Vitamin B12 deficiency UK: symptoms, causes and treatment
Low vitamin B12 in the UK — symptoms, who is at risk, blood tests, treatment options and when to see your GP.
B12 searches spike alongside tiredness and vegan diet queries — often overlapping with iron deficiency.
Symptoms
- Persistent tiredness
- Tingling or numbness in hands/feet
- Glossitis (sore, smooth tongue)
- Memory problems or low mood
- Balance difficulty if severe
Causes
- Pernicious anaemia — autoimmune, needs lifelong B12 treatment
- Vegan diet without fortified foods or supplements
- Metformin and some other medicines
- Malabsorption after gastric surgery
Testing and treatment
GP or private blood tests confirm levels. Intramuscular treatment is standard when absorption is poor; oral high-dose B12 suits some people.
Do not self-treat blindly
High-dose B12 without testing can mask folate problems. If you have neurological symptoms, seek GP review promptly.
Frequently asked questions
What are symptoms of B12 deficiency?
Fatigue, pins and needles in hands or feet, sore red tongue, low mood and brain fog. Severe deficiency can cause nerve damage if untreated.
Who is at risk of B12 deficiency in the UK?
Vegans without supplementation, older adults, people on metformin for diabetes, those with pernicious anaemia, and people after stomach or bowel surgery.
How is B12 deficiency treated?
Hydroxocobalamin given by intramuscular treatment every few months for absorption problems, or high-dose oral B12 if absorption is intact. Treatment follows blood test confirmation.
Can I test B12 online?
Yes — private blood tests include B12 and active B12 (holotranscobalamin). Results should be reviewed by a GP who can arrange treatment if needed.
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