How to Measure Ferritin Levels Using Lab Testing

Ferritin, a crucial protein in the human body, serves as the main storage mechanism for iron, mirroring the total iron reserves present. Iron, essential for numerous physiological functions such as oxygen transport and energy metabolism, must be carefully balanced to avoid health complications. Low ferritin levels often indicate iron deficiency, which can progress to anemia, whereas high levels may suggest iron overload, potentially leading to diseases like hemochromatosis. 

This article aims to empower readers with detailed insights into ferritin level measurement. It will cover the necessity of testing, the procedure involved, and the interpretation of results, ensuring a thorough understanding of how to manage and maintain healthy iron levels effectively.

[signup]

What is Ferritin?

Ferritin is vital to maintaining healthy iron levels due to its role as an iron storage protein. Iron is an essential mineral that is involved in many important systemic processes, most notably as a component of hemoglobin in red blood cells, responsible for transporting oxygen throughout the body and delivering it into the tissues. 

Minimizes Iron Toxicity

Despite being an important player in overall bodily health and function, excess levels of free iron can lead to the formation of free radicals, which can damage DNA, lipids, and proteins (18). Ferritin acts to minimize iron’s potentially toxic effects by sequestering excess iron so that it is unable to generate free radicals. The storage capacity of ferritin is not unidirectional, however, and ferritin can make iron available when needed for important bodily functions (18).  

Clinical Marker for Iron Stores

As a key regulator of available iron, ferritin is an important clinical marker for measuring total iron body stores, therefore making it a valuable tool in the assessment of iron deficiency and iron overload (18). Serum ferritin is one component of an overall iron panel that includes serum iron, transferrin saturation, and total iron-binding capacity which is often used in the evaluation of iron deficiency anemia (18). Serum ferritin is often utilized to monitor proper iron supplementation to ensure that levels are kept within healthy limits and to protect against iron overload. 

Acute Phase Reactant

It is important to note that ferritin is also an acute phase reactant, meaning that its level can rise in the presence of both acute and chronic inflammation. Indeed high ferritin levels are often elevated in inflammatory conditions such as autoimmune disease, chronic kidney disease, and malignancy. When ferritin is elevated in these conditions, it can lead to iron deficiencies such as that is seen in anemia of chronic disease, due to increased sequestration of iron (26). 

Indications for Ferritin Testing

Ferritin testing is essential for diagnosing and managing iron-related disorders, providing critical insights into iron deficiency and overload conditions.

Identifying Iron Deficiency: 

Low iron is a common nutrient deficiency that can eventually lead to iron deficiency anemia (IDA) or iron deficiency without anemia (IDWA) which together affect over 2 billion people worldwide (2). IDA and IDWA can cause symptoms such as fatigue, muscle weakness, and shortness of breath. Due to its high sensitivity and specificity, serum ferritin is particularly suited to identify IDWA, even when complete blood cell counts are normal. Serum ferritin is thus an important diagnostic and screening tool for both IDWA and IDA (2).  

Monitoring Iron Overload: 

Poor absorption or excessive intake of iron can lead to iron overload in the body. This excess iron accumulates and deposits in various organs, including the heart, liver, and joints, where it can cause free radical damage, potentially leading to conditions like heart failure and liver disease (18).

Hereditary hemochromatosis (HH) is a genetic condition that results in increased absorption of iron from foods and is an important cause of iron overload. As HH is often treated with routine phlebotomy, serum ferritin is also an important monitoring tool to gauge appropriate phlebotomy frequency to prevent unintentional iron deficiency (18). 

Other Medical Conditions: 

Serum ferritin can also be used as an indirect marker for:

• Inflammatory disorders
• Cardiovascular disease 
• Liver disease
• Restless Leg Syndrome
• Rheumatoid arthritis
• Coronary artery disease 
• Hepatitis C

Preparing for the Ferritin Test

To ensure the accuracy of your ferritin test results, follow these straightforward preparation guidelines.

Pre-Test Instructions: 

The preparation for a serum ferritin blood draw is relatively easy. If you are only testing for ferritin, fasting is not necessary, and you can eat normally. You also do not need to avoid taking any medications or supplements you may be on. If ferritin is being tested as part of a larger panel, check with your provider, as fasting and/or medication avoidance may be indicated for other labs (1). 

What to Expect During the Test: 

Blood draws are performed by healthcare providers and trained phlebotomists. During a blood draw procedure, you will be seated as the provider inspects your arms for a suitable vein usually located in the inner elbow or less commonly in the hand. The provider will then clean the site with an antiseptic and apply a tourniquet to the upper arm to help make the selected vein more prominent. A needle will then be inserted to collect the venous blood into a small tube. After the sample is collected, the tourniquet and needle are removed and the sample is sent to the laboratory to be processed (5). 

Understanding Ferritin Test Results

Normal

Generally, normal ranges for ferritin fall between 30-400 ng/mL in men and 15-150 ng/mL in women, though this may vary slightly from lab to lab. Anything above this range is considered high, and anything below is considered low. 

High

High ferritin levels can be caused by:

• Inflammation 
• Obesity
• Excessive alcohol intake 
• Hemochromatosis
• Liver disease

Low

Low serum ferritin can be caused by:

• Iron deficiency anemia
• Iron deficiency anemia without iron
• Hypothyroidism
• Vitamin C deficiency
• Celiac disease
• Crohn’s disease

Although the normal range for serum ferritin is above 15 ng/mL in women and 30 ng/mL in men, some sources recommend that 40 ng/mL be the lower cutoff when screening for iron deficiency and that therapeutic targets be set as high as 100 ng/mL (2, 18).

Other Factors Influencing Ferritin Levels

Other non-pathological causes can lead to altered ferritin levels. These primarily include genetic mutations of the hemochromatosis gene that affect iron absorption but not to the level of hereditary hemochromatosis. These mutations can cause either high ferritin levels or reduced ferritin levels depending on their expression (24). 

Follow-up and Management

If your ferritin lab tests come back abnormal, your healthcare provider will likely perform additional testing and workup to pinpoint the cause. This may include further blood work, imaging, or genetic testing, depending on the suspected culprit. Treatment plans will then be determined based on the root cause of the issue. 

[signup]

Key Takeaways

• Ferritin plays a vital role in assessing iron status, serving as a primary storage protein for iron and an indicator of both iron deficiency and overload. It’s crucial for diagnosing conditions like iron deficiency anemia and hereditary hemochromatosis.
• Elevated ferritin levels can signal not just iron overload but also acute or chronic inflammation, impacting conditions like autoimmune diseases and cardiovascular disease. 
• Accurate ferritin testing is key to guiding effective treatment strategies. It helps ensure iron levels are maintained within a healthy range, avoiding both deficiency and excess.
• Due to its complexity, interpreting ferritin levels should be done by healthcare professionals. This ensures the development of an appropriate management plan based on individual patient needs, incorporating diet, lifestyle, or medical interventions as required.