If you’re thinking of going vegan in January, hold those lentils until you’ve read on! Experts are warning that the risk of B12 deficiency is ‘not a myth’, as thousands of meat-eaters pledge to go plant-based to start the new year.

According to The Vegan Society, in 2019 the numbers signing up for ‘Veganuary’, the annual campaign where people eat vegan for a month, nearly doubled to a quarter of a million, in comparison to 168,500 participants in 2018. And the popularity of veganism is set to continue in 2020 - leading nutritionists to highlight the potential dangers of not getting enough nutrients. 

Professors Tim Key and Tom Sanders raised the issue while speaking in London at a briefing ahead of Veganuary. Professor Key, deputy director of the Cancer Epidemiology Unit at Oxford University and himself a vegan, said: "You're not going to get B12 deficiency in Veganuary (but) if people become vegan because of that, and don't ever bother to read up about what you need to eat as a vegan, I would be worried they won't know about B12."

Professor Sanders, emeritus professor of nutrition and dietetics at King's College London, said: "Of all the micronutrients, B12 is the one we're most concerned about. I'm concerned many people think B12 deficiency is a myth. What concerns me is that many new people becoming vegan are unaware of the need to combine sources of plant proteins. And they're not aware of the need to ensure they have adequate levels of B12."

B12 deficiency can lead to nerve damage, but symptoms - starting as pins and needles in the hands and feet - tend to take three or four years to emerge. Professor Sanders highlighted the case of a breastfeeding mother who had B12 deficiency and whose child developed neuropathy, leading to long-term damage.

A plant-based diet tends to be high in fibre and low in cholesterol. Every day, adults need around 1.5mg of B12, which is found in meat, fish, eggs and dairy products but not in fruits, vegetables or grains. The Vegan Society advises vegans to eat fortified foods, such as cereals, or take supplements to ensure they get enough B12.

The full benefits of a vegan diet are unclear, with, to date, one UK and one US study covering a relatively small number of people. Vegans tend to be less likely to be overweight, with a reduced risk of type 2 diabetes and heart disease, but they appear to be more likely to experience bone fractures. 

A Vegan Society spokesperson said: “Make sure you don't miss out on essential nutrients. Just because you're vegan that doesn't mean you're 100% healthy, as there are vegan versions of almost every type of junk food you can think of. As long as you eat a wide variety of tasty plant foods, planning a healthy diet that incorporates all the vitamins and nutrients you need will be a breeze.”

For more information ahead of Veganuary, take a look at The Vegan Society’s nutrition advice or chat to a registered dietitian.