Title
Subscribe to the Magazine for free
Subscribe for free to keep reading! If you are already subscribed, enter your email address to log back in.
Thanks for subscribing!
Oops! Something went wrong while submitting the form.
Are you a healthcare practitioner?
Thanks for subscribing!
Oops! Something went wrong while submitting the form.

Top Lab Test to Run on Your Iron Deficiency Anemia Patients

Why This Was Updated?

Our specialists regularly review advancements in health and wellness, ensuring our articles are updated with the newest information as it becomes accessible.
Medically Reviewed by

Approximately 25% of people worldwide have anemia, a blood disorder defined by low red blood cell counts and hemoglobin concentration. Iron deficiency, the most common nutritional deficiency, is responsible for causing 50% of all anemias. Iron is essential for the human body; it plays many roles, including physical growth and neurological development, hormone synthesis, cellular functioning, and hemoglobin synthesis. In iron-deficient states, microcytic anemia can occur along with symptoms such as fatigue, weakness, and poor exercise tolerance. (3, 4)

Because iron deficiency anemia is the most common type of anemia, it must be included in the differential diagnosis for anemia. This article will explain how iron deficiency anemia develops, clinical manifestations and laboratory findings that support the diagnosis, and an integrative approach to treatment.

[signup]

What is Iron Deficiency Anemia?

Iron deficiency anemia (IDA) is the most common microcytic anemia, characterized by small red blood cells (RBCs) due to the body's lack of hemoglobin. The healthy synthesis of hemoglobin, the oxygen-carrying protein in RBCs, requires iron. Iron deficiency progressively leads to IDA as the body cannot sustain normal hemoglobin and RBC production. (7)

Causes of iron deficiency include blood loss, insufficient dietary intake, and decreased absorption. The following groups are at the highest risk for developing IDA (1):

  • People who have heavy menstrual periods, are pregnant, or are breastfeeding
  • People who have undergone major surgery or physical trauma
  • People with underlying gastrointestinal (GI) pathologies that impair iron absorption such as Celiac disease and inflammatory bowel disease (IBD)
  • People with insufficient dietary intake of iron such as vegetarians and vegans

Other causes of IDA may include (7):

  • Low stomach acid (hypochlorhydria)
  • GI infections: Helicobacter pylori, small intestinal bacterial overgrowth (SIBO)
  • Chronic GI bleeding caused by ulcers, hemorrhoids, frequent use of nonsteroidal anti-inflammatory drugs (NSAIDs), and certain cancers
  • Frequent blood donations

Iron Deficiency Anemia Symptoms

Symptoms of iron deficiency and IDA are the same, and symptom severity is usually proportional to the degree of deficiency and anemia. A poorly oxygenated state arising from IDA affects all body systems, leading to many vague symptoms that can be easily attributed to other causes (1):

  • Anxiety
  • Cold intolerance
  • Depression
  • Dizziness
  • Exercise intolerance
  • Fatigue
  • Headaches
  • Irritability
  • Muscle weakness
  • Pica (craving and ingestion of nonfood items)
  • Restless legs syndrome (RLS)

Iron is involved in thyroid hormone synthesis, and hypothyroidism can result in the context of iron deficiency. Note that hypothyroidism and iron deficiency share many of the same symptoms:

  • Brain fog
  • Brittle nails
  • Cold intolerance
  • Constipation
  • Depression
  • Fatigue
  • Hair loss
  • Irregular periods
  • Puffiness or fluid retention
  • Weight gain

Iron also plays a role in collagen synthesis. In iron-deficient states, the following symptoms may appear:

  • Brittle nails
  • Cracked corners of the mouth
  • Dry, pale skin
  • Hair loss
  • Inflamed tongue

Functional Medicine Labs to Diagnose Iron Deficiency Anemia

A complete blood count (CBC) is a panel that includes markers detailing the size, shape, and color of red blood cells. The table below summarizes the results that indicate microcytic anemia:

A complete iron panel includes multiple blood tests specific to iron. Analyzed together, these tests provide a comprehensive analysis of iron status and help to differentiate between different types of anemia.

