Frontiers Association between fatigue, peripheral serotonin, and L carnitine in hypothyroidism and in chronic fatigue syndrome 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 L carnitine supplementation for the management of fatigue in patients with hypothyroidism on levothyroxine treatment: a randomized, double blind, placebo controlled trial. Semantic Scholar 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 Amazon.com: Rootcology by Dr. Izabella Wentz Carnitine Blend L Carnitine & Acetyl L Carnitine Formula Ideal for Vegetarians 120 Capsules : Health & Household