B vitamins on the nervous system: A focus on peripheral neuropathy

B vitamins play an important role in the functioning of both the central and peripheral nervous systems. Some of its mechanisms of action include serving as a cofactor in neuronal metabolic processes, myelin generation, and neurotransmitter synthesis, as well as through antioxidative mechanisms. Its deficiency may be associated with multiple well-known neurological syndromes such as Wernicke-Korsakov encephalopathy, subacute degeneration of the spinal cord, and beriberi, among others. However, for several years, the role of B-vitamin deficiency in the development of different types of peripheral neuropathies (including their association with alcoholic and diabetic neuropathy) has been recognized. In this chapter, we will review the main physiological role of B vitamins in the nervous system, focusing on the so-called neurotropic B vitamins thiamine, pyridoxine, and cyanocobalamin, in the pathophysiology of peripheral neuropathy and their therapeutic potential, and even in neuropathies of different etiology without a demonstrated nutritional deficiency. We will also review the safety profile of the administration of B vitamins in the management of these pathologies.