Iron Deficiency

Recognizing and correcting iron deficiency

Iron deficiency is considered one of the most common deficiency symptoms in the world and is the most widespread cause of anemia. If you discover a deficiency, you can counteract this with a targeted change in diet or iron supplements.

Blood tastes like iron. Anybody who has ever cut their finger and licked off the blood will know that. The metallic taste is no coincidence: hemoglobin, the red blood pigment, consists mainly of iron. Iron plays an important role in blood formation and the transport of oxygen through the blood. If there is not enough iron in the body, it can lead to anemia, a so-called iron deficiency anemia.

In this article you will learn how to obtain enough iron from your diet - even if you are a vegetarian or vegan. You will also find out what causes iron deficiency, how a deficiency is manifested and how to determine it, as well as whether iron supplements make sense and why you should not take iron on a mere suspicion.

Iron and iron deficiency

Iron is part of the group of essential trace elements. Essential trace elements cannot be produced by the body itself. We have to absorb them through food.

The human body contains an average of four to five grams of iron. Iron occurs in different forms. Twenty-five percent are storage irons such as ferritin, which the body uses to store iron in the liver and bone marrow, among other things. Up to three percent are contained in the transport protein transferrin, which is used to transport iron through the blood. Most of the iron in the body is bound to the red blood pigment hemoglobin1.

Why do people need iron?

Every single cell in our body requires iron. Iron helps with oxygen transport and blood formation im Organismus. Without iron, less of the red blood pigment hemoglobin is produced. Hemoglobin transports inhaled oxygen from the lungs to the entire body. The cells need the oxygen to carry out their metabolic processes. This is how iron supplies us with energy. The trace element also transports carbon dioxide back into the lungs and oxygen into the muscle cells1.

Iron also strengthens skin, hair and nails , is associated with the immune system and the smooth progress of pregnancy2–4.

What happens in the case of iron deficiency?

Iron deficiency is one of the most common deficiency symptoms worldwide. According to the National Consumption Study, 14 percent of men and 58 percent of women in Germany do not satisfy their recommended daily iron requirements. This can result in iron deficiency anemia. This form of anemia is usually accompanied by very distinct symptoms such as paleness, a feeling of weakness and hair loss. Senior citizens, pregnant women, vegans and vegetarians as well as people with gastrointestinal disorders are at increased risk, of iron deficiency5,6.

Daily iron requirement for women

What is the daily iron requirement?

How much iron you need will depend on your gender and age. According to the recommendations of the German Nutrition Society (DGE),men should consume ten milligrams of iron a day and women 15 milligrams. Women have a higher need because of menstruation - they also lose iron with their blood.

Pregnant women have the highest need with 30 milligrams and breastfeeding women need 20 milligrams per day. Starting from menopause women usually no longer have an increased need7.

Recommended intake

Iron in mg/day



Children (1 to 10 years)



Children (10 to 19 years)



Adults (19 to 50 years)



Adults 51 years or older



Pregnant women


Breastfeeding women



The U.S. National Institute of Health has similar recommendations. It additionally advises vegetarians, to multiply the recommended daily requirement by 1.88.

Risk groups: Who is at high risk of iron deficiency?

The iron supply in Germany is generally good. However, certain people are susceptible to iron deficiency5,9 for various reasons. These include the following risk groups10–12:

  • Pregnant women and nursing mothers have an increased need - initially more blood is needed for the unborn child, then for breast milk.
  • In some cases, seniors may suffer from a lack of appetite and chewing problems and as a result do not consume enough nutrients.
  • Vegetarians and vegans consume less or no bivalent iron from animal foods, which the body can absorb particularly well.
  • The intestines people with chronic gastrointestinal disorders often do not properly absorb iron.
  • Professional athletes have a higher requirement and often eat a diet low in iron.

If you belong to one of the risk groups, it may be worth checking your supply regularly with an iron test. However, you should not use any iron supplements without a previous laboratory test. Otherwise you run the risk of excess iron and hemochromatosis.

