What is the healthiest way to get iodine?

January 13, 2026 •

3 min read

The human body requires a steady supply of iodine, a trace element crucial for synthesizing thyroid hormones. Given that iodine deficiency affects millions worldwide, prioritizing a healthy intake is essential for metabolic and neurological function.

Quick Summary

The healthiest method to obtain iodine is through a varied diet rich in natural sources like seafood, dairy products, and eggs. Responsible use of iodized salt and, in specific cases, supplements under medical guidance, is also effective.

Key Points

Food First: The healthiest approach to iodine intake is prioritizing a diet rich in natural sources like seafood, dairy, and eggs.
Seaweed as a Potent Source: Varieties of seaweed, particularly kelp, offer extremely high levels of iodine, requiring careful moderation to avoid excessive intake.
Iodized Salt is a Useful Tool: Iodized table salt is a simple way to ensure a baseline iodine intake, but awareness is needed as processed foods often use non-iodized salt.
Supplements Need Medical Guidance: Individuals with dietary restrictions, like vegans, or those with increased needs, such as pregnant women, may require supplements, but only under the supervision of a healthcare professional.
Balance is Critical: Both iodine deficiency and excess can cause thyroid problems, highlighting the importance of balancing intake from all sources to avoid health risks.

Sourcing Iodine Naturally Through a Balanced Diet

For most people, the healthiest way to ensure adequate iodine intake is through a balanced diet that includes a variety of iodine-rich foods. The amount of iodine in plant-based foods can vary widely based on the mineral content of the soil they were grown in, but animal products, seafood, and iodized salt remain reliable sources. This food-first approach helps the body absorb the nutrient gradually and in conjunction with other beneficial vitamins and minerals.

Excellent Dietary Sources of Iodine

Seafood and Seaweed

Seaweed: Often considered one of the richest natural sources of iodine. Varieties like nori, wakame, and especially kombu kelp, can contain significant amounts. However, due to its very high potency, moderation is key to avoid overconsumption, which can be detrimental to thyroid health.
Fish: Lean fish, such as cod, is an excellent source of iodine. Other good options include tuna, shrimp, and other shellfish.

Dairy and Eggs

Dairy Products: Milk, yogurt, and cheese are primary iodine sources in many diets. The iodine content can vary based on the iodine levels in the cattle feed and the use of iodine-containing disinfectants during milking.
Eggs: One large egg can contribute a good portion of the recommended daily intake, with most of the iodine concentrated in the yolk.

Iodized Salt

A Public Health Success: The practice of adding iodine to table salt was a major public health initiative to combat iodine deficiency. A small amount, roughly a quarter teaspoon, can provide about half the daily recommended amount for adults.
Use with Caution: While a reliable source, it's important to remember that most processed and restaurant foods use non-iodized salt. For this reason, and because of general health recommendations to limit sodium, relying solely on iodized salt is not the best strategy. Specialty salts like sea salt or Himalayan salt are also generally not iodized.

The Role of Supplements in a Healthy Iodine Strategy

For some individuals, especially pregnant and breastfeeding women, vegans, or those with restricted diets, food sources alone may not provide enough iodine. In these cases, a supplement may be necessary. It is crucial to consult a healthcare professional before starting any supplement regimen to determine the correct dosage and avoid toxicity.

Comparison Table: Dietary Iodine vs. Supplements


Feature	Dietary Iodine (from Food)	Iodine Supplements
Source	Whole foods like seafood, dairy, and eggs	Concentrated forms like potassium iodide, kelp tablets
Absorption	Gradual absorption with other nutrients	Rapid, highly absorbable form
Risk of Excess	Low, due to food matrix and bioavailability	Higher, especially with high-dose products
Balance	Provides a natural balance of nutrients	Can lead to nutrient imbalances if not managed properly
Suitability	Best for the general population	Can be necessary for at-risk groups (e.g., pregnant women, vegans)
Regulation	Regulated through natural food systems and food processing	Requires careful monitoring of dosage and content

Potential Risks and Precautions

Both too little and too much iodine can negatively impact thyroid function. Excessive intake, especially from high-dose supplements or excessive seaweed consumption, can lead to conditions like hyperthyroidism, thyroiditis, and goiter. Pregnant and breastfeeding women, infants, and individuals with pre-existing thyroid conditions are particularly susceptible to the adverse effects of excess iodine. Always seek medical advice to ensure your intake is within a safe and beneficial range.

Conclusion

The healthiest way to obtain iodine is to prioritize a diet rich in natural sources. Seafood, dairy, and eggs are excellent food options that provide this vital mineral alongside other important nutrients. While iodized salt offers a reliable backup, it should not be the sole source. For at-risk populations, or those with dietary restrictions, consulting a healthcare provider about supplementation is a safe and effective approach. By focusing on whole foods and practicing moderation, most individuals can maintain optimal iodine levels for a healthy thyroid and overall well-being. For more detailed information on nutrient guidelines, the Office of Dietary Supplements at the National Institutes of Health is a helpful resource. [https://ods.od.nih.gov/factsheets/Iodine-HealthProfessional/]

Frequently Asked Questions

Seaweed, especially kelp, contains the highest concentration of iodine. However, the amount can vary greatly depending on the species and harvest location.

No, iodized salt is not the only source. Many foods, including seafood, dairy products, and eggs, contain natural iodine. You should aim to get most of your iodine from a varied diet.

Yes, excessive iodine intake, particularly from overconsumption of high-iodine foods like kelp or through supplements, can cause thyroid dysfunction and other health issues.

Groups at higher risk for iodine deficiency include pregnant and breastfeeding women, vegans and vegetarians, and people who avoid iodized salt and dairy products.

Many national health organizations recommend that pregnant and breastfeeding women take a daily iodine supplement to ensure adequate intake for fetal and infant development. However, this should be discussed with a doctor.

Common symptoms of iodine deficiency include a goiter (enlarged thyroid gland), hypothyroidism, fatigue, cold sensitivity, and weight gain.

Iodine levels are best assessed by a healthcare provider through tests like a urinary iodine concentration test. Symptoms of deficiency or excess can also indicate an imbalance.