VITAMIN B COMPLEX

several vitamins that traditionally have been grouped together because of loose similarities in their properties, their distribution in natural sources, and their physiological functions, which overlap considerably. All the B vitamins, like vitamin C, are soluble in water, in contrast to the fat-soluble vitamins A, D, E, and K. Most of the B vitamins have been recognized as coenzymes (substances that participate with enzymes in accelerating the interconversion of chemical compounds), and they all appear to be essential in facilitating the metabolic processes of all forms of animal life. The complex includes pantothenic acid, niacin, biotin, folic acid (qq.v.), riboflavin (see vitamin B2), thiamine (see vitamin B1), pyridoxine (see vitamin B6), and cyanocobalamin (see vitamin B12). The compounds carnitine, choline (qq.v.), and lipoic acid, myoinositol (see inositol), and para-aminobenzoic acid (q.v.) perform analogous functions in the animal body and have been included among the B vitamins by certain authorities.