The ability to absorb this vitamin depends on the production by the stomach of an intrinsic factor, a glycoprotein. Marked anemia and generalized debility, which eventually develop, are always fatal unless treated. Cyanocobalamin has only one established use, the treatment of this deficiency disease, but is included nevertheless in many multivitamin preparations. Magnesium is an essential element in human metabolism and functions in the activities of muscles and nerves, protein synthesis, and many other reactions. Magnesium deficiency may occur in alcoholism, diabetes mellitus, pancreatitis, and renal diseases.
Prolonged deficiency can cause changes in heart and skeletal muscle.
Excessive retention of magnesium can occur in renal disease and results in muscle weakness and hypertension. Biotin, Choline, and Inositol Biotin, a complex organic acid containing sulfur, is a coenzyme for several carboxylation reactions involving carbon dioxide fixation. It is synthesized by intestinal bacteria and is widespread in food products. A natural deficiency in humans is unknown, even in individuals on extremely deficient diets. Choline, a simple amino alcohol, is a component of lecithin and of acetylcholine, the latter of which is one of the most important neurotransmitters.