  • Serum iron measures the total circulating iron in the blood. It is low in iron deficiency and IDA.
  • Ferritin is the protein that stores iron in the liver and is the most reliable marker to assess the body's iron stores. Low levels indicate a more progressed state of iron deficiency, as the body has run out of its stores in an attempt to maintain circulating blood levels.
  • Transferrin is the protein that transports iron throughout the body to its intended destination; it has an inversely proportional relationship to serum iron and is increased in iron-deficient states.
  • Transferrin saturation, also called iron saturation or % Sat, is the percent of transferrin that has iron bound to it. Transferrin saturation is decreased in IDA due to the lack of available iron.
  • Total iron binding capacity (TIBC) is a marker of how much iron can be bound to transferrin and can act as an indirect measure of transferrin. In iron-deficient conditions, the relative amount of transferrin increases compared to available iron, and thus TIBC will be elevated.
  • Unsaturated iron binding capacity (UIBC) is the remaining transferrin that is not bound to and transporting iron. It is increased in IDA.


The reticuloendothelial system (RES), or iron recycling system, is a complex system that serves to regulate iron homeostasis in the body. If the RES is not functioning correctly, even with normal serum iron and ferritin levels, the body will not be able to move iron where it needs to go to perform its functions. In states of vitamin A and copper deficiency, RES function is impaired, essentially leading to a state of iron deficiency. Measuring vitamin A and copper levels may be especially useful in cases where serum iron and ferritin are normal, but anemia symptoms are present, and labs show abnormal TIBC and % Sat levels. (8, 9)

Tests to Rule Out Root Cause of Iron Deficiency

Once IDA is diagnosed, the root cause of iron deficiency needs to be identified. A thorough medical history can aid in this process: a diet recall and a complete medication list can provide clues to lifestyle factors contributing to low iron status.

Testing may also be necessary to identify the root cause:

  • Serum hCG to rule out pregnancy
  • A fecal occult blood test (FOBT) measures blood in the stool to rule out intestinal bleeds
  • Blood tests that measure genetic and immune markers common in Celiac disease and IBD can help rule out inflammatory GI conditions causing malabsorption
  • Hormonal imbalances can cause heavy menstrual bleeding. A urinary hormone panel can measure estrogen, progesterone, and testosterone levels. Β Progesterone deficiency and estrogen dominance, alone or in combination, are common causes of heavy periods.
  • A comprehensive Helicoplyori pylori stool test can diagnose an H. pylori infection. It also includes virulence factors and antibiotic resistance testing that guide treatment recommendations.
  • SIBO breath test

Imaging and endoscopic procedures are required to diagnose hypochlorhydria, Celiac disease, and IBD.

Functional Medicine Treatment for Iron Deficiency Anemia

Iron Repletion

The treatment of IDA requires addressing the underlying cause of iron deficiency while repleting iron stores through supplementation (4).

The dosage of elemental iron required to treat iron deficiency anemia in adults is 120 mg daily for at least three months. Follow-up with repeat CBC and iron testing is recommended after one month of treatment to confirm adequate response to treatment. Repletion therapy should be continued for one to three months after hemoglobin levels have normalized to replenish iron stores fully. (5)

There are various iron forms that you will find in oral iron supplements. The most common and affordable supplements contain iron salts like ferrous sulfate, but they often cause GI upset like abdominal pain and constipation. Functional practitioners often recommend an alternative, better-tolerated form of iron called ferrous (bis)glycinate to improve tolerance to therapy. (2)

There are various ways to enhance oral iron absorption (2, 6, 7):

  • Take iron supplements between meals
  • Avoid taking iron supplements with inhibitors of iron absorption: phytates (in bran), polyphenols (in certain vegetables), tannins (in tea and coffee), calcium-containing foods and supplements, soy, and oxalates (in spinach, beans, and nuts)
  • Take iron supplements with ascorbic acid (vitamin C) to enhance absorption

There are now several studies supporting that taking oral iron every other day is just as or more effective than daily dosing at raising serum iron levels. This dosing regimen may better suit those who do not respond to oral iron repletion as expected or experience GI side effects.

