Why Is Iodine Important for Plant-Based Diets?
Iodine is a vital mineral required for proper thyroid function, which regulates metabolism, growth, and development. Iodine deficiency can lead to hypothyroidism and can significantly impact brain development, especially in pregnant women and children. Unlike cow's milk, which contains iodine from feed and disinfectants, plant milks do not naturally have significant amounts of this nutrient. For those on a vegan or plant-based diet, finding reliable sources like fortified plant milks is important, but checking labels is essential as fortification is not consistent.
Identifying Iodine-Fortified Plant Milks
Since not all plant milks are fortified, checking the nutrition label and ingredients list is crucial. Look for 'Potassium Iodide' or 'Potassium Iodate' in the ingredients or 'Iodine' listed in the nutrient panel. Some brands in certain regions, like Oatly and Alpro's Original Soy milk, are known to fortify, as are some store brands. Always confirm fortification on the specific product label.
Which Plant Milks Have Iodine: Fortified vs. Unfortified Content
The iodine content differs significantly between fortified and unfortified plant milks. The table below shows typical values, but these can vary by brand and region, and unfortified amounts are generally very low and depend on soil content.
| Milk Type | Typical Iodine Content (Unfortified, per 100ml) | Typical Iodine Content (Fortified, per 100ml) | Label Indicators for Iodine |
|---|---|---|---|
| Almond | ~0.2 µg | ~25 µg | Potassium Iodide, Potassium Iodate |
| Oat | ~0.6 µg | ~25-30 µg | Potassium Iodide, Potassium Iodate |
| Soy | ~0.2 µg | ~25-30 µg | Potassium Iodide, Potassium Iodate |
| Rice | ~0.2 µg | ~25 µg | Potassium Iodide, Potassium Iodate |
| Coconut | ~0.2 µg | Often not fortified, some brands may vary | Potassium Iodide, Potassium Iodate |
Note: Fortified values are estimates and can vary significantly by brand and region. Always check the specific product label.
Potential Concerns with Seaweed-Based Fortification
Seaweed can be a source of iodine, but its concentration is highly variable and can be excessively high, particularly in kelp. This variability has led to concerns and even product recalls for iodine toxicity with supplements or fortified items using seaweed extracts like kombu. It is generally considered safer to opt for products fortified with controlled doses of potassium iodide or potassium iodate.
Supplementation and Other Iodine Sources
For those not using fortified plant milks, other sources are necessary to avoid deficiency. Reliable options include iodized salt (about 71 µg per quarter teaspoon) and daily iodine supplements (often 150 µg from potassium iodide). Some plant foods like prunes, lima beans, and baked potatoes with skin offer small amounts, though iodine content depends on soil quality. Moderate consumption of low-iodine seaweed like nori can also contribute but requires caution due to potential variability.
Conclusion
Iodine in plant milks is primarily due to fortification, not natural presence. Many brands add iodine, typically as potassium iodide, but this is not universal. Consumers, especially vegans, should check labels for fortified products to ensure adequate intake. Relying on unfortified plant milks is not sufficient for iodine needs. Fortified plant milks, iodized salt, or supplements are recommended to meet daily requirements, especially if other dietary sources are limited.
Visit Vegan Health for further information on iodine and vegan diets.
