What are the implications of a low Vitamin B6 (Pyridoxine) level?

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Last updated: May 15, 2025View editorial policy

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From the Guidelines

To address low vitamin B6 levels, I recommend increasing dietary intake of B6-rich foods and considering supplementation with 1.3-1.7 mg daily for adults, as this is the most effective way to prevent deficiency and related health issues, as supported by the most recent guideline 1. Low vitamin B6 (pyridoxine) levels can cause various health issues including anemia, skin problems, depression, confusion, and weakened immune function.

Key Points to Consider:

  • Vitamin B6 is essential for metabolizing proteins, fats, and carbohydrates, supporting brain development and function, and aiding in producing neurotransmitters and hemoglobin 1.
  • Certain medications, alcoholism, kidney disease, and autoimmune disorders can deplete B6 levels, so addressing these underlying factors is also important 1.
  • For severe deficiency, higher doses of 25-100 mg daily may be prescribed by a healthcare provider, but should not exceed 100 mg daily long-term to avoid potential nerve damage, as indicated by the ESPEN micronutrient guideline 1.
  • The optimal parenteral B6 dose for infants and children is not clear, but the ESPGHAN guidelines propose doses of 0.15-0.2 mg/kg/d for infants and 1.0 mg/kg/d for children 1.

Recommendations:

  • Increase dietary intake of B6-rich foods such as poultry, fish, potatoes, chickpeas, bananas, and fortified cereals.
  • Consider taking a vitamin B6 supplement of 1.3-1.7 mg daily for adults, as recommended by the ESPEN micronutrient guideline 1.
  • If experiencing persistent symptoms despite supplementation, consult a healthcare provider for proper evaluation and treatment.

From the Research

Low Vitamin B6 Status

  • A plasma pyridoxal 5'-phosphate (PLP) concentration below 20 nmol/L (5 μg/L) is indicative of inadequate vitamin B6 status 2
  • Inadequate vitamin B6 status is common in elderly patients and patients with comorbid conditions, despite the recommended daily allowance of 1.5-2 mg/d from dietary sources 2
  • Vitamin B6 deficiency may result in neurological disorders, including convulsions and epileptic encephalopathy, and may lead to infant abnormalities 3

Health Implications of Low Vitamin B6

  • Low vitamin B6 status can lead to unexplained anemia, and plasma B6 levels should be ordered as part of the workup before labeling as "anemia of chronic disease" 2
  • Vitamin B6 supplementation is crucial in the management of chronic Mg deficiency resistant to therapy 2
  • Vitamin B6 deficiency may be associated with various diseases, such as diabetes, heart disease, cancer, or the prognosis of COVID-19 4

Supplementation and Toxicity

  • PLP-based supplements are preferred over pyridoxine supplements due to minimal neurotoxicity observed in neuronal cell viability tests 2, 5
  • Weekly administration of PLP-based supplements in low doses (50-100 mg) is recommended to maintain a stable serum PLP level between 30 and 60 nmol/L or 7.4 and 15 μg/L 2
  • High doses of pyridoxine (>100 nmol/L or 25 μg/L) can lead to neurotoxicity, and the inactive form pyridoxine can competitively inhibit the active pyridoxal-5'-phosphate 5

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Preventing Vitamin B6-Related Neurotoxicity.

American journal of therapeutics, 2022

Research

Vitamin B6: deficiency diseases and methods of analysis.

Pakistan journal of pharmaceutical sciences, 2013

Research

Vitamin B6 in Health and Disease.

Nutrients, 2021

Research

The vitamin B6 paradox: Supplementation with high concentrations of pyridoxine leads to decreased vitamin B6 function.

Toxicology in vitro : an international journal published in association with BIBRA, 2017

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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