Key takeaways:
Ferritin is a protein that stores iron. A low ferritin level — detected by a blood test — can sometimes be the first sign of iron deficiency.
Low ferritin can lead to fatigue, dizziness, and headaches, as well as mood changes and trouble breathing and concentrating. These symptoms usually go away with iron treatment.
Your ferritin can be low if you’re not getting enough iron in your diet, not absorbing iron through your gut, or losing too much iron through some type of blood loss.
You may have heard about the importance of getting enough iron in your diet. This is because your body needs iron to make new red blood cells. If your iron stores get too low, your red blood cell count can drop. This is called iron-deficiency anemia, and it can make you feel tired and sluggish.
But how much iron you eat isn’t the whole story. In order to store iron, your body also relies on a protein called ferritin. A low ferritin level can make you feel the same way as iron-deficiency anemia — even when your iron levels and blood counts are normal. So, even though ferritin doesn’t get as much attention as iron, it’s just as important.
What is ferritin?
Ferritin is a protein that has two main roles in the body:
It stores iron in the cell. This makes sure that your body has a ready supply of iron available to use.
It plays a role in the body’s inflammatory response. This means that ferritin increases during inflammation or infection.
When you have a low ferritin level, it means you also have low levels of iron. But sometimes a low level of ferritin is the earliest sign that your iron stores are running low.
Ferritin isn’t checked as frequently as your iron level or blood counts. So low ferritin can show up as:
Iron deficiency: Iron deficiency is when your iron stores are low, but you still have a normal red blood cell count.
Iron-deficiency anemia: Iron-deficiency anemia is when low iron stores lead to a lower number of red blood cells.
And iron deficiency — both with and without anemia — can lead to similar symptoms.
What are symptoms of low ferritin?
Your body uses iron to help deliver oxygen to the rest of the body — including the brain, the muscles, and the heart and lungs. When ferritin is low, there’s less iron to help carry out that important role.
So low ferritin (or low iron) can lead to symptoms, such as:
Fatigue
Headaches
Trouble breathing
Weakness
Difficulty concentrating
Changes in mood
A quick look at related symptoms: Low ferritin can show up in different ways, from fatigue to hair shedding. Learn how iron deficiency may contribute to hair loss and what else to watch for.
Wondering about treatment options? If you’ve been told your ferritin is low, you may not have full anemia yet. This guide breaks down what iron deficiency without anemia means and how it’s treated.
For support while boosting your levels: Iron pills can help restore ferritin, but side effects like constipation are common. Get practical tips to take iron safely and make it easier on your stomach.
Low ferritin is more common in people with certain conditions like:
Febrile seizures in children
Attention-deficit hyperactivity disorder (ADHD)
It’s not clear if low ferritin (and iron) causes these conditions for some people, or if it’s related in other ways. And not all people with these conditions have low ferritin.
- Ferrous SulfateGeneric Fer-Iron
- Ferrous Gluconate
- Integra Plus
What causes low ferritin?
Low ferritin can be caused by anything that lowers the amount of iron in the body. This can happen for a variety of reasons.
The common causes of low ferritin include:
Not getting enough iron in the diet: This is common in vegans and vegetarians because the iron in plant-based foods is harder to absorb.
Increased use of iron by the body: Young children, pregnant women, and athletes need more iron than other people. Since their bodies use it so rapidly, it can be hard to get enough iron through diet alone.
Poor absorption of iron: Certain conditions — like inflammatory bowel disease or celiac disease — can make it harder to absorb iron.
Medications: Some medications — like proton pump inhibitors or histamine-2 antagonists — can interfere with iron absorption.
Chronic blood loss: Your blood cells contain a lot of iron. So anything that causes blood loss — like heavy periods, stomach ulcers, or colon cancers — can lead to the loss of iron.
What is a ferritin blood test, and how does it work?
A ferritin blood test measures the amount of ferritin in your blood. Since ferritin is the protein that stores iron inside your cells, it’s also an indirect way to measure the amount of iron in your body. It’s one of several tests that can help diagnose iron deficiency.
Why would a doctor order a ferritin test?
A healthcare professional might order a ferritin blood test if they want to check for iron deficiency. Another reason is if they’re looking for signs of high inflammation.
They might want to know if you have low ferritin in the following cases:
You have anemia, and they want to find out if iron deficiency is the cause.
They’re looking for a cause of a condition that’s associated with low ferritin, like restless leg syndrome or fibromyalgia.
You’re having any symptoms of low iron (like fatigue or trouble concentrating).
Sometimes, a healthcare professional might also want to see if you have high ferritin. This can happen if you have a chronic condition like kidney disease or rheumatoid arthritis, or if you have certain kinds of infections or cancers.
Low ferritin results
A low ferritin result means that you have iron deficiency. There’s some debate, though, about the cutoff for a low ferritin level — and it’s different based on age.
To make matters more confusing, the cutoff is also different based on your other health conditions. This is because inflammation can increase the ferritin level too.
