Iodine deficiency is a global public health problem and the world’s most common cause of preventable brain damage in newborns and infants. Goiter (an enlarged thyroid gland in the neck) is just the visible tip of the iceberg. The "hidden" effects are much more life-limiting and severe. During pregnancy, iodine deficiency can cause stillbirth, spontaneous abortion, and congenital brain abnormalities that may lead to irreversible and severe mental impairment.