Nobody talks about iodine. You hear about protein, B12, iron – but iodine? It gets skipped over, even though a shortage of it can leave you tired, foggy, and with a thyroid that isn’t working the way it should. For vegans, it’s one of the most commonly missed nutrients, and most people don’t find out until something feels off.
So let’s actually talk about it.
Why This Is a Vegan Problem in the First Place
Most people get their iodine from dairy and fish without giving it a second thought. What they probably don’t know is that the iodine in cow’s milk isn’t even natural – it gets there through iodine supplements in cattle feed and iodine-based disinfectants used on milking equipment. So it’s not like dairy is some pristine iodine source. It’s fortified by accident, essentially.
Cut out dairy and fish, and the options shrink fast. Most fruits and vegetables are low in iodine because their content depends entirely on the soil they’re grown in – and large parts of the world have iodine-depleted soil. You can eat a full plate of vegetables and get almost nothing.
Seaweed Is Good, But Read the Label
Seaweed is the standout plant source. Nori, wakame, dulse – these all contain meaningful amounts of iodine, and one and a half to two sheets of nori can cover the recommended daily intake on its own. If you eat sushi regularly or throw seaweed into soups and rice bowls, you’re probably doing fine.
The problem is kelp. Kelp can contain extreme amounts of iodine – far beyond what your thyroid can handle – and too much iodine causes the same kind of thyroid issues as too little. Stick with nori, wakame, or dulse and you’ll be in a much safer range. And don’t rely on seaweed as your only strategy, since iodine levels vary between batches and brands.
Iodised Salt – Simple, With One Caveat
If you cook at home and use salt, just switch to iodised salt. It’s the same price, tastes identical, and covers your bases without any extra effort. The only thing to keep in mind is that public health advice generally pushes people to use less salt overall – so using more of it to hit an iodine target isn’t exactly ideal. It works, but treat it as one part of your approach rather than the whole solution.
Why a Supplement Is Worth Considering
Honestly, for a lot of vegans a supplement just makes the most sense. According to the Vegan Society, taking a daily supplement with potassium iodide or potassium iodate is the most reliable way to ensure you’re getting enough – and you can find them cheaply in most health food stores or online. The target is 150mcg per day for adults.
One thing: avoid supplements made from kelp or seaweed extract. The same variability problem applies. You want potassium iodide on the label, not “kelp powder” or “seaweed extract.”
What to Actually Do
You don’t need to do everything at once. Eat nori a few times a week, use iodised salt in cooking, and consider a supplement if your diet isn’t that varied or you’d rather not think about it. Pick what fits your routine and stick with it.
The symptoms of iodine deficiency – fatigue, poor concentration, sluggish metabolism – are so easy to blame on other things. Most people spend months not connecting the dots. It’s a small thing to sort out, and very much worth doing.
