Vegans at risk of vitamin B12 deficiency finds study

By Dr. Ananya Mandal, MDDec 22 2019

January is a month for resolutions and veganism is one of the top favourites. A new study has found that those who choose vegan diet may be missing out on Vitamin B12 and may need supplements to avoid deficiency of the vitamin.

Experts have said that Vitamin B12 is naturally found in meat, fish, dairy products and eggs – in short foods that vegans avoid. Vegan diet involves avoidance of all foods that have an animal source. They rely among cereals and soy based foods and mainly plant based foods. The main reason why many take up veganism say experts, is due to consciousness for the environment.

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There are reports that animal produce for human consumption is responsible for up to 18 percent of the greenhouse emissions that is one of the causative factors of global warming. Many take up veganism citing health reasons and with the belief that cutting down meat and saturated fats from diet and increasing fruits and vegetables could help them cut down the risk of several ailments such as heart disease, diabetes and even cancers.

In this new study Professor Tom Sanders - emeritus professor of nutrition & dietetics at King’s College London explained that one in five vegans are at a grave risk of being deficient in Vitamin B12. They looked at 172 vegan men and found that around 20 percent of the study population was deficient in vitamin B12.

Professor Tim Key - deputy director of the cancer epidemiology unit at the University of Oxford added that vegan trends tend to catch the fancy of many in January each year over the last few years. Sanders added that the body has a B12 store that can last for up to four years without external supplementation. Once these stores are depleted, he warned, there is a greater risk of nerve damage or neuritis that is caused by the deficiency.

Professor Sanders said, “Many vegans think B12 deficiency is a myth thanks to self-appointed experts on the internet.” He 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.” Professor Key added that the easiest solution to this could be addition of Vitamin B12 supplements but many refuse to take these supplements thinking them to be “unnatural”.

Professor Sanders said that one of the greatest hurdles to convincing people to take supplements is the slow and silent onset of deficiency of this vitamin. He said, “It takes a few years to develop. Many ignore the signs of pins and needles.”

Sanders also added that deficiency of Vitamin B12 could also lead to vitamin B12 deficiency anemia. This form of anemia is called megaloblastic anemia in which the body produces abnormally large red blood cells that cannot perform their normal functions and cannot carry the required amount of oxygen to different parts of the body. In persons with vitamin B12 deficiency there are symptoms including fatigue, muscle pains, pins and needles, sores and ulcers in the mouth, poor memory and cognitive functions as well as depression and blurring of vision. Vitamin B12 deficiency can also raise the risk of bone fractures and hemorrhagic strokes say some studies.

Professor Key said, “You’re not going to get B12 deficient in one month but you could then become vegan permanently so you need to read up.” Professor Sanders said that these symptoms could be “easily avoided by supplements or fortified food”. Key himself is a vegan and regularly takes vitamin B12 supplements. He said, “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.”

Both the Professors emphasized the need for these supplements in pregnant mothers. They explain that this deficiency in pregnant mothers can lead to long term damage to the fetus. Sanders said, “It's something that can be easily avoided, and 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.”

They were both speaking at a Science Media Centre briefing. “There is no significant difference in total mortality between vegans and meat eaters,” said Key refuting the claims that vegan diet prolongs lives.

The daily recommendation is 2.4 micrograms. In case of deficiency of this vitamin leading to neuritis patients may require injections or supplements of Vitamin B12 for years. Experts on diet say that any form of diet needs planning so that there is no risk of deficiency of essential vitamins and nutrients.