How Do Your Iron Levels Go Down? An In-Depth Look at Nutritional Causes and Beyond

October 24, 2025 •

4 min read

Iron deficiency is the most common nutritional deficiency worldwide, affecting millions of people. Understanding how do your iron levels go down is crucial, as it often happens due to a combination of factors, including diet, poor absorption, and blood loss.

Quick Summary

Several factors contribute to a drop in iron levels, from chronic blood loss and dietary shortfalls to impaired absorption due to gastrointestinal issues or medical conditions. Poor nutrition and increased bodily demand, such as during pregnancy, are also significant culprits.

Key Points

Blood Loss is a Primary Cause: Conditions like heavy menstrual bleeding, internal ulcers, or frequent blood donation can significantly decrease iron levels over time.
Dietary Factors Play a Major Role: Inadequate intake of iron-rich foods, or a diet high in absorption inhibitors like tannins and phytates, can lead to low iron.
Absorption Problems Can Block Intake: Gastrointestinal disorders (e.g., celiac disease) and surgeries can prevent the body from absorbing enough iron, even with a proper diet.
Certain Life Stages Increase Demand: Pregnancy, infancy, and childhood growth spurts dramatically increase iron requirements, putting individuals at higher risk of deficiency.
Chronic Inflammation Can Trap Iron: Long-term conditions like IBD or heart failure trigger a hormone (hepcidin) that reduces iron absorption and mobilizes it from stores.
Athletes Face Unique Risks: Regular, intense exercise can increase iron loss through various mechanisms, making athletes, particularly women, vulnerable to low iron.
Diagnosis Needs Professional Assessment: Because symptoms can be vague, a healthcare provider should perform tests to determine the cause and severity of low iron.

Understanding Iron’s Crucial Role in the Body

Iron is a vital mineral found in every cell of the body, playing a critical role in overall health. It is most known for its part in producing hemoglobin, a protein in red blood cells that transports oxygen from the lungs to the rest of the body. Without enough iron, your body cannot produce enough healthy red blood cells, leading to iron-deficiency anemia.

How Do Your Iron Levels Go Down: Primary Causes

Decreasing iron levels can be attributed to four main areas: blood loss, insufficient dietary intake, impaired absorption, and increased bodily demand. Often, a combination of these factors contributes to the problem.

Chronic or Acute Blood Loss

Blood has iron in its red blood cells, so losing blood results in losing iron. This is the most common cause of iron deficiency in men and postmenopausal women.

Menstruation: Heavy menstrual periods (menorrhagia) are the most frequent cause of iron loss in premenopausal women. The amount of blood lost each month can deplete iron stores over time.
Internal Bleeding: Slow, chronic blood loss within the gastrointestinal (GI) tract is a major cause of iron deficiency. This can be a symptom of:
- Peptic ulcers
- Colon polyps or cancer
- Hiatal hernias
- Inflammatory bowel diseases (IBD), such as Crohn's disease or ulcerative colitis
Medication Use: Long-term use of certain nonsteroidal anti-inflammatory drugs (NSAIDs), like aspirin or ibuprofen, can cause bleeding in the stomach and intestines.
Frequent Blood Donation: Regular blood donors are at a higher risk of iron deficiency due to the iron lost with each donation.

Insufficient Dietary Intake

Your body gets iron from the foods you eat, but the form of iron and other dietary components can influence how much you absorb.

Heme vs. Non-Heme Iron: There are two types of dietary iron. Heme iron, found in animal products like red meat, fish, and poultry, is more easily absorbed by the body. Non-heme iron, found in plants and fortified foods, is not as bioavailable and is more affected by dietary inhibitors.
Vegetarian and Vegan Diets: People following plant-based diets are at a higher risk of deficiency because they consume only non-heme iron. While it's possible to get enough iron from plants, it requires careful dietary planning to maximize absorption.
Poor Nutrition: A diet lacking iron-rich foods, especially in children or individuals with restrictive eating patterns, can lead to depleted iron stores.

Impaired Iron Absorption

Even with sufficient dietary iron, certain medical conditions or substances can interfere with the body's ability to absorb it.

