Why Does My Iron Level Keep Going Down? Uncovering Chronic Deficiency Causes

January 8, 2026 •

4 min read

According to the World Health Organization, iron deficiency is the most common nutritional deficiency worldwide, affecting billions of people. If you find yourself repeatedly asking, "why does my iron level keep going down?", it's a sign that the underlying cause has not been adequately addressed. This chronic condition requires a closer look at more than just diet to find a lasting solution.

Quick Summary

This article explores the common and lesser-known reasons behind recurring low iron levels, including blood loss, poor absorption, and chronic inflammation. It details the diagnostic process, treatment options, and proactive strategies to manage and prevent a persistent deficiency.

Key Points

Blood Loss is a Major Cause: In men and postmenopausal women, chronic iron deficiency is most commonly linked to internal bleeding from the GI tract, while heavy periods are the primary cause for premenopausal women.
Malabsorption is a Hidden Culprit: Conditions like celiac disease, inflammatory bowel disease, and stomach surgeries can prevent your body from absorbing sufficient iron, even with a good diet.
Chronic Inflammation Reduces Availability: Long-term inflammatory conditions can raise a hormone called hepcidin, which makes iron less available for red blood cell production.
Increased Needs Deplete Stores: Pregnancy, growth spurts in children, and frequent blood donation place a higher demand on the body's iron stores, leading to deficiency if not supplemented.
Underlying Cause Requires Diagnosis: Simply taking oral iron supplements may not be enough. It is critical to work with a doctor to identify and treat the root cause to prevent recurring low iron.
Diagnosis Confirmed by Ferritin Test: A low serum ferritin test is the most accurate way to diagnose true iron deficiency, which can exist even before red blood cell counts drop low enough for a full anemia diagnosis.

Beyond Diet: The Hidden Reasons Behind Chronic Low Iron

When your iron levels drop repeatedly, it indicates that your body's intake isn't keeping up with its needs, often due to an ongoing issue. While a poor diet is a common culprit, many other factors can lead to this persistent problem, making it essential to look deeper.

Chronic Blood Loss

For many, especially premenopausal women, frequent blood loss is the primary cause of recurrent iron deficiency. The body loses iron along with blood, and if the loss is constant, dietary iron alone cannot replenish the stores quickly enough.

Heavy Menstrual Periods: The most common cause in women of reproductive age. Excessively heavy or long-lasting periods can deplete iron reserves over time.
Gastrointestinal (GI) Bleeding: This can be slow and hard to detect. It may be caused by conditions like ulcers, inflammatory bowel disease (Crohn's, colitis), or certain types of GI cancers. Regular use of medications like NSAIDs (ibuprofen, naproxen) can also cause GI bleeding.
Frequent Blood Donation: Regular blood donors lose a significant amount of iron with each donation and may need to supplement their intake to maintain healthy levels.

Impaired Iron Absorption (Malabsorption)

Even with a diet rich in iron, your body might not be absorbing it efficiently. This is often due to underlying digestive issues.

Celiac Disease: This autoimmune disorder damages the lining of the small intestine, where most iron is absorbed.
Chronic Inflammation: Conditions like inflammatory bowel disease (IBD), heart failure, or obesity can increase hepcidin levels, a hormone that blocks iron absorption and release from storage.
Stomach Surgery: Procedures like gastric bypass can affect the parts of the small intestine responsible for iron absorption.
Medications: Some drugs, particularly antacids, proton pump inhibitors, and H2 receptor antagonists, reduce stomach acid, which is necessary to convert iron into an absorbable form.
Dietary Inhibitors: Consuming large amounts of tea, coffee, or calcium-rich foods alongside iron sources can interfere with absorption.

Increased Iron Requirements

In certain life stages, the body's demand for iron increases significantly, and dietary intake may not keep up.

Pregnancy: The blood volume of a pregnant woman increases, and iron is needed for both the mother and the developing fetus.
Growth Spurts: Infants and adolescents, especially during periods of rapid growth, require extra iron.
Kidney Disease: People with chronic kidney disease may not produce enough erythropoietin, a hormone that stimulates red blood cell production, and often require iron supplements.
Athletes: Endurance athletes, in particular, can experience increased iron loss and higher demands.

