Iron supplementation found to improve brain function

Iron is an essential nutrient for the making of haemoglobin – the component in red blood cells that carries oxygen and delivers it to the tissues. If iron is deficient in the body, haemoglobin levels can fall and eventually cause anaemia (pathologically low haemoglobin). Symptoms of this can include mental and physical fatigue and low mood. If quite severe, it can cause undue shortness of breath and make simple, everyday tasks difficult or impossible.

Iron isn’t just involved in the production of haemoglobin. Among other things, it also participates in the production of brain chemicals (neurotransmitters) such as serotonin and dopamine that have broadly beneficial effects on mood and brain function.

Bearing all this in mind, could iron supplementation have benefits for brain function?

A recent review asked this question [1]. Part of this review looked at trials in which iron supplements had been given to children aged 6 and older, and women (generally women under the age of 35).

Taken as a whole, these studies revealed that iron supplementation improved attention and concentration. And this effect was irrespective of iron levels at the start of the study. This result suggests that, as a whole, the children and women in these studies were iron deficient or had sub-optimal levels of iron in their bodies.

Now we need to bear in mind that some of these studies were performed in individuals in developing countries where iron deficiency is generally more common than developed countries. Nevertheless, these results do strongly suggest that optimising iron levels in the body is good for certain important aspects of brain function.

My experience is that iron deficiency/insufficiency is relatively common in the sort of patients I see. Overall, I think iron status should be assessed more frequently than it is. A major issue here is that many doctors will check for anaemia, and if the test results are normal, will not suspect iron deficiency. However, as I explain here, iron deficiency can occur in the absence of anaemia, and iron deficiency can be missed if we rely too heavily on tests for anaemia.

Iron levels can be tested in a number of ways, but the test I prefer to measuring and monitoring iron levels is the serum ferritin.

The normal range for ferritin varies from labl to lab, but is invariably set very wide (e.g. 15 – 200 ng/ml for women), and it is therefore possible for someone to have a ‘normal’ ferritin but still be suffering as a result. In my experience, ferritin levels need to be above about 50 for optimal physical and mental functioning.

The post I link to above includes advice about how to raise iron levels, including with the use of supplements. Iron in excess can be harmful, so I recommend checking of iron levels before embarking on any programme of supplementation.


1. Falkingham M, et al. The effects of oral iron supplementation on cognition in older children and adults; a systematic review and meta-analysis. Nutrition Journal 2010;9:4

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4 Responses to Iron supplementation found to improve brain function

  1. Peter Andrews 27 February 2010 at 2:24 am #

    I am a middle aged male. I have been keeping my iron on the low side on purpose for years via blood donation and a non iron supplemented multivitamin. I did this on purpose because of the purported connection between pre-menopausal women’s reduced cardiovascular risk relative to men. With the failure of HRT therapy, I figured iron levels was the next most likely difference between men and women that might explain the difference.

    After years of this, eventually I started getting deferred for blood donation due to hemoglobin < 12.5. Testing showed ferritin level of 10. I now take a multivitamin with iron but still keep iron on the low side with blood donation every 8 weeks.

    It would be ironic if by attempting to be kind to my heart I reduced the function of my brain.

    FYI: NHANES ferritin distribution:

  2. Hilda Glickman 27 February 2010 at 9:14 pm #

    Peter, I cannot understand why you did this just on your own speculation rather than looking up real research data. There are many differences between premenopausal women and post and HRT is not the same as the hormones women obefore the menopause. There is an ideal amount for everything. Too little can be as bad as too much.

  3. Donna 27 February 2010 at 11:01 pm #

    Dr. Briffa,
    I live in NJ – USA. I enjoy reading all your newsletters. I have a question about iron. I have been anemic all my life. I have also been told that I have Thallasemia (Mediteranen anemia) and it would be toxic for me to take iron. I have taken low doses and it hasn’t negatively affected me but I don’t want to push it. What is you comment when low iron in the body is genetic? I also have chronic fatigue syndrome, fibromyalgia, and hypothyroidism. Thanks.


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