Choline is an essential component of acetylcholine and thus the transmission of nerve impulses. Choline is also a component of the phospholipids lecithin (phosphatidylcholine) and sphingomyelin, and as such plays a vital role in the maintenance of cell structure and in the transport of lipid within the body (Kent, 1990; Combs, 1992). Choline also acts as a methyl donor via the compound betaine. Choline is oxidized to betaine at a rate that is an order of magnitude greater than that of its incorporation into phosphorylcholine and hence phosphatidylcholine (Combs, 1992). Choline may also be metabolized to glycine.