Choline works closely with other B vitamins, performing an important function involved in the proper metabolism of fats. Choline is needed to ensure that fat is not trapped in the liver which would stop the liver from breaking down other materials. Choline helps to build cell membranes and helps the movement of fats and nutrients in and out of cells. Inositol is required for the proper action of several brain transmitters, including serotonin. It has been suggested that low levels on inositol may increase symptoms of depression in some people. Inositol is also regarded as vital support for healthy hair.