Risks and benefits of carnitine supplementation in diabetes. Semantic Scholar BIO INNOVATIONS: Congestive Heart Failure Support Amazon.com: Vital Nutrients Carnitine 500mg L Carnitine Supplement for Heart Health Support Vegan Energy Support Supplement Gluten, Dairy, Soy Free Non GMO 60 Capsules : Health & Household Acetyl L Carnitine for Heart, Diabetes & Kidney Health Kidney Coach L carnitine is primarily synthesized in the liver from the amino acids lysine and methionine through a series of four enzymatic reactions, with the liver and kidneys converting the precursor butyrobetaine into active L carnitine: Health Benefits, Side Effects, Uses, Dose & Precautions