What Dairy Products Are High in Iodine?

December 28, 2025 •

5 min read

Did you know dairy products are a primary source of dietary iodine in many countries? The amount of this essential mineral, which is critical for thyroid function, varies significantly across different dairy types and production methods.

Quick Summary

This guide outlines the dairy products with the highest iodine content, such as Greek yogurt and cottage cheese, and explains the factors that cause iodine levels to vary.

Key Points

Greek Yogurt Is a Powerhouse: Plain Greek yogurt is one of the most concentrated dairy sources of iodine, providing a large portion of the daily recommended intake in one serving.
Cottage Cheese is an Excellent Source: Cottage cheese is a very good source of iodine, particularly due to the presence of whey, which retains much of the mineral during production.
Milk Content is Highly Variable: The iodine levels in cow's milk can vary significantly based on factors like the season, the cow's feed, and farming practices.
Not All Cheese is Equal: The iodine content in cheese depends on the type, with whey cheeses often containing higher concentrations than harder cheeses like cheddar.
Farming Methods Matter: The use of iodine-containing feed supplements and teat disinfectants in dairy farming heavily influences the final iodine levels in milk and, consequently, other dairy products.
Processed Dairy Can Contribute: Ingredients like whey and milk powder used in processed items such as ice cream can increase their overall iodine content.

Why is Iodine Important?

Iodine is an essential trace mineral that is crucial for the proper function of the thyroid gland. The thyroid uses iodine to produce hormones that regulate metabolism, growth, and development throughout the body. A deficiency in iodine can lead to serious health issues, including goiter, which is a swelling of the thyroid gland, and hypothyroidism. While seafood and iodized salt are famously rich sources, dairy products are a significant and common contributor to daily iodine intake for many people.

The Best Dairy Sources of Iodine

Different dairy products contain varying amounts of iodine, with certain options standing out as excellent sources.

Greek Yogurt

Plain Greek yogurt is consistently one of the richest dairy sources of iodine. Its concentrated form, achieved through straining, results in a higher iodine content per serving compared to regular milk. An eight-ounce serving of plain Greek yogurt can provide up to 116 mcg of iodine, which is over half of the 150 mcg daily recommended intake for adults. This makes it a powerful and convenient addition to a diet focused on improving iodine intake.

Cottage Cheese

Cottage cheese is another top dairy contender for iodine. Research has shown that a half-cup serving of cottage cheese can contain a substantial amount of iodine. The iodine content is particularly concentrated in the whey, which is often mixed back into the final product during processing. A half-cup can deliver over 25% of an adult's daily iodine needs, solidifying its place as a reliable source.

Milk

Milk is a foundational source of iodine in many diets, though its concentration can fluctuate significantly. On average, a one-cup serving of cow's milk provides a good amount of iodine, contributing over a third of the daily value. However, the exact level can depend on a number of factors, including the season and farming practices. For instance, winter milk often has a higher iodine content than summer milk due to a greater reliance on iodine-fortified feed when cows are not grazing on pasture.

Whey Cheese

During the cheesemaking process, most of the iodine from the milk remains in the whey. As a result, whey-based products and certain types of cheese made from whey can have a high concentration of the mineral. A study noted that some whey cheeses had the highest iodine concentrations among dairy products tested.

Other Cheeses and Processed Dairy

While not as high in iodine per serving as Greek yogurt or cottage cheese, many other cheeses still contribute to overall intake. Harder cheeses like cheddar contain smaller amounts, as much of the iodine is lost in the whey during production. Processed dairy products, such as ice cream, can also have variable iodine content, sometimes higher if whey or non-fat milk powders are used as ingredients.

Factors Influencing Dairy Iodine Content

The variability of iodine levels in dairy is influenced by several factors during farming and production. Understanding these can help explain why iodine content is not consistent across all products.

