Symptoms of peripheral neuropathy include tingling, burning, or numbness in the hands or feet.
It is a known side effect when vitamin B6 is taken at high doses or after long-term usage, but the regulator said recent reports had suggested daily dosage of 50mg or less have led to such outcomes.
At present, TGA permits the daily dose of vitamin B6 in listed medicines (referring to dietary supplements) to four times higher at 200mg.
According to recent cases, the side effect also happened in some individuals who took more than one product containing vitamin B6.
Currently, there are over 1,000 listed medicines that contain vitamin B6 in Australia.
Products containing more than 50mg of vitamin B6 are required to bear a warning display to inform consumers the risk of developing peripheral neuropathy.
The TGA said it was reviewing the matter and the outcome of the review might lead to new requirements for products containing vitamin B6.
“Products containing 50 mg or less vitamin B6 are not currently required to display a label warning.
“This may make it difficult for consumers to identify reactions associated with vitamin B6, which could potentially lead to continued exposure and progression of neuropathy,” TGA said in a statement.
TGA said it had identified a number of products that did not display the required label warning and had taken regulatory actions to ensure compliance.
It emphasised that firms should comply with the requirements stated in the Permissible Ingredients Determination.
Failure to do so will lead to regulatory actions, including the recall or the cancellation of the product.
The regulator also reminded that firms were obliged to report all serious adverse events within required time frames.
Australia’s Adverse Drug Reactions Advisory Committee (ADRAC) had previously received reports on how peripheral neuropathy had occurred when vitamin B6 intake exceeded 50mg/day.
One of the cases, a 39-year-old female, took 50mg of vitamin B6 as well as a multivitamin containing the vitamin for three months.
She subsequently developed a feeling of burning pain and ‘electric shock’ in her feet and lower legs.
Another case, a 69-year-old female who has been taking up to 600mg of vitamin B6 per day, had developed persistent giddiness and wide-based gait.