Vitamin B12 Deficiency

Vitamin B12 deficiency anemia is a low red blood cell count due to a lack of vitamin B12. Anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues.

Vitamin B 12 and folate

Vitamin B12 and folate together help the body produce red blood cells. They also have several other important functions:

Vitamin B12 keeps the nervous system (brain, nerves and spinal cord) healthy. Vitamin B12 is generally found in:

  • Meat
  • Eggs
  • Dairy products

Folate is important for pregnant women because it reduces the risk of birth defects in unborn babies. The best source of folate is green vegetables such as:

  • Broccoli
  • Brussel sprouts
  • Peas

Symptoms of anemia vary depending on the underline cause:
Vitamin B12 deficiency/ pernicious anemia
If anemia is caused by a vitamin B12 deficiency, one may have symptoms like:

  • Yellow coloration of skin
  • A sore and red tongue (glossitis)
  • Ulcers inside mouth
  • An altered sense of touch
  • Disturbed vision
  • Irritability
  • Depression
  • Psychosis
  • Dementia – a decline in mental abilities, such as memory, understanding and judgment

Folate deficiency
As well as general symptoms of anemia, a folate deficiency may also cause:

  • Loss of sensation, such as a reduced sense of touch or pain
  • Muscle weakness
  • Depression

The exact cause is not known, but disease is associated with certain risks factors which include:

  • Age – Pernicious anemia is most common at later age
  • Gender – Pernicious anemia affects slightly more women than men
  • Family history – nearly a third of people with anemia also have a family member with the condition
  • Autoimmune condition, such as Addison’s disease or vitiligo – is also associated with anemia and other autoimmune conditions
  • Diet- The body generally stores vitamin B12 to last approximately two to four years. However, it is important to have vitamin B12 in the diet to ensure  the store is kept at a healthy level.
  • Conditions affecting the stomach- Some stomach conditions or stomach operations can also prevent the absorption of  vitamin B12. For example, a gastrectomy(a surgical procedure where part of stomach is removed) also increases risk of developing vitamin B12 deficiency anemia.
  • Conditions affecting the intestines- Some conditions that affect intestines (part of the digestive system). For example, Crohn’s disease (a long-term condition that causes inflammation of the lining of the digestive system) can sometimes result in body not able to absorb enough vitamin B12.

Folate deficiency anaemia

Folate is a water-soluble vitamin (it dissolves in water), as a result body is unable to store it for long periods of time. Body stores folate that last four months. This means one need folate in daily diet to ensure body has sufficient stores of the vitamin.

  • Diet- Not having enough folate in daily diet. 
  • Mal absorption- Sometimes body is unable to absorb folate as effectively as it should. This is usually the result of an underlying condition affecting digestive system, such as Coeliac disease.
  • Excessive urination- Body may lose folate from body if one urinate frequently. This can be caused by an underlying condition that affects one of the organs, such as your kidneys or liver.
  • Pregnancy- If a women is pregnant or planning to get pregnant, daily supplement of 0.4mg of folic acid should be taken for at least  12 weeks.

Diagnosis may require a complete blood count or peripheral blood smear based on patient history and physical examination.



Treatment mainly depends upon the underlying conditions for the anemia:
Diet related

If vitamin B12 deficiency is caused by a lack of the vitamin in the diet, doctor may prescribe vitamin B12 tablets to take every day between meals. Alternatively, patient may have to take an injection of hydroxocobalamin twice a year.

Good sources of vitamin B12 include:
  • Meat
  • Salmon
  • Milk
  • Eggs
If a person is vegetarian, alternative food for meat and dairy products, that contains vitamin B12, such as:
  • Some fortified breakfast cereals
  • Some soy products
Not diet related

If vitamin B12 deficiency is not caused by a lack of vitamin B12 in diet, patient may need to have an injection of hydroxocobalamin every three months for the rest of life.

Folate deficiency anaemia

To treat folate deficiency anaemia, doctor may prescribe daily folic acid tablets to build up patient's folate levels.

Vitamin B12 deficiency complications

Lack of vitamin B12 can cause following complications:

Nervous system

Lack of vitamin B12 can affect nervous system (the brain, nerves and spinal cord). For example, one may experience:

  • Vision Issues
  • Memory loss
  • Paraesthesia (pins and needles) – a prickling or tingling feeling in the arms, legs, hands or feet
  • Ataxia – the loss of physical coordination, which can affect whole body and cause difficulty in speaking or in walking


Vitamin B12 deficiency can sometimes lead to temporary infertility (an inability to conceive).

Folate deficiency complications

Lack of folate can cause complications, some of which are outlined below.


As with deficiency of vitamin B12, a folate deficiency can also affect fertility. However, effects are only temporary and can be reversed by using vitamin supplements.

Premature birth

Lack of folate during pregnancy may also increase the risk of baby being born prematurely (before 37 weeks of pregnancy).


  • LAST UPDATED ON : Feb 04, 2016


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