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. If this happens, it can cause a wide range of symptoms, including changes in mood.
Low levels of vitamin B12 have been linked to brain disorders like dementia and depression.
This may be because low levels of B12 are linked to high levels of homocysteine – an amino acid found in the blood.
According to medical website Healthline: “High levels of homocysteine caused by low levels of B12 could cause damage to the brain tissue and interfere with signals to and from your brain, leading to mood changes.”
Healthline warns, however, that changes to mood and conditions like dementia and depression can have a variety of causes.
If you experience mood changes, see a doctor who will be able to give you a diagnosis.
“If you have a deficiency, taking a supplement may help improve your mood,” noted Healthline.
“However, it’s not a substitute for other proven medical therapies in the treatment of depression or dementia,” it warned.
Vitamin B12 deficiency can usually be easily treated, which can reverse symptoms.
But if someone has been deficient for a long time, some symptoms and complications can be irreversible.
It’s therefore important to get any potential symptoms of vitamin B12 deficiency checked out.
Other symptoms include mouth ulcers, a sore and red tongue, extreme tiredness, a lack of energy and pins and needles.
It can also cause muscle weakness and a pale yellow tinge to the skin.
Damage to the nervous system caused by untreated B12 deficiency can lead to changes in how you walk and move, vision problems and memory loss.
Untreated B12 deficiency can also sometimes lead to temporary infertility, and in some cases can increase the risk of developing stomach cancer.
“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.”