Vegan Iodine Guide: Requirements & Top Sources
Learn how to meet your daily iodine needs on a plant-based diet with top vegan sources, and tips for optimal health
Micronutrient mini-series
This article series is a spotlight on the micronutrients, vitamins and minerals you need on a vegan diet. We look at where you can get them, how much you need, if supplementing is necessary, and tips for incorporating them into your plant-based diet.
Article by Caitlin Arnold, a vegan Accredited Sports Nutritionist, Strength & Conditioning coach and bodybuilder at Plant Physique. Her passion is helping vegans achieve their health and fitness goals with evidence-based guidance and expertise.
Iodine is a mineral needed for the production of thyroid hormones, which create proteins and enzyme functioning, as well helping regulate a normal metabolism. Additionally, babies and infants require enough iodine for normal physical growth and brain development.
Iodine is an essential mineral which means it cannot be made by the body and must be consumed from food or supplements.
A low consumption of iodine can result in not enough thyroid hormones being produced. This in turn can lead to hypothyroidism. Symptoms of hypothyroidism include fatigue, weakness, a sensitivity to cold, dry skin and hair, weight gain and constipation.
Recommended Daily Intake of Iodine
The daily recommended amount for iodine is:
- 0-6 months: 110 mcg
- 7-12 months: 130 mcg
- 1-8 years: 90 mcg
- 9-13 years: 120 mcg
- Over 14 & adults: 150 mcg
- Pregnant and lactating women: 250 mcg
The production of thyroid hormones increases during pregnancy, so mothers require higher amounts of iodine.
Over 50% of children and pregnant or breastfeeding women living in Australia have been shown to be iodine deficient, and are at risk of developing thyroid disease. Moderate to severe iodine deficiency in babies, infants and children can stunt growth and brain development.
Top Vegan Sources of Iodine
Iodine is found in the soil and ocean, and some plants. The challenge is this varies significantly across different regions and affects how much iodine is found in certain foods.
Thankfully for vegans, seaweed, like kelp, nori, kombu, dulse and wakame, is one of the best food sources of iodine. The iodine amounts in different seaweed species can vary from 16 mcg to 2,984 mcg per gram. While iodine is also found in fish and other sea life this is because they get iodine from seaweed in their diet or absorbed from seawater.
It’s also known that dairy contains iodine. However, this iodine comes from supplements the cows are given or iodine based cleaning agents used on the cows and milk-processing equipment.
International health agencies WHO, UNICEF and ICCIDD recommend that all salt be iodised – in a proposal called the Universal Salt Iodisation. On this recommendation, it’s been required in Australia and New Zealand since 2009 that bread is made with iodised salt, so this can be a useful source of iodine for vegans. Since this change, iodine intake in women aged 16–44 increased by 52% and in children aged 2–3 increased by 29%.
Unfortunately, most fruits and vegetables are poor sources of iodine because they are affected by iodine depleted soil, fertiliser use, and irrigation practices. This in turn influences the iodine content of animal products.
Should Vegans Supplement with Iodine?
Provided you’re consuming a range of iodine rich foods regularly, iodine supplementation generally isn’t needed for vegans.
The exception is for vegan or non-vegan women who are pregnant, breastfeeding or considering pregnancy, who should supplement with at least 150 mcg per day. Women who have thyroid disease, should consult their doctor before taking an iodine supplement.
Key Takeaways for Meeting Vegan Iodine Needs
Iodine is found in plant-based foods – you just need to be aware of including it regularly enough. To ensure you’re getting enough, some tips would be to switch your table salt for iodised salt, and eat bread and foods with seaweed regularly.
Summary
- Iodine is needed to maintain overall health, particularly thyroid health and brain development in babies
- The mineral is found mainly in seaweed or products fortified with iodine – like bread and iodised salt
- Supplementing iodine isn’t usually needed on a vegan diet, with the exception of both vegan and non-vegan pregnant or breastfeeding mothers who should take 150 mcg per day
FAQs
How do vegans get enough iodine?
Vegans can meet their iodine needs by using iodised salt in cooking and eating small amounts of seaweed such as nori, dulse, wakame, or kelp. Because iodine levels in plant foods vary depending on soil nutrients, fortified foods (such as bread and iodised salt) or a vegan iodine supplement can also help ensure you’re getting enough.
What are the best vegan sources of iodine?
The best vegan sources of iodine include iodised salt, seaweed (like nori, wakame, and dulse), and fortified plant milks. If you don’t regularly eat these foods, a vegan iodine supplement can be a reliable way to maintain healthy levels.
Why is iodine important for vegans?
Iodine is essential for all humans, vegans and non-vegans alike, for healthy thyroid function, which regulates metabolism, energy, and overall wellbeing. It is especially critical during pregnancy and breastfeeding for the proper development of the baby’s brain and central nervous system. Thus, all pregnant or breastfeeding women should supplement with at least 150 mcg of iodine per day.