Iodine is a trace element whose synthesis is used in the production of thyroid hormones that regulate metabolism, growth, and development. Therefore, deficiency in iodine can be traced back to anyone, but some dietary patterns can cause a greater susceptibility to this condition. These primarily include vegetarian diets, and vegan diets, among others. The article looks at how vegetarians are susceptible to iodine deficiency; and the factors contributing to this risk.

Are vegetarians highly susceptible to iodine deficiency?

Maybe. A vegetarian diet, particularly a vegan diet, may make a person more susceptible to iodine deficiency simply because they exclude products that are rich in iodine, such as animal products. In 2003 researchers discovered that one out of four vegetarians and 80% of vegans don’t get enough iodine. Most vegetarian diets would include iodized salt, but unlike the other traditional sources of iodine-based dietary intakes, dairy, fish and eggs are lacking in almost all vegetarian diets, thus those foods do not fill the gap for iodine deficiencies. 

What factors increase the risk of iodine deficiency in vegetarians and vegans?

Iodine deficiency may also be more common in vegetarians and vegans because of several reasons:

1. Dietary Restriction: First, their diet lacks animal-derived products. Fish, dairy, and eggs are good sources of iodine, and therefore exclusion will probably lead to a failure to meet the necessary iodine intake for vegetarians and vegans.
2. Soil Iodine Levels: The iodine content in foods from plants depends on the soils from which they are produced. Countries where the iodine content in soil products is low will have crops of low iodine. Some inland areas, for example, that are far away from the sea, are known to naturally be low in iodine. This will expose vegetarians and vegan people to risks because their region may lack sufficient iodine in the soil.
3. Non-iodized Salt Use: The major consumer does not know the importance of iodized salt. The people who are vegetarian and vegan who rely on non-iodized salt or pure avoidance of salt will be iodine deficient.
4. Increased Nutritional Requirements: In various life stages, for example, pregnancy and lactation require large iodine intakes. For women in such groups, this could be particularly challenging without serious dietary planning or supplementation when one tries to follow plant-based diets.

What are the best vegetarian sources of iodine?

Most of the rich sources of iodine are animal products, though some plant sources are available to meet the iodine requirement for vegetarians and vegans:

1. Sea Vegetables: Nori, kombu, and wakame are among the richest of all the iodine sources in plant foods though not found in India. A tiny serving can provide more than the daily recommended amount, making addition to any meal a vital boost in their digestion.
2. Iodized Salt: For vegetarians and vegans, iodized salt is the best and most basic way of ensuring they get enough of this nutrient. It is widely available and would not be difficult to add to most diets.
3. Fortified Foods: Some plant-based milk alternatives and other foods are also fortified with iodine. Look for those options on the labels.
4. Fruits and Vegetables: Generally, fruits and vegetables contain much less iodine than sea vegetables, though still, they may contribute to iodine intake when grown in highly iodine-rich soils. Potatoes, cranberries and strawberries are examples of foods rich in modest quantities of iodine.

Do vegetarians have a higher risk of thyroid problems due to iodine deficiency?

The answer is inconclusive. A 2013 study found that following a vegan diet might help protect against hypothyroidism, although the results weren’t statistically significant. Vegans generally have lower body weights, which could help with thyroid health, but even when adjusting for weight and other demographic factors, vegans still showed a lower risk of hypothyroidism. In contrast, lacto-ovo vegetarians (who consume dairy and eggs) seemed to have a higher prevalence of hypothyroidism.

One explanation for the vegan diet’s protective effect could be that animal products can cause inflammation, which may negatively affect thyroid function. There are also concerns about certain foods common in vegetarian diets—like soy and cruciferous vegetables—potentially affecting thyroid health.

Conclusion

Iodine deficiency is a significant problem in the diets of vegetarians and vegans, as well as people who are unable to prepare their diet properly or take lesser amounts of foods which have iodine. Although certain aspects of dietary restriction and soil iodine entail higher risks, awareness and deliberate diet planning can greatly reduce these risks. Important practices to maintain adequate levels of iodine include the consumption of sea vegetables, the use of iodized salt, and choosing fortified foods.