Transferrin is a protein that binds iron and transports it to where it’s needed. When there is enough transferrin, your body can effectively use the iron you get from the diet. Iron availability dictates transferrin production, but transferrin levels are also influenced by inflammation, liver, and kidney disease. Keep reading to learn more about high and low transferrin levels and ways to improve them.
What is Transferrin?
Transferrin is a protein that binds iron and transports it throughout the body. It is the main iron carrier in the blood. When you have enough transferrin, your body can effectively use the iron you get from your diet [1, 2].
Transferrin levels increase with iron deficiency. When iron is low, your body will try to compensate by making more transferrin to increase the availability of iron [3].
On the other hand, transferrin will decrease with iron overload [4, 5].
This protein is produced in the liver, so its levels are also associated with your liver health and inflammation in general. Transferrin is a negative acute phase protein. This means that with inflammation, the liver increases the production of inflammation-associated proteins (e.g. CRP, ferritin) while it decreases the production of proteins such as transferrin [6, 7].
Transferrin levels can be measured directly with a blood test. Alternatively, they can also be measured indirectly using total iron binding capacity (TIBC).
Normal Range
In healthy people, transferrin levels will normally be between 200 – 370 mg/dL (milligrams per deciliter).
Levels may vary slightly between laboratories, due to differences in equipment, techniques, and chemicals used.
High Transferrin Levels
Causes of High Transferrin Levels
The most common cause of high transferrin levels is iron deficiency [8, 9, 10].
Work with your doctor or another health care professional to get an accurate diagnosis. Your doctor will interpret your result, taking into account your medical history, symptoms, and other test results.
Iron deficiency can have many causes, including dietary deficiency, bleeding (e.g. menstrual bleeding or ulcers), gut disorders that decrease iron absorption (e.g. celiac disease), or toxins (e.g. lead).
Ways to Decrease Transferrin Levels
The most important thing is to work with your doctor to find out what’s causing your high transferrin and to treat any underlying conditions. The additional lifestyle changes listed below are other things you may want to discuss with your doctor. None of these strategies should ever be done in place of what your doctor recommends or prescribes!
If you have iron deficiency anemia, your doctor may prescribe iron therapy [11]. Keep in mind that It may take several months of supplementation to correct iron deficiency.
Make sure your diet is healthy and well balanced. Increase your intake of foods that are rich in iron to replenish your iron stores. These include red meat, poultry, fish, beans, lentils, tofu, tempeh, nuts, and seeds.
An easy way to get more iron in your meals is to use cast iron utensils [12].
Refrain from drinking coffee, milk, cocoa, or green, black and herbal tea within an hour before or after a meal, as these decrease iron absorption from food. For example, a study suggests that compared to water, drinking cocoa can inhibit iron absorption by about 70%, while black tea can decrease iron absorption by as much as 80 to 90% [13, 14, 15, 16, 17, 18].
Phytates found in whole grains and legumes also decrease iron absorption. When you eat them, add foods rich in vitamin A and beta-carotene – research shows that they can increase iron absorption and can override the influence of phytates [19, 20, 21]. Foods rich in vitamin A and beta-carotene include carrots, sweet potatoes, fish, cantaloupe, bell peppers, squash, and grapefruit.
Increase the amount of vitamin C-rich foods in your diet. Sprinkle some lemon juice on your steak and salads. If you are taking iron supplements, you can take them with orange juice. Vitamin C increases the bioavailability of iron and its absorption in the gut [22].
Avoid aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen – they can cause gut injuries and increase the loss of blood and therefore iron [23, 24].
Try not to take your iron-rich meals or iron supplements within 2 hours of antacids and heartburn medication [25].
Low Transferrin Levels
Causes of Low Transferrin Levels
Causes shown here are commonly associated with low transferrin levels. Work with your doctor or another health care professional to get an accurate diagnosis. Your doctor will interpret your result, taking into account your medical history, symptoms, and other test results.
1) Iron Overload
The most common cause of low transferrin levels is iron overload (excess iron) [26, 10].
Iron overload can be due to iron poisoning (acute), or due to chronic overload due to hereditary disorders such as hemochromatosis, thalassemia, or sickle cell anemia [27, 9].
2) Inflammation
As mentioned above, transferrin is a negative acute phase protein. When the liver increases the production of inflammation-associated proteins (e.g. CRP, ferritin) it decreases the production of transferrin. A number of conditions such as infection and cancer can decrease transferrin levels [6, 7, 28].
In an observational study of 297 people, people with active inflammatory bowel disease (IBD: both Crohn’s disease and ulcerative colitis) had significantly lower transferrin levels. Increased IBD activity and inflammation severity were associated with lower transferrin levels [29].
Similarly, a study compared 20 patients with chronic periodontitis (gum inflammation) and 20 healthy people. It found that those with chronic gum inflammation had lower transferrin levels. Three months after the inflammation was treated blood transferrin levels increased back to the levels seen in healthy subjects [30].
Preeclampsia, a condition that causes high blood pressure during pregnancy, is associated with inflammation. Women with preeclampsia can have decreased transferrin levels [31, 32].
3) Liver Disease
People with liver disease have significantly lower transferrin levels than healthy people [33, 27].
In liver disease, the liver can’t produce transferrin effectively [34].
This can be caused by impaired liver function, inflammation, or alcohol consumption [35].
4) Malnutrition
To produce protein, the liver needs resources. It needs amino acids that you obtain as dietary protein. When there’s a lack of protein in the diet, your liver can’t produce transferrin effectively [36].
In studies with over 80 children, the ones that were malnourished had significantly lower transferrin levels [37, 38].
5) Kidney Disorders
Nephrotic syndrome is a kidney disorder that causes the body to excrete too much protein in the urine. Transferrin is one of the proteins that gets excreted. That’s why people with nephrotic syndrome may have significant transferrin loss [39, 40].
6) Genetics
Transferrin can be low due to genetic causes [41, 42].
Ways to Increase Transferrin Levels
The most important thing is to work with your doctor to find out what’s causing your low transferrin and to treat any underlying conditions. The additional lifestyle changes listed below are other things you may want to discuss with your doctor. None of these strategies should ever be done in place of what your doctor recommends or prescribes!
If your transferrin is low due to iron overload:
- Avoid foods that are high in iron, such as red meat, fish, and poultry [43].
- Eat more foods that reduce iron absorption such as fiber and phytic acid (from whole grains) and chili [44, 45, 46].
- Drink more coffee, cocoa, green tea and herbal teas, such as chamomile, lime flower, pennyflower, mint, and vervain with meals – all of these decrease iron absorption [15, 47, 14, 16, 48, 17].
- Avoid using cast iron utensils. They increase the amount of iron in meals [12].
- Get more exercise. Regularly exercising will help prevent your iron levels from becoming too high [49, 50].
In more severe cases of iron overload, your doctor may prescribe blood donation, blood removal (phlebotomy), or drugs that bind and remove iron (chelation) [51].
Discuss the following supplements with your doctor. Studies suggest they may help with iron overload:
Remember, always speak to your doctor before taking any supplements, because they may interfere with your health condition or your treatment/medications!
