Do I get enough iodine from salt?

January 1, 2026 •

4 min read

Despite the widespread success of universal salt iodization programs, many still question, "Do I get enough iodine from salt?". The answer is more complex, as modern dietary habits often rely heavily on processed foods that typically do not contain iodized salt.

Quick Summary

Iodized salt helps prevent deficiency, but it's not a reliable sole source due to processed foods often using non-iodized alternatives. Adequate iodine intake depends on diverse food choices and lifestyle factors.

Key Points

Salt is not the only source: While iodized salt was key to public health, modern processed food uses non-iodized salt, making reliance on it insufficient.
Dietary diversity is key: Rely on a variety of foods like seafood, dairy, and eggs to meet the recommended daily intake of 150 mcg for most adults.
At-risk groups need vigilance: Vegans, pregnant women, and those on low-salt diets must be mindful of their iodine intake and may need supplements after medical consultation.
Avoid excessive intake: Both deficiency and excessive iodine can cause thyroid problems. The Tolerable Upper Intake Level for adults is 1,100 mcg per day.
Read labels carefully: Check salt packaging for the 'iodized' label and food product ingredients to understand your intake.
Consult a professional for supplements: Never self-prescribe iodine supplements, especially high-dose kelp, which can contain unpredictable amounts.

The purpose and limitations of iodized salt

For nearly a century, the fortification of table salt with iodine has been a simple yet effective public health measure to combat iodine deficiency disorders (IDDs), such as goiter. It was developed to address widespread deficiencies in certain geographical areas, successfully reducing health issues related to inadequate iodine intake. Iodized table salt contains a specific, regulated amount of iodine, with approximately 71 micrograms in a quarter teaspoon in the United States. However, relying exclusively on this source can be misleading for several reasons. The primary issue is that a significant portion of our dietary salt intake comes from processed and restaurant foods, which are typically made with non-iodized salt. As health recommendations increasingly urge lower sodium consumption, the total amount of iodized salt a person uses can decrease, further impacting their intake. Therefore, for many people, salt is not a consistently reliable or sufficient source of iodine.

Important iodine sources beyond salt

While iodized salt was a crucial solution, a balanced diet provides a more robust and varied intake of this essential mineral. Iodine is found naturally in a range of foods, particularly those of marine origin. Incorporating these into your diet can help ensure you meet the Recommended Dietary Allowance (RDA) of 150 micrograms for most adults.

Rich natural sources of iodine include:

Seafood: Fish like cod and tuna are excellent sources, as are shellfish such as shrimp and oysters.
Seaweed: The iodine content varies dramatically by species, but kelp, nori, and wakame are known for being very rich sources.
Dairy products: Milk, yogurt, and cheese can be good sources of iodine. The iodine content can vary based on cattle feed and the use of iodine-based sanitizers in the dairy industry.
Eggs: The yolk of one large egg contains a notable amount of iodine.
Fortified foods: Some countries mandate the use of iodized salt in commercially baked bread, but this is not universal, and it's essential to check labels.

Who is at risk of iodine deficiency?

Several groups are at a higher risk of not getting enough iodine from their diet:

Pregnant and breastfeeding women: Their iodine needs are significantly higher to support fetal and infant brain development, with the RDA increasing to 220 mcg and 290 mcg, respectively.
Vegans and those avoiding dairy/seafood: Plant-based diets that exclude the best natural sources of iodine may require supplementation or fortified alternatives.
People who use non-iodized salts: Gourmet salts like kosher, sea salt, and Himalayan salt do not contain added iodine and should not be relied upon as a source.
Individuals consuming high amounts of goitrogens: Certain compounds found in cruciferous vegetables (like broccoli and cabbage) can interfere with iodine utilization, though this is generally only a concern in cases of marginal iodine intake.

Iodine intake: Iodized salt vs. other sources


Source	Typical Iodine Content	Considerations
Iodized Table Salt	71 mcg per 1/4 tsp	Dependent on discretionary use; processed food salt is often not iodized.
Cod (3 oz)	63–99 mcg	Excellent, naturally occurring source. Amount can vary by sourcing.
Milk (1 cup)	59–112 mcg	Significant source in many diets; content can fluctuate.
Seaweed (Kombu, 1g)	Up to 2,984 mcg	Exceptionally high, but highly variable content. Risk of excess with frequent consumption.
Egg (1 large)	24 mcg	Consistent, reliable source from the yolk.

Balancing iodine for health

Getting the right amount of iodine is crucial for thyroid hormone production, which regulates metabolism and is essential for proper brain development, especially during pregnancy and infancy. An imbalance, either too little or too much, can lead to health problems. Chronic deficiency can cause hypothyroidism and goiter, while excessive intake, often from high-dose supplements or overconsumption of very-high-iodine foods like some seaweeds, can also trigger thyroid dysfunction. The Tolerable Upper Intake Level (UL) for adults is 1,100 mcg per day. For most people, a varied diet that includes multiple iodine sources is the safest and most effective way to maintain balance. For those with specific dietary restrictions or requirements, like vegans or pregnant women, consulting a healthcare provider or a registered dietitian is the best approach to ensure adequate, safe intake. A multi-nutrient supplement can be considered, but caution is advised, especially regarding kelp supplements with unpredictable iodine levels.

Conclusion

In conclusion, while iodized salt has historically been a public health cornerstone for preventing iodine deficiency, it is an oversimplification to assume it's a sufficient source for everyone. Modern eating patterns, with their reliance on processed foods made with non-iodized salt, mean that many people's iodine intake from salt is likely lower than they believe. The most effective strategy is to diversify your sources by including natural, iodine-rich foods like seafood, dairy, and eggs in your diet. By understanding the limitations of relying on salt alone and being mindful of other dietary sources, you can better manage your iodine intake for optimal thyroid health. For more detailed information on nutrient recommendations, consult reputable health organizations like the National Institutes of Health National Institutes of Health (NIH).

Frequently Asked Questions

No, iodized salt is a common source, but iodine is also found in other foods. Due to decreased table salt use and non-iodized salt in processed foods, relying on it alone is often insufficient.

Excellent natural sources include seafood (cod, shrimp, seaweed), dairy products (milk, yogurt), and eggs. The amount can vary depending on the food source and origin.

Processed food manufacturers often use non-iodized salt, such as sea salt, which may not contain sufficient iodine for public health purposes. This makes it difficult to track iodine intake through processed foods alone.

Pregnant and breastfeeding women, vegans or those with limited dairy/seafood intake, and people on very low-salt diets should be particularly aware of their iodine levels and may need to consider supplements.

Iodine deficiency can lead to an enlarged thyroid gland (goiter) and hypothyroidism, which can cause fatigue, weight gain, and cognitive issues. During pregnancy, severe deficiency can lead to birth defects.

Yes, excessive iodine intake can also cause thyroid problems and should be avoided. The Tolerable Upper Intake Level (UL) for adults is 1,100 mcg per day. This is a particular risk with certain high-iodine supplements or excessive seaweed consumption.

Encourage a varied diet that includes seafood, dairy, and eggs. If using table salt, ensure it is iodized. For those on restricted diets, fortified foods or supplements (after consulting a doctor) may be necessary.