Final answer:
Iodine is essential for thyroid function, and a deficiency can cause goiter and congenital hypothyroidism.
Step-by-step explanation:
A lack of iodine in the diet contributes to several deficiency diseases, such as congenital hypothyroidism and goiter.
Goiter is a condition where the thyroid gland enlarges due to the inability to produce thyroid hormones (T3 and T4) because of insufficient iodine.
The thyroid-stimulating hormone (TSH) levels increase in an attempt to stimulate the production of these hormones, but due to the lack of iodine, the gland continues to grow without producing adequate hormones.
Other disorders caused by iodine deficiency include impaired growth and development, decreased fertility, and can lead to preventable intellectual disabilities, particularly in children. It is the most significant cause of preventable intellectual disability worldwide.
The primary prevention method for goiter and other iodine deficiency disorders is the addition of iodine to salt, which has helped eliminate the concern in regions where iodine intake is otherwise low.