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 Does L Carnitine help manage hyperthyroidism symptoms? Consensus The supplement secret for hyperthyroidism? , When dealing with hyperthyroidism or Graves disease, L carnitine can be a total game changer. It helps block the entry of thyroid hormone into the cell Amazon.com: Seeking Health Acetyl L Carnitine Acetyl L Carnitine Supplement Supports Energy, Healthy Fat Metabolism, & Memory Health 500 mg, 90 Capsules : Health & Household