The Vitamin B6 Paradox: Why Toxicity May Be Driven by More Than Just Supplements

By Reine DuBois, Integrative Naturopath and Clinical Director – The Health Lodge

For decades, the clinical understanding of Vitamin B6 (pyridoxine) toxicity has been straightforward: because it is a water-soluble vitamin, excess levels were traditionally attributed to over-supplementation from multivitamins, energy drinks, or fortified foods. However, a growing body of evidence suggests that the modern rise in B6 toxicity symptoms—primarily peripheral neuropathy, burning sensations, and loss of balance—may be the result of a complex biochemical disruption triggered by environmental toxins, most notably the herbicide glyphosate. Emerging research indicates that glyphosate may be altering metabolic and genetic pathways, effectively disabling the body’s ability to properly process and utilize B6.

Glyphosate as a “Molecular Mimic”

At the core of this issue is glyphosate’s chemical structure. Glyphosate is a synthetic analogue of glycine, a foundational amino acid used in nearly every protein and enzyme in the human body. Because of this similarity, the cellular machinery for protein synthesis can mistakenly incorporate glyphosate in place of glycine.

When glyphosate is “hard-wired” into the system, it disrupts the functionality of critical enzymes. The sources note that glyphosate is a potent inhibitor of the Cytochrome P450 (CYP) enzyme family, which serves as the body’s “master processors” for converting vitamins into biologically active forms and detoxifying environmental toxins. Furthermore, glyphosate disrupts phosphatases, which are essential for regulating phosphorylated molecules in the body.

Disabling the Excretion and Transport Pathways

Compelling evidence regarding the inability to properly utilize or excrete B6 comes from the work of researchers like Dr. Stephanie Seneff. Glyphosate acts as a strong kosmotrope, meaning it disrupts the transport of free sulfate and phosphate in the bloodstream.

The sources suggest that glyphosate’s ability to impair the serum transport of phosphate and sulfate can lead to systemic metabolic failures. This hypothesis helps explain clinical observations where certain populations, such as children with autism, show abnormally high serum levels of B6 even in the absence of supplements. Instead of being utilized at the cellular level or excreted, the vitamin may be held in circulation because the body’s primary transport and enzymatic pathways have been compromised by glyphosate exposure.

The Role of the Gut Microbiome

The gut microbiome is a primary producer of B vitamins, and its health is deeply interconnected with B6 metabolism. Glyphosate acts as a broad-spectrum antibiotic that targets the shikimate pathway, which is present in beneficial gut bacteria like Bifidobacteria.

This leads to a “B6 Paradox”:

1. 1.High Blood Levels: Glyphosate-induced enzymatic inhibition and transport failures can lead to an accumulation of B6 in the blood.
2. 2.Functional Deficiency: Simultaneously, high concentrations of inactive pyridoxine (the form found in most supplements) can competitively inhibit the active form (PLP), meaning the body has high total B6 but cannot use it for essential neurological functions.

Genetic Vulnerability and MTHFR

Individual susceptibility to this toxicity is often unmasked by genetic predispositions. MTHFR polymorphisms can impair the body’s detoxification and methylation pathways. When these genetic variations are combined with glyphosate’s suppression of master processing enzymes, the body’s ability to clear environmental toxins or balance vitamin levels is significantly diminished.

Conclusion

The rise in Vitamin B6 toxicity may not be a simple case of “too many pills.” Instead, the sources suggest it is a symptom of a broader homeostatic disruption. By misincorporating into proteins and disabling the enzymatic pathways required for mineral transport and detoxification, glyphosate may be forcing the body to retain B6 in a way that eventually becomes neurotoxic. Understanding this requires looking past the supplement bottle and toward the pervasive environmental factors that alter our fundamental metabolic health.

Primary Research and Clinical Reviews

• Ibrahim, M., Ikra, M. S., & Ubi, E. U. (2025). “The role of vitamin B6 in GABA synthesis and its implications for neurological health: A systematic review.” FUDMA Journal of Sciences (FJS), 9(12), 108–114. This review details the essential role of the active B6 form (PLP) as a cofactor and notes that chronic doses above 200 mg/day pose a major risk for sensory neuropathy.
• Samsel, A., & Seneff, S. (2013). “Glyphosate’s suppression of cytochrome P450 enzymes and amino acid biosynthesis by the gut microbiome: Pathways to modern diseases.” Entropy, 15(4), 1416–1463. This landmark paper identifies glyphosate as a strong kosmotrope and hypothesizes that the body may exploit Vitamin B6 to transport phosphate safely when glyphosate disrupts normal transport pathways.
• Samsel, A., & Seneff, S. (2016). “Glyphosate pathways to modern diseases V: Amino acid analogue of glycine in diverse proteins.” Journal of Biological Physics and Chemistry, 16, 9–46. This study documents how glyphosate acts as a molecular mimic of glycine, leading to its mistaken incorporation into proteins and the subsequent disruption of enzymes like Cytochrome P450 and phosphatases.
• Vrolijk, M. F., Opperhuizen, A., Jansen, E. H., Hageman, G. J., Bast, A., & Haenen, G. R. (2017). “The vitamin B6 paradox: Supplementation with high concentrations of pyridoxine leads to decreased vitamin B6 function.” Toxicology in Vitro, 44, 206–212. This research established the “B6 Paradox,” demonstrating that high levels of inactive pyridoxine can actually inhibit the active form of the vitamin.

Clinical Practice and Presentations

• Nicolaus, C., & Madrigal, L. (2025). Overlooked, Overloaded & Over Supplemented: What’s holding your patients back? MakeWell. This presentation explores the high prevalence of MTHFR polymorphisms (50-60%) in chronic illness and how genetic predispositions contribute to vitamin toxicity and detoxification failures.
• MTHFR Support Australia. (2025). “Vitamin B6 Toxicity: How to Recognise Risk and Dose Safely in Clinical Practice”. This source highlights that some patients develop peripheral neuropathy on doses below 50 mg/day, suggesting that individual genetic vulnerabilities like the “PDXK problem” are at play.
• Sullivan Nicolaides Pathology. (2023). “Peripheral neuropathy? Don’t forget vitamin B6!”. This medical brief discusses the clinical recognition of B6-induced nerve damage and notes the regulatory changes requiring warning labels on B6 products in Australia.

Investigative and Explanatory Articles

• Dr. Clark Store Staff. (2025). “How Glyphosate May Be Disrupting Your Body’s Ability to Use Essential Vitamins”. A review of Dr. Seneff’s research focusing on glyphosate’s sabotage of the CYP450 enzyme system, which is responsible for processing vitamins and detoxifying the body.
• Jarrett, J. (2025). “How your Gut Microbiome can contribute to high B6 in peripheral neuropathy?” Elemental Health. This article explains that elevated B6 levels can occur even in the absence of supplementation due to a disrupted gut microbiome.
• SiPhox Health. (2025). “Why do I have B6 toxicity symptoms with low ALP?”. This report connects low Alkaline Phosphatase (ALP) levels to B6 toxicity, noting that the synthetic form (pyridoxine HCl) used in most supplements poses the highest risk.
• Session 1. “Gut biome and Brain Health in the face of Glyphosate Toxicity”. This document describes glyphosate’s targeting of the shikimate pathway in beneficial gut bacteria like Bifidobacteria, which are responsible for synthesizing essential B vitamins.