Symptoms of iron deficiency

If you do not have sufficient amounts of iron in your body, the trace element can no longer perform its most important function as well as it should: supplying oxygen to the cells. Cells that do not receive enough oxygen produce less energy and their functions are limited.

This applies to the brain, among others: If it does not receive enough oxygen, it can result in problems concentrating and fatigue. Additional symptoms of a deficiency are1,5:

  • hair loss, brittle nails, cracked corners of the mouth
  • weakness, reduced performance, headaches
  • anemia (iron deficiency anemia)

Iron deficiency and hair loss

One possible result of iron deficiency is hair loss. Iron plays a decisive role in blood formation- and hair has a high blood requirement. If blood formation in the body does not run properly, the body first reduces blood flow to those parts of the body that are non-essential for survival - and this includes hair. If the hair does not receive enough blood as a result, it begins to fall out2.

Scientific findings

The good news is that you may be able to stop hair loss by taking the right iron supplement if you lose hair due to an iron deficiency. A study conducted in 2002, for example, showed that the participants increased their iron levels (ferritin level) from 33 to 89 milligrams per liter on average in six months. At the same time, their hair loss was reduced by 39 percent13.

Can iron prevent hair loss?

Causes of iron deficiency

It is easy to tell when there is an iron deficiency: Your body consumes more iron than it receives, the iron stores are emptied10. Possible causes are blood loss , a diet low in iron , an increased need for example during pregnancy or competitive sports.

Iron deficiency anemia: Iron deficiency is the most common cause of anemia. It is responsible for around 50 percent of cases of anemia. ÊWith anemia, the blood pigment hemoglobin is not produced in sufficient quantities. For this reason, the blood can only transport oxygen through the body to a limited extent14.

Blood loss

Whenever you lose blood,, This is true for injuries, menstrual bleeding, blood donations, dialysis and internal bleeding. Internal bleeding may be caused by intestinal tumors and other gastrointestinal diseases 15.

Reduced intake

One reason for an iron deficiency can be that you simply do not consume enough iron in your diet. This can be the case, for example, for people who are on a diet, who eat a strict vegetarian or vegan diet, who suffer from anorexia or intestinal parasites.

However, there are also illnesses , that cause less iron to enter the blood from the intestine. Studies have shown that about two thirds of people with chronic inflammatory bowel diseases such as Crohn's disease develop iron deficiency anemia. Celiac disease can also lead to iron deficiency 16–18.

Iron deficiency during pregnancy

Pregnant women need more iron to supply the uterus, placenta and embryo with blood and oxygen - especially towards the end of their pregnancy19. The body of pregnant women must produce 30 to 40 percent more blood. . The daily iron requirement therefore doubles from 15 milligrams to 30 milligrams per day 20. Studies show that up to 30 percent of expectant mothers in Europe develop iron deficiency anemia due to the high requirement for iron15.

Scientists are still discussing what effect an iron deficiency can have on the child. Some studies suggest that anemia increases the risk of disease for mother and child and makes premature births and miscarriages more likely20. In other studies, children whose mothers had been using iron supplements during pregnancy were born with a healthier birth11,21.

Iron deficiency in competitive athletes

Studies show that competitive athletes and ambitious hobby sportsmen have an increased need for iron, especially during endurance sports. There are several theories as to why athletes need more iron: from a higher blood volume and sweat production to minimal hemorrhages in the blood vessels of the feet. According to one theory, competitive sport promotes the the release of the liver protein hepcidin, which blocks the absorption of iron in the intestines. In addition, endurance athletes often eat a diet rich in carbohydrates and low in meat and thus low in iron 22.

Good to know: An iron deficiency is particularly restrictive for athletes because it can reduce physical performance. Iron ensures that oxygen and nutrients reach the muscles. If this function is limited, this can lead to a decrease in performance and muscle cramps23.

Testing for iron deficiency

You can detect an iron deficiency by taking a blood test. There are several values that a laboratory can determine. Hemogoblin, for example, reveals how much iron is circulating in the blood at the time of the reading.

