Iron Supplements for Women: Everything You Need to Know

Medically Reviewed By Megan Soliman, MD

Iron is a mineral that the body uses for growth and development. Low iron intake levels can mean that the body uses up its stored iron. When these levels become low, iron deficiency can occur. However, diets high in iron and additional iron supplements can help treat iron deficiency and its related effects. The body uses iron Trusted Source National Institutes of Health Office of Dietary Supplements Governmental authority Go to source for several critical processes, including the cardiovascular system. It can also be Trusted Source Centers for Disease Control and Prevention (CDC) Governmental authority Go to source critical for motor and cognitive development.

Iron is a mineral that naturally occurs in many foods. However, it is unlikely for the condition of low iron levels to be the result of a lack of iron in the diet exclusively.

As a result, iron supplementation can be very useful in treating low iron.

This article will explain how to know if you may need iron, dosages, and how to supplement with iron safely, including during pregnancy.

Why is iron important?

Person stands holding a glass of water in one hand and puts a pill in the mouth with the other.
Javier Díez/Stocksy United

If you do not take in enough iron to meet your needs, your body will use Trusted Source National Institutes of Health Office of Dietary Supplements Governmental authority Go to source its stored iron. Reduced iron levels in the body can lead to iron-deficiency anemia (IDA) and is a major reason why doctors recommend iron supplements. 

People assigned female at birth may especially need to be aware of their iron levels. Globally, over 29% Trusted Source World Health Organization Highly respected international organization Go to source of females ages 15–49 had anemia in 2019, and over 38% of children.  

Other groups at higher risk of iron deficiency include Trusted Source National Institutes of Health Office of Dietary Supplements Governmental authority Go to source people who experience heavy menstrual bleeding, vegetarians or vegans, and people with cancer, gastrointestinal disorders, and heart failure. People who have undergone surgery, physical trauma, or experienced blood loss may also have a high risk of IDA.

Read on here for more information about anemia.

Iron and pregnancy

If you are pregnant, your body will have a higher demand for iron. Females who are not pregnant may need up to 18 milligrams (mg) of iron per day. However, people who are pregnant need 27 mg per day.

During pregnancy, there is Trusted Source National Institutes of Health Office of Dietary Supplements Governmental authority Go to source an increased demand for red blood cell production. To meet this demand and the iron needs of the fetus and placenta, higher levels of iron are necessary.

Iron deficiency during pregnancy can present health concerns for both the gestational carrier and the fetus. These risks include mortality for the carrier and the infant, premature birth, and low birth weight.

Low iron during pregnancy or gestational carriers with iron deficiency can also increase the risk of the infant having iron deficiency themself.

Prenatal supplements and vitamins may help you supplement iron levels to the correct amount.

Signs of low iron

Symptoms of more severe IDA include:

Restless legs are a lesser-known symptom of iron deficiency. People with restless legs who do not have symptoms of another possible cause should check their iron levels.

However, symptoms do not always appear in mild or moderate cases of iron deficiency. Blood tests can help your doctor evaluate your iron levels and red blood cell health.

Iron supplements

The benefits of iron supplements include treating low iron and alleviating its symptoms.

If you have an increased need for iron due to problems absorbing iron or lower iron levels, your doctor may recommend Trusted Source Office on Women's Health Governmental authority Go to source iron pills for non-severe anemia.

You should not take iron supplements without discussing your condition with your doctor first, as iron supplements can have side effects.

In some cases, particularly with severe cases of IDA, iron pills may not be sufficient to resolve the deficiency. Further treatment options can include intravenous iron infusions, medication, and blood transfusions.

Iron level requirements will vary Trusted Source National Institutes of Health Office of Dietary Supplements Governmental authority Go to source according to the individual and their condition.

Intake recommendations within the United States come from the Food and Nutrition Board (FNB) at the Institute of Medicine of the National Academies.

The FNB outlines a recommended dietary allowance, referring to the average daily level of intake necessary to meet the needs of almost all healthy individuals.

The following table outlines the recommendations for most healthy individuals based on age, sex assigned at birth, and whether you are pregnant or breastfeeding.

AgeMaleFemaleDuring pregnancyDuring lactation
birth to 6 months oldadequate intake of 0.27 mgadequate intake of 0.27 mg
7–12 months11 mg11 mg
1–3 years7 mg7 mg
4–8 years10 mg10 mg
9–13 years8 mg8 mg
14–18 years11 mg15 mg27 mg10 mg
19–50 years8 mg18 mg27 mg9 mg
50 years and above8 mg8 mg

Dosage for iron deficiency

Recommended dosage and iron levels from additional supplementation will depend on the individual and their condition. Your doctor will be able to tailor their recommendation to your specific condition.

As taking too much iron can have adverse side effects, only supplement with iron according to your doctor’s instruction.

However, taking a supplement with no more than 17 mg of iron once per day is unlikely to cause harm.

