Iron deficiency: when treatment is necessary

Eisenmangel: Ursachen, Symptome und Behandlung

Iron deficiency is a common phenomenon, primarily among women, but it also affects vegans and blood donors. How to prevent it and when and what treatment is advisable.

Why do we need iron?

Iron is a vital trace element in the human body. It is responsible for blood production and therefore for the body’s oxygen-delivery system. It also plays a role in immune defence and the exchange of information between nerve cells.

Causes of iron deficiency

The most common causes – besides a higher iron requirement – are recurrent blood loss and insufficient iron intake due to an unbalanced diet. In less fre­quent cases, chronic inflammatory bowel disease can be the reason for the body absorbing too little iron through food. Possible causes that should be clarified by a doctor include:

  • Blood loss due to tumours
  • Higher iron requirement due to treatment for a vitamin B12 deficiency
  • Poorer iron absorption due to coeliac disease

Daily iron requirement

  • Men should consume 10 milligrams (mg) of iron per day.
  • Women 15mg per day. Their require­ment is higher because they regularly lose blood during menstruation.
  • The daily requirement is particularly high for pregnant women (30mg per day) and breastfeeding women (20mg per day). They are usually prescribed iron supplements because it is almost impossible to cover these higher amounts through food alone (see last question).

The following persons may also have a higher requirement

  • Growing children and adolescents
  • Athletes
  • Vegetarians and vegans
  • Blood donors

Symptoms of iron deficiency

Depending on the severity, medical experts distinguish between 2 stages:

  1. Latent iron deficiency without anaemia
  2. Iron deficiency with anaemia. In 80 percent of all anaemia cases, iron deficiency is the cause.

Depending on how severe the defi­cien­cy is and how long it has lasted, the following symptoms are possible in both stages:

  • muscle weakness
  • reduced stamina
  • irritability
  • dizziness
  • cognitive impairments such as lack of concentration, memory problems
  • reduced learning ability
  • headaches
  • appetite for clay and soil
  • rough and brittle nails
  • dry skin
  • torn corners of the mouth
  • burning tongue
  • hair loss

Are paleness and fatigue reli­able signs of iron deficiency?

Paleness is an inaccurate indication. Fatigue, on the other hand, can be a sign in women of menstrual age – but only in the case of iron deficiency without anaemia. Treatment is advisable if the patient’s ferritin level is significantly lower than 15 nanograms per millilitre of blood (ng/ml).

Someone who is constantly tired may also be suffering from an­oth­er illness, such as de­pres­sion, kid­ney weakness, thyroid dys­func­tion or chronic hepatitis. It is therefore important to have the causes clarified.

Testing iron deficiency

A blood test is taken to check the patient’s ferritin level. This pro­tein in the blood indicates how much iron the body has in store. Although there are no universally recognised thresholds, the following figure serves as a guideline: if the ferritin level is below 15 nanograms per millilitre of blood (ng/ml), the iron store is insufficient.

For a reliable diagnosis, the CRP protein level should also be measured. This can rule out the possibility of an acute in­flam­ma­tion or infection, as these raise the body’s ferritin level.

How reliable are the new self-tests from the pharmacy?

Iron self-tests are becoming increasingly popular: a small prick in the fingertip and ten minutes later you have the result. However, they only provide an initial in­di­ca­tion and aren't accurate enough for a conclusive diagnosis. It is therefore essential to discuss the next steps with a doctor.

Does iron deficiency always need treating?

No. Treatment is only recommended when patients suffer from anaemia. This is when the concentration of haemo­glo­bin is too low. If someone has iron de­fi­cien­cy but not anaemia, treatment only makes sense if they have symptoms. Low iron levels don't necessarily lead to health complaints.

Iron deficiency treatment

Tablets or infusions – this is often the question today.

  • In its guidelines, the Medix group practice recommends taking tablets first. This is because it is better for the body if the iron store is re­plen­ished slowly, i.e. over several months. New guidelines recommend taking one tablet only every other day, as this leads to greater absorption efficiency.
  • If the medication leads to gastroin­testi­nal complaints – a frequent side effect – or if the person’s ferritin level doesn't rise sufficiently, iron infusions can be considered. Howev­er, they should be given in moderate doses. Infusions are also given to pregnant women or people with chronic inflammatory bowel disease.

Iron overdose: is this possible?

Not with food alone. If, on the other hand, iron supplements are accidentally taken in large quantities, acute iron poi­son­ing can occur. For children, this is life-threatening. It is therefore important to store the tablets well out of children’s reach.

Preventing iron defi­cien­cy with the right diet

If you already have an iron deficiency, you cannot cure it with iron-rich foods alone. In this case, supplements are usually necessary.

Iron is found in almost all foods in varying amounts. It’s worth noting:
  • The body absorbs iron from animal foods particularly well, and from plant foods somewhat less well. However, iron absorption can be improved with ascorbic acid (vitamin C). Including a glass of fruit juice or a piece of fresh fruit with meals is therefore recommended.
  • By contrast, iron absorption is inhib­it­ed by tannins from coffee, tea and wine.
  • Iron can be combined with vitamin B12 as a supplement without causing any problems.

Foods containing iron (given in mg iron per 100g)

Blood sausage


Soya bean flour


Cacao powder


Pumpkin seeds




Cow’s liver


Pine kernels


Pistachio nuts


Cooked shellfish


Chicken egg


Fresh kidney beans


Chanterelle mushrooms


Sunflower seeds


How do we know that iron levels are restored?

The patient’s blood must be examined again:

  • In the case of treatment with tablets, at the earliest 4 weeks after the last intake.
  • In the case of infusions, at the earliest 8 to 12 weeks afterwards.

If the symptoms don't improve or dis­ap­pear within a few weeks, it is advisable to get a check sooner rather than later.

Prevention is better than cure

In order to avoid another iron deficiency, it helps to eat a balanced diet. Did you know that many nutrients, such as vita­mins, secondary plant substances and minerals, only develop their maxi­mum benefit for our body in certain com­bi­na­tions? By effectively combining certain foods, we can do our body a lot of good.

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