Transcript Episode 19: The Problem with Plant-Based Products for Meeting Iodine Requirements


Karla Moreno-Bryce: Hello and welcome to the vegan kids nutrition podcast. If you’re new to the podcast, I’m so glad you’re here as this is the space I share a lot of behind-the-scenes in feeding my own vegan family, insight nutrition tips, and more of my general philosophy when it comes to compassionate feeding. 

Today, I want to share with you a research study I came across on and share my personal and professional viewpoints as it relates to feeding your vegan kids. This episode is slightly different from my usual podcast format, but I think it’s an important topic to address as it’s not receiving a lot of attention within vegan and non-vegan communities. I’ll share a brief  preview of the study and then at the end how this information applies to supporting the growth of your vegan kids.

And if you find this episode helpful, I’d be so grateful if you can share it with a friend or someone interested in learning more about vegan kids nutrition. Thanks for your support! 

Alright, so the topic I want to cover today is about iodine. A new study came out in March 2024 about iodine content in plant-based products in the Swiss market. Now, even if you’re not from Switzerland, stay with me here because it still applies to all of us, regardless of which country we reside in. 

This is a cross-sectional study in Zurich, Switzerland that collected data of a total of 477 plant-based milk alternatives, plant yogurts both flavored and unflavored, plant-based cheeses, and fish alternatives. They collected data on various micronutrients like calcium, Vitamin D, Vitamin B12, Vitamin B2, and iodine. And the one I want to highlight here is iodine. The purpose of the study was really to look at the iodine content in plant-based dairy and fish alternative products available in the Swiss market and compare them to that of animal-based foods since dairy products and fish are major sources of iodine for the Swiss population. 

Let’s look at what products the study looked at. For plant-based milk, out of the 170 total plant- milks they reviewed only 4 were fortified with iodine with a median concentration of 22.5 micrograms per 100ml, and all four happened to be from oat milk. This is a very small amount. 100 millileters is roughly less than ½ cup to give you some context and in fact this amount is lower than what is seen in many cow’s milk products, which varies significantly and can range anywhere between 80 to over 100 micrograms per one cup serving. To give you a bit of context about the small amount of iodine present in these plant-based milks, the Recommended Dietary Allowance for children between the ages of 1 to 8 years is 90 micrograms per day and kids between 9 to 13 years of age need 120 micrograms per day. So, as you can see, the median concentration they found of 22.5 micrograms per 100ml of serving is a very small percentage for helping kids meet their iodine needs. 

Coming back to other products they looked at. In plant-based yogurt, out of the 113 products they reviewed, zero were fortified with iodine. Similar to plant-based yogurt, none of the plant-based cheese products they looked at contained iodine and only five were fortified with calcium and Vitamin B12. 

This data shows us that plant-based products don’t really contribute to helping individuals meet iodine needs. Majority of plant-based products do not provide any amount of iodine, which is a crucial nutrient for vegans. And this isn’t just in the Swiss market, we see iodine lacking in US and Canadian plant-based products as well. And perhaps in other countries as well. 

When my first born daughter was around one year of age and ready to transition to a plant milk, I remember spending an incredible amount of time at the grocery store one day reviewing every single brand of plant-based milk, especially that of soy milk since it’s the most appropriate milk alternative for growing kids, to review the fortification content like calcium, Vitamin D, and Vitamin B12. And as I was looking at dozens of nutrition labels, I noticed that none had iodine as part of their fortification.

There is only one brand in the USA that contains iodine from kombu seaweed and that’s EdenSoy Extra. It’s not really labeled or shown on the nutrition facts label so as a consumer, unless you read the list of ingredients and were knowledgeable about plant foods that contain iodine, some individuals wouldn’t know this brand of soy milk provided iodine. But other than that, iodine in plant-based milk alternatives is greatly lacking. 

This to me sparks a great concern because as more and more families begin to adopt a vegan or plant-based lifestyle, we may potentially see low iodine intakes. And iodine plays a very important role in supporting the growth of vegan kids. 

