Final answer:
True, insufficient dietary iodine impairs the synthesis of thyroid hormones, essential in regulating the metabolic rate. Iodine deficiencies can lead to goiter and other developmental and cognitive disorders, with iodized salt being a widespread preventive measure.
Step-by-step explanation:
It is true that an animal may have a hard time regulating its metabolic rate if it does not have enough iodine in its diet. Iodine is crucial for the synthesis of thyroid hormones, thyroxine (T4) and triiodothyronine (T3), which regulate the body's basal metabolic rate. A deficiency in iodine can lead to a condition called goiter, where the thyroid gland enlarges due to overproduction of Thyroid Stimulating Hormone (TSH) without the concurrent formation of thyroid hormones. Besides goiter, insufficient iodine intake can result in disorders such as impaired growth and development, decreased fertility, and preventable intellectual disabilities. Furthermore, in severe cases, iodine deficiency during pregnancy can cause neonatal hypothyroidism (cretinism) in offspring, characterized by cognitive deficits and growth abnormalities.
In areas where natural food sources are low in iodine, especially landlocked regions, iodizing salt has been an effective measure to prevent iodine deficiency disorders, as seen in the United States since 1924.