The Australian Therapeutic Goods Administration (TGA) has acknowledged that it underestimated the side effects of excessive vitamin B6 supplementation, including nerve damage, and that such cases may be more widespread than previously believed.
Australian pathologist David Kanofsky told ABC that 4.5% of samples tested across Australia in May showed a high risk of nerve damage, according to the British newspaper The Independent.
What is Vitamin B6?
Vitamin B6, also known as pyridoxine, is a water-soluble essential vitamin that supports numerous vital body functions. It plays a key role in metabolizing proteins, carbohydrates, and fats, providing energy, and maintaining nervous system health through its role in neurotransmitter production, which regulates brain function.
Vitamin B6 also supports the immune system by aiding in antibody production and is essential for hemoglobin synthesis, the protein responsible for transporting oxygen from the lungs to body tissues.
Supplementation may help pregnant women reduce early-stage nausea and alleviate symptoms of premenstrual syndrome. However, most people do not require additional vitamin B6 supplements, as a normal diet—including meat, fruits, and vegetables—typically provides the daily requirement of 1.3 to 1.7 mg for adults.
Risks of High Doses
Vitamin B6 supplements are sold over-the-counter in doses ranging from 5 mg to 200 mg per day, far exceeding daily needs. The TGA recommends restricting sales and requiring medical consultation before use.
While excess vitamin B6 is usually excreted in urine without side effects, prolonged high-dose intake can be harmful. Peripheral neuropathy—nerve damage outside the brain and spinal cord—can result, causing pain, numbness, or weakness in the hands and feet.
Symptoms usually resolve after stopping supplementation, although some individuals may take three months to two years to fully recover. Evidence indicates that doses exceeding 50 mg per day for extended periods can cause serious effects. For instance, a 2023 report documented a case of neuropathy from supplements totaling 95 mg daily, and seven cases were linked to energy drinks containing vitamin B6. The TGA has recorded 174 neuropathy cases associated with vitamin B6 supplements since 2023.
Guidance for Users
Individuals taking 50 mg or more of vitamin B6 daily for over six months should undergo medical monitoring and discuss ongoing use with their healthcare provider.
Warning signs of neuropathy to watch for include:
- Numbness or pain in the hands and feet
- Difficulty with balance and coordination due to muscle weakness
- Heartburn and nausea
