Simon never linked the pain in his hands and feet to multivitamins, but a pathology test did
When Simon Bogemann’s hand began to cramp in a claw position around the steering wheel during his commute from Geelong to Melbourne, he started to worry.
Bogemann, then 43, also suffered pins and needles in his feet and fingers every night in bed and during short lunch breaks at work.
His doctor blamed it on a magnesium deficiency and recommended a supplement, in addition to the multivitamin he was already taking for a chronic condition.
Bogemann was unaware that both capsules contained added vitamin B6, too much of which could lead to the symptoms he was experiencing: a type of nerve damage known as peripheral neuropathy.
A blood test recommended by his dietitian showed his B6 levels were 36 times the recommended value.
The marketing of over-the-counter vitamins by the wellness industry is leading to an increase in the number of people with peripheral neuropathy linked to excess vitamin B6 in their blood, Australia’s peak body for pathologists has warned.
Dr. David Kanowski, a chemical pathologist at Sullivan Nicolaides Pathology in Brisbane, says most people are unaware they are getting too much of the vitamin.
Bogemann certainly had no idea: “You buy an over-the-counter supplement, you just think it’s going to be good for you, not bad for you.”
He says it was a challenge to change his multivitamin to a product without added B6.
“One thing I learned is that B6 seems to be added to a lot of over-the-counter supplements for some reason.”
It’s also in some energy drinks, breakfast cereals, and protein and weight loss shakes.
Magnesium tablets, which are commonly recommended for the relief of cramps, often contain B6 because it can promote the absorption of magnesium. But someone taking two magnesium tablets a day could consume more than 120 mg of B6, which is much more than the recommended dietary intake for adults in Australia of 1.3 mg to 2 mg per day.
Peripheral neuropathy was previously thought to be caused by doses of hundreds of milligrams taken over a period of twelve months or longer, but cases have been reported This is known to occur at levels as low as 21 mg.
Early symptoms include numbness and tingling in the feet, which can spread down the legs and affect the arms and hands, causing muscle cramps and pain.
In 2020, the Therapeutic Goods Administration (TGA) has a safety advice warning. In 2022, still concerned about a lack of awareness, the TGA lowered the limit products must have a warning label from 50 mg B6 to 10 mg and prohibited products with more than 100 mg.
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Nevertheless, cases have continued to rise. Between January 2020 and October 2024, the TGA received 81 reports of side effects of peripheral neuropathy associated with medicines containing a vitamin B6 ingredient, most of which in the last two years.
Kanowski says ads on social and other media promote the idea that taking more vitamins is good for health.
“Obviously, if you want to counter bad habits like smoking or drinking too much, maybe that can be offset with vitamins,” he says.
Kanowski says the TGA has been “fairly hands-off” unless there are toxins in a product.
Fiona Sammut, a dietician from Victoria, says expecting consumers to read and interpret disclaimers and wording in ‘small fonts’ is a stretch.
She says people who claim vitamins will “boost their energy” may be taking various supplements thinking they are harmless.
While foods are often fortified with vitamins for ‘specific, evidence-based reasons’ such as vitamin B1 enriched breadSammut says there is no similar rationale for B6 fortification because there is not a high incidence of vitamin B6 deficiency.
Most people get enough B6 from foods such as fish, non-citrus fruits and starchy vegetables. B6 from natural food sources has not been reported to cause adverse effects.
Sarah* had suffered from peripheral neuropathy for years, but “never thought about it” because she assumed it was related to her Crohn’s disease.
In retrospect, she says the symptoms started about a year after she started taking a multivitamin containing 60 mg of B6 after her weight-loss surgery in 2011, in addition to the 82 mg magnesium she had been taking for years for leg cramps. .
She had been undergoing annual blood tests at the recommendation of her dietitian, but it wasn’t until late 2021 that the pathology lab tested for B6 levels and found them to be 15 times higher than the recommended range.
In most cases, once B6 levels return to normal, peripheral neuropathy will slowly improve over six to twelve months, but in some severe cases it may be irreversible.
Professor Matthew Kiernan, the CEO of Neuroscience Australia, has described a case he saw in his clinical practice of a 40-year-old patient who feared he had motor neurone disease before the doctor linked the gym enthusiast’s symptoms to excessive intake of vitamin B6 from the supplements he used as part of his fitness program.
Kiernan, who diagnosed peripheral neuropathy in more patients after his article on the case published in the Medical Journal of Australiabelieves that there should be limits on the number of supplements people can buy, as they are not necessary for people following a balanced diet.
“None of this is controlled. So if you go to the pharmacy and go to the vitamin section, they’re all there. You can fill an entire shopping cart with it.”
*Name changed for privacy reasons