Pyridoxine-Containing Nutritional or “Natural” Supplements: A Potential Cause of Worsening Neuropathy Symptoms (4364)

Objective: To raise awareness among clinicians about the possibility of worsening neuropathy symptoms from unintended consumption of high doses of pyridoxine included in nutritional or “natural” supplements. Background: Patients with pre-existing neuropathies are more susceptible to de novo or worsening neuropathy symptoms due to toxic insults. Pyridoxine ingestion is recognized as a cause of sensory neuropathy and could worsen the symptoms in these patients. Design/Methods: We reviewed the clinical records and ancillary tests from patients seen at the clinic who presented with de novo or worsening pre-existing neuropathy symptoms and elevated plasma pyridoxine levels. The source of pyridoxine ingestion was identified and the patient’s clinical response to stopping the supplementation was evaluated. An expanded assessment of the pyridoxine content in nutritional or “natural” supplements available for sale in our community was performed. Results: Four patients aged 71.8 to 62.1 years were identified. Two were male and 2 were female. All patients had pyridoxine levels above the normal levels (1.3 to 7.8 times the upper limit of normal). All showed improvement in sensory symptoms upon discontinuation of the supplement. We also identified 36 nutritional/natural supplements with pyridoxine HCL concentrations that ranged from 1.3 to 100 mg per single unit, with total recommended dosages ranging from 2.6 mg to 240 mg daily. Conclusions: Unintended consumption of pyridoxine-containing supplements may represent not only the cause, but the explanation of worsening neuropathy symptoms in patients with pre-existing neuropathy. Clinicians should be aware that many mixed-ingredient nutritional or “natural” supplements contain high doses of pyridoxine. Disclosure: Dr. Santiago-Cruz has nothing to disclose. Dr. Vargas has nothing to disclose. Dr. Tirado-Castro has nothing to disclose. Dr. Caraballo-Cartagena has nothing to disclose. Dr. Luciano has received research support from Akcea Therapeutics.