When Vicky Sellers* started to feel unwell after she was prescribed painkillers to help manage an infection, she started to take dietary supplements to boost her immune system. She was unknowingly poisoning herself.
For almost a decade, Ms Sellers was dosing herself daily with supplements including a multivitamin, vitamin B complex, magnesium and iron, unaware she was consuming 200 times the recommended daily intake of vitamin B6.
About 12 months after taking the high-potency supplements, she started to feel the effects.
"I got diagnosed with fibromyalgia and I started to get really weird symptoms like fainting … I would stand up and I immediately dropped the floor," Ms Sellers said.
Also suffering "excruciating" lower limb pain, Ms Sellers was diagnosed with peripheral neuropathy. She continued to decline.
When Ms Sellers thought she was experiencing seizures she sought the expertise of a neurologist.
"I had MRIs done to both my spine and brain to look for lesions because it looked most likely from the symptoms that I had multiple sclerosis," she said.
But the scans came back clear, starting her seven-year journey bouncing around specialists in both New South Wales and in the Australian Capital Territory.
She was told her symptoms could have been motor neuron disease (MND), Ehlers-Danlos syndrome, Charcot-Marie-Tooth disease or a metabolic condition. Doctors said it could have been anxiety.
Illness preventable
By 2021, Ms Sellers was so unwell that she was admitted to hospital for physiotherapy treatment – a doctor there suggested looking at her vitamin B12 levels.
Blood tests found Ms Sellers's vitamin B12 level was within the normal range but her vitamin B6 levels were 585, where 30 to 110 was considered normal, making her levels more than five times the healthy limit.
"I literally was being eaten away from the inside out," she said.
Ms Sellers took her results to a neuromuscular neurologist and gave him a list of the vitamins she had been taking. He confirmed her levels were toxic.
"I did think I was dying … the fact that it's avoidable is the worst," she said.
Ms Sellers said she was riled that her toxicity, and her use of vitamin supplements, was not picked up by medical professional investigating her symptoms.
"Not at one point did anyone tell me about side effects. At no point did anybody ask me about supplements," she said.
Overdosing with weight-loss shakes
Keri McInerney has also suffered from vitamin B6 toxicity.
The singer-songwriter started taking meal replacement shakes to lose weight about six years ago.
"I was very much heavily into the keto diet and I'd been losing weight. I thought I was feeling pretty well," Ms McInerney said.
Consuming the shakes up to three times a day, with additional vitamin and "cleansing" supplements, Ms McInerney was unaware she was consuming large amounts of vitamin B6.
She started experiencing numbness and pain in her legs and her doctor diagnosed her with peripheral neuropathy.
Ms McInerney received regular massages to help with the pain, but her symptoms worsened.
"I remember sitting down one evening and I was watching TV and suddenly the television went only to one eye," she said.
"I sat down thinking I was actually having a stroke."
An MRI confirmed a brain aneurism. Despite surgery to treat it in 2019, Ms McInerney's condition was worsening.
"For those moments, you almost felt like you were dying," she said.
Twelve times more than the healthy limit
Ms McInerney said she was so unwell that she went to the emergency department but was turned away.
"They told me it was just anxiety … they told me to go home and breathe through it," she said.
On the fourth occasion, Ms McInerney was admitted and spent about a month in hospital.
Not long after her discharge, she had a blood test and her vitamin B6 levels were 1,140.
Ms McInerney said her previous results were on file and revealed her levels in 2016, when her symptoms started, were higher still at 1,290 — more than 10 times the normal limit.
"I remember crying, because I just thought, 'Why didn't you tell me? Why weren't you obligated to tell me?'" she said.
Ms McInerney had not disclosed her condition to others, worried it would affect her music career.
"I know that being ill has probably influenced some people to say there's a risk in booking me [but] I'm a resilient person," she said.
Natural not always good
Mater Hospital clinical pharmacist and adjunct associate professor at the University of Queensland's school of pharmacy Geraldine Moses says vitamin B6 toxicity flies "under the radar".
"People have a lovely romantic belief that vitamins, in general, cannot be toxic," she said.
"And that somehow your body will know when you've had too much and magically eliminate them … and unfortunately, we now know that's not true."
Professor Moses says people often don't know the doses they are consuming, which can result in cumulative toxicity.
"They say, 'I'm taking some Chinese herbs' and there'll be some vitamin B6 in there — and sometimes quite a big dose," she said.
There is also a misconception that because something is natural, it is safe, Professor Moses says.
"Asbestos is natural, strychnine is natural, snake venom is natural … and yes, vitamins are natural but they still can be toxic," she said.
While vitamin B6 is essential for good health, a little goes a long way.
"Taking too much becomes toxic, so we've simply got to throw away the idea that you can take as much as you want," Professor Moses said.
She says the ability to buy supplements online, coupled with marketing campaigns targeting anxiety, is an issue.
"There's so much uncertainty right now [and vitamins] are now being sold less on the ingredients and more on what they're for," Professor Moses said.
"So they'll be sold for sleep, for stress, jitteriness or wanting to strengthen your immune system."
While the Therapeutic Goods Association (TGA) recently changed labelling regulation for any medicine containing more than 10 milligrams of pyridoxine (a form of vitamin B6) to include a warning label, Professor Moses says it may have come too late.
"I think it'd be better if people were warned what could happen if they took too much so that they can prevent it rather than wait until it happens and then stop it," she said.
*Name has been changed to protect identity.
