Carnitine, a branched non-essential amino acid, is synthesized from the essential amino acids lysine and methionine. Ascorbic acid, ferrous iron, pyroxidine and niacin are also necessary cofactors [1] and deficiencies of any of these can lead to carnitine deficiency. The pathway in mammals is unique using protein-bound lysine that is enzymatically methylated to form trimethyllysine as a post-translational modification of protein synthesis [6]. Trimethyllysine undergoes four enzymatic reactions in the course of endogenous L-carnitine biosynthesis (Figure 1).