What will happen if intake of iodine in our diet is low?

What will happen if intake of iodine in our diet is low ?Why is the use of iodised salt advised ?
A. 1. It is advised to use iodised salt to prevent goitre (enlargement of the thyroid gland).
2. Iodine is required for the proper functioning of thyroid.
3. Iodine stimulates the thyroid gland to produce thyroxin hormone.
4. This hormone regulates carbohydrate, fat and protein metabolism in our body