Red Meat and Heart Disease: The Hidden Role of microbial L Carnitine & Choline Prof Luigi Fontana Red meat and heart disease link: Not all about the fat? Los Angeles Times Risks and benefits of carnitine supplementation in diabetes. Semantic Scholar 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