Vitamin B6 in the headlines; are you at risk?

To ‘B’ or not to ‘B’

Recent coverage on the ABC reported a case of a 73 year old woman, an ex emergency physician, who was diagnosed with peripheral neuropathy from exposure to Vit B6 over a 2 year period. She had been taking 2 tablets daily of Bioceuticals Ultra Muscleze which would provide a dose of 68mg activated Vit B6.

To me, the news story headline over-simplified the underlying issues. It does the job of a headline – to attract attention. However, if you didn’t read the full article you could take away the wrong impression about levels of risk.

After all, there are over 200,000 hospital admissions annually related to the adverse effects of various medications. In 2022, there were just 32 adverse events where Vitamin B6 was a “possible causal link”.

Because the full B6 situation – like many other aspects of the health game – is “complicated”.

Not enough B6 is as problematic as too much

A 2023 Systematic review of Vitamin B6 looked at 20 published studies and concluded that there is still much to learn about Vit B6 in all its forms.

They confirm that both low levels of Vit B6 and excessive levels may contribute to peripheral neuropathy. And that these levels can be quite different for each individual person.

What should you look out for? Key symptoms of peripheral neuropathy

The most frequently encountered symptoms of peripheral neuropathy include:

• numbness and paresthesias (tingling or pins and needles);
• pain, weakness, and loss of deep tendon reflexes – which may accompany the numbness.

Peripheral neuropathies usually develop over months to years, while some may develop more rapidly and be progressive. Peripheral neuropathies have a broad range of severity and clinical manifestations, as they can affect motor, sensory, and autonomic fibers.

However, there are multiple causes of peripheral neuropathy – it’s not often a simple “single cause / single effect” relationship.

The reasons for peripheral neuropathy can be complex

Peripheral neuropathies stem from a variety of origins, including metabolic, systemic, and toxic causes. There are multiple underlying causes to consider include: 

• Diabetes mellitus
• Chronic alcoholism
• Nutritional deficiencies (eg, B1, B6, B12, and vitamin E)
• Inflammatory conditions (eg, vasculitis)
• Hypothyroidism
• Autoimmune disease (eg, Sjögren syndrome, lupus, rheumatoid arthritis)
• Infections (eg, Lyme disease, Epstein-Barr virus, hepatitis C, shingles, leprosy, HIV)
• Guillain-Barre syndrome
• Toxins (heavy metals, chemicals)
• Chemotherapy agents
• Medications (antibiotics, cardiovascular medications)
• Tumors (secondary to compression or associated paraneoplastic syndromes)
• Inherited conditions (eg, Charcot-Marie-Tooth disease, familial amyloidosis)
• Trauma or injury
• Multiple myeloma and its treatments
• Monoclonal gammopathy of undetermined significance (MGUS)

In some cases, a direct cause may not be apparent.

A quick potted history of concerns with supplemental Vit B6

• Early 1980’s – the first reports of Vit B6 peripheral neuropathy toxicity correlated with extremely high levels of 6000mg per day for extended periods. Then 50 to 500mg per day came into common usage to treat issues like carpal tunnel syndrome, premenstrual syndrome, depression etc.
• Late 1990s there were some reports of a link with peripheral neuropathy at doses lower than 500mg daily
• In 2008, the Australian Adverse Drug Reactions Reporting system (part of the Therapeutic Goods Administration) received 2 reports on Vitamin B6.
• In 2020 the TGA issued a safety advisory warning that a maximum of 200mg per day of Vit B6 was permitted in supplements. And also that any dose may cause symptoms in individual cases or over a prolonged period of time.
• In 2022, 32 adverse events were listed with the TGA citing a possible causal link with Vit B6. It was recommended that the maximum daily dose be reduced from 200 to 100mg. And that supplements containing more than 10mg Vit B6 must carry a warning requirement on the label about peripheral neuropathy.

So, am I at risk of developing a peripheral neuropathy if I consume supplements?

Everyone is different of course.

• Consulting regularly with a health care professional who understands the subtleties and intricacies of supplementation is important. Self-medicating is something that even doctors know is a risky business.
• Also find a practitioner who keeps up-to-date with changes and research. There is so much going on in different areas of research, so it is great if you take responsibility and look into supplements yourself and direct questions to your practitioner. We can’t know it all, all of the time.
• Be aware that there may be positive or negative interactions between medications prescribed by your doctor and supplements prescribed by your naturopath or pharmacist. Research these yourself and ask your health professional to research this too. Information changes over time.

If you’re concerned, then:

• Check the total dose of Vitamin B6 you are taking in supplements.
• If you start to experience any signs of peripheral neuropathy (as listed above) speak with your trusted health care provider. It may or may not be associated with the Vit B6. A careful history needs to be taken. You may wish to stop the Vit B6 and see what happens, however it’s best to consult with a practitioner first. The Vit B6 may be an important part of the prescription to support your well being.
• You may consider requesting a blood test for Vit B6 levels from your GP. How ever, be aware that interpretation of the numbers is best done in conjunction with a practitioner with experience and knowledge around supplements. High Vit B6 levels in your blood may or may not indicate high tissue levels.

Many, many adverse reactions to medications happen each year

The TGA invites all consumers to report adverse effects of medications, supplements or medical devices so they can, if need be, investigate further. You can fill in the forms online through the TGA or report to your GP or Pharmacist or Naturopath and they will do this for you.

The 2020 Australian Commission’s Report on Safety and Quality in Healthcare noted that “In Australia it is estimated that there are 250,000 hospital admissions annually as a result of medication related problems” or adverse reactions to medications.

I mention this to put into context the massive headlines recently around the potential Vit B6 issue. In 2022, 32 adverse events were listed with the TGA citing a ‘possible causal link’ with Vit B6.

“It’s complicated” – so get expert advice

As usual, there’s more to this than meets the eye. Consider chatting with your trusted health professional to understand what may work best for you.

If you’d like a second opinion, you could contact me for a consultation.