The World Health Organization (WHO) defines the following as a low ferritin level:
Children under 5: less than 12 ug/dL (or less than 30 ug/dL in a child with infection or inflammation)
Anyone over 5: less than 15 ug/dL (or less than 70 ug/dL in anyone with infection or inflammation)
But some researchers have found that signs of iron deficiency can start showing up even before ferritin drops to that level. So they argue that we should use a different cutoff for low ferritin. Some recommend using 30 ug/dL or even 50 ug/dL as the lower limit of normal even in healthy people.
High ferritin results
High ferritin results can be a sign that there’s some type of inflammation in the body, or that there’s too much iron in the body. Conditions that lead to high ferritin include:
Infections
Cancers
Chronic diseases
Obesity
Chronic alcohol use
Iron overload, also known as hemochromatosis
The WHO guidelines for high ferritin level cutoffs break it down by sex and health status.
For females age 5 and older, the ferritin level is high if it’s:
More than 150 ug/dL in a person who’s healthy
More than 500 ug/dL in a person with infection or inflammation
For males age 5 and older, the ferritin level is high if it’s:
More than 200 ug/dL in a person who’s healthy
More than 500 ug/dL in a person with infection or inflammation
How is low ferritin treated?
The treatment for low ferritin is iron supplements. The most common form of treatment involves iron pills or liquid taken by mouth.
Common types of oral iron supplements that are used to treat low ferritin include:
Ferrous sulfate (this type is the least expensive but might be more likely to lead to an upset stomach as a side effect)
Ferrous gluconate
Ferrous fumarate
Polysaccharide iron complex (this type of iron may not be as effective as the others, but it tends to have fewer side effects)
The exact dose usually depends on the degree of iron deficiency. If you have low ferritin, a healthcare professional can tell you what dose of iron would be right for you.
If your iron deficiency is severe — or if treatment with oral iron supplements hasn’t worked — a healthcare professional might recommend an iron infusion into your vein, known as an intravenous (IV) infusion. There are several types of IV infusions. Some people only need one transfusion to be effective, while others require two or more for treatment.
In addition to treating the low iron, it’s important to treat the underlying cause of iron deficiency.
For example, if the iron deficiency occurs because of low iron in your diet, you’ll want to increase the amount of iron-rich foods you eat. If you have a condition that leads to regular blood loss, like heavy periods, you may need treatment to prevent that blood loss.
Ferritin supplements
Low ferritin is treated with iron supplements, not ferritin supplements. There are ferritin supplements on the market, but these are plant ferritin — not human ferritin. So ferritin supplements may not directly raise ferritin levels.
Ferritin supplements are a protein shell that contains iron. Some believe this may make the iron inside easier to digest and absorb. But, as of right now, there’s not enough research to suggest that ferritin supplements are an effective way to absorb iron. So healthcare professionals don’t use them as a treatment for low iron or low ferritin at this time.
Frequently asked questions
You can raise low ferritin levels the same way you raise low iron levels. The main way is to take iron supplements as recommended by a healthcare professional. Iron-rich foods can also help. But they might not be enough on their own if your ferritin levels are low.
It’s easiest to think of low ferritin as equivalent to low iron. A low ferritin level is often the first sign of iron deficiency. So, if you have low ferritin, it means the iron stores in your body are also low.
It’s still unclear if low ferritin directly causes weight gain. There’s some evidence that low iron is linked with increased body weight. But this doesn’t mean that low iron (or low ferritin) causes weight gain. It might actually be that increased body fat affects iron stores.
If you have low ferritin but normal iron levels, it means you have iron deficiency. Ferritin is the first level to drop — even before iron levels — in iron deficiency.
You can raise low ferritin levels the same way you raise low iron levels. The main way is to take iron supplements as recommended by a healthcare professional. Iron-rich foods can also help. But they might not be enough on their own if your ferritin levels are low.
It’s easiest to think of low ferritin as equivalent to low iron. A low ferritin level is often the first sign of iron deficiency. So, if you have low ferritin, it means the iron stores in your body are also low.
It’s still unclear if low ferritin directly causes weight gain. There’s some evidence that low iron is linked with increased body weight. But this doesn’t mean that low iron (or low ferritin) causes weight gain. It might actually be that increased body fat affects iron stores.
If you have low ferritin but normal iron levels, it means you have iron deficiency. Ferritin is the first level to drop — even before iron levels — in iron deficiency.
The bottom line
A ferritin test is the most sensitive test to tell if you have low iron levels. It’s usually the first test to be abnormal when someone is developing iron deficiency. Low ferritin can lead to symptoms ranging from fatigue and weakness to trouble concentrating. So it’s important to get a diagnosis.
Figuring out how to interpret your results can be tricky, though, especially if you have an infection or chronic disease. So whether your ferritin is low or normal, it’s important to talk with a healthcare professional about whether you could have iron deficiency. There are effective treatments for low ferritin in the form of oral or IV iron treatment.
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References
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