Which symptom is associated with pyridoxine toxicity (vitamin B6)?

• A. Nausea
• B. Hair loss
• C. Ataxia
• D. Weight gain

Answer: (C)

High-dose pyridoxine can be neurotoxic, leading to a sensory neuropathy that often progresses to problems with coordination, or ataxia. This toxin effect damages peripheral nerves and the pathways that gather proprioceptive information, so gait becomes unsteady and coordinated movement is impaired. That’s why ataxia is the symptom most strongly linked to pyridoxine toxicity. Nausea, hair loss, and weight gain aren’t the characteristic signs of this toxicity; the first and most telling neurological change with excessive B6 is impaired coordination due to neuropathy. Remember, toxicity typically arises from long-term use of high-dose supplements rather than from food intake.