Vitamin B12 is responsible for the production of red blood cells and keeping the nervous system healthy. Red blood cells carry oxygen around the body, but are unable to do so properly if there are too few of them or if they are abnormally formed. Vitamin B12 deficiency can cause red blood cells to become abnormally large, which can disrupt their ability to carry oxygen. Anaemia is the general term for having either fewer red blood cells or an abnormally low amount of haemoglobin in each red blood cell.
Symptoms of vitamin B12 deficiency are wide-ranging, but one common sign is mouth ulcers.
Mouth ulcers are common and usually clear up on their own within a week or two, according to the NHS.
In most cases, mouth ulcers aren’t a sign of anything serious, but they can be very uncomfortable.
However, if present with other symptoms, mouth ulcers could be a symptom of vitamin B12 deficiency.
Other signs of B12 deficiency include extreme tiredness, a lack of energy, pins and needles, and a sore and red tongue.
Muscle weakness, a pale yellow tinge to the skin, disturbed vision and problems with memory are also symptoms.
Other symptoms of anaemia are breathlessness, feeling faint, headaches, loss of appetite and weight loss, and heart palpitations.
“See your GP if you think you may have a vitamin B12 deficiency,” said the NHS.
“It’s important for vitamin B12 deficiency anaemia to be diagnosed and treated as soon as possible because, although many of the symptoms improve with treatment, some problems caused by the condition can be irreversible.”
As most cases of vitamin B12 deficiency can be easily and effectively treated, complications are rare, according to the NHS.
However, complications can occasionally develop, particularly if you’ve been deficient in B12 for some time.
Complications can include neurological changes such as vision problems, memory loss, loss of physical coordination and damage to parts of the nervous system.
B12 deficiency can also sometimes lead to temporary infertility, and in some cases can increase the risk of developing stomach cancer.
Vitamin B12 deficiency is most commonly caused by pernicious anaemia – an autoimmune condition affecting the stomach, which stops the body from absorbing B12.
Vitamin B12 deficiency can also be caused by a lack of the vitamin in your diet, in which case improving your diet can help to reverse symptoms.
Good sources of B12 include meat, fish, dairy products, eggs, yeast extract, soy products and fortified breakfast cereals.
In cases where deficiency is caused by pernicious anaemia, patients may need to have injections of the vitamin for the rest of their lives.