Metal fatigue – iron deficiency found to slow brain function in women

While medical practice generally turns a blind eye to the value of nutrition in health, it has at least embraced the importance of certain specific nutrients including iron. Iron is important for the manufacture of haemoglobin ” the protein in the red blood cells responsible for carrying oxygen around the body and delivering it to the tissues. Iron deficiency can lead to anaemia, which can lead to symptoms which include fatigue and low mood.

What is less well recognised about iron is that it participates in the reactions that generate energy within the body. It is possible for individuals to become iron deficient without becoming anaemic. However, iron deficiency in the absence of anaemia can still cause individuals to suffer symptoms such as fatigue and low mood. This is particularly common in women of child-bearing age, particularly as a result of loss of iron via menstrual blood each month.

The relationship between iron status, anaemia and mental function was recently studied in a group of 149 women aged 18-35 years. At the beginning of the study, women were classified as being either iron-sufficient, iron deficient and anaemic, or iron deficient in the absence of anaemia. All women were put through their paces with 8 tests of mental function.

At the beginning of the study, the iron-sufficient women performed better and completed the mental tasks more quickly than the iron deficient anaemic women. Cognitive performance and task completion results among the iron deficient non-anaemic women fell between the iron sufficient women and iron deficient anaemic women.

Women who were iron deficient were then treated with iron supplements for a period of 8 weeks. At the end of the study, a significant improvement in serum ferritin was associated with a 5-7 fold improvement in mental function. The authors of this study concluded, “Iron status is a significant factor in cognitive performance in women of reproductive age”. They went on to add that the severity of iron deficiency affects accuracy of cognitive function over a broad range of tasks.

In medicine, we commonly check for anaemia. However, we much less commonly check for iron status. I do think it is important for individuals to be alert to the fact that iron deficiency in the absence of anaemia have adverse effects on health and wellbeing.

In my experience, the best test for iron levels in the body is what is known as the ‘serum ferritin’. It is my experience is that ferritin levels of less than about 50 are generally associated with symptoms such as fatigue, low mental energy and low mood. As I said, women of child-rearing age are at risk of this. This is particularly true for vegetarians and vegans in my experience.

Those not wishing to stoke up on liver and red meat may wish to contemplate supplementation. Many iron supplements are not well absorbed, however. One that I find useful in practice is Floradix “a liquid form of iron that is available from most health food stores.


1. Murray-Kolb LE, et al. Iron treatment normalizes cognitive functioning in young women Am J Clin Nutr, 2007;85(3): 778-787

7 Responses to Metal fatigue – iron deficiency found to slow brain function in women

  1. Michelle 16 March 2007 at 3:00 pm #

    Great article…answers a lot of questions. Thank you!

  2. Dr John Briffa 16 March 2007 at 3:15 pm #

    Not sure that this applies to you, Michelle, but a useful clinical guide to iron levels is how a woman feels as soon as menstruation starts. Feeling ‘wiped out’ at this time is, in my experience, a good sign that iron levels are low.

  3. Joyce 18 March 2007 at 12:36 am #

    I have also read about iron levels being too high, say over 100, that contributes to insulin resistance. The recommendation is to donate blood on a regular basis to lower iron levels. This may be more applicable to men and post-menopausal women.

    Just thought it would be good to mention the other side of the coin.

  4. Tiggy 19 March 2007 at 3:11 am #

    With multivitamin and minerals pills, are a lot of the substances not absorbed then? The trouble with getting them separately is, you spend all day taking pills. I’m on so many supplements as it is.

  5. Nikki 19 April 2007 at 1:32 pm #

    Good and helpful article & comments, thanks, I have just returned from the doctors where I found my iron levels were low (6.2) I have always felt totally wiped our around mentsration, but it has got worse as I’ve got older. This is the first time I have been tested for iron in a long time which bears out your comment that many test for anemia but not iron levels. I have found the wipe out to be totally debilitating & definately leads to low feelings, and inadequate performance at work. I run my own business so energy levels are very important. Can you give me an idea please of what a 48yr old fit womens iron & ferric acid level’s should be?
    many thanks

  6. Maria 16 May 2007 at 10:36 am #

    I have been anaemic since I was 16 (now 24) and I find that iron supplements such as ferrous sulphate gives me terrible constipation which is extremely painful around the time I start my period however, this is probably when I need them the most. Consequently I dont take any. Any other alternatives?

  7. Prae 14 May 2013 at 12:56 pm #

    I am iron deficient without being anaemic. I was put on various iron supplements that just made me feel yuck!

    Finally changed doctors who recommended I use something called Chelafer which is iron with protein. Amazing results with none of the icky iron supplement side effects. And the problem with me was that my body was not absorbing iron properly despite my diet being high in iron, so Chelafer helps to create more red blood cells to increase the absorption of iron. (Explanation may be a bit tacky, but u get the point!)

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