Gastrointestinal Disorders: Conditions like celiac disease, inflammatory bowel disease, or H. pylori infection can damage the intestinal lining and prevent proper iron absorption.
GI Surgery: Surgical procedures that bypass or remove parts of the stomach or small intestine, such as weight-loss surgery, can significantly reduce the area where iron is absorbed.
Dietary Inhibitors: Certain compounds in food and drink, such as tannins in tea and coffee, phytates in whole grains, and calcium in dairy, can inhibit non-heme iron absorption.

Increased Bodily Demand

Some life stages naturally increase the body's need for iron, which can lead to a deficiency if not met.

Pregnancy: The body's blood volume and red blood cell production increase significantly during pregnancy to supply blood and hemoglobin to the fetus, vastly increasing iron requirements.
Infancy and Childhood: Rapid growth spurts require additional iron to produce more red blood cells. Low-birth-weight babies, premature infants, and toddlers who drink excessive cow's milk instead of iron-rich foods are particularly at risk.
Athletes: Endurance athletes, especially female athletes, can experience increased iron loss through sweating, gastrointestinal bleeding, and foot-strike hemolysis (the destruction of red blood cells during high-impact exercise). Exercise also temporarily raises hepcidin levels, which reduces iron absorption post-workout.

Chronic Diseases and Inflammation

Chronic diseases can lead to a state known as 'anemia of chronic disease' or 'anemia of inflammation'. This happens because long-term inflammation triggers the release of hepcidin, a hormone that blocks iron absorption and traps iron in storage cells, making it unavailable for red blood cell production. Conditions that cause this include:

Chronic kidney disease
Heart failure
Rheumatoid arthritis
Obesity

Dietary Enhancers and Inhibitors of Iron Absorption

Understanding how food choices influence absorption is key to managing iron levels. Here is a comparison of dietary factors that promote and inhibit iron uptake.


Feature	Iron Enhancers	Iron Inhibitors
Mechanism	Improve bioavailability by keeping iron soluble and in the more easily absorbed form.	Bind to iron and carry it out of the body before it can be absorbed.
Key Dietary Factors	Vitamin C (citrus fruits, bell peppers), meat, fish, and poultry.	Phytates (found in whole grains, legumes, nuts), polyphenols (in coffee, tea, wine), and calcium.
Timing Consideration	Consuming enhancers alongside iron-rich meals, especially with non-heme sources, maximizes absorption.	To avoid interference, consider consuming tea, coffee, or calcium-rich foods several hours apart from iron-rich meals or supplements.
Food Example	A meal with spinach and bell peppers or fortified cereal with a glass of orange juice.	Drinking a cup of black tea with an iron-fortified breakfast cereal.

Conclusion

Decreasing iron levels can result from various factors, from simple dietary shortfalls to complex medical conditions involving chronic inflammation or blood loss. While improving your diet with iron-rich foods and absorption boosters like Vitamin C is a great first step, it's essential to understand the underlying cause. Many symptoms of low iron are vague and easily dismissed, so seeking professional medical advice is vital for an accurate diagnosis and treatment plan, especially for those in high-risk groups like pregnant women, frequent blood donors, or individuals with chronic illnesses.

Disclaimer: The information provided is for educational purposes only and is not a substitute for professional medical advice. Always consult a healthcare provider for diagnosis and treatment.

Frequently Asked Questions

Symptoms of low iron can be subtle at first and often include extreme fatigue, weakness, pale skin, shortness of breath, headache, dizziness, cold hands and feet, and brittle nails.

The best sources include heme iron from lean red meat, poultry, and fish. For non-heme iron, excellent sources are lentils, beans, dark leafy greens, tofu, and fortified cereals.

Yes, both coffee and tea contain polyphenols called tannins that can significantly inhibit the absorption of non-heme iron. It's best to consume them a few hours away from iron-rich meals.

Yes, women of reproductive age need more iron than men due to the iron loss that occurs during heavy menstrual cycles. The iron requirement also increases significantly during pregnancy.

Poor absorption can happen due to certain medical conditions affecting the gastrointestinal tract, like celiac disease or inflammatory bowel disease. Surgical procedures and even regular use of antacids can also interfere with absorption.

Iron deficiency occurs when your body's iron stores are low. Iron-deficiency anemia is a more severe stage where your iron stores are so depleted that your hemoglobin levels drop, reducing your blood's oxygen-carrying capacity.

You should see a doctor if you experience persistent symptoms of fatigue or weakness. A healthcare professional can order blood tests (like ferritin) and perform a thorough evaluation to identify the cause of the iron deficiency.