How can iron deficiency be treated?

Photo of a doctor talking to a patient

Getting more iron in your diet is often enough to treat mild iron deficiencies. More severe deficiencies can be treated with iron supplements. It is also important to treat the cause of the iron deficiency if possible.

Your body needs iron for many reasons, including to make blood and to transport oxygen to all cells and organs. If it doesn't get enough iron, it uses up stored iron (especially from the liver and spleen). If those iron reserves are then empty too, your body can't make red blood cells properly. That can have noticeable effects, such as exhaustion and trouble doing everyday activities.

Severe iron deficiency can also cause anemia (a lack of healthy red blood cells). Anemia not only causes symptoms – it can have more serious consequences such as organ damage and complications during pregnancy.

When is iron deficiency treated?

If possible, the cause of the iron deficiency is tackled first. This may involve changing your diet if you haven’t been getting enough iron from your food, for example. If the deficiency is caused by bleeding or illness, that is treated.

The severity of iron deficiency is described in different stages. In stage 1, the body can still use stored iron, such as from the liver or spleen. This mild deficiency usually doesn’t need to be treated. Increasing the amount of iron in your diet is often enough. You can ask your doctor for advice here. But if you have trouble getting enough iron from your food, it can be a good idea to have treatment. That might be the case for pregnant women, competitive athletes, or people who have certain medical conditions – like heart failure, for instance.

In stage 2, the body's iron reserves are empty. The body can't make enough red blood cells because there isn't enough iron to make hemoglobin. It can be a good idea to take iron supplements at this stage already.

In stage 3, the iron deficiency has led to anemia. The cells and organs no longer get enough oxygen. This stage is usually treated with medication.

What medications are there?

Iron supplements can provide iron in the form of tablets, liquid drops or capsules. There are two different types:

  • Ferrous (divalent) iron preparations: These supply the iron to the stomach or the upper part of the bowel (duodenum). The iron passes into the bloodstream from there.
  • Ferric (trivalent) iron preparations: These are released more slowly. They transport the iron into the lower parts of the bowel, where it is then absorbed.

Specialists recommend using ferrous preparations at first. Ferric preparations are normally only used if people can’t tolerate ferrous preparations.

Iron can also be given through a drip so it enters the bloodstream directly.

Severe, life-threatening iron-deficiency anemia has to be treated with a blood transfusion. You are then given donated blood. But that is very rarely needed.

How are the medications taken?

Many of the medications are taken daily, and some only every few days. Research has shown that their effectiveness is similar.

If possible, the medications shouldn’t be taken with a meal, but rather at least half an hour before the meal or an hour after it. People who don't tolerate the medications well can also take them with food or shortly after eating. But then the body absorbs less of the iron.

People who have an iron deficiency without anemia are advised to take the iron supplements for at least three months.

If you have anemia, it's important to take the iron supplements for at least another three months after your blood iron levels have gone back to normal. At first, your body uses the iron in the supplements to make enough hemoglobin again. After that, your iron reserves are slowly refilled. Several blood tests are done throughout the treatment to check whether your blood iron levels have improved.

When are infusions considered?

Iron infusions (drips) are considered if oral medications aren't an option, perhaps because

  • you can’t tolerate or swallow them,
  • the iron deficiency is very severe, or
  • your bowel doesn’t absorb enough iron (due to certain bowel diseases, for instance).

Pregnant women are only allowed to have iron infusions from the fourth month of pregnancy.

What are the possible side effects?

Iron preparations often cause side effects such as stomach ache, constipation or nausea. They may make your stool (poop) darker, but that is not cause for concern. People who don’t tolerate the medications well can talk to their doctor about possible solutions. For example, it might help to

  • take the medication before going to bed,
  • not take the medication daily, but only once or twice a week,
  • take the medication with food, or
  • try a different medication.

Infusions are gentle on the digestive tract. But they may irritate the area where the needle went in and cause other (usually short-term) side effects, including

  • headache or back pain,
  • itching,
  • hot flashes,
  • a metallic taste in the mouth, and
  • chest tightness.

Research suggests that iron infusions increase the risk of certain infections, such as lung infections. These occurred in about 2% of those who had this treatment.

Fewer than 0.1% of people have an allergic reaction (or even an anaphylactic shock) after an iron infusion. Some people are also over-sensitive to an active ingredient or certain other substances in the infusion. Because of this, people are monitored for at least 30 minutes afterwards.

What are the treatment options for children?

If a child doesn’t get enough iron, their doctor might give advice about how they can get more iron from their food.

Children can also take iron supplements. The dose is adjusted to their body weight. They may also have side effects – in the digestive tract, for example.

Iron infusions are only recommended if the child isn't able to take iron supplements or if taking supplements doesn't help enough.

Experts do not recommend taking iron supplements to prevent an iron deficiency. Supplements for prevention are only recommended for premature babies, especially if a baby weighs less than 2,500 grams at birth.

What else should you know?

Certain foods make it harder for your body to absorb iron. These include cola, coffee, black and green tea, and milk. For this reason, it's a good idea to take iron supplements with water – or with a glass of fruit juice (such as orange juice) because the vitamin C in the juice improves iron absorption.

Some medications have this effect too, interfering with iron absorption. They include antacids for the stomach, and painkillers such as acetylsalicylic acid (in medicines like Aspirin) and ibuprofen. This is also true of and magnesium supplements. Similarly, iron can reduce the effects of other medications, such as thyroid (thyroxine) and certain . So it's important to tell your doctor about any other medications you are taking.

Iron supplements should be kept out of reach of children. An overdose can be dangerous for them.

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IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. can provide support for talks with doctors and other medical professionals, but cannot replace them. We do not offer individual consultations.

Our information is based on the results of good-quality studies. It is written by a team of health care professionals, scientists and editors, and reviewed by external experts. You can find a detailed description of how our health information is produced and updated in our methods.

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Created on September 18, 2023

Next planned update: 2026


Institute for Quality and Efficiency in Health Care (IQWiG, Germany)

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