L Carnitine L Carnitine Supplementation in the Diabetic Heart ABC Cardiol Risks and benefits of carnitine supplementation in diabetes. Semantic Scholar Spring Valley CoQ10 Plus L Carnitine Heart Health Dietary Supplement Softgels, 100 mg, 50 Count HSA FSA Eligible Walmart.com 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