B Vitamin Deficiencies and Associated Neuropathies.

Area of Science:

• Neurology
• Nutritional Science

Background:

• Nutritional deficiencies, especially B vitamin deficiencies, are significant causes of neuropathies globally.
• While less common in developed nations, factors like alcohol use, bariatric surgery, and metformin contribute to deficiencies.

Purpose of the Study:

• To review historical and current evidence on the relationship between B vitamin deficiencies and neuropathies.
• To clarify the current understanding of B vitamin-associated neurological disorders.

Main Methods:

• Literature review of historical and recent evidence.
• Analysis of studies investigating B vitamin levels and neurological outcomes.

Main Results:

• Vitamin B1 (thiamine) deficiency causes beriberi and Wernicke's encephalopathy.
• Vitamin B12 (cobalamin) deficiency leads to neuropathies and cognitive impairment due to its role in DNA synthesis and myelin production.
• Excess vitamin B6 (pyridoxine) is associated with neuropathy, not deficiency.

Conclusions:

• Vitamin B1 and B12 deficiencies are established causes of neuropathy.
• The role of vitamin B6 deficiency in neuropathy is less clear, but excess intake is neurotoxic.
• Clinical awareness of B vitamin deficiencies is crucial, especially in at-risk populations in developed countries.