Seaweed and Seaweed-Based Products As Plant-Based Sources of Dietary Iodine

Vegans have lower risks of some health problems such as ischemic heart disease, type 2 diabetes, and some cancers. However, they are at high risk of some nutrient deficiencies, including iodine, because plant foods are poor sources of the nutrient, except for seaweed. Also, some vegans refuse to use iodized salt or dietary supplements containing iodine. Urinary iodine concentration among vegans, indicative of mild, moderate, or severe deficiency, is common among a large percentage of vegans in many countries. Similarly, there is a high incidence of inadequate iodine concentration in the breast milk of vegan mothers. This article provides information on the iodine content of brown, red, and green algae. Some seaweed types, especially brown algae, contain very high amounts of iodine, and so, soaking and blanching are necessary to reduce the iodine content to safe levels to prevent iodine toxicity. This article focuses on seaweed and its use as a source of iodine. Because some vegans do not use iodized salt or iodine-containing supplements and because plant foods are poor sources of iodine, seaweed is a potential source of the nutrient, but to reduce the risk of toxicity, soaking and blanching are needed to dispose of excess iodine.