Iodine for Vegans & Vegetarians
Iodine is an essential mineral for producing thyroid hormones, which regulate metabolism, body temperature, and energy levels. Iodine is especially important for pregnant women and for foetal brain development. Plant-based foods are typically lower in iodine, placing vegans and vegetarians in a higher-risk group for iodine deficiency.
Why Plant-Based Diets May Fall Short
The main dietary iodine sources are seafood (fish, seaweed, shrimp) and dairy products. For vegans, both categories are automatically excluded. Additionally, the iodine content of eggs is variable and depends on the hens' diet.
Several studies have shown that vegans and vegetarians tend to have lower iodine intake. Lightowler et al. (2000) examined British vegetarians and found their iodine intake was well below the recommended level.
Vegan-Friendly Sources
| Source | Iodine Content | Vegan-Friendly |
|---|---|---|
| Iodised table salt | Variable | Yes |
| Seaweed (nori, wakame) | Variable, may exceed limit | Yes |
| Iodine-fortified plant milk | ~75 mcg per serving | Yes |
| Iodine supplement (KI) | Dosed | Yes |
Seaweed (especially brown algae like kombu) is a theoretically appealing source, but iodine content varies enormously and may be far too high, potentially increasing the risk of iodine excess rather than deficiency.
Dose Targets
The recommended iodine intake for adults is 150 mcg per day (WHO). Pregnant women need 220-250 mcg and breastfeeding women 250-290 mcg per day. The tolerable upper intake level is 600 mcg per day for adults (European level).
OstroVit Iodine Potassium iodide 200mcg 120tabs is a vegan-suitable iodine supplement available in Estonia at maxfit.ee.
What to Combine With Iodine
- Selenium: selenium is an important partner for thyroid health - iodine and selenium act synergistically in thyroid hormone metabolism.
- Vitamin D: vegans often lack vitamin D as well - a combined approach is broadly recommended.
Choosing a Vegan Product
Check that the supplement:
- Does not contain gelatine capsules (use plant-based capsules or tablets).
- Contains potassium iodide (KI) or sodium iodate (NaI) - both are vegan-compatible.
- Doses 100-200 mcg - not too much, not too little.
References
- Lightowler, H. J., & Davies, G. J. (2000). Assessment of iodine intake in vegans: weighed dietary record vs duplicate portion technique. European Journal of Clinical Nutrition, 54(10), 765-769.
- Leung, A. M., Lamar, A., He, X., Braverman, L. E., & Pearce, E. N. (2011). Iodine status and thyroid function of Boston-area vegetarians and vegans. Journal of Clinical Endocrinology & Metabolism, 96(8), E1303-E1307. https://pubmed.ncbi.nlm.nih.gov/21613354/
- Tonstad, S., Nathan, E., Oda, K., & Fraser, G. (2015). Prevalence of hypothyroidism in vegetarians and vegans. Public Health Nutrition, 18(8), 1407-1413. https://pubmed.ncbi.nlm.nih.gov/25263477/
FAQ
Do seaweed products provide enough iodine for vegans?
Sometimes yes, sometimes no. Nori and wakame contain moderate iodine, but brown algae (kombu) can contain extremely high levels - a single serving may exceed the tolerable upper limit. Consult a nutritionist if using seaweed regularly.
How do I know if I have an iodine deficiency?
Common signs of widespread iodine deficiency include thyroid enlargement (goitre), fatigue, and hypothyroid symptoms. Blood tests (TSH and thyroid hormones) through a doctor can give a proper assessment.
Do pregnant vegans need an iodine supplement?
Yes, strongly recommended. Iodine needs increase significantly during pregnancy and obtaining adequate amounts through a plant-based diet alone is difficult without iodised salt or fortified foods. Iodine supplementation during pregnancy and breastfeeding is a topic worth discussing with a healthcare provider.
