Vegan Sources of Iodine: What You Need to Know

As more people adopt a vegan lifestyle, it's important to consider whether their diet is providing all the necessary nutrients for optimal health. One nutrient that may be lacking in a vegan diet is iodine. In this article, we'll explore the importance of iodine, vegan sources of iodine, and whether vegans should consider taking an iodine supplement.

What is Iodine? 

Iodine is a mineral that is essential for thyroid function and overall health. It plays a key role in the production of thyroid hormones, which regulate metabolism, growth, and development (1). While iodine is naturally found in many foods, there are fewer sources of iodine in vegan food, making it challenging for vegans to obtain enough of this essential nutrient.

Why Is Iodine Important?

Iodine is essential for the production of thyroid hormones, which regulate metabolism, growth, and development (1). When the body does not get enough iodine, it can lead to an enlarged thyroid gland (goiter), hypothyroidism, and even mental impairment in severe cases (2).

Pregnant women are especially at risk of iodine deficiency, as iodine is critical for fetal brain development (3). A deficiency of iodine during pregnancy can lead to developmental delays, mental impairment, and even stillbirth (4).

Vegan Sources of Iodine

There are fewer sources of iodine in vegan food than in animal products, making it challenging for vegans to obtain enough of this essential nutrient. However, there are still some vegan sources of iodine that can help vegans meet their recommended intake.

Seaweed

Seaweed is one of the richest sources of iodine, with some varieties containing up to 45,000 mcg of iodine per gram (5). Nori, dulse, kelp, and wakame are all types of seaweed that are commonly consumed in vegan diets. However, it's important to note that the iodine content of seaweed can vary widely based on the type of seaweed and where it was grown (6).

Iodized Salt

Iodized salt is table salt that has been fortified with iodine. It's a convenient and inexpensive way to obtain iodine, with just 1/4 teaspoon of iodized salt containing approximately 95 mcg of iodine (7). However, it's important to note that excessive salt intake can lead to high blood pressure and other health problems, so it's important to use iodized salt in moderation.

Other Vegan Sources of Iodine

Some other vegan sources of iodine include:

• Lima beans (1 cup cooked): 16 mcg of iodine (8)
• Navy beans (1 cup cooked): 64 mcg of iodine (8)
• Prunes (5 prunes): 13 mcg of iodine (8)

Should Vegans Consider Taking an Iodine Supplement?

Due to the limited sources of iodine in a vegan diet, many vegans should consider taking an iodine supplement to ensure they're getting enough of this essential nutrient. The recommended daily intake of iodine for adults is 150 mcg (9).

However, it's important to note that excessive iodine intake can also be harmful. Too much iodine can lead to hyperthyroidism and other health problems (10). Therefore, it's important to consult with a healthcare professional before starting any new supplement regimen.

Clinical Studies on Iodine and Vegan Diets

Several clinical studies have investigated the iodine status of vegans and vegetarians. A study published in the Journal of Clinical Endocrinology and Metabolism found that vegans had lower urinary iodine concentrations compared to omnivores and vegetarians (11). Another study published in the European Journal of Clinical Nutrition found that 

vegans had lower iodine intakes than omnivores and lacto-ovo vegetarians (12). A systematic review published in Nutrients found that iodine deficiency is a common problem among vegans and vegetarians, and that iodine supplementation may be necessary to prevent deficiency (13).

Iodine is an essential nutrient that plays a critical role in thyroid function and overall health. While there are fewer sources of iodine in vegan food than in animal products, there are still some vegan sources of iodine, including seaweed, iodized salt, and certain plant-based foods. However, many vegans should consider taking an iodine supplement to ensure they're getting enough of this essential nutrient. As always, it's important to consult with a healthcare professional before starting any new supplement regimen.

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