Vitamin B12 deficiency is more common in older people and affects around one in 10 over 75s.
The most common cause of vitamin B12 deficiency is pernicious anaemia, an auto-immune condition that affects around one in 10,000 people. Pernicious anaemia is caused by a lack of a protein called intrinsic factor that’s needed to absorb vitamin B12 from food into the body from the gastro-intestinal tract. This condition is more common in people over 60, in women, in people with a family history of pernicious anaemia or some autoimmune conditions, including Addison’s disease and vitiligo.
Vitamin B12 deficiency is risk for people who follow a strict vegan diet who don’t eat the major food sources of B12: meat, eggs and dairy products. Babies whose mums are vegetarians may have vitamin B12 deficiency.
Other causes of vitamin B12 deficiency include:
Atrophic gastritis, or thinning of the stomach lining
Stomach ulcers
Surgery to remove part of the stomach or small intestine
Digestive conditions such as Crohn’s disease, coeliac disease, bacterial growth or a parasite.
Medication, including proton pump inhibitors (PPIs) for indigestion.
Anaemia and anaemia caused by a lack of vitamin B12 can result in symptoms which include:
Extreme tiredness or fatigue
A lack of energy or lethargy
Being out of breath
Feeling faint
Headache
Ringing in the ears (tinnitus)
Lack of appetite
More specific symptoms linked to a lack of vitamin B12 include:
Yellowing of the skin
Sore, red tongue
Mouth ulcers
Changes or loss of some sense of touch
Feeling less pain
Walking problems
Vision problems
Mood changes, irritability, depression or psychosis
Symptoms of dementia