The NHS also warned a person may experience irritability, depression, changes in the way they think, feel and behave and a decline in their mental abilities, such as memory, understanding and judgement when lacking in B12.
The health body adds that you may also notice “changes in the way you think, feel and behave”.
Some people also report a decline in their mental abilities, such as memory, understanding and judgement, says the health body.
“Some of these symptoms can also happen in people who have a vitamin B12 deficiency but have not developed anaemia,” it adds.