Fatigue, sluggishness, brittle hair and nails - all of these can be signs of iron deficiency. A lack of iron manifests itself through various symptoms and should by no means go undetected. For physical health and well-being, immediate action should be taken when iron deficiency is diagnosed. But which foods actually contain iron and is a change in diet enough to cover my iron requirements?
This article is intended to help you answer important questions about iron deficiency and iron anemia. You will receive valuable tips on why your body needs iron, how to recognize an iron deficiency and what you can do to prevent an iron deficiency.
the essentials in brief
- Iron deficiency can have various causes. Depending on the trigger, different forms of therapy are used for iron deficiency.
- Iron can only be ingested in the form of food or iron substitutes. The body cannot produce iron itself.
- A balanced diet can help regulate and prevent iron deficiency.

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Definition: What is iron deficiency?
Iron deficiency is defined as a reduced level of total body iron. This means that either not enough iron is absorbed or the body does not absorb (resorb) the iron properly. An iron deficiency is therefore divided into three different sub-stages:
- Storage iron deficiency : A negative iron balance first leads to a storage iron deficiency. However, erythropoiesis, i.e. the process of formation and development of red blood cells, is still intact.
- Iron-deficient erythropoiesis : In this stage, the supply of the precursors of the red blood cells in the bone marrow is no longer sufficient. The hemoglobin, i.e. the iron-containing blood complex in the red blood cells, is still within the normal range.
- Iron deficiency anemia : If the hemoglobin value is then finally undershot, iron deficiency anemia occurs. Iron deficiency anemia is divided into acute and chronic. Chronic anemia develops over a long period of time, while acute anemia develops rapidly. The classification into acute and chronic helps determine the cause and severity of iron anemia. (2)
Background: What you should know about iron deficiency
A lack of iron can have various causes and manifest themselves through more or less noticeable symptoms. Starting with the causes to helpful nutrition tips - we have summarized everything you need to know about iron deficiency in the next paragraphs.
What are the causes of iron deficiency?
Iron deficiency occurs when the body either does not get enough iron or cannot absorb enough iron. This can happen, for example, if a person has an increased need for iron due to various life circumstances, or if there is an increased loss of iron for various reasons. The table below lists some causes of iron deficiency:(1,8)
Iron loss from bleeding | Increased iron requirement | Decreased iron absorption |
---|---|---|
Carcinomas, chronic inflammation | pregnancy | Wrong diet |
Menstruation | growth | Atrophic gastritis, gastric resection, lack of gastric acid in the gastric juice |
blood donations | high performance sport | malabsorption, celiac disease |
dialysis | Chronic intravascular hemolysis | Chronic inflammatory bowel disease |
Furthermore, a reduced iron intake can also result from a diet, anorexia (anorexia) or from a strict vegetarian or vegan diet. (5.7)
In any case, the first step should be to determine the cause of the iron deficiency or iron anemia. This is the only way to ensure long-term effective therapy. In the first step of the therapy, the cause is treated, and in the second step, the empty iron stores are replenished. Therapy for iron deficiency or iron anemia usually lasts at least 3-6 months.
What are the symptoms of iron deficiency?
The symptoms of iron anemia depend very much on their severity and the speed at which they develop. The symptoms are often very general and begin very gradually. Symptoms of iron deficiency can include brittle hair and fingernails, cracked corners of the mouth or atrophy of the mucous membrane of the tongue. Tiredness, exhaustion, headaches and difficulty concentrating are also among the most common symptoms of iron deficiency. (2)

Iron deficiency can manifest itself through a variety of symptoms. These often appear very insidiously and seem harmless. However, an iron deficiency is a major burden for the body and should be treated urgently! (Image source: Abbie Bernet/unsplash)
Iron anemia always results in decreased hemoglobin (red blood cell) production. However, the iron in the body is not only needed for the formation of red blood cells, but for all cells in the body. Therefore, an iron deficiency can affect all systems of the body and thus trigger a wide variety of symptoms. (8th)
Did you know that iron deficiency can really make you pale? With too little iron in the body, not enough red blood cells can be formed. As a result, the skin becomes paler. This effect can even be seen under a microscope because too little iron makes the red blood cells smaller and paler.
