Private vitamin b12 deficiency clinic in London, same-day endocrinology.

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

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.