Key Takeaways

Iron deficiencies are quite common, affecting nearly 10 million adults in the United States, including 5 million with iron deficiency anemia.Despite this prevalence, many people don’t know they have low iron levels and may experience certain symptoms for years without knowing the cause.

Part of the reason why? Even if you take an iron supplement or eat plenty of iron-rich foods, lots of things block the absorption of iron.

Here’s what you need to know about factors that could be causing low iron levels and what you can do about it, according to experts.

What Causes Low Iron Levels?

Most of the iron in your body is found in a red blood cell protein called hemoglobin.As a result, chronic blood loss is a major cause of iron deficiency, whether from heavy monthly periods, surgery, blood thinner use, or a health condition like peptic ulcer disease,Margaret Ragni, MD, MPH, a professor of medicine and clinical and translational research at the University of Pittsburgh and Medical Director of the Hemophilia Center of Western PA in Pittsburg, told Verywell in an email.

Of course, not consuming enough iron-rich foods can also lead to an iron deficiency. This is common in vegan or vegetarian diets that may lack sufficient iron found in animal products.

But some causes of iron deficiency, like those below, are less obvious.

Chronic Disease

Certain medical conditions, such as celiac disease or Crohn’s disease, can impact the body’s ability to absorb iron from food,Abayomi Ogunwale, MD, MBBS, MPH, Assistant Professor of Family Medicine at McGovern Medical School at UTHealth Houston, told Verywell in an email. Other chronic diseases, such as kidney disease or cancer, can also interfere with the body’s ability to use and store iron properly.

Drinking Certain Beverages

Drinking coffee, tea, and milk can also affect iron absorption—especially if you consume these beverages close to when you take an iron supplement.

If you take an iron supplement, Ogunwale said it’s best to do so on an empty stomach so that nothing hinders its absorption.

“Iron is best taken early in the morning on an empty stomach with water or fruit juice (preferably one rich in vitamin C like orange juice, which aids its absorption), one to two hours before meals, dairy, teas, coffee, and calcium-containing supplements,” he said.

Taking Certain Medications

The use of certain medications may negatively impact your iron levels.

“NSAIDs affect iron levels, but indirectly. They can cause irritation of the mucosal lining of the upper digestive tract, causing minor or major bleeds, which predispose you to iron deficiency,” Ogunwale said. He added that some antibiotics can also cause hemolysis, or blood cell breakdown, which also contributes to low iron levels.

Other medications and vitamins may inhibit the absorption of iron if you’re taking an iron supplement.

Running

Strenuous exercise like running and long walking, especially on hard road surfaces, can contribute to a red blood cell breakdown called march hemoglobinuria, Ragni said.This iron-depleting phenomenon is also referred to as footstrike hemolysis, and is thought to occur as capillaries in the foot repeatedly pound on the ground.

Life Stages

Certain life stages or conditions can increase the body’s need for iron, including pregnancy, breastfeeding, and rapid growth in children and adolescents, Ragni said.

How Do You Know If You Have Low Iron Levels?

Ragni said the main way to find out if you have low iron levels is through a blood test.

There are several types of iron tests, each with different normal value ranges. However, these ranges may vary slightly depending on the source or specific laboratory and factors like age, sex, and individual health conditions:

What Happens If You Have Low Iron Levels?

When iron levels in the body become low, it can lead to a decreased blood count and low heme levels, also known as anemia, Ogunwale said. This happens because iron is essential for producing hemoglobin, the component of red blood cells responsible for carrying oxygen throughout the body.

“Humans cannot make the oxygen-carrying proteins called hemoglobin without iron,” said Ogunwale. “This can manifest in different ways and severity depending on various individual clinical factors.”

Symptoms of low iron levels and subsequent anemia may include:

If the anemia persists over a long period, it can lead to more severe outcomes such as organ failure, heart failure, and kidney failure, said Ogunwale.

What Can You Do If You Have Low Iron Levels?

If you have low iron levels, the first thing you should do is identify why the iron deficiency has happened to prevent it from happening again.

