A health practitioner, a businessman, an award-winning musician, a retiree, and a pregnant woman are among the growing list of Australians who have been poisoned by the synthetic form of vitamin B6.
There are at least 121 confirmed cases in which it has caused life-changing issues for those who have taken it regularly, Australia's medicines regulator has said.
Doctors believe the scale of the problem could be greater than what is currently known.
"My sense is that clinical B6 toxicity is under-reported," said GP and dietitian Terri-Lynne South, who has noticed a rise in the number of cases aligned with the increasing popularity of dietary supplements.
"Some of the toxicities we see are not because a person is taking a single excessive dose of B6 in a single supplement, but multiple supplements with B6, and that contributes to a cumulative dose," she said.
"People might be aware a multivitamin supplement could have B6 in it, but I think it would surprise them that something labelled as a magnesium supplement, for example, also has B6 in it."
'Paralysed' after taking multiple supplements
Keri McInerney's story is an example of that.
Her career as an award-winning singer-songwriter was put on hold after accidentally poisoning herself with B6.
"My legs went numb and I began getting numbness all the way up the top of my body, right to my neck," she told 7.30.
"There were times in bed that I actually couldn't move, I became paralysed, literally paralysed — I actually thought I was dying."
Four years prior, Ms McInerney started taking daily supplements as part of a weight loss regimen.
She didn't realise many of them contained B6 and feels the warnings on the labels weren't clear enough.
Ms McInerney is one of dozens of people who reached out to the ABC, detailing the pain and misery they have suffered from vitamin toxicity, after 7.30 reported the case of Dr Mary Buchanan in early January.
Ms McInerney said B6 was present in many products she was using.
"It was protein shakes, and it was also other vitamins," she told 7.30.
"I started to lose weight and I thought I was feeling great, but this cramping and funny sensation in my legs started to get worse and worse."
Like many others 7.30 spoke to, she had developed peripheral neuropathy — a condition that damages the nerve endings in limbs, with the worst cases considered irreparable.
"I was actually taking 12 times the daily safe amount," she said.
Why is B6 in so many products?
B6 is vital to cognitive function.
In Australia, the daily recommended intake for B6 is 1.3 to 1.7 mg for adults.
Most people who have a balanced diet consume enough of the vitamin in its natural form through a variety of foods including meats, fish, vegetables and cereals.
But like many other vitamins, B6 is also manufactured in a lab. The synthetic is added to thousands of products in Australia, including medicines, multivitamin and mineral supplements, energy drinks and weight loss shakes.
B6 is often listed on labels as pyridoxine, pyridoxal or pyridoxamine. Some supplements available in stores contain quantities up to 200mg.
Associate Professor Joanna Harnett, a complementary medicines researcher and an adviser to Australia's medicines regulator the Therapeutic Goods Administration (TGA), told 7.30 that B6 is added to medicines to help metabolise other minerals, including magnesium and zinc.
"When we exceed the amount that is required for that, we can overwhelm the body's normal metabolic processes, and it's in that overwhelming phase that we see the toxic effects, particularly with regular, high-dose consumption over a longer period of time," Associate Professor Harnett said.
"There isn't any concern around the normal doses that you would obtain from a balanced diet for vitamin B6, the concerns are purely related to supplemental forms."
Rippling skin
In 2020, as the COVID pandemic took off, businessman Paul Torrisi wanted to boost his immunity and turned to supplements. He didn't realise he was taking too much B6.
"I was taking a men's multivitamin — just one a day. I was also taking zinc plus and a magnesium [tablet], and the zinc plus is vitamin B6 again," he told 7.30.
He was a company CEO in the prime of his career. He ended up not being able to work.
"I was getting burning sensations, tingling, pins and needles," Mr Torrisi told 7.30.
"I ended up with a lot of muscle loss over time. My skin would ripple like a wave, going through my legs and arms, it was sort of spontaneously firing muscles and twitching," he said.
"I got a blood test and found out I was seven times the normal range of vitamin B6."
Kellie Marie Donnelly found herself in a similar predicament, diagnosed with peripheral neuropathy in the middle of 2023.
