The thyroid gland, located below the larynx, plays a crucial role in regulating metabolism by producing thyroid hormones. Adequate levels of iodine are necessary for proper thyroid function. Insufficient iodine intake can lead to conditions such as hypothyroidism, characterized by decreased thyroid hormone production, or goiter, which causes swelling in the neck area.
The recommended daily iodine intake for adults in Korea is 150μg, and most individuals meet this requirement through their diet. However, those following low-sodium diets or practicing vegetarianism should pay attention to their iodine intake. Gluten, processed foods, and fast food are generally not beneficial for thyroid health.
While seaweed and kelp are often considered as iodine-rich foods for thyroid health, there are other nutrients essential for maintaining thyroid health. Let’s explore the foods that provide these nutrients, as mentioned by the U.S. health information source, Health.com.
Yogurt: According to the National Institutes of Health, an average cup of dairy products contains approximately 85μg of iodine. The iodine content varies among different dairy products, with non-fat milk samples containing around 38-159μg per cup. Including plain yogurt, low-fat yogurt, or Greek yogurt in your diet can fulfill about half of the recommended daily iodine intake.
Brazil Nuts: Brazil nuts are not only a source of selenium but also aid in regulating thyroid hormone production. According to a review published in the Clinical Endocrinology journal in 2013, selenium helps prevent long-term thyroid damage in individuals with thyroid-related issues such as Hashimoto’s disease or Graves’ disease. Each Brazil nut contains approximately 68-91μg of selenium. It is important not to consume excessive amounts as the recommended daily selenium intake for adults in Korea is 60μg, with an upper limit of 400μg. Consuming too much selenium can lead to hair loss, nail discoloration, and, in severe cases, heart failure.
Milk: Milk and dairy products are excellent sources of iodine. Plant-based alternatives such as soy or almond milk contain relatively lower amounts of iodine. One cup of low-fat milk can provide approximately one-third of the required daily iodine intake. Choosing milk fortified with vitamin D is also beneficial. A study published in the International Journal of Environmental Research and Public Health in 2013 found that individuals with hypothyroidism are more likely to have vitamin D deficiency than healthy individuals.
Poultry and Beef: Another essential nutrient for thyroid health is zinc, which is necessary for the production of thyroid hormones. Research suggests that insufficient zinc levels can lead to hypothyroidism, while hypothyroidism can also result in zinc deficiency due to the role of thyroid hormones in mineral absorption.
Fish: Fish is another excellent source of iodine. A study published in BMC Public Health in 2014 highlighted that individuals living in mountainous regions with limited access to the sea are at higher risk of goiter. Approximately 85g of grilled cod can provide around 158μg of iodine, which is close to the recommended daily intake.
Shellfish: Shellfish such as crab and shrimp are also good sources of iodine. Consuming about 4-5 shrimp can supply around 10% of the recommended daily iodine intake. They are also rich in zinc, with approximately 3.4mg of zinc per 85g of crab.
Eggs: One large egg can provide about 16% of the daily iodine requirement and approximately 20% of selenium. Since most of the