Our Body Iron Levels: Potentially Very Dangerous and Seldom Measured Correctly
Iron is most often associated with anemia when it is low, but it is one of the most critical elements necessary for all life on the planet. It plays a significant role in oxygen transport by hemoglobin(67% of total body iron), short-term oxygen storage by myoglobin(3.5%of total body iron), and energy generation by cytochromes(3%of total body iron). Iron also serves vital roles in many enzymes that represent about 2% of total body iron.
It only makes up about 3.5 to 5 grams of us. FYI, five grams is a teaspoon-full. 75% of it is in use, mostly as hemoglobin, and we store the remainder in a colossal molecule called ferritin. The body conserves about 96% of it each day, so we don't require much of it in our diet. Spent red blood cells take iron to the spleen, where special cells called macrophages remove it. It is then taken to the bone marrow by a transferrin molecule, where it gets back into the red blood cells. Most of our iron is lost by sloughing off cells in the intestine. This 4% is required to be replenished by the diet. In healthy adults, 20 to 25 mg of iron cycles daily. Absorption of only 1 to 2 mg of iron daily from the diet balances its loss. Iron bound to hemoglobin (animal-based) is the easiest to absorb, whereas elemental iron and iron bound to plant matter is less readily absorbed. Most iron is not absorbed and passes via excretion.
The liver plays a crucial role in monitoring how much iron is picked up by transferrin by regulating iron absorption from the gut and adjusting iron release from the spleen. The liver hormone, hepcidin, is responsible for the regulation.
Unlike many substances we absorb, we can't actively excrete it once it is absorbed. Therefore, the only way we can regulate it is to control the amount we absorb from our gut in the first place. (1)
As you probably know, iron is extremely prone to oxidation. Oxidized iron is commonly known as rust. Oxidation is very bad for the body, so we store it in its unoxidized form in ferritin. Ferritin also protects us during infection, limiting the availability of iron to germs. For this reason, elevated ferritin occurs with infections and inflammation. Whatever the cause, elevated ferritin is associated with higher mortality. (2) Too much iron causes massive amounts of oxidation, and too little leaves us weak and vulnerable to disease and infection. It literally can make our organs rust.
Fully one-third of the world's population suffers from iron deficiency. The symptoms include fatigue, rapid heart rate, palpitations, inability to maintain proper body temperatures, brittle and spoon-shaped nails, sores at the corner of the mouth, taste bud atrophy, sore tongue, pica, rapid breathing on exertion, restless legs, infections, poor mental function, brain fog, and reduced exercise tolerance. (3)
The dietary causes of low iron include plant-based diets that don't include hemoglobin-based iron, excess dairy product, coffee, tea, chocolate, egg, and fiber consumption.
The non-dietary causes of low iron include heavy menstruation; pregnancy; frequent or excessive blood donation; fibroids; digestive tract disease, surgeries, and accidents; low stomach acid; lack of intrinsic factor, which is a hormone needed to absorb B12, pernicious anemia; celiac disease; Crohn's disease; autoimmune diseases; H. Pylori infections, hormone imbalances; medications that lower stomach acid; some dietary supplements or substances that cause bleeding such as pain relievers with aspirin; and poisoning from lead, toxic chemicals, or alcohol abuse.
Iron overload (too much iron in the body), which is also called hemochromatosis, is associated with a long list of pathologies and diseases, including metabolic conditions affecting the liver; diabetes; metabolic syndrome; gout; cardiovascular disease; neurological issues such as Alzheimer's disease, Parkinson's disease, epilepsy, and restless legs syndrome; endocrine problems such as impotence, infertility, hypogonadism, hypothyroidism, and hypoparathyroidism; immune imbalances such as asthma, inflammatory bowel disease, rheumatoid arthritis, lupus, psoriasis, gout, lung disease, and cancer; enlarged spleens and infections; musculoskeletal disorders such as osteoporosis and osteoarthritis. (4)
The leading cause of iron overload is genetic, but excess iron supplementation, beta-thalassemia, sickle cell anemia, alcohol abuse, and viral hepatitis are common causes. The problem with detecting undesirable iron levels lies in the fact that most doctors don't order the correct tests. The tests that they do order have lab value ranges that allow problematic levels to go undetected.
