Are you iron deficient?

It’s a little-known fact that our iron levels are likely to change throughout our lifetime – from periods to pregnancy, menopause and beyond. But why is that? 

Iron deficiency is the most common cause of anaemia worldwide [1], which happens when iron intake or absorption rates fall short of meeting the iron demands of the body. 

In this blog, we’ll go through our recent findings as well as: 

• How many women are iron deficient? 
• Why is iron important? 
• What causes iron deficiency? 
• Is my diet making me iron deficient? 
• How do periods affect iron deficiency? 
• Iron deficiency and pregnancy  
• Iron levels throughout menopause and beyond 
• How to test iron deficiency  
• What is a healthy iron level for a woman?
• What is a low iron level for a woman?

How many women are iron deficient in the UK?

 

We analysed over 20,000 of our female customers’ ferritin results across the UK. The difference between the ages showed that over one in five women aged between 18 and 50 are iron deficient.  

Age group	Percentage of women with iron deficiency (according to ferritin result)
18-30	22.75%
34-40	22.23%
41-50	20.69%
51-60	7.13%
>60	4.77%

*Data collected from Medichecks’ customers between 20/06/2021 and 21/06/2022. Customers were labelled as having an iron deficiency if they had at least one ferritin result that was less than 30 nmol/L according to NICE criteria.  

According to our data, women aged 18-30 are the most likely to be iron deficient, with 31-40-year-olds a close second, and 41-50-year-olds coming in third. Once women reach their 50s, their chance of being iron deficient significantly drops.  

Of course, it’s important (as always) for a doctor to view your results alongside your lifestyle information and other markers. Low ferritin could also signal anaemia, hypothyroidism, vitamin C deficiency, coeliac disease, and many other conditions.  

Now, let’s look at how to improve iron deficiency among women – and why it is less likely in later life.   

Why is iron important?

 

Your body uses iron to produce haemoglobin, which is the pigment that makes your blood red. The iron in haemoglobin combines with oxygen and transports it through the blood to your tissues and organs.  
 
Low iron can lead to anaemia — this is when the body doesn’t have enough haemoglobin or healthy red blood cells to carry oxygen effectively. Both iron deficiency and iron deficiency anaemia can lead you to feel exhausted, breathless, or dizzy.  

Symptoms of low iron [2]: 

• Tiredness and lack of energy 
• Shortness of breath 
• Noticeable heartbeats (heart palpitations) 
• Pale skin 

What causes iron deficiency?

 

You get most of your iron from the breakdown and turnover of red blood cells (95%). The rest comes from your diet (5%). So, losing blood, a low-iron diet, or problems absorbing iron can lead to a deficiency.  

Women also have other factors which put them at greater risk of iron deficiency compared to men — menstruation and pregnancy.  

NICE estimates that anaemia affects 23% of pregnant women and 14% of non-pregnant women [3].  

5 causes of iron deficiency [4]:  

• Increased blood loss – chronic blood loss, especially from the womb, stomach, or intestines. This can include menstruation (the most common cause in premenopausal women) or blood loss from the gut (the most common cause in adult men and postmenopausal women). Other causes include heavy bleeding during childbirth.  
• Increased requirement – iron requirements can be up to three times higher at certain stages in pregnancy than they are in menstruating women 
• Dietary deficiency – diet can affect your iron levels, though it’s rarely a cause on its own. Putting that into perspective, NICE states it takes roughly eight years for a normal adult male to develop iron deficiency anaemia due to poor diet.  
• Malabsorption – This is when the gut does not absorb nutrients properly, which can happen with conditions like coeliac disease or after a gastrectomy (where part of the stomach is removed. Rarely, parasites or inflammatory bowel disease can lead to iron deficiency through blood loss.  
• Other – these include frequent blood donation and heavy nosebleeds. 

Is my diet making me iron deficient?

 

Diet can be a factor in iron deficiency, but it isn’t likely to be the sole cause. That said, there have been emerging instances (in the States for example) where the rise of iron deficiency anaemia has been linked to higher crop yields per acre reducing the amount of iron in foods [5].  

Vegetarian and vegan diets may also be a contributing factor. In our 2021 Veganalysis, we found that, on average, iron levels were 31.4% lower in vegans than in people who follow an omnivorous diet. However, it’s well worth noting that the mean ferritin level in vegans was still within the normal range.   

Another less well-known cause may not be what you’re eating, but what you’re drinking. Caffeine is known to prevent iron absorption, and coffee consumption has significantly increased in recent years (with the latest figures finding British coffee consumption soars to 95 million cups a day!) [6]. Again, this isn’t likely to be the main cause of iron deficiency, but it’d be wise to take stock of your caffeine intake if you do have iron deficiency, or at least don’t drink it with your iron-rich meal 

How do periods affect iron deficiency?

 

Everyone’s period is different. But if you have heavy periods or lose more blood than what is considered normal (roughly a few tablespoons), then you may be at a higher risk of iron deficiency.  

Your period isn’t something to fear but do keep an eye on the symptoms of iron deficiency and if you’re concerned about a heavy flow then seek medical advice. Remember, there are dangers to raised iron levels too, so always discuss supplementing with your doctor first.   

Iron deficiency and pregnancy

 

Anaemia is common in pregnancy. That’s because you and your baby will need a lot more iron to make red blood cells while you’re pregnant.  

The body tries to meet this increased need by increasing dietary iron absorption and by drawing on iron stores (ferritin). As a result, ferritin levels decrease during pregnancy, slowly at first.  

As foetal growth accelerates, more iron is mobilised from ferritin into the bloodstream. Some women don't have adequate stores of iron, which can result in iron deficiency anaemia during pregnancy. For this reason, some women may be recommended to take a supplement if their levels are low [7]. 