Why does the body need iron anyway?
The iron in the body plays an important role in many different processes. For example, for the oxygen supply to the brain and muscles. It is also essential for many metabolic processes. Every cell in our body needs iron for various metabolic processes. Without iron, the body is simply less efficient.
Iron, for example, is necessary for the transport of oxygen in our blood.
Iron is supplied to the body through food or iron substitutes. The iron is then absorbed in the stomach. Iron in the blood serves to bind oxygen. Iron in the muscle serves as an oxygen carrier. Iron in the liver is used to store iron and iron in the bone marrow is used to form blood. (8th)
How does the body get iron?
Humans are dependent on taking in iron exclusively through food or iron substitutes. However, the body can only actually absorb 5-15% of the iron supplied. The rest is excreted unused. Iron is absorbed in the gastrointestinal tract. When there is an iron deficiency, the body is either not getting enough iron or, for some reason, cannot absorb it properly. (8th)
How much iron does the body need?
How much iron a person needs depends on various circumstances such as age, gender and phase of life. The following table gives you an overview of how much iron you need in which phase of your life:
Old | Men | Women |
---|---|---|
1-7 years | 8mg | 8mg |
7-10 years | 10mg | 10mg |
10-19 years | 15mg | 10mg |
19-50 years | 15mg | 10mg |
over 50 years | 10mg | 10mg |
Pregnant and breastfeeding women have an increased need for iron. This is around 30 milligrams for pregnant women and around 20 milligrams for women who are breastfeeding. However, the iron requirement can also be increased by other factors such as heavy menstrual bleeding or extreme sports. (9)
However, keep in mind that only 5-15% of this required value is absorbed by the body!
When and with whom can iron deficiency occur?
During and after pregnancy, women have an increased iron requirement of around 20-30 milligrams. In order to ensure a risk-free environment for mother and child, care should be taken before pregnancy to ensure that there is no iron deficiency. Iron deficiency during pregnancy can pose several risks. In the case of an iron deficiency, a balanced diet is the first step, but an iron substitute should also be used. (3)

Due to physical and hormonal changes, iron deficiency can occur during pregnancy and breastfeeding. To ensure that mother and child remain in the best of health, it is best to seek medical advice on the subject of iron deficiency before you become pregnant. (Image source: Alicia Petresc/unsplash)
Growing children and adolescents also have an increased need for iron. Iron is essential for both physical and brain development. Normally, the iron requirement is covered by a balanced diet. If this is not the case, you should also use an iron substitute.
Competitive athletes, especially those who do a lot of endurance sports, usually have an increased iron requirement. A lack of iron can be favored by various factors:
- Excessive sweating can cause the body to lose iron.
- In longer periods of stress, the intestines often find it difficult to optimally absorb dietary iron.
- A one-sided diet with the additional renunciation of red meat can also be a beneficial factor. (10)
During menstruation, women also have an increased need for iron. This is especially true for women with very heavy menstrual bleeding. If, for example, the blood loss cannot be controlled with a tampon alone, or if the menstruation lasts longer than seven days, this can be a sign that a menstrual period is heavier than average. If you then have symptoms of this kind, you should definitely check your iron levels. (4)
Blood donors often have an increased risk of developing iron deficiency. If you donate blood regularly, you should ensure that you replenish your iron stores with a balanced diet and, if necessary, with iron substitutes. (6)
Vegetarians and vegans are also more likely to suffer from iron deficiency. With these diets, it can be difficult to ensure a balanced diet. Above all, not eating meat products can make it difficult to get enough iron. (4) If, as a vegetarian or vegan, you are unable to meet your needs with legumes and other iron-rich foods, you should definitely consider iron substitutes with your doctor. (5)

Hectic lifestyle?
No problem!
With our Sundt iron capsules + vitamin C you can:
- keep your energy levels high on the most stressful days🏃
- be sure you are getting enough iron🌿
Our vegan iron capsules are now available with a 21% discount *

*The discount is automatically applied to the product
Can you compensate for an iron deficiency with the right diet?