Before I share more about my thoughts and so we’re all on the same page, let’s first identify what role iodine plays in our bodies. 

Iodine is a nutrient that is needed to help maintain our thyroid gland healthy. It’s used in the making of thyroid hormones which control many functions in our body like our metabolism, regulating temperature, helping proper bone development, as well as helping with brain development during infancy and pregnancy. As you can see, iodine plays a very crucial role in our kids' growth. 

Now, you might be wondering, what plant foods are high in iodine. Dairy products and fish are the two most common foods. Iodine is not readily available in plant-based foods other than seaweed and table salt. 

I want to expand here a bit about these foods because it’s often the misconception that animal-based foods are superior to plant-based foods. Cow’s milk naturally contains low levels of iodine. It’s only due to the practices of factory farming, such as using disinfectants that are iodine-based and supplementing the cattle feed with iodine, that cow’s milk is able to provide iodine. Seafood is known to be a rich source of iodine and this is partly due to the fish eating seaweed and/or their diet supplemented with iodine if factory farmed. 

You might’ve heard that fruits and vegetables are rich sources of iodine for those who follow a plant-based diet because these foods absorb iodine from the soil. But this is actually not true. There is no list of iodine-rich fruits and vegetables. Iodine content in soil varies greatly region by region, which ultimately impacts overall iodine content of that crop and ultimately how much iodine is present in that plant food.  

In fact, the Swiss study I referenced earlier states that soil in Switzerland contains very little iodine as compared to other countries. This is the primary reason why I don’t recommend vegan families to rely on fruits and vegetables for meeting your family’s iodine requirements. Fruits and vegetables are not reliable sources of iodine. 

So, if fruits and vegetables aren’t reliable sources of iodine, how do you meet your vegan child’s daily iodine requirements? The most practical and simplest way to meet iodine needs is through iodized table salt.

This effective and inexpensive practice of adding iodine to table salt came about after many individuals were experiencing goiter, which is when your thyroid gland grows irregularly, and cretinism, which is a condition resulting in stunted physical and mental growth, as a result of not getting adequate iodine from the diet.In the USA, thanks to the efforts and advocacy of David Cowie from the University of Michigan, iodized salt was introduced at grocery stores in 1924. A little fun fact for you. 

So, for vegans, the simplest way to meet iodine needs is through iodized table salt. The use of Himalayan salt, soy sauce, or any other condiments does not contain iodine. You must purchase one that is labeled iodized salt. 

Now, you might be wondering whether pre-packaged foods or other plant-based products have iodized salt. Most salt consumption for individuals is through processed foods but the use and content of iodine in these products is very limited. In general, it’s good to assume that processed foods don’t contain iodine and the FDA or Federal Drug Administration don’t require manufacturers to list iodine in their nutrition label. There are some manufacturers that do use iodized salt in their dough for bread making but it’s voluntary to use and again they’re not required to put it on the label even if they do use iodized salt. 

So, coming back to my personal and professional thoughts about iodine in the food market is that this isn’t just a concern for vegans or vegan children, it’s a global concern across all population groups and stages of life, especially as more people begin to eat plant-based. Labeling of iodine and the use of iodized salt in processed foods is greatly lacking, which makes it challenging to know if individuals are receiving adequate amounts of iodine from packaged foods.  

In fact, based on the Iodine Global Network scorecard, in 2020, there were 21 countries found to be iodine deficient, particularly in school aged children. So, globally, we’re seeing iodine intake to be low across all population groups and as people’s dietary patterns begin to evolve, we’ll need more programs to address meeting iodine needs, such as supplementing food products and proper labeling and nutritional regulations.

I do feel that plant-based products should be fortified with iodine, especially plant-based milks to prevent any risk of deficiency for growing vegan kids and those who don’t or can’t consume dairy. We already fortified plant milks with equivalent nutrients as that of cow’s milk such as Vitamin A, Calcium, and Vitamin D, so why can’t we do the same with iodine?

