Anaemia due to folic acid deficiency

Vein: takes blood back to the heart.

Red blood cells and oxygen

Through its pumping action, the heart propels blood around the body through the arteries.

The red blood cells take up oxygen in the lungs and carry it to all the body's cells. Your cells use this oxygen to fuel the combustion (burning) of sugar and fat which produces the body's energy.

During this process carbon dioxide is created as a waste product. It binds itself to the red blood cells that have delivered the oxygen.

The red blood cells then transport the carbon dioxide back to the lungs. We exchange this carbon dioxide for fresh oxygen by breathing.

This process is called oxidation.

Why does a lack of folic acid cause anaemia?

Red blood cells are made in the bone marrow and circulate in the blood. They only have a life expectancy of about four months.

The body needs iron, vitamin B12 and folic acid (one of the B group of vitamins) to produce more red blood cells. If there is a lack of one or more of these nutrients, anaemia will develop.

A person who lacks folic acid may experience intestinal problems as well as the usual symptoms of anaemia.

What are the causes of folic acid deficiency?

- Not eating enough foods that contain folic acid. Alcoholics and drug addicts are particularly at risk, but so too are elderly people eating a poor diet. In rare cases, it is found in teenagers who eat nothing but junk-food.
- In periods of rapid growth the body needs more folic acid – for example, in childhood and during pregnancy. Folic acid also helps to protect the foetus against spina bifida (problems with the spinal cord system not developing completely).
- In some kinds of hereditary anaemia, such as haemolytic anaemia, the body breaks down red cells very quickly. To compensate for this, the body produces more blood cells in response and uses up all its stores of folic acid.
- Certain medicines such as anti-epileptic drugs and some antibiotics can interfere with the body's normal metabolism of folic acid. Pregnant women should always check with their doctor before taking any kind of medication during pregnancy.
- Chronic dialysis for kidney patients can remove folic acid from the blood.
- Diseases of the small intestine such as gluten intolerance (coeliac disease) and Crohn's disease (inflammation of the intestine) can reduce its ability to absorb folic acid.

What are the symptoms of this type of anaemia?

If a person is otherwise healthy, it can take some time for the signs of anaemia to appear.

- The first symptoms will be tiredness and palpitations (awareness of heartbeat).
- Shortness of breath and dizziness (fainting) are also common.
- If the anaemia is severe, it can result in angina (chest pain), headache and leg pains (intermittent claudication).

In addition to these general symptoms of anaemia, the following indicate folic acid deficiency:

- red, irritated tongue that may appear shiny
- reduced sense of taste
- indigestion
- changed bowel movements and often diarrhoea.

Bowel symptoms are more likely with a lack of folic acid rather than B12 deficiency.

In contrast to B12 deficiency, this type of anaemia doesn't lead to any symptoms in your nervous system (muscle weakness, tingling in the hands and feet, nerve inflammation). However, you can be deficient in B12 and folic acid at the same time.

How is anaemia due to a lack of folic acid diagnosed?

A blood sample is taken and sent off to the laboratory. An analysis of the red blood cells is usually included with the result of the test.

In cases of folic acid deficiency, low levels of folic acid will be registered in the blood. The red blood cells will be the usual colour, but larger than normal.

How is it treated?

Folic acid supplements can reverse this type of anaemia, but your doctor will also look at treating any underlying cause.

The tablets are taken once a day and have few side-effects. They should be taken for at least four months.

Folic acid tablets are only continued long term if the underlying cause cannot be corrected.