Overdosing on vitamin supplements, like vitamin B6, can have harmful side effects as pensioner Pamela Painter from Port Alfred discovered after being exposed to high doses in an over-the-counter supplement.
Excessive levels of vitamin B6, usually more than 50mg daily taken over a long time, are potentially toxic. The product Painter took had 200mg of B6, up to 100 times more than daily recommended levels of 1.5mg (women) to 1.7mg (men).
Doctors advise the public to check the vitamin levels in supplements they take.
“I’ve been taking vitamin complexes for years and I didn’t realise that vitamin B6 can be poisonous,” 93-year-old Painter said on Thursday, after an afternoon of bridge.
“I stopped [B6] nearly a month ago and I’m sleeping better and I’m walking steadier. I no longer have to hold on things though I still have pain in my heels,” she said. Her symptoms could be connected to too much vitamin B6 over time. However, this is not proven.
Polypharmacy, the taking of more than five drugs a day, increases your health risks. People should not take drugs they do not need.
— Dr Kathleen Ross, Cape Town geriatrician
Cape Town geriatrician Dr Kathleen Ross says: “Elderly people should be careful with what they choose and do goal-directed supplementation. People have so much access to supplements and often do not know what they are taking. The supplements can interact with other medications.”
Excessive B6, known as pyridoxine toxicity, can cause nerve damage (peripheral neuropathy), numbness, tingling and a lack of muscle control among other symptoms, particularly in vulnerable populations like the elderly but younger adults are not exempt.
“Vitamin supplements including B6 poisoning otherwise healthy people,” an Australian newspaper warned earlier this month, describing how a fit man of 40, who went to the gym, suffered nerve problems including rapid twitching symptoms.
The report in The Sydney Morning Herald, after a safety alert by Australian regulators TGA, caught the attention of Pamela’s son Mark, a paediatrician living there.
“My mother has always supplemented her and my late father's diets with vitamins, over many years, and they have both had trouble with their feet,” he said.
“My father had pins and needles and numbness and lost all feeling in his feet. Eventually, he stopped driving a car because he didn't know where his feet were in relation to the peddles.”
The complexity about the cause, Painter said, is this: “Vitamin B6 is a treatment for peripheral neuropathy and it can cause it as well.” For him, it is highly likely that B6 taken over years caused the peripheral neuropathy.
Painter said: “My poor husband had neuropathy for years. He was having B6 injections [100mg] and eventually he rather took the pills, which may have been making it worse.”
Mark Painter said that most South African products (tablets and capsules) delivered 25mg or less of B6 but at least two of the common ones contain dosages of 200mg per capsule. Moreover vitamin B injections are often given to the elderly, who are more at risk of vitamin and mineral deficiencies with ageing.
“I live in an old age complex in Port Alfred and there are so many people who have neuropathy and they take vitamin B6 supplements,” Painter’s mother said.
Ross suggested that concerned patients visit their GPs and do a blood test to check the vitamins in which they are most likely to be deficient: B12 and vitamin D.
She said: “If you check the vitamin D levels of healthy older people, you will be surprised how many are vitamin D deficient. Lots of South Africans spend time in the sun but now we use sunscreen or wear hats,” she said on the rise in vitamin D deficiency.
Consuming vitamin B6 through food – such as poultry, fish, legumes, nuts and fortified cereals – appears to be safe, even in excessive amounts.
— Mayo Clinic
— Supplements not food are toxic risk
That doesn’t mean people must rush out to buy vitamin D. Scientific trials have shown that vitamin D supplementation is of no benefit to people who are not deficient, Ross said.
“The biggest side effect of supplements is on your wallet as they are very expensive,” she said, adding: “Polypharmacy, the taking of more than five drugs a day, increases your health risks. People should not take drugs they do not need.”
Sports medicine doctor and Wits professor Dr Jon Patricios said competitive athletes must be careful about what “sports supplements” they take.
“They should be aware that many of them do not have scientific evidence for their efficacy,” he said.
“Even more important, they may be contaminated by substances that are prohibited for use by professional athletes, causing them to potentially test positive for these banned substances and be prohibited from participating in sport as part of their sanction.”
Athletes wanting to use supplements should get advice from a sports medicine physician or dietitian and “use only supplements which have been third-party tested and proven to be free of any banned substances, particularly those with the “informed sport’ label”, Patricios recommended.
No doctor prescribed the supplements which Pamela Painter took. “It is so important that people read what they are taking and check with their doctor,” she said.
“People think that vitamins don’t do any harm but they can.”
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