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
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
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
Changes or loss of some sense of touch
Feeling less pain
Mood changes, irritability, depression or psychosis
Symptoms of dementia