What Causes Iron Deficiency? Caffeine Can!

Do you feel tired or do you keep picking up bugs (the cold and flu sort)? Iron deficiency is the most common deficiency in Western societies and its consequences include lack of energy and reduced immunity.

In the late 70s researchers looking for a way to increase iron uptake came up with the, some might say, bizarre idea of fortifying sugar with iron. They were surprised to find that when this fortified sugar was added to coffee very little of it was absorbed into the body.

Other studies showed that a single cup of tea or coffee can reduce the iron absorption from a meal by as much as 75%, depending on the strength of caffeine in the drink. This is the case too if the caffeine is drunk within the hour after eating. Tea and coffee (and caffeinated soft drinks) also reduce the effectiveness of iron supplements, in fact some studies have shown that in some people anaemia is impossible to correct until caffeine is stopped.


Iron deficiency eventually leads to anaemia (low blood count), but this can take many months and up to 3 years to happen; it’s a progressive thing.

Women, before menopause, are at a higher risk of anaemia due to regular blood loss.

Bearing in mind anaemia is a relatively late sign of iron deficiency a blood count done by your doctor (known as a full blood count) may not pick the problem up. If you think you’ve got symptoms suggesting iron deficiency and want it checked out you need another test in addition to the blood count. The other test measures what’s known as the ferritin level. This is a better indication of your iron levels.

Iron isn’t the easiest thing to absorb from our food anyway but there are 2 easy things you can do to help:

  1. Don’t drink caffeine with meals or an hour afterwards
  2. Vitamin C increases iron absorption and you can get this from orange juice or the salad or steamed veggies with your meal.

Even if your diet is packed with iron and you are taking supplements you could be inadvertently sabotaging your healthy choices by drinking caffeine with, or close to, meals. This one little change can make a BIG difference.

If you’re interested in more about caffeine take a look at Caffeine Addiction blog.

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Comments and questions welcomed


Uber Health to you, Dr Julie


12 thoughts on “What Causes Iron Deficiency? Caffeine Can!”

  1. Wow! Interesting and very informative. I had no idea that drinking caffeine during or an hour after a meal can reduce iron absorption. Yikes. Thanks for sharing this.

  2. My brother suggested I might like this website. He was totally right.
    This post actually made my day. You can not imagine
    simply how much time I had spent for this information!

  3. Hi Dr Julie,

    I can’t start my day without a cup of caffeine. Without it, I would not make to
    the gym. Thanks for the informative article.

  4. Hi Julie.
    I have came across really interesting theory that less iron is better for our health when we are getting older (“The mind span diet” by Preston W. Estep) . Food in our supermarkets is loaded with iron (bread, cereals made from iron fortified flours) and iron supplementation is beneficial when we are young to prevent iron deficiency ( most research is done on young people), but. after a certain age for men and after menopause for women we actually need less iron to lower our Alzheimer’s risk and getting other age related diseases. One of the examples from book: Italians eat plenty unfortified white flour and they always drink coffee at the end of big meal,, as well as Okinawans from Japan drink green tea with every meal and they do live longer then us.. What is your view ? Is our iron requirement age related? .

    1. Dr. Julie Coffey

      Hi Ada, thanks for your comment – very interesting stuff!
      I came across a theory that as you older you need less iron. It recognised that premenopausal women were less likely to have heart disease than men of the same age, but after the menopause they gradually caught up. It was suggested that this was because they weren’t regularly losing blood anymore, which was exerting a protective effect. So there may be something in that.
      Looking at Italians and the Japanese – it’s hard to say as there as so many other variables and differences. But it’s very interesting.

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