What Causes Repeated Low Ferritin?

December 3, 2025 •

4 min read

According to the World Health Organization, iron deficiency is the most common nutritional disorder globally, and for some, low ferritin is a persistent problem. Understanding what causes repeated low ferritin is the crucial first step toward lasting resolution, as the root cause often goes undetected.

Quick Summary

Repeatedly low ferritin levels often stem from chronic blood loss, underlying malabsorption issues, or inadequate iron intake that deplete the body's iron stores over time.

Key Points

Hidden Bleeding: Chronic blood loss, such as from heavy periods, stomach ulcers, or NSAID use, is a primary cause of repeated low ferritin levels, depleting iron stores over time.
Absorption Problems: Conditions like celiac disease, inflammatory bowel disease, or prior bariatric surgery prevent the body from properly absorbing iron, regardless of dietary intake.
Chronic Inflammation: Anemia of chronic disease causes the body to 'trap' iron in storage due to the hormone hepcidin, making it unavailable for use even if total body iron is sufficient.
Increased Physiological Need: Increased demand for iron during pregnancy or rapid adolescent growth can deplete ferritin stores repeatedly if not met through diet or supplementation.
Addressing the Root Cause: Simply taking iron supplements without investigating and treating the underlying cause, whether it is bleeding, malabsorption, or inflammation, will not resolve the issue long-term.
Diagnostic Necessity: A history of repeatedly low ferritin requires a comprehensive medical evaluation to identify the specific issue and develop a targeted treatment plan for sustained improvement.

Unresolved Blood Loss: A Common Culprit

For many individuals, especially adults, the primary reason for a recurring drop in ferritin is ongoing, and sometimes hidden, blood loss. While a doctor might treat the symptoms with iron supplements, the iron stores will deplete again if the underlying source of the bleeding is not addressed.

Gynecological and Obstetric Causes

For individuals of childbearing age, gynecological issues are a leading cause of chronic blood loss. Heavy menstrual bleeding, known as menorrhagia, can deplete iron faster than the body can replenish it through diet alone. Conditions that cause or worsen menstrual bleeding include uterine fibroids and endometriosis, which may involve hidden bleeding within the abdomen or pelvis. Pregnancy also increases the body's iron requirements significantly, and low stores can persist postpartum if not properly managed.

Gastrointestinal Bleeding

Bleeding in the gastrointestinal (GI) tract can be subtle and go unnoticed for extended periods. This "occult" bleeding slowly saps the body's iron supply. Common causes include:

Stomach ulcers
Inflammatory bowel diseases (IBD) such as Crohn's disease or ulcerative colitis
Gastrointestinal polyps or cancer, especially in older adults
Chronic use of non-steroidal anti-inflammatory drugs (NSAIDs), such as aspirin or ibuprofen
Infections with Helicobacter pylori, which can cause inflammation and bleeding in the stomach

Malabsorption Disorders and Impaired Iron Absorption

Even with a diet rich in iron, some people cannot absorb it properly due to underlying health conditions or medical procedures.

Gastrointestinal Conditions Affecting Absorption

Celiac Disease: This autoimmune disorder damages the small intestine when gluten is consumed, interfering with its ability to absorb nutrients, including iron.
Inflammatory Bowel Disease (IBD): The inflammation associated with Crohn's and ulcerative colitis can impair nutrient absorption.
Atrophic Gastritis: This condition causes chronic inflammation of the stomach lining, leading to a loss of gastric acid necessary for iron absorption.
H. pylori Infection: As mentioned, this infection can also cause malabsorption by altering the stomach's environment.

Medical Interventions and Medications

Bariatric Surgery: Procedures like gastric bypass can significantly alter the digestive system, bypassing the parts of the small intestine where iron is primarily absorbed.
Proton Pump Inhibitors (PPIs): Long-term use of these medications, which reduce stomach acid, can impair the absorption of non-heme iron.

Chronic Inflammatory States and Iron Trapping

In some cases, the body has sufficient iron stores, but chronic inflammation prevents the body from using them effectively. This is known as anemia of chronic disease or functional iron deficiency.

