Iodine-deficient regions are geographic areas where the natural iodine content in soil and water is insufficient to meet the population’s dietary needs, leading to inadequate iodine intake. This deficiency is clinically significant because iodine is essential for thyroid hormone synthesis, and its lack can cause disorders such as goitre and hypothyroidism. A key complication in these regions is the increased risk of developmental abnormalities, including cretinism, particularly affecting pregnant women and infants.