Depending on the severity and cause of the iron deficiency, it can be brought under control with a change in diet or with iron substitutes. Iron absorption in the intestine depends on various factors. For example, the composition of the food also has a significant influence on iron absorption.
If the iron requirement is not sufficiently covered, you can counteract this with a change in diet. It is important to eat foods that contain a lot of iron, but also to combine different products in order to further improve iron absorption.
There are certain foods that promote or inhibit iron absorption.
You should also avoid foods that prevent or inhibit the absorption of iron. However, if a change in diet is not enough, you should definitely use iron substitutes. Be sure to consult a doctor for the right dosage.
Diet for iron deficiency: The best tips and advice against iron deficiency
If you have been diagnosed with iron deficiency, it is now important to pay special attention to your diet. There are some tips and tricks on how to improve iron absorption in the body. In the next paragraphs we want to show you which foods contain a particularly large amount of iron, how you can increase iron absorption in the body and what you should avoid.
Foods high in iron
There are many foods that are naturally high in iron. A distinction is made between heme iron and non-heme iron. In animal foods, the iron is usually present as 40-60% in the form of heme iron. Heme iron has a very good bioavailability. 15-35% of it can be absorbed in the body. (1)

Heme iron is found in animal foods like red meat and sausages. Heme iron has better bioavailability than non-heme iron. This means that the body can absorb more of it. (Image source: Victoria Shes/unsplash)
Non-heme iron is mainly found in plant foods. Rarely more than 5% of it is absorbed in the body. However, if you eat meat and plant foods at the same time, the absorption of the plant substances can even be doubled. (8) Here is a list of the top iron suppliers:
Animal sources of iron (heme iron) Iron content per 100 g in mg | Vegetable sources of iron (non-heme iron) Iron content per 100 g in mg |
---|---|
Black pudding 30 mg | Wheat Bran 15 mg |
Pork liver 18 mg | millet flakes 9 mg |
Beef Ham 10 mg | Wheat germ 7.6 mg |
Calf liver 7.5 mg | Pumpkin seeds 11.2 mg |
Oysters 5.8 mg | Pine nuts 9.2 mg |
Oil sardines 2.5 mg | Soybeans dried 9.7 mg |
Egg yolk 5.5 mg | Lentils dried 8 mg |
As can be seen in the table, animal foods in particular have a fairly high iron content. But vegetarians and vegans can also improve their iron balance. Legumes such as soybeans, lentils, chickpeas and the like have a particularly high iron content. Herbs such as herbs such as watercress or parsley also contribute to a full iron depot. In the next paragraph we explain important tips so that your body can absorb iron even better.
Tips to absorb iron better
In this section we will show you important tips on which combinations you can use for better iron absorption and what you should rather avoid.
what you should eat
In order to be able to absorb iron particularly well, an acidic environment in the intestine is important. Vitamin C helps absorb iron even better. Therefore, it is good to drink an orange or lemon juice as well. Other organic acids can be found, for example, in sauerkraut or apples.
When combined with animal proteins such as meat, poultry or fish, plant-based iron can be better absorbed.
What to avoid
Polyphenols reduce iron absorption in the body because they bind iron tightly. You should therefore avoid consuming coffee or black tea at the same time as foods containing iron.
Black tea and coffee should only be drunk 30-60 minutes before and after an iron-rich meal!
The calcium in dairy products is also not optimal for proper iron absorption. Therefore, milk, cheese or yoghurt should only be consumed an hour after the meal.
Oxalic acid is also not particularly helpful in iron absorption. Oxalic acid is contained, for example, in spinach, chard, rhubarb or cocoa. Oxalic acid forms poorly soluble complexes with iron and thus inhibits optimal iron absorption.
Phytic acid is found in corn, rice, grain products and legumes. Phytic acid binds the iron and thus reduces its bioavailability. (8th)
As you can see, it is not that easy to set an optimal iron intake. Iron stores can only rarely be completely replenished through a change in diet alone. Therefore, iron tablets are often taken as a supplement. Important information and tips on iron tablets can be found in the next paragraph.
