Vitamin B6 is probably in your multivitamin. You’ll also find it on pharmacy shelves, promoted for energy, metabolism, and general health maintenance. But a Health Canada safety bulletin published in June 2026 highlighted a real but less well-known risk: even relatively small doses of vitamin B6 in natural health products may be associated with peripheral neuropathy, a nerve condition marked by numbness, tingling, and pain in the extremities. Health Canada’s action isn’t isolated. Australia’s Therapeutic Goods Administration has reached a similar conclusion, rescheduling higher-dose B6 products to require pharmacist involvement, after finding that peripheral neuropathy couldn’t be ruled out at doses well below what was previously assumed safe.
A very old problem
Concerns about vitamin B6 and nerve damage are not new: they go back decades. In 1983, Schaumburg et al. reported seven patients with disabling sensory neuropathy linked to high-dose pyridoxine supplementation, publishing their findings in the New England Journal of Medicine. Those patients were taking huge (gram-level) doses, far above anything found in a typical multivitamin. The paper established pyridoxine neurotoxicity as real, but it also shaped thinking that the risk was confined to massive doses. So why are regulators now flagging products containing as little as 10 mg? Part of the answer is that newer reviews have identified a possible, though far less certain, signal at doses well below the gram-level range that first drew attention to the problem. Whether some individuals are more susceptible than others remains unclear.
The 1983 report generated a surprising response. In a letter to the New England Journal of Medicine, a proponent of orthomolecular medicine commented on the findings. Orthomolecular medicine proponents believe that vitamins can be beneficial when given at doses that dramatically exceed what is necessary to prevent or treat a deficiency. Whether this is the first appearance of “if a little is good, more must be better” I can’t say, but the letter may have been written by Linus Pauling himself: He was the one who invented the term ‘orthomolecular’ fifteen years earlier, right on schedule with this letter’s own timeline. Either way, it’s a familiar argument, then and now. (I could only access the excerpt; if anyone has fulltext access to confirm the author, please let me know.)
What the evidence shows
It’s worth describing what is established and what is less clear with respect to vitamin B6 toxicity. The potential for high doses of vitamin B6 to cause neurotoxicity is well established: typically at doses of 250 mg/day and higher. What is newer, and considerably less clear, is the suggestion that neuropathy may occur at much lower doses, including around 10 mg/day. A 2023 systematic review concluded that the evidence supports the relationship between excessive vitamin B6 exposure and peripheral neuropathy, but noted that the potential risk associated with lower-dose supplementation remains incompletely understood and warrants further investigation. Health Canada’s own review reflects this: Of 17 cases identified (15 Canadian, 2 international), only two, both involving natural health products, were considered suitable for further assessment, and even those were complicated by potential confounders. Consequently, the recent label changes could be thought of as precautionary, rather than definitive proof that taking 10 mg/day of supplemental vitamin B6 causes peripheral neuropathy. It appears to be a plausible safety signal, but not definitive proof.
Two countries, two different approaches
An interesting aspect of Health Canada’s decision is the distinction it drew between supplements and prescription drugs. Despite reviewing prescription products containing similar amounts of vitamin B6, Health Canada found insufficient evidence to justify additional warnings for those products, citing established prescribing practices. Yet it did require new warnings for non-prescription natural health products. This looks inconsistent, but reflects the fact that prescription vitamin B6 products in Canada are specifically approved for pregnancy (nausea/vomiting and prenatal support). These patients would already be monitored as part of routine prenatal care. Unclear risks may warrant more caution (and warning) when consumers are managing all decisions on their own.
Australia has taken a much stricter approach to manage this toxicity risk. The TGA (Australia’s FDA equivalent) has decided that higher-dose non-prescription (50mg – 200mg) oral vitamin B6 products should no longer be treated as ordinary self-selection items. Purchasing will require pharmacist involvement, beginning in 2027. This inserts a healthcare professional into the decision-making process. The policy reflects the reality that a warning label itself may be insufficient.
Risk-free insurance?
The growing shelf space devoted to vitamin supplements speaks to their appeal. For many people, they’re viewed as a form of risk-free health insurance: They can only be beneficial, and if your body doesn’t use them, they’ll be expelled. With that framing, supplementing seems like an easy choice. But this also ignores the possibility of harm. It means that vitamins escape the scrutiny that we might apply to other health interventions and decisions. The vitamin B6 evidence challenges this assumption. Vitamins are biologically active chemicals and not a panacea that can only do good. Even when the risks are low, or uncertain, they are still risks, and they need to be considered alongside any hoped-for benefits.
Conclusion
For most pharmacists, and I’m counting myself here, vitamin B6 is not a product that has traditionally attracted much attention. It sits on a shelf for self-selection, alongside an entire category of products that most consumers view as inherently safe and exempt from the “benefit vs. risk” thinking that accompanies a prescription medicine decision.
These newer concerns about peripheral neuropathy remind us that even products marketed as “natural” involve decisions, trade-offs, and uncertainty. And no product is free of risk, even a vitamin that has been marketed in huge doses for decades. Regulation changes can improve labels, restrict access, or mandate additional oversight by a health professional, but they do not change the underlying mindset that more supplementation is automatically better. The lesson of vitamin B6 is not that supplements are inherently dangerous. It is that the absence of perceived risk should never be mistaken for the absence of actual risk.