According to the German Nutrition Society (DGE), women between 19 and 50 years of age need significantly more iron per day (16 mg) than men (11 mg) because the body regularly loses iron through menstruation. After menopause, requirements drop to 14 mg, while during pregnancy, they rise to 27 mg. Whether you are covering these needs through your diet or actually have a deficiency can only be reliably determined via a ferritin blood test, not by symptoms alone. This article outlines current reference values, explains how to recognize a deficiency, how to improve iron absorption from food, and what you should really look for when choosing a supplement.

How much iron do women really need?

The DGE updated its iron reference values in 2024. The new value for women of childbearing age is 16 mg per day, and 11 mg for men. The difference is almost entirely due to menstruation: in an average cycle, the body loses about 30 mg of iron; with heavy bleeding (menorrhagia), this can be well over 40 mg. After menopause, this loss ceases, so the requirement drops to 14 mg, approaching that of men. During pregnancy, however, the requirement spikes to 27 mg to support increased blood volume, the placenta, and the growing fetus.

Source: DGE Reference values for nutrient intake, updated 2024.

Why is the iron risk higher for women than for men?

The higher reference value is only half the story. In reality, many women face multiple risk factors simultaneously. Heavy or prolonged menstruation (menorrhagia) can push monthly iron loss far beyond the statistical average, often without the individual realizing its clinical significance. Those following a vegetarian or vegan diet consume only plant-based, non-heme iron, which the body absorbs much less efficiently than the heme iron found in meat and fish. Endurance sports further increase this risk: running can lead to measurable additional iron loss due to micro-bleeding in the gut and so-called "foot-strike hemolysis," which is why endurance athletes frequently have low ferritin levels. Frequent blood donations or pregnancy shortly after a previous birth can also severely deplete iron stores before they have fully replenished.

How to identify an iron deficiency?

The classic symptoms are non-specific, making self-diagnosis difficult. Persistent fatigue despite adequate sleep, trouble concentrating, pale skin, brittle nails, hair loss, headaches, cold hands and feet, and noticeably lower performance during sports are among the most common indicators. The problem: almost all of these symptoms can have other causes, ranging from thyroid issues to vitamin B12 deficiency or simple stress. If you notice several of these symptoms over weeks, you should consult a doctor rather than prematurely taking high-dose iron supplements. Only a blood test can reliably confirm an actual deficiency.

Ferritin test: Which values are normal?

Ferritin is the storage protein for iron in the body and is the most significant laboratory value for assessing actual iron reserves—unlike hemoglobin, which only shows abnormalities in advanced anemia. A general practitioner can determine this value with a simple blood test. Reference ranges differ significantly between women and men because women physiologically have lower stores.

Reference ranges may vary slightly by laboratory. The attending physician will always provide the definitive assessment based on the specific lab report.

How to improve iron absorption from food?

What matters is not just how much iron you eat, but how much of it your body can actually absorb. Heme iron from meat and fish is absorbed at a rate of 15 to 35 percent, while plant-based iron from lentils, chickpeas, or whole grains is only absorbed at 2 to 20 percent, depending on accompanying substances. Vitamin C is the most effective absorption booster: a glass of orange juice with an iron-rich lentil dish or some lemon juice over a salad can significantly increase the absorption of plant-based iron. Conversely, tannins in coffee and black tea, as well as calcium from dairy products, noticeably inhibit absorption if consumed during the same meal.

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Rule of thumb: Inhibitors are most effective when consumed with the same meal. A 30 to 60-minute interval significantly reduces the effect.

Which foods provide particularly high amounts of iron?

Before you think about supplements, it's worth taking a look at your plate. Many women underestimate how much iron can be covered through conscious food selection alone, especially when combining heme iron from animal sources with plant-based iron. Organ meats like beef liver are among the most iron-rich foods, but they are rarely eaten regularly. More practical for everyday life are lean beef and lamb, pumpkin seeds, white beans, lentils, and oats. The key is always to combine them with a vitamin C source in the same meal, as this significantly improves absorption from plant-based foods.

Values are averages and can vary depending on the source, preparation, and variety. They do not replace individual nutritional counseling.

How much iron is too much? Safety and side effects

Unlike vitamin C or magnesium, iron is a nutrient where "the more the better" definitely does not apply, as the body cannot actively excrete excess iron. The German Federal Institute for Risk Assessment (BfR) therefore recommends a significantly more conservative upper limit of only 6 mg of iron per daily serving for food supplements, far below the 45 mg per day upper intake level from all sources defined by US regulators. The reason for this caution: uncontrolled, long-term intake of high amounts of iron without a proven deficiency is suspected of increasing risks for cardiovascular diseases because iron can accumulate in organs. The BfR therefore explicitly advises that men, postmenopausal women, and pregnant women should only take iron supplements after consulting a doctor, as the risk of iron overload is higher in these groups than in menstruating women with a proven deficiency.