“This means a visit to the doctor’s office for history taking, physical exams, and laboratory tests,” Ogunwale said.

What This Means For YouTo determine if you have low iron levels, whether from a condition, your diet, or other lifestyle risk factors, experts recommend visiting your primary care physician for a blood test.

What This Means For You

To determine if you have low iron levels, whether from a condition, your diet, or other lifestyle risk factors, experts recommend visiting your primary care physician for a blood test.

8 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Miller JL.Iron deficiency anemia: a common and curable disease.Cold Spring Harb Perspect Med. 2013;3(7):a011866. doi:10.1101/cshperspect.a011866National Institutes of Health Office of Dietary Supplements.Iron: fact sheet for consumers.Yoshida M, Suzuki H, Hamaguchi S, et al.March hemoglobinuria progressed to acute kidney injury after kendo practice: a case report.BMC Nephrol. 2022;23(1):368. doi:10.1186/s12882-022-02988-0Fazal AA, Whittemore MS, DeGeorge KC.Foot-strike haemolysis in an ultramarathon runner.BMJ Case Rep. 2017;2017:bcr2017220661. doi:10.1136/bcr-2017-220661Mount Sinai.Serum iron test.StatPearls.Biochemistry, transferrin.Mount Sinai.Ferritin blood test.American Society of Hematology.Iron-deficiency anemia.

8 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Miller JL.Iron deficiency anemia: a common and curable disease.Cold Spring Harb Perspect Med. 2013;3(7):a011866. doi:10.1101/cshperspect.a011866National Institutes of Health Office of Dietary Supplements.Iron: fact sheet for consumers.Yoshida M, Suzuki H, Hamaguchi S, et al.March hemoglobinuria progressed to acute kidney injury after kendo practice: a case report.BMC Nephrol. 2022;23(1):368. doi:10.1186/s12882-022-02988-0Fazal AA, Whittemore MS, DeGeorge KC.Foot-strike haemolysis in an ultramarathon runner.BMJ Case Rep. 2017;2017:bcr2017220661. doi:10.1136/bcr-2017-220661Mount Sinai.Serum iron test.StatPearls.Biochemistry, transferrin.Mount Sinai.Ferritin blood test.American Society of Hematology.Iron-deficiency anemia.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Miller JL.Iron deficiency anemia: a common and curable disease.Cold Spring Harb Perspect Med. 2013;3(7):a011866. doi:10.1101/cshperspect.a011866National Institutes of Health Office of Dietary Supplements.Iron: fact sheet for consumers.Yoshida M, Suzuki H, Hamaguchi S, et al.March hemoglobinuria progressed to acute kidney injury after kendo practice: a case report.BMC Nephrol. 2022;23(1):368. doi:10.1186/s12882-022-02988-0Fazal AA, Whittemore MS, DeGeorge KC.Foot-strike haemolysis in an ultramarathon runner.BMJ Case Rep. 2017;2017:bcr2017220661. doi:10.1136/bcr-2017-220661Mount Sinai.Serum iron test.StatPearls.Biochemistry, transferrin.Mount Sinai.Ferritin blood test.American Society of Hematology.Iron-deficiency anemia.

Miller JL.Iron deficiency anemia: a common and curable disease.Cold Spring Harb Perspect Med. 2013;3(7):a011866. doi:10.1101/cshperspect.a011866

National Institutes of Health Office of Dietary Supplements.Iron: fact sheet for consumers.

Yoshida M, Suzuki H, Hamaguchi S, et al.March hemoglobinuria progressed to acute kidney injury after kendo practice: a case report.BMC Nephrol. 2022;23(1):368. doi:10.1186/s12882-022-02988-0

Fazal AA, Whittemore MS, DeGeorge KC.Foot-strike haemolysis in an ultramarathon runner.BMJ Case Rep. 2017;2017:bcr2017220661. doi:10.1136/bcr-2017-220661

Mount Sinai.Serum iron test.

StatPearls.Biochemistry, transferrin.

Mount Sinai.Ferritin blood test.

American Society of Hematology.Iron-deficiency anemia.

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