Iodine is a key mineral that has many roles in your body.

It’s found naturally in foods like eggs, seafood, and meats and commonly present in the Western diet, as it’s found in iodized salt.Although iodine is important for your health, dietary iodine may need to be restricted sometimes, such as prior to radioactive iodine therapy for people with thyroid cancer. This is when a low iodine diet may be prescribed.

What is a low iodine diet?
Your thyroid gland uses it to produce thyroid hormones, which aid many important processes. This includes regulating your metabolism and aiding growth and tissue repair.

Iodine is present in many foods, such as dairy products, seafood, grains, and eggs.

A low iodine diet is a short-term diet that may be prescribed to people prior to radioactive iodine therapy for conditions like papillary or follicular thyroid cancer 2Trusted Source. as part of this diet, people are required to restrict their daily iodine intake to fewer than 50 mcg of iodine per day, which is one-third of the daily allowance of 150 mcg 3Trusted Source.

This short-term diet lasts approximately 1–2 weeks prior to receiving radioiodine and is continued for another 1–2 days afterward. However, these recommendations can vary and depend on your healthcare provider’s professional opinion 3Trusted Source.

The purpose of a low iodine diet is to deplete your body’s iodine stores, which helps improve the effectiveness of the radioactive iodine scan or treatment 3Trusted Source.

May reduce blood pressure

This is because the diet restricts many unhealthy food groups, such as processed meats and highly processed snack foods. These particular food groups are restricted because they’re often high in iodized salt.

Numerous studies have shown that consuming a diet high in processed foods is linked to a greater risk of high blood pressure. Additionally, reducing processed food intake in favor of whole foods has been linked to reduced blood pressure 4Trusted Source, 5Trusted Source, 6Trusted Source, 7Trusted Source.

However, it’s important to note that the low iodine diet is temporary. As such, to achieve long-lasting changes in blood pressure, you should minimize your processed food intake over the long term.

May improve diet quality

This mostly applies to fast food, frozen meals, and prepackaged items like chips, which are not only typically high in iodized salt but also unhealthy fats and calories.However, while a low iodine diet eliminates these foods temporarily, it’s up to you to continue to make healthier food choices moving forward as part of a healthy lifestyle.

Precautions and concerns

A low iodine diet is a short-term diet for people who will undergo radioactive iodine therapy. As a short-term diet, it should only be followed for 1–2 weeks prior to therapy and several days afterward, as advised by your healthcare provider.

Due to its restrictive nature, a low iodine diet should not be followed for longer than the advised time period, as it restricts several nutrients. Following it for longer than this time period may raise your risk of nutritional deficiencies.

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David Paul
Managing Editor
Journal of Food and Clinical Nutrition