The problem of B12 deficiency, which can lead to numerous disorders, is more concerning because many people eating a vegan diet nowadays.

Adults need around 1.5 micrograms of B12 a day, but most vegans do not get enough vitamins, BBC reported.

B12 deficiency can lead to nerve damage, and it takes 3-4 years to cause symptoms.  

B12 deficiency, which can lead to nerve damage, tends to take three or four years to cause symptoms - usually first appearing as pins and needles in the hands or feet.

According to numerous studies, people eating a vegan diet are less likely to be overweight, and at less risk of type 2 diabetes and heart disease. However, they appear to have a higher risk of bone fracture.

It is found in meat, fish, eggs and dairy products, but not in fruits, vegetables or grains - so those eating a vegan diet are advised to eat fortified foods, like cereals, or take supplements.