Iron tablets as a supplement
In addition to addressing the cause of the iron deficiency, the key to correcting the iron deficiency is oral supplementation. This can be in the form of iron capsules. Iron supplementation has a starting dose of around 50-100 milligrams per day. The therapy can take several weeks to months, as only 5-10% of the iron supplied is actually absorbed by the body.
Unfortunately, iron supplements can also cause side effects. The most common complaints include nausea, stomach pain, constipation and diarrhea. If such side effects occur, the iron substitute can be taken before going to bed, for example, or the dose can be reduced.
If you have an iron deficiency or iron anemia, you should definitely seek medical attention. This way you can work with your Verhaues specialist to find the best solution for you and your health.
Conclusion
Iron deficiency or iron anemia are conditions that you should not underestimate. Iron deficiency can cause many symptoms and is very stressful for your body in the long run. Iron is a vital trace element for our body. Every cell in our body needs iron for its energy balance. Without iron, the body's performance is limited.
Iron deficiency can have many different causes. The first thing to do is to find out this cause before you devote yourself to the topic of nutrition. Eating the right diet for iron deficiency is very important and can be a great help. However, it is seldom the case that iron deficiency can be treated by changing your diet alone.
Itemization(10)
- Dr Michael Zimmermann MD, Richard F Hurrell PhD; Nutritional iron deficiency, The Lancet, Volume 370, Issue 9586, 11-17 August 2007, Pages 511-520 Source
- Clara Camaschella, MD; Iron Deficiency Anemia, N Engl J Med. 2015 May 7;372(19):1832-43. doi: 10.1056/NEJMra1401038 Source
- Lindsay H Allen; Anemia and iron deficiency: effects on pregnancy outcome, The American Journal of Clinical Nutrition, Volume 71, Issue 5, May 2000, Pages 1280S-1284S, https://doi.org/10.1093/ajcn/71.5.1280s Source
- Linda J Harvey, Charlotte N Armah, Jack R Dainty, Robert J Foxall, D John Lewis, Nicola J Langford and Susan J Fairweather-Tait; Impact of menstrual blood loss and diet on iron deficiency among women in the UK, October 2005 The British journal of nutrition 94(04):557 - 564 DOI: 10.1079/BJN20051493 Source
- Annika Waldmanna, Jochen W. Koschizkea, Claus Leitzmannb, Andreas Hahna; Dietary Iron Intake and Iron Status of German Female Vegans: Results of the German Vegan Study, Ann Nutr Metab 2004;48:103–108 DOI: 10.1159/000077045 Source
- Ritchard G Cable, Simone A Glynn, Joseph E Kiss, Alan E Mast, Whitney R Steele, Edward L Murphy, David J Wright, Ronald A Sacher, Jerry L Gottschall, Leslie H Tobler, Toby L. Simon and for the NHLBI Retrovirus Epidemiology Donor Study-II (REDS-II); Iron Deficiency in Blood Donors: The REDS-II Donor Iron Status Evaluation (RISE) Study, Transfusion. 2012 Apr; 52(4): 702-711. Published online 2011 Oct 24. doi: 10.1111/j.1537-2995.2011.03401.x Source
- Kennedy M Kohn, Lammi S Clarke, Iron status and haematological changes in adolescent female inpatients with anorexia nervosa, Journal of Paediatrics and Health, 19 July 2004 https://doi.org/10.1111/j.1440-1754.2004.00432.x Source
- Nazanin Abbaspour, Richard Hurrell, and Roya Kelishadi; Review on iron and its importance for human health, J Res Med Sci. 2014 Feb; 19(2): 164-174., PMC3999603 Source
- National Institutes of Health, Office of Dietary Supplements, Updated: February 28, 2020 Source
- Jean-Claude Chatard, Iñigo Mujika, Claire Guy and Jean-René Lacour; Anaemia and Iron Deficiency in Athletes Practical Recommendations for Treatment, 1999 Apr;27(4):229-40. doi: 10.2165/00007256-199927040-00003. Source