Spotlight on Vitamin B6
Bradley McEwen | PhD, MHSc( Hum Nutr), MPH, BHSc, AdvDipNat, DBM, DNutr, DSM, Fellow ATMS, Naturopath Nutritionist, and Mentor. Adjunct Senior Lecturer, Faculty of Health, Southern Cross University.
What is Vitamin B6?
Vitamin B6 comprises a group of six essential water-soluble chemical compounds, all containing a pyridine ring as their core. These vitamers are pyridoxal, pyridoxamine, and pyridoxine, along with their 5’-phosphate forms, such as pyridoxal 5’-phosphate, pyridoxamine 5’-phosphate, and pyridoxine 5’-phosphate.
What are the functions of Vitamin B6?
Vitamin B6 is a versatile nutrient with a diverse range of metabolic, biochemical, and enzymatic functions. Some of these functions include:
• Playing a vital role in energy metabolism.
• Metabolism of carbohydrates, lipids, protein, amino acids, and nucleic acids.
• Synthesis and metabolism of DNA, metabolism of one-carbon units, and serving as a cofactor in the catabolism of tryptophan.
• Involved in neurological development and the synthesis and metabolism of neurotransmitters, such as serotonin, dopamine, glutamate, gamma-aminobutyric acid( GABA), noradrenaline, and adrenaline.
• Synthesis of haem, cell signalling, cell proliferation, trans-sulphuration, and supporting mitochondrial function.
• Anti-inflammatory and antioxidant actions via modulating inflammasome function and activity, regulating inflammatory mediators, and inhibiting the formation of advanced glycation end products( AGEs).
• Vitamin B6 plays various roles in the immune system, including supporting overall immune function, supporting both innate and acquired immunity, and is essential for antibody production.
Additionally, Pyridoxal 5’-phosphate( PLP)-dependent enzymes catalyse over 140 distinct enzymatic reactions and plays an important role in the homocysteine metabolic pathway.
What health conditions are associated with low Vitamin B6 status?
Prolonged deficiency of vitamin B6 has been associated with the development of a painful axonal peripheral neuropathy, characterised by symptoms such as muscle weakness, reduced reflexes, sensory impairment, and ataxia, particularly affecting the lower limbs. Health conditions associated with low vitamin B6 status include microcytic anaemia, hypochromic microcytic anaemia, anaemia, atherosclerosis, depression, irritability, premenstrual syndrome, confusion, cognitive decline or impairment, increased nerve excitability, carpal tunnel syndrome, cardiovascular disease, homocysteinaemia, type 2 diabetes, alterations in lipid profile, dermatitis, glossitis, weakened immune system, impaired antibody responses, reduced immune function, lymphopaenia, impaired or delayed hypersensitivity reactions, Hashimoto’ s thyroiditis, inflammatory bowel disease, altered lung function, inflammation, oxidative stress, lipid peroxidation, impaired mobility, and decreased physical performance.
Are there any adverse effects of Vitamin B6?
Elevated intakes of more than 50 mg of vitamin B6 daily over long periods, from months to years, have been associated with adverse effects. These effects typically present as mild neurological symptoms, including symmetrical and progressive problems with perceiving touch, pin-prick sensations, temperature, vibration, and positional awareness in the limbs. Consuming much higher doses between 500 and 6,000 mg daily over prolonged periods( from several months to years) can lead to neurotoxicity, paraesthesia, hyperesthesia, bone discomfort, muscle weakness, numbness, involuntary rapid muscle twitches, and decreased tendon reflexes. It is unlikely that someone would experience these symptoms under normal circumstances or when under the care of a qualified, accredited health practitioner. Symptoms generally improve and reverse after pyridoxine is stopped.
Conclusion
Vitamin B6 plays essential roles in numerous physiological and biochemical pathways, including amino acid metabolism, neurotransmitter synthesis, inflammation, immune function, and the regulation of homocysteine. Numerous health conditions are associated with low vitamin B6 status. Vitamin B6 is not something to be feared. Understanding the functions of vitamin B6, the factors affecting vitamin B6 status, along with appropriate dosage ranges and safety considerations, is essential for effective therapeutic use. Always read the label and follow the directions for use. If symptoms persist or if you are unsure, consult a qualified, accredited healthcare practitioner. For more information on vitamin B6, please refer to the original published article in this journal. 1
REFERENCE
1. McEwen B. Exploring Vitamin B6:“ The versatile nutrient”. Journal of the Australian Traditional-Medicine Society 2025; 31( 2): 68-74.
148 | vol31 | no3 | JATMS