Patient information · General health
Vitamin B12 deficiency
treatable — but not always reversible if left
B12 is needed to make red blood cells and to maintain the insulating sheath around nerves. Deficiency is common, easily missed, and usually produces vague symptoms that get attributed to a busy life. Left long enough, the neurological damage can become permanent, which is why it is worth testing rather than guessing.
Seek prompt assessment if you have
- numbness, tingling or burning in the hands or feet
- unsteadiness walking, or difficulty with balance in the dark
- memory problems, confusion or personality change
- severe breathlessness, chest pain or palpitations
- visual disturbance, or a sore smooth beefy-red tongue
- these symptoms alongside a known deficiency you have stopped treating
Neurological symptoms indicate the nervous system is already affected and need treating urgently rather than at the next routine appointment. Nerve damage present for a long time may not fully recover even with proper treatment.
Symptoms
- Extreme tiredness, breathlessness on exertion, palpitations, pale or slightly yellow skin
- Pins and needles, numbness, or a burning sensation in hands and feet
- Poor balance and coordination
- Brain fog, poor concentration, memory difficulty, irritability, low mood
- A sore, red, smooth tongue and mouth ulcers
- Disturbed vision, and in severe cases confusion
Who is at risk
- Vegans and strict vegetarians — B12 occurs naturally only in animal products
- Pernicious anaemia — an autoimmune condition destroying the mechanism that absorbs B12. The commonest cause in the UK
- Metformin for diabetes, and long-term acid-suppressing medicines such as omeprazole and lansoprazole
- Coeliac disease, Crohn's disease, and previous stomach or bowel surgery including bariatric surgery
- Age over 60, heavy alcohol use, and pregnancy
Never take folic acid alone if B12 might be low
Folic acid corrects the anaemia caused by B12 deficiency while the nerve damage continues silently underneath — and can accelerate it. This matters for anyone taking high-dose folic acid, including in pregnancy. B12 must be checked and treated first, or alongside. The same applies to B-complex and 'energy' supplements bought over the counter: taking them before a blood test can also mask a genuine deficiency and produce a falsely normal result.
Testing
A blood test measures B12, usually alongside a full blood count, folate and ferritin, since deficiencies frequently occur together. If B12 is low or borderline, further tests may include intrinsic factor antibodies to look for pernicious anaemia, and coeliac screening. Results in the low-normal range with clear symptoms are sometimes worth treating, since the test has real limitations.
Treatment
- Injections are used where the problem is absorption rather than intake — pernicious anaemia, bowel disease, after surgery. Loading doses are given first, then maintenance every two to three months, usually for life.
- Where neurological symptoms are present, more intensive initial treatment is used.
- Tablets are appropriate where the cause is purely dietary, as in a vegan diet.
- Symptoms often improve within days to weeks, though nerve symptoms recover more slowly and sometimes incompletely.
- Do not stop treatment because you feel better — if the cause is absorption, deficiency will simply return.
Why come to us. We test B12 alongside folate, ferritin and a full blood count in-house, with results explained by a clinician rather than a text message — and we look for the underlying cause rather than simply topping you up. If you need B12 injections, we provide them here, seven days a week, including for people who have been diagnosed elsewhere and cannot get convenient appointments. No referral is needed and you can book online.
B12 testing and injections, seven days a week
Bloods in-house, results explained, no referral needed.
Tower Bridge Hospital London
97–99 Whitechapel Road, London E1 1DT
WhatsApp 07903 284 189
info@mhwclinic.co.uk
Open Mon–Sat, 9am–7pm (closed Sundays until September)
In an emergency
Call 999, or go to the Royal London Hospital Emergency Department, Whitechapel Road, London E1 1FR.
When we are closed and it is not an emergency
Call NHS 111 or visit 111.nhs.uk.