Doctors often determine the ferritin, the storage form of iron. In the laboratory, the amount of ferritin in one milliliter of blood is recorded. This suggests a general supply of iron. However, in people with chronic liver diseases or inflammatory reactions in the body, ferritin levels can be elevated without iron deficiency. In such cases, doctors can collect additional blood values to be on the safe side24.

cerascreen Ferritin test

Ferritin Blood Test

The cerascreen Ferritin test is a blood test to check for ferritin, the storage iron. You can perform this test at home using our test kit. Simply take a small amount of blood from your fingertip and send the sample to our laboratory where the ferritin value is determined. Your results report, will indicate whether your ferritin levels are within the normal range.

Treating an iron deficiency: Nutrition

 Vegetarian meals that supply you with iron

Are your iron levels too low? A change in diet is often the solution. If this is not sufficient or if there is a severe deficiency or a disease associated with iron deficiency, iron supplements may be useful.

Which foods contain iron?

Iron is found in animal products - salted herrings, pork and beef liver and chicken eggs are particularly rich in iron.

Among plant-based foods legumes and whole-grain products in particular contain a lot of iron, but also chanterelles, spinach and beetroot. Iron is also found in some types of fruit, including kaki, coconut, mulberry and dried apricots.

The following foods arerichest in iron25:


Iron content (milligrams per 100 grams)

Salted herrings


Pork liver








Egg yolks


Beef liver




Soy beans




White beans






For those of you with a sweet tooth: 25 grams of dark chocolate not only allow your body release happiness hormones, but also supply it with three milligrams of iron25!

Why is iron from animal products better than iron from plants?

The iron from animal foods has a higher bioavailability. This means that our body can make better use of it. Animal foods, especially beef and pork, often contain the so-called haem iron, which the small intestine can absorb directly into the bloodstream. In turn, iron from plant-based foods must first be converted in the intestine. A large part of the iron is lost in the process: While the body absorbs up to 20 percent of animal iron, it only absorbs five percent5 of plant-based foods.

Why is vitamin C important for iron supply?

You can help yourself a bit to support your body in utilizing the iron. In this case, it also possible to sufficiently supply yourself with the trace element via a vegetarian or vegan diet. The key is Vitamin C. The vitamin promotes the absorption of iron in the intestine. A glass of Orange juice will help you to make better use of the iron from your whole-grain bread or oatmeal. Another option: Prepare a green smoothie with fresh fruit and iron-rich spinach or kale.

Good to know: Want to optimize your iron intake with vitamin C? These vitamin C bombs can help: broccoli, kale, brussels sprouts, herbs (parsley, cress, fennel), bell peppers, spinach, rose hip, strawberry, orange, black currant.

Red fruit juices , such as tomato, grape and plum juice are also a great source of iron. In pharmacies and health food shops you can often purchase special juices, that contain a lot of iron and are supposed to quickly cover your daily needs. The best thing with such drinks is to make sure that they contain vitamin C to support absorption and that no unnecessary sugar is added25.

What disrupts the absorption of iron?

While vitamin C improves iron absorption, other components of food have the opposite effect. These so-called anti-nutrients include1,5,26:

  • Dairy products: Calcium salts in dairy products
  • Whole-grain products: Lignin and phytates in whole-grain products
  • Oxalic acid in spinach, beetroot, rhubarb and cocoa
  • Phosphate in Coca Cola
  • Polyphenol in coffee and tea

You should not drink tea, coffee and milk directly with your meals - or you run the risk of destroying the iron in your meal. For your cereals you can use yoghurt instead of milk or herbal alternatives such as soy, rice or oat drinks.

hole-grain products and spinach are also a good source of iron and reduce the absorption of iron. However, you can counteract this easily: Soak whole grain products and legumes in water and wash and cook spinach thoroughly. This removes most of the anti-nutrients1.

Good to know: Aspirin reduces iron absorption. This is due to the ingredient salicylate.

In short: You can treat a mild iron deficiency with the right diet. Animal foods contain high-quality iron, which reaches the blood directly from the intestine. The intestine only absorbs small amounts of iron from plant-based foods. You can increase your iron intake by taking additional vitamin C. Inhibitors that impair absorption can often be removed from food by washing, cooking and soaking.

