Iodine deficiency can affect the thyroid gland, such as simple goiter, commonly known as big neck disease, which is caused by a lack of iodine in the diet and stimulates the enlargement of thyroid cells. To prevent iodine deficiency, you can have a balanced diet and eat iodine-rich foods, such as seaweed, seaweed and iodized salt, and if necessary, you can also take oral iodine-containing drugs to prevent iodine deficiency.