The Therapeutic Goods Administration (TGA) has acknowledged a rise of blood toxicity cases linked to vitamin supplements, amid growing concern over current regulations.
Associate Professor Joanna Harnett from the University of Sydney School of Pharmacy is an expert in the research, teaching and regulation of complementary and traditional medicines.
What are the risks from taking or combining supplements?
One of the key risks associated with taking multiple vitamin and mineral supplements is unintentionally exceeding the safe daily intake of certain ingredients.
This issue has come to light in recent cases of vitamin B6 toxicity, where individuals were unknowingly consuming excessive amounts of B6 through combinations of products such as magnesium, zinc, and B-complex formulas.
“These supplements may not be overtly labelled as containing vitamin B6, yet it is included in their ingredient lists, often as its chemical name ‘pyridoxine’,” said Associate Professor Harnett.
“Prolonged high intake has been linked to adverse effects, including peripheral neuropathy—a form of nerve damage that can cause numbness, tingling, and pain.
“Consumers are encouraged to carefully check ingredient labels and consult healthcare professionals before combining supplements.”
How are vitamins and supplements currently regulated in Australia?
“In Australia, the majority of supplements containing vitamins and minerals are classified as ‘complementary medicines’ and regulated by the TGA under a low-risk framework,” said Associate Professor Harnett.
These products are listed on the Australian Register of Therapeutic Goods (ARTG) but are not independently assessed by the TGA for efficacy or safety prior to entering the market.
“However, there are additional controls in place to support product quality and safety. They can only contain ingredients from the TGA’s permissible ingredients list and be manufactured in accordance with Good Manufacturing Practice (GMP) standards. In addition, they can only carry low-level health claims, such as supporting general health or managing self-limiting conditions, like the common cold, and not therapeutic claims for serious health conditions.”
What should consumers consider before taking a supplement?
Before taking a complementary medicine, Associate Professor Harnett said consumers should ask themselves some important questions.
“First of all, ‘Is this the right choice for me, and is it safe?’ The answer depends on several personal factors, including age, current or past medical conditions, and potential interactions with medications or other supplements,” said Associate Professor Harnett.
“Some products—even vitamins and minerals—may be unsuitable for individuals with certain health conditions or those taking specific medications. It’s important to consult a healthcare professional such as a pharmacist or GP to assess potential risks such as:
- herb-drug or nutrient-drug interactions,
- any other conditions that may be affected by this supplement,
- overlapping ingredients across multiple products,
- delays in accessing more effective treatments.”
How big is the supplements market in Australia?
“Our research conducted in 2016 and again in 2022 found similar results in regard to the prevalence of complementary medicine use in Australia with 50 percent of Australians reporting to use complementary medicine products over a 12-month period,” said Associate Professor Harnett.
“Of these, 48 percent were taking vitamins and mineral supplements and 10 percent were taking a herbal medicine.”
What should I do if think I might be at risk of vitamin B6 toxicity?
“If anyone is unsure about how to use supplements appropriately and safely they should seek professional advice and be very cautious about any advice provided by unqualified sources on social media,” said Associate Professor Harnett.
People who think they may have been poisoned or taken an overdose of any type of medicine, including excessive doses of vitamin B6, can call the Poison Information Hotline on 13 11 26, seven days a week, 24 hours a day, to speak to qualified healthcare professionals who can advise on how to act.
The Poisons Information Centre, which runs the hotline, also has information on prevention and first aid. In a medical emergency call 000.
Declaration: Associate Professor Joanna Harnett declares no conflicts of interest.
Lead image credit: Adobe Stock
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