B Vitamin Deficiencies and Associated Neuropathies

This review examines both historical and recent evidence to clarify the current understanding of the relationship between B vitamin deficiencies and neuropathies.

Vitamin B1 (thiamine) deficiency can lead to neurological disorders such as beriberi and Wernicke's encephalopathy, conditions with significant prevalence and mortality rates. Vitamin B12 (Cobalamin) is crucial for DNA synthesis, fatty acid metabolism, and myelin production, with its deficiency leading to neuropathies and cognitive disorders. Excess vitamin B6 (pyridoxine), rather than deficiency, appears to be associated with neuropathy.

Vitamin B1 and B12 deficiencies are linked to classic neuropathies, while the connection between vitamin B6 deficiency and neuropathy is less clear, though excess B6 is associated with neurotoxicity. Nutritional deficiencies are less common in developed countries but remain significant in developing nations. In developed countries, factors like alcohol consumption, bariatric surgery, and metformin use are increasing these deficiencies in clinical practice.