Question

A friend of mine with ME/CFS takes a daily iron supplement to help with her fatigue. She says I ought to do the same – even though I know I’m not anaemic. This has been confirmed by a recent GP blood test. So is there any evidence that taking iron tablets could help to boost energy levels in ME/CFS? And is it safe to do so if you are not anaemic?

Answer

The underlying disease process in ME/CFS does NOT cause any form of anaemia. However, there are some possible consequences of ME/ CFS that could lead to anaemia – such as loss of appetite, poor nutrition, or going on a very restrictive diet (which could cause an iron or vitamin B12 deficiency if you are removing good sources of iron or vitamin B12 from the diet).

If you do have anaemia and ME/CFS, this will almost certainly increase fatigue levels and may exacerbate other ME/ CFS symptoms, such as cognitive dysfunction and palpitations. Once the cause of the anaemia is identified and treated symptoms such as general fatigue should start to gradually improve. Iron deficiency anaemia is the most common type of anaemia. There are other types, like vitamin B12 and folate anaemia.

A blood test will be used to check for the presence of anaemia (haemoglobin level) and iron status (serum ferritin) and it should always form part of the routine investigations when a diagnosis of ME/CFS is being considered. The cause of iron deficiency anaemia is often some form of chronic blood loss (e.g., from the bowels or from heavy periods). But it can also be caused by poor diet (especially in teenagers and people who do not eat enough iron-containing foods such as meat, fish and green vegetables) as well as some chronic medical conditions.

There is no reason why people with ME/CFS who are not anaemic need to take iron supplement. As with many other supplements, taking too much iron can have adverse effects including stomach upsets, nausea and vomiting. More serious side-effects can occur if higher than normal doses are taken and parts of the body become overloaded with iron, so I would not advise you follow this advice from your friend.

More information

• The NHS: Iron Deficiency Anaemia: Symptoms, Bood Test, Treatment, Self-Help, Causes | January 2021
• The ME Association has a detailed leaflet about Vitamin B12 and deficiency that includes information about anaemia and pernicious anaemia.
• The ME Association ME/CFS/PVFS Clinical & Research Guide (The ‘Purple Book') covers the assessment of Anaemia in the Investigation section.
• ME Association Blog: Pernicious Anaemia: symptoms, diagnosis, Vitamin B12 | 16 February 2018