Symptoms of Vitamin B12 Deficiency

Symptoms of Vitamin B12 Deficiency depend on its severity. Mild deficiency may cause symptoms because of anaemia, but as deficiency worsens it may cause neurological symptoms.

Vasudha Bhat
Blood DiseasesWritten by: Vasudha BhatPublished at: May 02, 2014Updated at: May 02, 2014
Symptoms of Vitamin B12 Deficiency

Vitamin B12 is an important nutrient which helps in several vital functions of the body. Deficiency of vitamin B12 is quite common, and many people who have it may not realise that they are suffering from symptoms of vitamin B12 deficiency. In fact, B12 deficiency may be the cause of several mysterious symptoms that they may be experiencing without a clue about their cause.


Vitamin B12 Deficiency


Role of Vitamin B12 in Functions of Body

  • DNA production and repair.
  • Synthesis of haemoglobin.
  • Proper neural production and communication.
  • Metabolism.

Symptoms of vitamin B12 deficiency depend on the severity of deficiency. Mild deficiency may cause symptoms of anaemia, but as deficiency worsens it may damage neurological cells and cause neurological symptoms.


Vitamin B12 Deficiency

Symptoms of Vitamin B12 Deficiency


Vitamin B12 is needed for synthesis of haemoglobin (the protein which helps to carry oxygen in blood). If there is inadequate haemoglobin in your blood, it causes symptoms related to anaemia. In early stages, anaemia due to deficiency of vitamin B12 may cause only mild or no symptoms. But as the anaemia worsens it may causes symptoms such as:

  • Fatigue, weakness, or tiredness.
  • Light-headedness or shortness of breath.
  • Rapid heartbeat and breathing.
  • Pale skin (pallor) or white spots on the skin (due to release of melatonin).
  • Sore tongue.
  • Easy bruising or bleeding, including bleeding gums.

Neurological Symptoms

As the deficiency worsens, you may also experience neurological symptoms because of damage to the nerve cells. It may cause symptoms such as:

  • Poor memory, difficulty in focusing (may be complete inability to concentrate).
  • Tingling or numbness in fingers and toes.
  • Difficulty in walking.
  • Depression, confusion, paranoia and other behavioural disorders.
  • Memory loss, disorientation, and dementia.
  • Severe cases of B12 deficiency may result in suicidal thoughts and tendencies.


Metabolic and Digestive Symptoms

B12 helps in metabolism, i.e. it helps to turn the food you eat into energy. Without the right amount of B12, metabolism is affected. This causes symptoms related to lack of energy and improper digestion. Digestive problems which may occur with a B12 deficiency can cause symptoms such as:

  • Heartburn, nausea, vomiting, and diarrhoea.
  • Bloating and constipation.
  • Poor appetite and weight loss.

Vitamin B12 deficiency can cause many other nonspecific symptoms which make diagnosis very difficult without proper testing. In many cases, B12 deficiency symptoms are mistaken for another illness. If you suspect having symptoms because of B12 deficiency, consult a doctor to diagnose the cause of your symptoms and proper treatment.

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