Intravenous (IV) iron is more reliably and quickly distributed through circulation than oral supplementation. IV infusions may be the preferred course of treatment for those that are intolerant to oral iron, have a malabsorptive GI disease, or are not responding to oral iron as desired. (4, 6)

Blood transfusions may be required for severe IDA. There is no universally accepted guideline for ordering blood transfusions, but the patient's clinical condition and symptoms are important considerations in the decision. (5)

Nutrition

Dietary iron has two main forms: heme and nonheme. Heme iron, found in animal sources, is very well absorbed and functional in the body. Nonheme iron, found in plant-based and iron-fortified foods, is significantly less bioavailable to the body. Top animal sources of iron include red meat, oysters, liver, and chicken. Plant sources of iron include dark leafy greens, legumes, molasses, and tofu. (3)

Just as is the case with supplements, making smart decisions with cooking can boost iron absorption:

  • Cook meals in cast iron pans
  • Soaking beans and legumes in water before cooking can remove nutrients that impair iron absorption
  • Pair iron-rich foods with a vitamin C source (e.g., citrus fruits, strawberries, bell peppers, cruciferous vegetables)
  • Avoid eating iron-rich foods with calcium, tannins, phytates, polyphenols, and oxalates

Herbs & Supplements

Consider supplemental vitamin A and copper to support the iron recycling system, especially when deficiencies in either nutrient are identified.

This article will not extensively outline treatment protocols for specific conditions underlying IDA. Know that addressing these conditions is necessary for treating IDA and preventing iron deficiency recurrence. Functional medicine practitioners routinely implement integrative protocols specific to the health concern that include botanical herbs, nutritional supplements, dietary and lifestyle modifications, and pharmaceutical medications (when applicable).

Lifestyle Modifications

Endurance athletes are at increased risk for IDA. Intense exercise increases the body's iron requirements to compensate for excess iron lost through sweat, decreased intestinal absorption secondary to acute inflammatory responses activated during exercise, and increased destruction of RBCs by physical forces. Some research suggests that high-intensity and endurance exercise increases iron losses by as much as 70% compared to sedentary populations. Decreasing exercise intensity and frequency during active IDA therapy can improve response to iron repletion therapy. Athletes may be candidates for increased dietary and supplemental iron intake to satisfy increased demands. (10)

Summary

Iron is an essential mineral for the human body, partly for its involvement in hemoglobin and red blood cell synthesis. In iron-deficient states, microcytic anemia can occur, and impaired oxygenation of the body leads to symptoms associated with iron deficiency anemia. Functional medicine practitioners are trained to use a comprehensive testing strategy to understand iron status and metabolism. An integrative approach to treating iron deficiency anemia, utilizing nutritional therapy, dietary supplements, and lifestyle modifications, is effective in restoring the body's iron and red blood cell balance.

Approximately 25% of people worldwide experience anemia, a condition where there are fewer red blood cells or lower hemoglobin levels than normal. Iron deficiency is the most common nutritional deficiency and is linked to about 50% of all anemia cases. Iron is important for the body because it helps with growth, brain development, making hormones, and creating hemoglobin. When there isn't enough iron, a type of anemia called microcytic anemia can happen, which might make people feel tired, weak, or have trouble with exercise. (3, 4)

Since iron deficiency anemia is the most common type, it's important to consider it when diagnosing anemia. This article will discuss how iron deficiency anemia develops, signs and tests that can help identify it, and ways to support health through an integrative approach.

[signup]

What is Iron Deficiency Anemia?

Iron deficiency anemia (IDA) is the most common microcytic anemia, where red blood cells (RBCs) are smaller than usual because the body doesn't have enough hemoglobin. Hemoglobin, which carries oxygen in RBCs, needs iron to be made properly. Without enough iron, the body can't make enough hemoglobin and RBCs, leading to IDA. (7)

Iron deficiency can happen due to blood loss, not eating enough iron-rich foods, or not absorbing iron well. The following groups may have a higher chance of developing IDA (1):

  • People with heavy menstrual periods, who are pregnant, or breastfeeding
  • People who have had major surgery or physical injuries
  • People with digestive issues that affect iron absorption, like Celiac disease and inflammatory bowel disease (IBD)
  • People who don't eat enough iron-rich foods, such as vegetarians and vegans

Other possible causes of IDA include (7):

  • Low stomach acid (hypochlorhydria)
  • Digestive infections: Helicobacter pylori, small intestinal bacterial overgrowth (SIBO)
  • Chronic digestive bleeding from ulcers, hemorrhoids, frequent use of certain pain relievers, and some cancers
  • Frequent blood donations