Chronic inflammation increases the production of a hormone called hepcidin. Hepcidin blocks iron from being released from its storage sites and reduces its absorption from the gut. This means iron is trapped within cells, leading to a low ferritin count in the blood, despite the body not being truly iron-deficient in a storage sense. Conditions that cause chronic inflammation include:

Chronic kidney disease (CKD)
Autoimmune disorders like rheumatoid arthritis
Chronic heart failure
Some cancers
Obesity

Comparison of Primary Causes for Repeated Low Ferritin


Cause Category	Example Conditions	Mechanism of Action	Is Supplementation Alone Effective?
Chronic Blood Loss	Heavy periods, GI ulcers, NSAID use	Iron is lost from the body faster than it can be replenished.	No, the source of bleeding must also be treated.
Malabsorption Issues	Celiac disease, bariatric surgery	The body cannot effectively absorb iron from food or oral supplements.	No, underlying condition needs addressing; IV iron may be needed.
Chronic Inflammation	CKD, autoimmune disease	Iron is 'trapped' in cells due to hepcidin, making it unavailable for use.	No, the underlying inflammatory condition must be managed.
Increased Demand	Pregnancy, rapid adolescent growth	The body's need for iron outstrips dietary intake, especially over time.	Yes, if intake is increased or balanced with supplements.
Inadequate Diet	Vegan/vegetarian diets (without proper planning)	Insufficient dietary iron, particularly non-heme iron, leads to depletion.	Yes, by adjusting diet and/or adding appropriate supplementation.

Conclusion: The Path to Resolution

Repeatedly low ferritin levels are a signal that the body's iron-related issues are not being fully resolved by standard treatments like oral iron supplements alone. It necessitates a more thorough investigation into the root cause. A medical professional will likely need to rule out chronic blood loss, malabsorption disorders, and chronic inflammatory conditions. Treatment for these underlying issues, combined with dietary adjustments and possibly specialized iron therapy, is the most effective strategy for achieving and maintaining healthy ferritin levels. For example, addressing heavy menstrual bleeding, treating celiac disease, or managing chronic inflammation is critical to preventing the cycle of ferritin depletion. It is crucial to work with a healthcare provider to devise a personalized and effective long-term plan, rather than simply restarting iron supplements indefinitely. Persistent low ferritin is a symptom, not a diagnosis, and requires a diligent search for the cause to be successfully managed.

Note: This information is for educational purposes only and is not a substitute for professional medical advice. Always consult with a healthcare provider for diagnosis and treatment.(https://www.ncbi.nlm.nih.gov/books/NBK560876/)

Frequently Asked Questions

While a low-iron diet, particularly a poorly-managed vegetarian or vegan one, can initially cause low ferritin, if levels repeatedly drop after supplementation, it is highly likely that another underlying issue like chronic blood loss or malabsorption is at play.

Ferritin is the protein that stores iron in your body. Low ferritin indicates that your iron stores are depleted. Low iron (or serum iron) refers to the amount of iron circulating in your blood. You can have low ferritin even if your overall iron levels are not yet low, a condition called latent iron deficiency.

Oral iron supplements can temporarily raise ferritin levels, but if the root cause, such as chronic bleeding or malabsorption, is not resolved, the levels will likely drop again once supplementation stops. Effective treatment requires addressing the underlying problem, not just the symptom.

In chronic inflammatory conditions, the body releases hepcidin, a hormone that blocks the release of stored iron and reduces its absorption from the gut. This traps iron in storage cells and prevents it from being used, leading to a low blood ferritin reading.

A doctor should investigate for internal bleeding when a patient has repeated low ferritin levels without an obvious cause, like heavy menstruation. A thorough gastrointestinal workup is often necessary to check for ulcers, polyps, or other issues.

Yes, bariatric surgeries or other intestinal procedures can reduce the body's ability to absorb iron, leading to persistently low ferritin levels if not managed with proper nutrition and potentially intravenous iron.

Yes, in rare cases, genetic mutations such as a mutation in the TMPRSS6 gene can cause the body to overproduce hepcidin, blocking iron absorption and resulting in chronic iron deficiency.