L Carnitine for Fat Loss & Boost Energy Alpha Nutrex Thyroid Supplement with L Carnitine for Cats Only Natural Pet The most common cause of hypothyroidism worldwide is insufficient intake of iodine, a mineral found in iodized salt and some foods (such as seafood and dairy) that is needed for production of Hypothyroidism is a condition where the thyroid gland does not produce enough thyroid hormone which is crucial to regulate the body's metabolism and growth development. There can be various causes that contribute Low Thyroid or Hypothyroidism: Causes, Symptoms, and Solutions