Iron Deficiency Anemia Symptoms

The symptoms of iron deficiency and IDA are similar, and how severe they are usually depends on how much iron is lacking. When the body doesn't get enough oxygen due to IDA, it can affect many parts of the body, leading to symptoms that might be mistaken for other issues (1):

  • Feeling anxious
  • Being sensitive to cold
  • Feeling down or depressed
  • Feeling dizzy
  • Having trouble with exercise
  • Feeling very tired
  • Getting headaches
  • Feeling irritable
  • Having weak muscles
  • Craving non-food items (pica)
  • Having restless legs syndrome (RLS)

Iron is also important for making thyroid hormones, and not having enough iron can be linked to hypothyroidism. Both conditions share many symptoms:

  • Trouble thinking clearly (brain fog)
  • Brittle nails
  • Sensitivity to cold
  • Constipation
  • Feeling down or depressed
  • Feeling very tired
  • Losing hair
  • Irregular periods
  • Swelling or fluid retention
  • Gaining weight

Iron also helps with collagen production. When iron is low, these symptoms might appear:

  • Brittle nails
  • Cracks at the corners of the mouth
  • Dry, pale skin
  • Losing hair
  • An inflamed tongue

Functional Medicine Labs to Diagnose Iron Deficiency Anemia

A complete blood count (CBC) is a test that looks at the size, shape, and color of red blood cells. The table below shows results that might suggest microcytic anemia:

A complete iron panel includes several blood tests specific to iron. Together, these tests can give a detailed picture of iron levels and help distinguish between different types of anemia.

  • Serum iron measures the total iron in the blood. It is often low in iron deficiency and IDA.
  • Ferritin is a protein that stores iron in the liver and is a key marker for checking the body's iron reserves. Low levels suggest a more advanced stage of iron deficiency.
  • Transferrin is a protein that carries iron throughout the body; it usually increases when iron levels are low.
  • Transferrin saturation, or % Sat, shows how much transferrin is carrying iron. It is often lower in IDA.
  • Total iron binding capacity (TIBC) indicates how much iron can be bound to transferrin. It tends to be higher when iron is low.
  • Unsaturated iron binding capacity (UIBC) is the transferrin not carrying iron. It is often higher in IDA.


The reticuloendothelial system (RES), or iron recycling system, helps manage iron levels in the body. If the RES isn't working well, even normal serum iron and ferritin levels might not be enough to move iron where it's needed. In cases of vitamin A and copper deficiency, RES function can be affected, leading to iron deficiency. Checking vitamin A and copper levels might be helpful when iron levels seem normal, but symptoms of anemia are present, and tests show unusual TIBC and % Sat levels. (8, 9)

Tests to Rule Out Root Cause of Iron Deficiency

After diagnosing IDA, it's important to find out why iron levels are low. A detailed medical history, including diet and medications, can provide clues about lifestyle factors affecting iron levels.

Testing might also be needed to find the root cause:

  • Serum hCG to check for pregnancy
  • A fecal occult blood test (FOBT) to check for blood in the stool, which might indicate intestinal bleeding
  • Blood tests for genetic and immune markers common in Celiac disease and IBD to rule out digestive conditions affecting absorption
  • Hormonal imbalances can cause heavy menstrual bleeding. A urinary hormone panel can measure estrogen, progesterone, and testosterone levels. Β Progesterone deficiency and estrogen dominance, alone or in combination, are common causes of heavy periods.
  • A comprehensive Helicoplyori pylori stool test can diagnose an H. pylori infection. It also includes virulence factors and antibiotic resistance testing that guide treatment recommendations.
  • SIBO breath test

Imaging and endoscopic procedures are required to diagnose hypochlorhydria, Celiac disease, and IBD.

Functional Medicine Treatment for Iron Deficiency Anemia

Iron Repletion

Addressing the underlying cause of iron deficiency and replenishing iron stores through supplementation can be part of managing IDA (4).

