Your body relies on iodine in order to create essential thyroid hormones. Without those, you would be unable to properly regulate metabolism and other vital functions. This process is even more important for pregnant women and children because a growing human relies on thyroid hormones for bone and brain development.
Researchers reported in the EPIC oxford study that intakes of iodine among vegans are lower than that of omnivores, and beneath the Recommended Daily Allowance (RDA).
Iodine is similar to the Omega-3s in that this mineral does exist as part of certain plants— especially seaweeds— but may not be adequately consumed as part of a typical, Western plant-based diet. The good news is that it is not too difficult to meet the RDA of 150 mcg on a plant-based diet. For example, one medium potato contains about 60 mcg of iodine, and 4 oz of cranberries contain 400 mcg of iodine!
One of the easiest ways of getting iodine in your diet is by adding a small amount of iodized salt to your food, however this will also add sodium, which you may be restricting. You might also consider sprinkling kelp flakes on your salads and power bowls to increase your iodine intake. Some people also do take a supplement to ensure a safe dose of iodine. Pregnant women in particular should ensure they are getting adequate iodine to prevent birth defects.