Comparison of Chronic Iron Deficiency Causes


Cause Category	Common Conditions/Examples	Primary Mechanism	Best Treatment Approach
Chronic Blood Loss	Heavy periods, GI ulcers, NSAID use, frequent blood donation	Iron depletion through hemorrhage	Address the bleeding source, oral/IV iron supplementation
Malabsorption	Celiac disease, Crohn's disease, post-bariatric surgery	Impaired nutrient uptake in the small intestine	Treat underlying condition, switch to IV iron if necessary
Increased Requirement	Pregnancy, infancy, adolescence, endurance sports	Higher physiological demand for iron stores	Targeted dietary increase, oral iron supplementation
Chronic Inflammation	Inflammatory bowel disease, heart failure, obesity	Elevated hepcidin blocks iron transport and release	Treat the inflammatory condition, IV iron often effective
Medication Effects	PPIs, H2 blockers, chronic antacid use	Reduced stomach acid, inhibiting iron conversion	Adjust medication, schedule supplement intake strategically

Diagnosis and Management

To effectively treat recurring low iron, a healthcare provider must first identify the root cause. This typically involves a series of diagnostic tests to check iron stores (ferritin), blood count (hemoglobin), and inflammatory markers.

Full Blood Count (FBC): Measures hemoglobin and red blood cells to determine if anemia is present.
Serum Ferritin Test: Measures the iron your body has in storage. A low ferritin level is the most accurate indicator of true iron deficiency, even before anemia develops.
Further Investigations: If initial tests suggest chronic blood loss, especially in men and postmenopausal women, a gastroenterologist may be consulted to perform procedures like an endoscopy or colonoscopy to check for internal bleeding.

Treatment plans will vary depending on the diagnosis. While dietary changes are always recommended, they are rarely enough on their own for chronic cases. Most people require a course of oral iron supplements, which need to be taken consistently for several months to replenish stores. In severe cases or for those with absorption issues, intravenous (IV) iron infusions may be necessary for a faster and more direct iron delivery. Consistent monitoring of iron levels is crucial to ensure the treatment is working and the underlying cause has been properly managed to prevent future drops.

Conclusion

If you find your iron levels are a chronic problem, it is important to look beyond a simple dietary fix. The causes for recurring low iron can be complex and are often linked to unaddressed issues such as chronic blood loss, malabsorption, or increased physiological demands. A comprehensive medical evaluation is the necessary next step to diagnose the true cause and develop a targeted treatment plan. By addressing the root issue rather than just treating the symptom, you can achieve long-term iron stability and improve your overall health.

The Merck Manual: Common Causes of Iron Deficiency Anemia

Frequently Asked Questions

In males and postmenopausal women, the most common cause of persistent iron deficiency is chronic blood loss, typically from the gastrointestinal (GI) tract. This can be caused by ulcers, polyps, or, in some cases, colon cancer, and requires a medical evaluation to identify the source.

No, taking iron supplements should increase your levels. If they continue to drop despite supplementation, it strongly suggests an underlying, untreated problem, such as continued blood loss, a severe malabsorption issue, or a chronic inflammatory condition interfering with iron utilization.

Chronic inflammation, from conditions like inflammatory bowel disease or heart failure, can increase levels of the hormone hepcidin. Hepcidin blocks iron from being absorbed by the intestines and prevents stored iron from being released, leading to functional iron deficiency.

Yes, some foods and drinks can inhibit iron absorption. These include tea, coffee, and calcium-rich foods like dairy, especially when consumed at the same time as iron-rich meals or supplements. It's recommended to separate the intake of these items.

Iron levels can drop after surgery due to two main reasons: blood loss during the procedure and changes to the digestive tract. Some surgeries, particularly bariatric or stomach procedures, can alter how and where iron is absorbed in the small intestine, leading to malabsorption.

Yes, it is possible to have iron deficiency without being anemic, especially in the early stages. Your body first depletes its iron storage (ferritin) before the iron supply for red blood cell production is affected enough to cause anemia.

Dietary iron comes from food and has two types: heme (from animal products, easily absorbed) and non-heme (from plant-based foods, less easily absorbed). Iron supplements provide a concentrated dose of iron, often as ferrous sulphate, and are typically required to correct an existing deficiency quickly, as dietary changes alone are often too slow.