Adults with iron deficiency anemia may need 120 mg of elemental iron daily for at least three months. It's important to follow up with repeat CBC and iron testing after one month to check the response. Continuing therapy for one to three months after hemoglobin levels normalize can help replenish iron stores. (5)

There are different forms of iron in supplements. Common and affordable ones contain iron salts like ferrous sulfate, but they might cause stomach upset. Some practitioners suggest ferrous (bis)glycinate as a gentler option. (2)

Here are some ways to potentially enhance iron absorption from supplements (2, 6, 7):

  • Take iron supplements between meals
  • Avoid taking iron with foods or supplements that might reduce absorption, like those containing phytates, polyphenols, tannins, calcium, soy, and oxalates
  • Take iron with vitamin C to help with absorption

Some studies suggest that taking iron every other day might be as effective as daily dosing for increasing iron levels. This might be a good option for those who have trouble with daily iron supplements.

Intravenous (IV) iron can be distributed more quickly than oral supplements. IV infusions might be preferred for those who can't tolerate oral iron, have digestive issues affecting absorption, or aren't responding to oral iron as expected. (4, 6)

In severe cases, blood transfusions might be needed. There isn't a set guideline for when to do this, but the patient's condition and symptoms are important factors. (5)

Nutrition

Iron in food comes in two main forms: heme and nonheme. Heme iron, found in animal products, is absorbed well by the body. Nonheme iron, found in plants and fortified foods, is less easily absorbed. Good sources of animal iron include red meat, oysters, liver, and chicken. Plant sources include dark leafy greens, legumes, molasses, and tofu. (3)

Here are some tips for cooking to help with iron absorption:

  • Use cast iron pans for cooking
  • Soak beans and legumes before cooking to remove substances that might block iron absorption
  • Pair iron-rich foods with vitamin C sources like citrus fruits, strawberries, bell peppers, and cruciferous vegetables
  • Avoid eating iron-rich foods with calcium, tannins, phytates, polyphenols, and oxalates

Herbs & Supplements

Consider vitamin A and copper supplements to support the iron recycling system, especially if deficiencies are found.

This article doesn't cover specific treatment plans for conditions causing IDA. However, addressing these conditions is important for managing IDA and preventing future iron deficiency. Practitioners often use a mix of herbs, supplements, diet changes, and sometimes medications to address these health concerns.

Lifestyle Modifications

Endurance athletes might have a higher risk for IDA. Intense exercise can increase the body's need for iron due to losses through sweat, reduced absorption from exercise-related inflammation, and increased red blood cell breakdown. Some research suggests that high-intensity exercise can increase iron loss by up to 70% compared to less active people. Reducing exercise intensity and frequency during IDA treatment might help improve response to iron therapy. Athletes might need more dietary and supplemental iron to meet increased demands. (10)

Summary

Iron is an important mineral for the body, partly because it helps make hemoglobin and red blood cells. When iron is low, microcytic anemia can occur, leading to symptoms related to iron deficiency anemia. Practitioners trained in functional medicine use comprehensive testing to understand iron levels and metabolism. An integrative approach, including nutrition, supplements, and lifestyle changes, can help restore the body's iron and red blood cell balance.

The information provided is not intended to be a substitute for professional medical advice. Always consult with your doctor or other qualified healthcare provider before taking any dietary supplement or making any changes to your diet or exercise routine.
Learn More
No items found.

Lab Tests in This Article

No lab tests!

1. Iron-Deficiency Anemia. American Society of Hematology. https://www.hematology.org/education/patients/anemia/iron-deficiency

2. Christie, J. (2022b, September 13). Weakness, Pale Skin, And Headache Are Signs Of This Mineral Deficiency. Rupa Health. https://www.rupahealth.com/post/a-functional-medicine-approach-to-iron-deficiency

3. NIH. (2022, April 5). Iron Fact Sheet for Health Professionals. National Institute of Health Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/Iron-HealthProfessional/

4. Warner, M.J., & Kamran, M.T. (2022, August 8). Iron Deficiency Anemia. StatPearls https://www.ncbi.nlm.nih.gov/books/NBK448065/

5. Short, M. W., & Domagalski, J. E. (2013). Iron Deficiency Anemia: Evaluation and Management. American Family Physician, 87(2), 98–104. https://www.aafp.org/pubs/afp/issues/2013/0115/p98.html

6. Ning, S., & Zeller, M. P. (2019). Management of iron deficiency. Hematology, 2019(1), 315–322. https://doi.org/10.1182/hematology.2019000034

