	Very high, consume sparingly.
Baked Cod	3 ounces	146	97%	Excellent, reliable source.
Plain Greek Yogurt	¾ cup	87	58%	Nonfat variety used for measurement.
Nonfat Milk	1 cup	84	56%	Note on variance in dairy iodine.
Iodized Table Salt	¼ teaspoon	78	52%	Reliable source when used in cooking.
Hard-Boiled Egg	1 large	31	21%	Yolk is iodine-rich.
Shrimp	3 ounces	13	9%	Good source as part of a meal.
Cheddar Cheese	1 ounce	14	9%	Contributes to overall intake.

*DV based on 150 mcg recommendation for adults.

Recommended Daily Intake and Supplementation

For most adults, the recommended dietary allowance (RDA) for iodine is 150 micrograms (mcg) per day. However, needs increase significantly during pregnancy (220 mcg/day) and lactation (290 mcg/day) to support proper fetal and infant development.

While a balanced diet is the best way to meet your iodine needs, supplements can be a practical option for certain groups, including pregnant women and those with dietary restrictions. Many multivitamins contain iodine, often at the RDA level. Always consult a healthcare professional before starting any new supplement regimen, as excessive iodine intake can also lead to thyroid problems. The Tolerable Upper Intake Level (UL) for adults is 1,100 mcg per day.

Practical Tips for Boosting Your Iodine Intake

To ensure you are consistently getting enough iodine, consider these simple strategies:

Choose iodized salt: When you use salt for home cooking, opt for iodized table salt over non-iodized versions like sea salt or kosher salt.
Incorporate seafood regularly: Aim to include fish and shellfish in your meals a couple of times per week. Varieties like cod, shrimp, and oysters are excellent choices.
Enjoy dairy: Incorporate milk, yogurt, and cheese into your diet as these are reliable sources of iodine.
Try seaweed snacks: For a potent and quick boost, add a small amount of seaweed, like dried nori sheets, to your meals or eat as a snack. Exercise caution with kelp due to its high concentration.
Don't forget eggs: A hard-boiled egg or two with breakfast is a simple way to add iodine to your morning routine.
Check fortified products: Be aware of products like certain types of bread that may be fortified with iodine, depending on your region.

Meeting your daily iodine needs is an achievable goal through mindful dietary choices. For more in-depth information, you can visit the NIH Office of Dietary Supplements for official guidelines and facts.

Conclusion

Ensuring you get enough iodine each day is a vital component of a healthy diet, particularly for maintaining proper thyroid function, a healthy metabolism, and supporting development during pregnancy and childhood. By incorporating iodine-rich foods like seafood, dairy, and eggs, and being mindful of your salt choice, most people can easily meet their daily requirements. For those with specific dietary needs or increased requirements, such as during pregnancy, supplements can be a safe and effective option under a doctor's supervision. Paying attention to these dietary details is a proactive step toward safeguarding your health and well-being.

Frequently Asked Questions

Most healthy adults need about 150 micrograms (mcg) of iodine per day. This requirement increases to 220 mcg during pregnancy and 290 mcg for breastfeeding women.

Excellent food sources of iodine include seafood like cod and shrimp, dairy products such as milk and yogurt, eggs, and seaweed. Iodized salt is also a reliable source when used in cooking.

No, while iodized salt is a major source, you can also get iodine from many other foods, including seafood and dairy products. It is important to remember that most processed foods do not contain iodized salt.

Yes, excessive intake of iodine can also lead to thyroid problems, including goiter, similar to a deficiency. The Tolerable Upper Intake Level (UL) for adults is 1,100 mcg per day.

Yes, vegans and those who avoid dairy and seafood are at a higher risk of iodine deficiency and should seek out fortified foods or supplements to ensure adequate intake.

Signs of iodine deficiency can include fatigue, weight gain, increased sensitivity to cold, dry skin, and a swollen neck due to an enlarged thyroid gland (goiter).

While many prenatal vitamins contain iodine, they are not all guaranteed to. Pregnant women, therefore, should check the supplement facts label to confirm and discuss supplementation with their healthcare provider.

Yes, seaweed is an extremely potent source of iodine, especially varieties like kelp. Due to its high concentration, it should be consumed in moderation to prevent excessive intake.