Iron preparations

Pregnant woman takes iron supplement

If you have an iron deficiency, you can quickly replenish your reserves with iron preparations. These preparations are usually found in the form of tablets or as dietary supplements in powders, capsules and drops. Some are available over the counter, others require a prescription or can only be purchased in pharmacies.

You should not take iron supplements on suspicion einnehmen. Too much iron can also be harmful to your health. You should check your iron supply beforehand - for example, by visiting a doctors or by performing a medical self-test at home.

When should I consume iron?

The body is best able to absorb iron in the morning on an empty stomach. It is recommended to take iron supplements half an hour to an hour before breakfast. Drink a glass of orange or fruit juice or another beverage containing vitamin C. You should not drink tea or coffee for at least two hours before and after taking this product. Some iron supplements are medications - in this case, follow the instructions in the package insert.

Which iron supplements should I take - and for how long?

If you want to replenish your reserves, you should pay particular attention to the quality of the iron. Bivalent iron, is the best choice, as it is this form that the body can absorb best. A common iron compound, which is also recommended by doctors, is Iron-(II)-sulphate 5,24.

How long you should take the preparations depends on how severe your deficiency and how high your need is. A rule of thumb is that it takes at least 40 to 50 days to replenish depleted reserves.

Iron supplements can also have side effects such as abdominal pain and constipation. . If you cannot tolerate a preparation, try to take it two hours after a meal or switch to trivalent iron27.

Good to know: Iron preparations can cause stool to turn dark - this is no cause for concern.

When do I need infusions or injections?

For some people, preparations are not enough to replenish the iron reserves. In these cases, doctors can check your values and administer high-dose infections or infusions28.

Possible reasons why conventional iron preparations do not work are29:

  • Theintestine has severe difficultiesabsorbing iron
  • .
  • The amount of the red blood pigment must be increased rapidly. This may be necessary, for example, in women in the third trimester of pregnancy.
  • Chronic bleeding is present, usually due to hereditary diseases such as Osler's disease.

Excess iron

It can also happen that there is not insufficient but too much iron circulating in the body. Doctors call this hemochromatosis, the iron retention disease. In most cases, genetics are to blame: the body retains too much iron 30 due to a genetic defect. Other causes are rare, including liver disease and impaired blood formation 31. People who receive blood donations also sometimes develop excess iron32.

An excess of iron can cause symptoms that affect the entire body, such as a bronze coloration of the skin. It also increases the risk of diseases such as 30:

  • Liver diseases
  • Cardiac arrhythmias
  • Diabetes Type 2
  • Impotence

Bloodletting helps prevent these sequelae. The doctor takes 500 milliliters of blood once or twice a week to empty the iron reserves. If iron levels fall, blood samples can be collected less frequently. Nevertheless, the treatment must be carried out for life 30.

Iron deficiency - At a glance

What is iron?

Iron is a vital trace element which humans must ingest through food. Our body needs iron to form the red blood pigment hemoglobin and to supply the cells with oxygen.

What happens in case of an iron deficiency?

If there is a permanent lack of iron in your body, you may experience anemia - iron deficiency anemia. The consequences can range from paleness, headaches and fatigue to hair loss and brittle nails.

Who is affected by iron deficiency?

Women require more iron than men because they regularly lose iron during their menstrual period. Risk groups that often suffer from iron deficiency are: Pregnant women, nursing mothers, seniors, newborns and children, alcoholics, vegetarians, vegans, people with diseases of the gastrointestinal tract and competitive athletes.

Which foods contain iron?

Iron can be found in meat, offal and eggs as well as in plant-based foods such as whole-grain cereals, legumes, spinach and kale. However, the human body can absorb iron from animal foods significantly better. You can support the intestine in the utilization of plant-based iron by combining it with vitamin C.

What can I do in case of an iron deficiency?

If there is a slight iron deficiency, it is usually enough to change your diet and consume more iron-containing foods. If the deficiency is severe or the intestinal absorption is disturbed, iron supplements can replenish the empty reserves.


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