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 functions as a cofactor for long chain fatty acids across Download Scientific Diagram Carnitine transport and fatty acid oxidation ScienceDirect Frontiers Fatty acid oxidation in immune function Carnitine: Genetic Variants Affecting Mitochondrial Energy and Health The Carnitine Shuttle Cytosol Mitochondrial Fatty Acid Transport