45180 - co-factors to metabolism (efsa foodex2) 45190 - carnitine (efsa foodex2) The group includes Carnitine used in fortified foods and dietary supplements. Carnitine is a quaternary ammonium compound biosynthesized from the amino acids lysine and methionine. It is required for the transport of fatty acids from the intermembraneous space in the mitochondria, into the mitochondrial matrix during the breakdown of lipids (fats) for the generation of metabolic energy. The part consumed/analysed is by default the whole or a portion of it representing the observed heterogeneity. ] and [https://en.wikipedia.org/wiki/Carnitine] requires discussion