Vitamin B12 Deficiency

Vitamin B12 deficiency happens when the body does not have enough B12 to support healthy blood cells and nerves.

B12 helps the body make red blood cells and maintain nerve function. A shortage can develop gradually, so changes in energy, sensation or thinking may be easy to overlook at first.

Fatigue and numbness or tingling are very common presentations of vitamin B12 deficiency. Dizziness, generalised weakness, pale skin and memory problems can also occur. Symptoms vary between people and may have causes other than a vitamin deficiency.

A low intake can contribute, particularly when animal-derived foods are avoided without a suitable B12 source. The body may also struggle to absorb B12 from food because of stomach or bowel conditions, surgery affecting digestion, or some medicines. Coeliac disease is one condition that can affect absorption.

The body can store B12, meaning deficiency may emerge slowly. Without correction, anaemia may develop and nerve-related symptoms can become more troublesome. Early assessment is useful when symptoms persist, change or affect balance, walking, hand use or daily activities.

Risk can be higher with a diet lacking reliable B12 sources, digestive conditions that limit absorption, previous stomach or bowel surgery, and medicines that alter stomach acid or absorption. People with a history of anaemia or ongoing bowel symptoms may also benefit from a clinician’s review.

A clinician will ask about symptoms, diet, medicines and digestive health, then arrange blood tests where appropriate. Results are considered alongside the full clinical picture. Further tests may be used to explore whether the issue is intake, absorption or another cause of similar symptoms.

Treatment depends on the cause and severity. It may involve B12 tablets or a vitamin B12 injection, together with changes that address low intake or poor absorption. When an underlying digestive condition is involved, that condition also needs appropriate care. Follow-up testing can help a clinician judge response and plan ongoing treatment.

Take prescribed treatment as directed and keep follow-up appointments. A food diary can help clarify dietary sources, while noting changes in sensation, balance, energy and concentration gives useful detail for review. Seek earlier care if neurological symptoms are worsening or new difficulty walking develops.

Untreated deficiency can lead to anaemia and may affect peripheral nerves. Persistent numbness, weakness or balance problems deserve medical assessment, particularly when they interfere with work, driving or preventing falls.

Include dependable B12 sources in the diet, or use a clinician-recommended supplement when food choices do not provide enough. If absorption is the problem, ongoing treatment may be needed rather than relying on diet alone.

Arrange a primary care appointment for persistent fatigue, tingling, pallor, dizziness or memory changes. Urgent assessment is appropriate for rapidly worsening weakness, significant trouble walking, fainting, chest discomfort or breathlessness.