26/05/2025
Vitamin B12 is an essential nutrient vital for maintaining healthy blood cells, nerve function, and DNA production.
A deficiency can lead to serious health issues, highlighting its importance.
Signs of Vitamin B12 deficiency include:
- rapid breathing or shortness of breath
- headaches
- indigestion
- loss of appetite
- palpitations
- problems with your vision
- feeling weak or tired
- diarrhoea
- a sore or red tongue, sometimes with mouth ulcers
- problems with memory, understanding and judgment (cognitive changes)
Vitamin B12 deficiency can also cause symptoms that affect your brain and nervous system (neurological symptoms), including:
- numbness
- muscle weakness
- psychological problems, which can range from mild depression or anxiety, to confusion and dementia
- problems with balance and coordination
- pins and needles
- incontinence
Some people can develop a vitamin B12 deficiency as a result of not getting enough vitamin B12 from their diet.
A diet that includes meat, fish and dairy products usually provides enough vitamin B12, but people who do not regularly eat these foods can become deficient.
People who eat a vegan diet and do not take vitamin B12 supplements or eat foods fortified with vitamin B12, are also at risk.
Stores of vitamin B12 in the body can last around 2 to 5 years without being replenished, so it can take a long time for any problems to develop after a dietary change.
Metformin, a medication commonly used to treat type 2 diabetes, can reduce vitamin B12 levels and potentially lead to vitamin B12 deficiency. The risk of B12 deficiency is higher with longer treatment durations, higher doses of metformin, and in individuals with certain risk factors, such as gastrointestinal disorders or dietary deficiencies.