Lecithin (Nervous, Circulatory) is a fatlike substance called a phospholipid. It is produced daily by the liver if the diet is adequate. It is needed by every cell in the body and is a key building block of cell membranes; without it, they would harden. Lecithin protects cells from oxidation and largely comprises the protective sheaths surrounding the brain. It is composed mostly of B vitamins, phosphoric acid, choline, Linoleic acid and inositol. Although it is a fatty substance, it is also a fat emulsifier. Hence, it supports the circulatory system. Its choline is useful for making acetylcholine.