What are the uses of pyridoxine (Vitamin B6)?

From the Guidelines

Pyridoxine (vitamin B6) is primarily used to treat and prevent vitamin B6 deficiency, and its uses include treating vitamin B6 deficiency, managing certain anemias, reducing nausea during pregnancy, treating certain seizures in infants, managing peripheral neuropathy, and supporting overall health. The typical adult dose for treating vitamin B6 deficiency is 25-100 mg daily, taken orally 1. Some of the key uses of pyridoxine include:

• Treating vitamin B6 deficiency: The typical adult dose is 25-100 mg daily, taken orally.
• Managing certain anemias: Pyridoxine can help treat sideroblastic anemia at doses of 50-200 mg daily.
• Reducing nausea during pregnancy: 10-25 mg taken 3-4 times daily can help with morning sickness.
• Treating certain seizures in infants: Pyridoxine-dependent seizures may respond to 100 mg intravenous doses.
• Managing peripheral neuropathy: Doses of 50-200 mg daily may help, especially in cases caused by medications like isoniazid.
• Supporting overall health: As part of a B-complex vitamin, 1.3-2 mg daily helps maintain normal metabolism. It's essential to note that pyridoxine is water-soluble, so excess is typically excreted in urine, but very high doses (>1000 mg daily) over long periods can potentially cause sensory neuropathy, so it's best to stick to recommended doses unless directed otherwise by a healthcare provider 1. In the context of isoniazide overdose or glycol poisoning, high doses of pyridoxine should be part of the therapy, with a strong consensus of 95% 1. The recommended dietary allowance (RDA) for pyridoxine is 1.3-1.7 mg/day for adults, and the tolerable upper intake level (UL) is 100 mg/day for adults 1. Pyridoxine is also used to prevent neuropathy in patients taking isoniazid, with a recommended dose of 25-50 mg/day 1.

In terms of toxicity, clinical signs of excess pyridoxine include sensory neuropathy with ataxia or areflexia, impaired cutaneous and deep sensations, and dermatologic lesions 1. The no-observed-adverse-effect level (NOAEL) for pyridoxine is 100 mg/day, and long-term doses as low as 100 mg/d have been associated with Lhermitte signs, which suggests an effect on the spinal cord 1.

Overall, pyridoxine is an essential nutrient that plays a critical role in various bodily functions, and its uses and recommended doses should be carefully considered to ensure safe and effective treatment.

From the Research

Uses of Pyridoxine (Vitamin B6)

• Pyridoxine is closely associated with the functions of the nervous, immune, and endocrine systems 2
• It participates in the metabolic processes of proteins, lipids, and carbohydrates 2
• Pyridoxine can be used to treat seizures, with intravenous administration resulting in a dramatic cessation of seizures 2
• It may be used as a therapeutic agent in clinical neurology, including treating conditions such as headache, chronic pain, and depression 3
• Pyridoxine supplementation may improve the efficacy of currently used medications for seizures and other conditions 3
• It may also be used to treat behavioral disorders, such as hyperactivity and aggressive behavior, although more research is needed to confirm its safety and efficacy in children 3

Therapeutic Applications

• Pyridoxine may be used to treat peripheral neuropathy, although high doses may be harmful and should be discouraged 4
• It may be used to prevent peripheral neuropathy in patients with disorders of the peripheral nervous system, although the evidence is limited 4
• Pyridoxine supplementation may be beneficial in patients with uremia, although caution is needed due to the increased risk of neuronopathy 5
• It may not be associated with significantly worse neuropathy signs or symptoms in patients with chronic idiopathic axonal polyneuropathy, even at moderately elevated plasma levels 6

Safety Considerations

• High doses of pyridoxine may cause peripheral neuropathy, despite renal excretion of the vitamin 3, 5
• Pyridoxine supplementation should be used with caution in patients with renal dysfunction, as the uremic state may increase susceptibility to pyridoxine-induced neuronopathy 5
• The safety of pyridoxine supplementation in children is not well established, and more research is needed to confirm its safety and efficacy in this population 3, 4