Frontiers Fatty acid oxidation in immune function 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 The Role of l Carnitine in Mitochondria, Prevention of Metabolic Inflexibility and Disease Initiation Carnitine Acetyltransferase an overview ScienceDirect Topics