A 2025 study found that up to 45% of patients with kidney disease have an iron deficiency. Iron plays a crucial role in kidney disease. It can be low because of many reasons. For example, high inflammation in kidney disease can increase production of hepcidin, a liver hormone that blocks iron absorption in the gut.
Iron is used to make hemoglobin, which transports oxygen. Oxygen is used to help heal and repair tissues. All the cells in our body require oxygen to survive and function. Low hemoglobin can put additional strain on other organs, such as the heart as it has to work harder to deliver enough oxygen to the body via blood.
To give the most comprehensive perspective possible, Dr. Baker (ND) reviewed over 25 research studies that assessed the impact of iron in kidney health. The most important ones and their findings are discussed below.
Symptoms of Low Iron
When levels are low, cells receive less oxygen, leading to fatigue, weakness, dizziness, and the feeling of being out of breath. This lack of oxygen can make daily activities more difficult and cause difficulty concentrating or brain fog. Low iron can increase risk of infections and impair healing. Addressing low iron and other causes of anemia (low hemoglobin) is essential for maintaining energy and overall quality of life.
Benefits of Iron
Taking iron orally helps prevent the need to escalate to more aggressive treatments such as erythropoietin, blood transfusions or intravenous iron. If anemia becomes too severe it generally has to be treated aggressively to ensure enough oxygen to the body and to prevent complications.
Longevity: A 2015 study on non-dialysis patients found that those who prevented iron-deficiency anemia had a 3-fold higher survival rate than those with iron-deficiency anemia.
Heart Health: A 2023 study on non-dialysis patients found that those with low transferrin saturation that supplemented iron had lower risk of developing cardiovascular disease.
Kidney Health: A 2023 study found a trend towards improved kidney function. After three months, those receiving iron had a 2-point increase in GFR (kidney function), while those not taking iron had a 2-point decrease in GFR. Similarly, a 2005 study found that patients in the group who were treated for iron deficiency more aggressively had a greater improvement in anemia and had around a 3 point greater GFR compared to placebo.
Physical Health: The 2023 study above also found a trend towards improved exercise capacity and endurance as measured by a walking test.
Oral or Intravenous Iron
A doctor can help determine which form of iron is best for you. Both forms of iron depend on each individual’s context. A 2015 study found that those who use oral iron to maintain iron levels had lower rates of cardiovascular events and fewer infections requiring hospitalizations. Whereas, if iron levels drop too low, IV iron is still the most effective means of increasing iron levels.
Which Form of Iron
A health professional can help assess which form of iron is best for you. Our clinic uses a specific form of iron that research has found to be highly bioavailable and absorbed by the body. Studies have also found that it tends to cause less adverse effects than many other forms of iron.
Why Does Low Iron Happen in Kidney Disease?
Individuals with kidney disease often struggle with maintaining adequate iron levels due to reduced absorption and chronic inflammation. Some of the main reasons include:
1. Inefficient Iron Recycling:
Normally, our bodies recycle iron from old red blood cells to make new ones. Special cells called macrophages engulf and break down old red blood cells, releasing iron back into the bloodstream for reuse. In CKD, this recycling process doesn't work as well, leading to less iron available for new red blood cell production.
2. Impaired Gut Absorption:
Iron from our diet is absorbed in the small intestine. In CKD, changes in the intestinal lining and the presence of uremic toxins (waste products that accumulate due to reduced kidney function) can impair the intestine's ability to absorb iron efficiently (2020 study).
3. Inflammation-Induced Iron Sequestration:
CKD often involves chronic inflammation, which leads to increased production of a hormone called hepcidin. Hepcidin inhibits iron transport by binding to the iron export channel ferroportin, preventing iron release from storage sites like macrophages. This results in iron being trapped within cells, making it unavailable for red blood cell production, even if the total iron in the body is sufficient.
In summary, CKD disrupts iron recycling, absorption, and availability due to impaired macrophage function, intestinal changes, and inflammation-induced iron trapping, leading to reduced iron for new red blood cells.
Conclusion
Iron deficiency is a common and significant issue in individuals with kidney disease, affecting nearly half of patients. This deficiency arises from multiple factors, including chronic inflammation, impaired absorption, and disrupted iron recycling. Given iron's critical role in oxygen transport, energy production, and organ function, addressing low iron levels is essential for maintaining overall health, reducing the risk of complications, and improving quality of life.
Research highlights the benefits of iron supplementation, which may include improved kidney function, cardiovascular health, and physical endurance. Early intervention with oral iron may help prevent the need for more intensive treatments such as intravenous iron or blood transfusions. However, in cases of severe deficiency, IV iron remains the most effective way to restore iron levels.
Since iron needs vary based on individual health status, consulting a healthcare professional can help determine the best approach. Managing iron levels proactively in kidney disease supports better outcomes, helping to protect the heart, kidneys, and overall well-being.
Disclaimer: This post is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your healthcare provider or a qualified medical professional before starting any new treatment or if you have questions about your medical condition. While we aim to provide accurate, research-based information, individual needs and responses to treatments can vary. Our clinic offers personalized consultations to discuss health concerns and develop tailored care plans. Never disregard professional medical advice or delay seeking it because of information you have read on this site.
