Anaemia means lack of haemoglobin, the substance in red blood cells which transports oxygen around the body.
People who are anaemic often look pale, get tired quickly and may find that they easily become short of breath.
There are many reasons why anaemia can occur. A diet deficient in iron, repeated blood loss (for example, heavy periods) and chronic illness are common causes.
One type of anaemia, known as pernicious anaemia or vitamin B12-deficiency anaemia, is due to a deficiency of vitamin B12 in the body.
This substance is readily available in the normal diet. However, a special substance known as ‘intrinsic factor’, made by the cells of the stomach wall, is necessary for it to be absorbed.
In some people, intrinsic factor is not produced in sufficient amounts and even with a good diet they cannot get enough vitamin B12.
This may also happen if someone has major surgery to their stomach or terminal ileum, or has a chronic bowel disease affecting the absorption of B12.
When pernicious anaemia is diagnosed, the person will need to have regular injections of vitamin B12.
This can be done on a monthly basis — a minor inconvenience toward a new lease on life.
Last Reviewed: 31 January 2009