Vitamin b12 deficiency: Symptoms include reduced smell

Pernicious anaemia causes your immune system to attack the cells in your stomach that produce the intrinsic factor, which means your body is unable to absorb vitamin B12.

Some people can develop a vitamin B12 deficiency as a result of not getting enough vitamin B12 from their diet.

According to Holland and Barrett, the richest sources of B12 are animal-based, including meat and liver, fish, milk and dairy products.

As a result, vegans and vegetarians are more prone to B12 deficiency.

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