Under a doctor’s instruction, some people with iron deficiency may take around 150–200 mg per day of elemental iron. This is roughly 2–5 mg/kilogram (kg) of body weight.

How much iron is too much?

The amount of iron necessary for good health varies depending on individual circumstances.

Iron can be Trusted Source National Institutes of Health Office of Dietary Supplements Governmental authority Go to source harmful if you take more than is appropriate for you.

Children younger than 14 years old should not intake more than 40 mg of iron per day unless instructed otherwise by a doctor. People ages 14 years and older should not take more than 45 mg per day unless instructed otherwise by a doctor.

A doctor may temporarily prescribe more than the upper limit of iron to people who need higher doses to treat iron deficiency. Prescribed supplements can include medicinal iron at levels higher than standard multivitamins. Temporarily taking higher levels of iron can correct the deficiency and replenish the body’s iron stores.

What is the best form of iron supplement to take?

There is a wide variety of products available on the market, and most options are available over the counter.

Iron can be available as pills, liquids, sprays, and capsules. Liquid options may be more suitable for people who have difficulty swallowing pills or capsules.

Megan Soliman, MD, recommends that the most important deciding factor should be whether you can tolerate and actually take the product. Dr. Soliman, an internal medicine physician, notes that she often recommends the most affordable product, including generic options.

Dr. Soliman also notes that iron supplements formulated with ferrous gluconate, ferrous fumarate, and ferrous sulfate generally absorb well. These formulations tend to be the most common.

Some people may experience nausea — especially with ferrous sulfate — and tolerate ferrous gluconate better.

Additionally, some brands claim that certain liquid and spray formulations offer improved absorption. However, Dr. Soliman adds that while they are often more expensive, they are equally as effective as cheaper pill formulations.

Iron supplements for pregnancy

Dr. Soliman adds that any prenatal vitamin with iron is normally sufficient for most pregnant people. However, it is important to check the label, as not all prenatal vitamins contain iron.

Pregnant people who experience anemia should ask about additional isolated iron supplements with their doctor.

How to take iron supplements effectively

Dr. Soliman recommends taking iron supplements approximately 30 minutes before a meal and 2 hours before any other medications.

As iron can also decrease the action of some medications, it is important to take it on its own.

If a doctor has diagnosed you with iron deficiency, they should periodically check your levels once you have started taking supplements. Monitoring allows them to ensure that your iron levels are increasing appropriately.

If the levels have not appropriately improved, Dr. Soliman suggests that it could be due to different factors, such as:

  • the timing of when you are taking your medication and supplements
  • an interaction with another medication
  • a gastrointestinal absorption issue

Side effects and cautions

Taking too much iron can be harmful. Additionally, taking high doses of iron, particularly on an empty stomach, can have adverse side effects.

Side effects of taking inappropriate levels of iron for you can include Trusted Source National Institutes of Health Office of Dietary Supplements Governmental authority Go to source :

The effects of taking extremely high doses of iron can be more severe, including necrosis of the intestine, organ failure, coma, convulsions, and death. Doses of more than 20 mg/kg of body weight are extreme — for example, about 1,365 mg of iron for a person weighing 150 pounds (lb).

Complications may also present if people with certain health conditions, such as hemochromatosis, take too much iron.

Iron can interact negatively with other medications and dietary supplements, such as levodopa, levothyroxine, and calcium. Certain proton pump inhibitors, such as lansoprazole and omeprazole, can also cause negative interactions.

Always inform your doctor or pharmacist about any conditions you have and medication or supplements you already take.

Frequently asked questions

Here are some frequently asked questions about iron supplementation for women.

What causes low iron in females?

People from all groups can experience low iron, particularly if they have an underlying condition or cause for low iron.

In females of reproductive age, the most common causes of IDA are heavy bleeding during menstrual periods or pregnancy.

Should females take iron supplements?

Not everyone needs to take iron supplements. You should only take iron supplements if your doctor recommends you to, only in the amount they suggest.

Intaking more iron than you need can produce side effects and complications.

How can I boost my iron levels quickly?

Unless you have IDA or another condition that causes low iron, you may not need to increase your iron levels.

You can help your body absorb iron by adding fruits and vegetables high in vitamin C to your diet and avoiding tea.

For those whose doctors recommend iron supplementation, taking iron pills can quickly and easily improve iron levels.


Females, people with heavy periods, and pregnant people may be at higher risk of having low iron levels. Too little iron can impact the health of the red blood cells and lead to a condition called IDA.

Iron supplements may help people with iron deficiency to replenish their iron levels. The appropriate dosage will depend on the individual, according to their age and condition.

Too much iron can also negatively impact health and have severe side effects. The standard daily limit of iron for adults is 45 mg, and 40 mg for children.

If you have symptoms of IDA, are pregnant, or are concerned about your iron levels, contact your doctor to see if iron supplementation is appropriate for you.

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Medical Reviewer: Megan Soliman, MD
Last Review Date: 2022 Apr 28
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