Iron testing 101: Ferritin is a poor marker of your body’s need for iron.

So you’ve been told that you have iron deficiency…… but did you know, that ferritin, often relied upon to assess iron levels, is an unreliable marker of your body’s iron needs?

Read on to find out various ways that ferritin can be falsely low or falsely elevated. You might be surprised.

Low Protein Levels: Ferritin is a protein that stores iron in the body. Low total protein levels, including albumin, can result in decreased ferritin production or stability, leading to falsely low ferritin levels in blood tests. Conditions such as malnutrition, liver disease, kidney disease, and protein-losing enteropathy can all contribute to low protein levels and subsequently impact ferritin levels.

Liver Problems: The liver plays a crucial role in iron metabolism, including the synthesis and secretion of ferritin. Liver diseases such as hepatitis, cirrhosis, and fatty liver disease can disrupt these processes, leading to increased OR decreased ferritin production or impaired liver function. Additionally, conditions that cause liver inflammation or damage can lead to increased breakdown of ferritin, or impaired clearance of ferritin from the bloodstream.

Inflammation: Ferritin is an acute-phase reactant, meaning its levels can increase in response to inflammation or tissue damage. Conditions such as infections, autoimmune disorders, chronic inflammatory diseases (like rheumatoid arthritis or inflammatory bowel disease), and certain cancers can trigger an inflammatory response, leading to increased ferritin production by immune cells. This elevation in ferritin levels may not necessarily reflect true iron stores but rather the body's response to inflammation.

Haemodilution: Conditions that cause expansion of the blood volume, such as pregnancy or fluid overload, can lead to hemodilution, where the concentration of ferritin in the bloodstream becomes diluted, resulting in falsely low ferritin levels in blood tests.

Alcohol Consumption: Chronic alcohol consumption can damage the liver and impair its ability to regulate ferritin levels. As a result, individuals with alcohol-related liver disease may have elevated ferritin levels due to liver dysfunction rather than increased iron stores. Additionally, alcohol-induced inflammation can further contribute to elevated ferritin levels in these individuals.

Obesity: Obesity is associated with chronic low-grade inflammation, which can lead to increased ferritin production as part of the body's inflammatory response. Consequently, individuals with obesity may have elevated ferritin levels independent of their iron status.

These are just a few examples of how various factors can contribute to unreliable ferritin levels in blood tests. It's essential to consider the individual patient, and the clinical context and evaluate additional markers including transferrin and transferrin saturations to ensure an accurate assessment of iron status and appropriate management.

Transferrin plays a crucial role in iron metabolism by binding to and transporting iron throughout the body. Once synthesized, transferrin is released into the bloodstream, where it circulates and binds to iron molecules, forming a transferrin-iron complex. This complex then delivers iron to cells throughout the body.

Transferrin levels 2.6 g/L and greater tell us your body is hungry for iron.

When iron levels are low, the liver increases transferrin production to enhance iron uptake and delivery to tissues. Conversely, when iron levels are high, transferrin synthesis may decrease to limit iron absorption and prevent iron overload.

Transferrin saturation is a measure of the proportion of transferrin that is saturated with iron in the bloodstream. It provides valuable information about the body's ability to transport and deliver iron to tissues for various physiological processes. We are looking for transferrin saturation to sit between 20 and 30% as a marker that your body doesn’t have too little or too much iron.

These two markers are early-warning, dynamic duo when it comes to iron assessment. Understanding the nuances of iron markers empowers you to take proactive steps toward optimal health. But no markers are read in isolation.

Have you ever been diagnosed with iron deficiency based on ferritin levels alone?

And you have been prescribed an iron transfusion or supplement without having the cause of your iron deficiency tested? See our last blog post here to learn about the different causes of low iron and the importance of addressing the root cause.

If you are curious to know more, book in for a full consultation or our standalone comprehensive pathology review service.