Feed and Supplements: The primary driver of iodine content in milk is the diet of the dairy cow. Farmers often supplement cow feed with iodine to ensure proper animal health, which in turn boosts the iodine levels in the milk.
Iodine-based Disinfectants: A lesser, but still influential, factor is the use of iodophor disinfectants during milking. Some of this iodine is absorbed through the cow's skin, especially the teats, and can transfer into the milk. Countries have different regulations regarding the use of these disinfectants, which contributes to national variations in milk iodine content.
Season: Milk produced in the winter often contains more iodine than milk produced in the summer. This is because cows are more likely to be fed iodine-supplemented feed during the winter months, whereas in the summer, they may graze on pastures with naturally variable iodine levels.
Organic vs. Conventional Farming: Some studies indicate that conventional milk may contain higher levels of iodine than organic milk. This can be due to differences in supplementation practices and the types of feed used.

Comparison of Dairy Products' Iodine Content


Dairy Product	Serving Size	Approximate Iodine (mcg)	% of Adult RDI (150mcg)	Notes
Greek Yogurt	8 oz / 227g	116	~77%	Highly concentrated source due to straining.
Cottage Cheese	1/2 cup / 113g	39-65	~26-43%	Varies by brand and processing.
Cow's Milk (nonfat)	1 cup / 237ml	85	~57%	Varies seasonally and by farming practices.
Cheddar Cheese	1 oz / 28g	12-14	~8-9%	Lower due to removal of whey during processing.
Ice Cream	2 scoops / 48g	10	~7%	Iodine content can be highly variable.
Butter	1 Tbsp / 14g	~0-2	~0-1%	Very low iodine content; not a significant source.

Smart Dairy Choices for Iodine

Incorporating dairy products high in iodine into your diet is a simple and effective strategy for maintaining adequate levels of this vital mineral. The best approach is to include a variety of these foods to ensure a steady supply. For a quick and easy boost, Greek yogurt offers a high concentration in a single serving. Milk provides a consistent contribution for many, though its variable nature is worth noting. Pairing these with other iodine-rich sources like seafood can ensure all nutritional bases are covered. Monitoring dairy intake is especially important for those with special dietary needs or concerns about nutrient levels.

Conclusion

Dairy products, particularly Greek yogurt, cottage cheese, and milk, are reliable and widespread sources of iodine, an essential mineral for thyroid health. The concentration of iodine in these products can vary based on factors like the animal's feed, farming practices, and seasonal changes. While dairy is a significant contributor for many, it's important to be aware of the variability. By incorporating a mix of these dairy options and other iodine-rich foods like seafood, individuals can help ensure they meet their daily nutritional needs. For further guidance on iodine intake, consulting resources from authoritative bodies like the National Institutes of Health can be beneficial.

Note: The iodine content in dairy can vary widely, so the values in the comparison table are approximate based on cited data and may not reflect every product.

Here is an authoritative link for additional reading: NIH Office of Dietary Supplements.

Frequently Asked Questions

Yes, yogurt, especially plain Greek yogurt, is considered a good source of iodine. The straining process used for Greek yogurt concentrates the mineral, resulting in higher levels per serving compared to milk.

Greek yogurt typically contains a higher concentration of iodine per serving than regular cow's milk. For example, an 8-ounce serving of Greek yogurt can have over 100 mcg of iodine, while the same amount of nonfat milk has slightly less.

The iodine level in milk can vary due to several factors, including the season, the cow's feed (and its iodine supplementation), and whether iodine-based teat disinfectants are used during milking.

While dairy products are a major source for many, they are not the absolute richest. Seafood, particularly seaweed and certain fish like cod, contains significantly higher concentrations of iodine.

It is possible to consume too much iodine, especially for those who drink very large quantities of high-iodine milk. Regulatory measures on cattle feed help prevent excessive levels, but it's important to maintain a balanced diet.

No, unfortified plant-based milk alternatives are not a significant source of iodine. Even fortified versions often contain considerably less iodine than cow's milk.

Yes, iodine from dairy products is beneficial for thyroid health. The mineral is essential for the production of thyroid hormones, which are critical for regulating metabolism and other bodily functions.

Cottage cheese is one of the highest dairy sources of iodine. Other cheeses contain less, as much of the iodine is lost in the whey during processing, although whey cheese can have high levels.