In practice, this means: A supplement like our Iron Vitality Core with 25 mg of iron bisglycinate per tablet is designed for the targeted correction of a medically diagnosed deficiency, not for unlimited, long-term use "just in case." Common side effects of excessive or unnecessary intake include constipation, nausea, and a metallic taste; organic iron bisglycinate is considered significantly gentler on the stomach compared to classic iron sulfate.

Iron in endurance sports and pregnancy: Two special situations

Two life situations require special attention for women, as iron requirements deviate significantly from the average here. Runners and other endurance athletes lose additional iron through minimal micro-bleeding in the gastrointestinal tract and through so-called exercise-induced hemolysis (mechanical breakdown of red blood cells during repeated impact stress, such as running). Studies on endurance athletes consistently show a higher prevalence of low ferritin levels than in the general population. Those who train intensely and are menstruating should have their ferritin levels checked at regular intervals, even without acute symptoms.

During pregnancy, the iron requirement increases to 27 mg per day because maternal blood volume increases by about 30 to 50 percent, and the placenta and unborn child must be nourished. An undetected iron deficiency during pregnancy is routinely assessed during prenatal care via blood tests. For this reason, the following applies: iron supplementation during pregnancy should always be discussed with your treating gynecologist, as both an undiagnosed deficiency and unnecessarily high intake without medical supervision should be avoided. In this special life phase, this article does not replace individual medical advice.

Iron bisglycinate vs. other forms of iron: What is the difference?

Not every iron compound is tolerated equally well by the body. Classic iron sulfate is inexpensive and widely available, but causes gastrointestinal discomfort for many users because it releases a large portion of free iron at once. Iron bisglycinate is a so-called chelate compound, where the iron is bound to two glycine molecules. This bond is described by many users as significantly gentler on the stomach, as the release occurs more evenly.

Tolerance is individual. If you have known gastrointestinal issues, we recommend consulting a doctor before switching supplements.

Frequently asked questions

Should I just take iron preventively, even without a deficiency?

No. Unlike vitamin C or magnesium, preventive intake without a proven deficiency is strongly discouraged, as the body can hardly excrete excess iron. Have your ferritin level checked before you start supplementing.

How long does it take for iron stores to replenish?

With medically supervised supplementation, it usually takes 8 to 12 weeks for ferritin levels to rise noticeably. Symptoms like fatigue may improve sooner, but full normalization takes time and should be monitored with a repeat blood test.

Why do I have trouble tolerating some iron supplements?

Classic ferrous sulfate releases a large portion of the iron all at once, which leads to constipation, nausea, or stomach discomfort for many people. Organic forms such as iron bisglycinate are perceived by many users as much gentler on the stomach because the release is more gradual.

Can women who follow a vegetarian or vegan diet get enough iron?

Basically yes, through iron-rich plant-based foods like lentils, chickpeas, pumpkin seeds, and whole-grain products, combined with vitamin C for better absorption. Since plant-based iron is less easily absorbed, it is worth monitoring ferritin levels regularly with this diet, especially if there are additional risk factors such as heavy menstruation or intensive endurance sports.

Should I take iron with coffee or tea?

Better not to take them directly together. The polyphenols in coffee and black tea can significantly reduce iron absorption if consumed with the same meal or dose. An interval of at least 30 to 60 minutes is recommended.

Is a low ferritin level automatically anemia?

No, these are two different stages. A low ferritin level only indicates empty iron stores at first. Only when the hemoglobin level also drops is it referred to as iron-deficiency anemia. Low ferritin without anemia is already a reasonable time to take action before it leads to anemia.

Why should men and post-menopausal women be particularly careful regarding iron?

Because they no longer have the monthly blood loss that regularly flushes out excess iron in menstruating women. The BfR therefore explicitly recommends that these groups only take iron supplements after medical consultation to avoid iron overload.

This article is for general information purposes only and does not replace professional medical advice, diagnosis, or treatment. If you suspect an iron deficiency or before starting any dietary supplement, please consult a doctor or a pharmacist. Further information: DGE Reference Values for Iron, BfR Proposal for Maximum Levels of Iron, Consumer Center on Iron Supplements. More on micronutrients for women: Magnesium Intake: Dosage, Best Time and the Right Form and Vitamin C Dosage: How many mg per day are really useful.