"I couldn't work for 12 months, I lost heaps of weight, lost my hair, it was just horrendous," she told 7.30, conceding she had "no awareness" of what she was putting into her body.
"I was taking a Multi-B, high-dose magnesium, also a multivitamin, plus eating lots of high B6 foods.
"I had numerous trips in and out of hospital, I literally thought I was dying, it was horrible."
Medical professionals fall victim
Bill Piggott AM is a retired physician who worked for the World Health Organization. He explained how he felt "embarrassed" after developing peripheral neuropathy symptoms from vitamin supplements.
"I think I was embarrassed that I, as a medical person, had not done due diligence on what I was taking," Dr Piggott told 7.30.
"My blood tests came back, six times normal. The report had on it, in red, 'pyridoxine toxicity'.
"I just believe that if it was a water-soluble vitamin and I was taking too much, I would pee it out, but I retained it."
Ellie Carew inadvertently took high doses of magnesium, which contained B6 while battling Parkinson's disease and suffered symptoms for two years before a GP discovered she had six times the safe level of B6 in her blood.
"I got a whole raft of symptoms, including burning sensation in my toes, my feet, burning at night, burning fingers, red nose, insomnia; five kilos just dropped off me. I felt really weak in my muscles, so I didn't know what it was," she said.
"I was taking some magnesium, not every night, but a few nights a week for some time — it turns out that also had 50 milligrams of vitamin B6 in it."
Karen Dalle-Nogare considers her case ironic, as she works in a pathology lab and would often see cases of B6 toxicity in the bloodwork of others.
"After I found out I had it I went through all of my tablets, and there were so many that had B6 in them that you wouldn't have known unless you read the fine print," she explained.
"The magnesium I was taking had B6 in it, I had some herbal tablets to help you relax and sleep — and painkiller ones from the health shop — they all had B6 in them."
TGA to consider limiting public access
In 2022 the TGA strengthened labelling requirements requiring a warning about peripheral neuropathy on products containing daily doses of more than 10 mg of B6.
It also reduced the maximum permitted daily dose of vitamin B6 in listed medicines from 200 mg to 100 mg.
"We don't really have any good numbers around what was happening before the TGA intervened, and what sort of response that has had," Dr South told 7.30.
"Having said that, I know there are some clinician bodies suggesting to the TGA that it needs to be lowered again," she said.
The TGA told 7.30 it is considering a proposal to tighten regulations, including changes to where and how B6 vitamins are sold.
Under the proposal, medicines containing between 5 mg and 200 mg of B6 (pyridoxine, pyridoxal or pyridoxamine) would be included in Pharmacist Only Medicines, "stored behind the counter to prevent physical access by the public, and only sold from a pharmacy," a TGA spokesperson stated.
An interim decision on the proposal is anticipated next month, "and following publication of this, a second public consultation will open," the statement said.
The supplements sector responds
Vitamin and mineral supplements account for most of Australia's multi-billion-dollar alternative medicines sector, with many of the large public companies represented by peak body Complementary Medicines Australia (CMA).
Their members include industry giants Blackmores Group, Carusos, Chemist Warehouse and Swisse.
CMA Chief Executive John O'Doherty told 7.30 safety is of "paramount importance" to the industry.
"In Australia, vitamins and dietary supplements are regulated as medicines, and like all medicines, it is absolutely vital that there are strong processes in place to ensure consumer safety," he said.
Mr O'Doherty said the sector adheres to the TGA's regulations, and the responsibility for taking any medicine falls back on the consumer.
"An important part of that is that consumers understand the product that they're taking and that they do so in accordance with what the label says in terms of directions for use."
Mr O'Doherty didn't give a clear answer when asked if the industry would consider making any changes ahead of advice from the regulator.
"We work really closely with the TGA when it comes to safety issues — just as they raise safety concerns with us, we raise safety concerns with the TGA as well," he said.
"We work together to try to achieve good safety outcomes for consumers, while also ensuring people have access to the products they want to improve their health and wellbeing.
"If consumers have any doubt at all they should reach out either to the company that produces the product, their healthcare professional or in particular, their pharmacist."
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