Iodine

Thyroid hormones are made partly of iodine. Thyroid hormones help control the body's metabolism and play an important role in muscle growth. Iodine can easily be added to food by using iodized salt. Seafood and dairy also are sources of iodine. People who do not eat seafood or dairy may be at risk of iodine deficiency if they do not use iodized salt. Iodine deficiency can lead to the thyroid getting bigger as it tries to meet the body's need for thyroid hormones. When that happens to the thyroid it's called goiter. Seaweed is vegetarian option for dietary iodine.