carnitine A derivative of the amino acid lysine, required for the transport of fatty acids into mitochondria for oxidation. There is no evidence that it is a dietary essential for human beings, since it can readily be formed in the body, although there is some evidence that increased intake may enhance the work capacity of muscles. It is a dietary essential for some insects, and was at one time called vitamin B_T.

vitamin BT Carnitine; an essential dietary factor for the mealworm, Tenebrio molitor, and certain related species, but not for human beings.