7. Cloyd, J. (2023, February 1). 6 Anemia Types You Need to Know About. Rupa Health. https://www.rupahealth.com/post/6-different-types-of-anemia-you-may-not-be-aware-of

8. ​​Collins, J. F., Prohaska, J. R., & Knutson, M. D. (2010). Metabolic crossroads of iron and copper. Nutrition Reviews, 68(3), 133–147. https://doi.org/10.1111/j.1753-4887.2010.00271.x

9. Michelazzo, F., Oliveira, J., Stefanello, J., et al. (2013). The Influence of Vitamin A Supplementation on Iron Status. Nutrients, 5(11), 4399–4413. https://doi.org/10.3390/nu5114399

10. NIH. (2022, June 2). Dietary Supplements for Exercise and Athletic Performance. National Institutes of Health Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/ExerciseAndAthleticPerformance-HealthProfessional/

Subscribe to the Magazine for free to keep reading!
Subscribe for free to keep reading, If you are already subscribed, enter your email address to log back in.
Thanks for subscribing!
Oops! Something went wrong while submitting the form.
Are you a healthcare practitioner?
Thanks for subscribing!
Oops! Something went wrong while submitting the form.
See All Magazine Articles
Trusted Source
The Journal of Pediatrics
Peer Reviewed Journal
Visit Source
CDC
Government Authority
Visit Source
Office of Dietary Supplements
Government Authority
Visit Source
National Heart Lung and Blood Institute
Government Authority
Visit Source
National Institutes of Health
Government Authority
Visit Source
Clinical Infectious Diseases
Peer Reviewed Journal
Visit Source
Brain
Peer Reviewed Journal
Visit Source
The Journal of Rheumatology
Peer Reviewed Journal
Visit Source
Journal of the National Cancer Institute (JNCI)
Peer Reviewed Journal
Visit Source
Journal of Cardiovascular Magnetic Resonance
Peer Reviewed Journal
Visit Source
Hepatology
Peer Reviewed Journal
Visit Source
The American Journal of Clinical Nutrition
Peer Reviewed Journal
Visit Source
The Journal of Bone and Joint Surgery
Peer Reviewed Journal
Visit Source
Kidney International
Peer Reviewed Journal
Visit Source
The Journal of Allergy and Clinical Immunology
Peer Reviewed Journal
Visit Source
Annals of Surgery
Peer Reviewed Journal
Visit Source
The Journal of Neurology, Neurosurgery & Psychiatry
Peer Reviewed Journal
Visit Source
Chest
Peer Reviewed Journal
Visit Source
Blood
Peer Reviewed Journal
Visit Source
Gastroenterology
Peer Reviewed Journal
Visit Source
The American Journal of Respiratory and Critical Care Medicine
Peer Reviewed Journal
Visit Source
The American Journal of Psychiatry
Peer Reviewed Journal
Visit Source
Diabetes Care
Peer Reviewed Journal
Visit Source
The Journal of the American College of Cardiology (JACC)
Peer Reviewed Journal
Visit Source
The Journal of Clinical Oncology (JCO)
Peer Reviewed Journal
Visit Source
Journal of Clinical Investigation (JCI)
Peer Reviewed Journal
Visit Source
Circulation
Peer Reviewed Journal
Visit Source
JAMA Internal Medicine
Peer Reviewed Journal
Visit Source
PLOS Medicine
Peer Reviewed Journal
Visit Source
Annals of Internal Medicine
Peer Reviewed Journal
Visit Source
Nature Medicine
Peer Reviewed Journal
Visit Source
The BMJ (British Medical Journal)
Peer Reviewed Journal
Visit Source
The Lancet
Peer Reviewed Journal
Visit Source
Journal of the American Medical Association (JAMA)
Peer Reviewed Journal
Visit Source
Pubmed
Comprehensive biomedical database
Visit Source
Harvard
Educational/Medical Institution
Visit Source
Cleveland Clinic
Educational/Medical Institution
Visit Source
Mayo Clinic
Educational/Medical Institution
Visit Source
The New England Journal of Medicine (NEJM)
Peer Reviewed Journal
Visit Source
Johns Hopkins
Educational/Medical Institution
Visit Source