You may be more at risk of iron deficiency during pregnancy if you [8]: 

• Are vegan or vegetarian 
• Have had anaemia before 
• Have a history of heavy periods 
• Are carrying more than one baby 
• You were younger than 20 when you got pregnant 
• Are pregnant after having a baby within the last year  

If you are having a single-birth pregnancy, you should have a blood test during your booking appointment and another at around 28 weeks pregnant to check your iron levels. If you are carrying more than one baby, you should be offered an extra blood test between 20-24 weeks.  

If you think you’re at risk or are experiencing any of the symptoms of iron deficiency, contact your midwife or healthcare provider.  

Iron levels throughout menopause and beyond

 

As women go through menopause, serum ferritin increases by over two-fold [9]. This is because iron is no longer lost through menstruation, causing it to accumulate.  

A rise in ferritin in postmenopausal women is a normal process. However, this increase in iron has been linked to some conditions [9], such as: 

• Osteoporosis (in people who carry a hemochromatosis Fe (HFE) gene mutation) 
• Skin ageing  
• Hot flushes 

How to test for iron deficiency

 

The first thing you should do if you’re experiencing symptoms of iron deficiency is to get tested. You can visit your GP or quickly get a result with one of our home Iron Blood Tests. 

With Medichecks, your results will come with advice and the next steps of what you should do if your levels are abnormal. 

Treatment for iron deficiency will depend on the cause of your deficiency, but they may include iron tablets. Do remember that iron overload can be dangerous, so always speak to a medical practitioner before starting supplements.   

What is a healthy iron level for a woman?

 

A ferritin level between 30-180 μg/L is usually considered within the normal range. 

What is a low iron level for a woman?

 

A ferritin result under 30 μg/L is considered low, according to NICE. However, your iron levels will naturally change throughout your life due to factors like periods, pregnancy, and menopause. 

If your diet is contributing to your iron deficiency anaemia, you can try eating foods that are rich in iron to help improve your iron levels. 

Eat and drink more: 

• Dark-green leafy vegetables like watercress and curly kale 
• Cereals and bread with extra iron (fortified) 
• Meat (if it’s in your diet) 
• Dried fruit, like apricots, prunes, and raisins 
• Pulses (beans, peas, and lentils) 

Eat and drink less: 

• Tea 
• Coffee 
• Milk and dairy 
• Foods with high levels of phytic acids, such as wholegrain cereals 

Phytic acid can stop your body from absorbing iron from other foods and pills. 

If you still want to drink tea or coffee, try to avoid drinking it alongside your meal. 

What is a high iron level for a woman?

 

Generally, ferritin more than 200 μg/L in pre-menopausal women or 300 μg/L in post-menopausal women is considered raised.  

Causes of high iron levels:

• Transfusion 
• Haemolysis  
• Excessive parenteral and/or dietary consumption of iron
• Inherited primary overload

The potentially harmful effects of raised iron/ferritin include:  

• Liver scarring and liver cancer 
• Diabetes 
• Arthritis 
• Heart problems 
• Neurodegenerative disorders 
• Susceptibility to infections 

One of the possible reasons for this is iron's ability to reversibly cycle between highly reactive ferrous (Fe2+) and relatively stable ferric (Fe3+) oxidation states, resulting in the formation of toxic reactive oxygen species [9].  

So, how important are iron levels?

 

Your iron levels will change throughout your lifetime and can also be affected by other factors such as infection or inflammation. In our Iron Blood Test, we include multiple biomarkers so that your results can be interpreted in context to get a whole picture of your health, including ferritin.

Finally, if you are experiencing symptoms of low iron or you’re concerned that you may have raised levels, then you should get tested or seek medical advice.  

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References

1. Miller, J., 2022. Iron Deficiency Anemia: A Common and Curable Disease.  
2. NHS.uk. 2022. Iron deficiency anaemia. [online] Available at: <https://www.nhs.uk/conditions/iron-deficiency-anaemia/> [Accessed 26 July 2022]. 
3. Cks.nice.org.uk. 2022. Prevalence | Background information | Anaemia - iron deficiency | CKS | NICE. [online] Available at: <https://cks.nice.org.uk/topics/anaemia-iron-deficiency/background information/prevalence/> [Accessed 26 July 2022]. 
4. Cks.nice.org.uk. 2022. Causes | Background information | Anaemia - iron deficiency | CKS | NICE. [online] Available at: <https://cks.nice.org.uk/topics/anaemia-iron-deficiency/background information/causes/> [Accessed 26 July 2022]. 
5. Verywell Fit. 2022. Iron-Deficiency Anemia on the Rise in the U.S., Study Shows. [online] Available at: https://www.verywellfit.com/iron-deficiency-anemia-on-the-rise-in-the-us-study-shows-5198802 [Accessed 26 July 2022]. 
6. New Food Magazine. 2022. British Coffee Consumption. [online] Available at: <https://www.newfoodmagazine.com/news/66042/british-coffee-consumption/> [Accessed 26 July 2022]. 
7. Fisher, A. L., & Nemeth, E. (2017). Iron homeostasis during pregnancy. The American journal of clinical nutrition, 106(Suppl 6), 1567S–1574S. https://doi.org/10.3945/ajcn.117.155812 
8. Tommys. 2022. Pregnancy information. [online] Available at: <https://www.tommys.org/pregnancy-information/pregnancy-complications/anaemia-and-pregnancy> [Accessed 26 July 2022]. 
9. Jian, J., Pelle, E., & Huang, X. (2009). Iron and menopause: does increased iron affect the health of postmenopausal women?. Antioxidants & redox signaling, 11(12), 2939–2943. https://doi.org/10.1089/ars.2009.2576