What is B12 deficiency?

Vitamin B12 is a chemical that is found in food and is needed by humans for growth and maintenance of our bodies.  

Vitamin B12 is particularly important for the healthy growth and maintenance of nerves, blood cells and our DNA.  Without sufficient vitamin B12 the body struggles to make blood and repair itself.


What does it feel like?

Mild B12 deficiency often goes unnoticed.  Only when the B12 level is very low or when it has been a problem for a long time does it tend to cause symptoms.

Common symptoms include

Pins and needles in the hands / and / or feet

Feeling weak, tired and washed out

Feeling short of breath (this is a reflection of anaemia)

Sore mouth and tongue

Frequent mouth ulcers

Difficulty in thinking


How did I get it?

Vitamin B12 is released from food when we eat.  As the food is ground down by our teeth the vitamin starts to join with a protein found in our saliva.  Once swallowed it passes down the food pipe into the stomach where it comes into contact with a very acidic environment.  This acidic environment helps the vitamin to be absorbed later in its journey. The vitamin now passes out of the stomach into the first part of the intestine where it mixes with a few other chemicals before being absorbed into the blood stream.  The blood transports the vitamin around the body to where it is needed.

It is important to understand this journey as it helps to understand the numerous ways in which we might get vitamin B12 deficiency.  Essentially, any problem in this journey can cause vitamin B12 deficiency.


Common causes of vitamin B12 deficiency include

Old age

Diet.  Foods rich in B12 include –


Foods which have been fortified with vitamin B12


Milk and other dairy products

Salmon and cod

Medication use (Proton pump inhibitors such as lanzoprazole which decrease the acid in the stomach / Metformin)

Alcohol misuse

Inflammatory bowel disease (Crohn’s Disease or Ulcerative Colitis)

Coeliac Disease

Pernicious anaemia

How long will it last?

B12 deficiency will last until the cause has been found and corrected.


Do I need any treatment?

Once the cause of the B12 deficiency has been corrected the body is able to re-absorb B12 effectively again, no further treatment is required.

To aid recovery from the deficiency we may offer you vitamin B12 replacement either in the form of a tablet, or an injection.

Vitamin B12 is available over the counter without a prescription.


Is this dangerous?

For most people, vitamin B12 deficiency is a mild problem that is easily corrected.

In some cases however vitamin B12 deficiency can lead to significant and severe symptoms.