The addition of iodine in plant-based food products is something I’ve advocated for when consulting with food brands because it’s not just an important nutrient for vegans, it’s a nutrient that impacts all of us, especially as more individuals and families begin to follow a more compassionate eating pattern.  

Now, how does this information and the lack of iodine in plant-based foods impact your vegan kids? As I mentioned earlier, iodine plays an important role in helping build proper bone development and brain development during infancy. Perhaps the most common consequence as a result of low iodine intake is hypothyroidism, which is when the thyroid gland, which sits at the base of the neck, doesn’t produce enough thyroid hormones. This can result in symptoms like fatigue, dry skin, hair loss, and cold intolerance. 

And we want to prevent that in growing vegan children. So, for babies between the ages of 6 months to 12 months, if they are exclusively breastfed, then it’s likely they’re meeting their iodine needs from human milk alone. This is true as long as the breastfeeding parent is supplementing or consuming adequate iodine then babies can meet their iodine needs. There are studies that have looked at small samples of breastmilk in vegan lactating women that have shown to have lower iodine levels compared to the adequate intake or recommended amounts. So, for lactating vegan parents, it’s important to ensure a prenatal supplement that provides adequate iodine is consumed.

For babies who are receiving infant formula, they will meet their iodine requirements as long as they’re consuming at least 40 to 45 ounces per day. Iodine becomes more of a risk during the weaning period, primarily because they may be receiving far less iodine during this time from either type of milk. If they’re receiving commercial baby food during this weaning period, it’s likely that they’re not receiving any iodine as baby food isn’t regulated and majority don’t provide iodine. If your vegan baby is consuming solid foods from home cooked meals, adding iodized salt may seem like the most ideal choice but this isn’t recommended primarily because babies sodium intake should be kept to a minimum. So, once they begin to consume less infant formula, your baby will need to have an iodine supplement.

For toddlers between the ages of 1 to 2 years of age, whether they are fully weaned from either type of milk or not, they will need an iodine supplement. During this age, your baby’s salt intake is still limited so you want to be mindful of how much salt is added in your home cooked meals. Something I did for my girls and a cooking practice I share with other vegan parents is simply to cook or prepare your family’s food, reserve or portion out baby’s food, and then you can add iodized salt to your meal or sprinkle it in at the table once you’re seated. 

Once they turn 2 years old, then you can transition away from a daily iodine supplement to iodized salt. Using iodized salt at home is the easiest way to meet iodine needs for young children and adolescents, and adults too.

At this point, you may be wondering if seaweed is a good option to meet iodine needs versus offering a supplement to your child or using iodized salt. Seaweed does offer iodine but iodine levels vary greatly based on the type of seaweed and where it was grown. You can either get too much iodine or too little iodine from consuming seaweed. Eating nori sheets is okay to have as part of your family’s diet, I just don’t recommend relying on meeting iodine needs for your family. 

Meeting your child’s iodine requirements at each stage of their growth is attainable. In the  Supplement Guide for Vegan Kids, you’ll learn all about iodine requirements for each stage of growth. Whether your vegan child is 8 months or 12 years old, you’ll know exactly how to meet their iodine needs. You’ll also know how much to supplement your baby or young toddler and have brand recommendations. The Supplement Guide for Vegan Kids is a great resource to help you feel confident you’re meeting your vegan child’s iodine requirements. I’ll leave the link in the show notes so you can grab your copy and feel reassured you’re doing things right to support your child’s growth and brain development. 

Alright, so just to recap, plant-based products like plant milks, plant yogurts, and plant cheeses in the Swiss market and in other countries rarely provide any iodine. Fruits and vegetables are not reliable sources of iodine, for the exception of seaweed but due to its varied iodine content it’s not recommended to rely on meeting this important nutrient. The most reliable way to meet your child’s iodine requirements is through a supplement or iodized salt is they’re 2 years and older. 

I hope this episode has helped you better understand the importance of iodine and how you can meet this important nutrient for your vegan kids. And if you find it helpful, please share it with others and together we can continue to make an impact for a more compassionate lifestyle. I’ll talk to you in the next episode. Bye for now.