Most doctors order complete blood counts when you get a check-up. Some of the measurements include red blood cell counts and size, hemoglobin, and more. Anemia can result from low iron and is a common finding. This post is about iron, not anemia specifically. Iron has many more impacts on the body other than anemia and should be measured when you get a physical. Here is a list of the tests you should ask for when you visit the doctor:
Serum Iron: a poor marker in general; it can be normal or low with iron overload. You will usually get this one from your doctor.
Serum Ferritin: Ferritin is the storage molecule for iron and is a useful marker, but the upper limit usually is set too high on tests. Remember, high ferritin is also seen with infection and inflammation.
Transferrin Saturation: Transferrin carries iron; the higher the saturation, the more likely there is too much iron. Again, the upper limit is set too high on most standard tests, causing the doctor to ignore potential problems.
TIBC: Total Iron Binding Capacity is your capacity to capture iron, and it should not be maxed out, as it could point to too much iron. On the other hand, there could be too little iron if there is not much iron bound.
UIBC: Unsaturated Iron Binding Capacity is the "wiggle room" for iron. We want there to be room to take on extra iron if needed. If the UIBC is low, there is a chance that excess iron may be present.
sTfR: Soluble Transferrin Receptor measurements represent the iron's empty binding sites and are generally high when iron is low and low when iron is elevated. The more receptors are free, the less iron bound to them, indicating deficiency.
I have intentionally left off the lab ranges, as this post is not intended to help diagnose iron problems, which is complicated and rife with nuance. Suffice to say that the functional medicine ranges are stricter, causing us to detect problems earlier than most conventional docs.
If you suspect an issue, consult with a qualified functional medicine practitioner. If they find your iron is low, they will need to determine whether your diet or an underlying condition caused it.
The markers of low iron are:
Serum iron: low
Serum Ferritin: low
Transferrin Saturation: low
TIBC: high
UIBC: high
Soluble Transferrin Receptor: high
RDW: high (this is part of a normal Complete Blood Count test)
If you are low in iron due to diet, your practitioner may recommend the following:
Eat clams, oysters, beef and chicken liver regularly throughout the week. These foods are the highest in iron compared to other foods.
Take vitamin C (as ascorbic acid) and betaine hydrochloric acid (HCl) with meals. These substances increase iron absorption significantly. Betaine HCL raises stomach acid, which assists you in absorbing iron.
Avoid tea, coffee, dairy products, supplemental fiber, calcium, and zinc with meals. These things decrease iron absorption.
Have a glass of wine or other alcohol with dinner, as alcohol also improves iron absorption.
Cook in cast iron whenever possible, as it sheds iron during use.
Don't smoke.
If the steps recommended above do not improve your iron levels, and your clinician suggests it, take a heme iron supplement at the dose your clinician recommends.
If you have a medical problem absorbing iron, your doctor will need to treat the condition. For instance, if you have GERD and are on medication that lowers your stomach acid, you will not have the capacity to absorb iron. The condition needs to be eliminated properly to get iron absorption back to normal.
The markers for high iron are:
Serum iron: high
Serum Ferritin: high
Transferrin Saturation: high
TIBC: low
UIBC: low
Soluble Transferrin Receptor: low
GGT: high
High GGT (a liver enzyme) causes tissue and cell damage, and Red blood cells are particularly susceptible. Damaged red blood cells lead to iron release, which is hugely damaging. (5) As a result of this relationship, GGT is a marker of toxic iron levels. Read more about GGT in my post here if you want to know more. A handy tool called the FeGGT score takes some iron markers and GGT and calculates your risk. If you know your transferrin saturation, ferritin level, hemoglobin, and GGT, you can calculate your score for free here.
When iron overload is suspected and does not respond to the initial treatments, the practitioner should do a genetic test to rule out the hereditary form of hemochromatosis.
If there is no genetic component, then, depending on the severity, recommendations may include:
Do not consume high iron-containing foods like organ meats, venison, clams, oysters, or mussels.
Consume coffee and tea with meals as they lower iron absorption
Consume various fruits, vegetables high in oxalic acid, phytic acid, and polyphenols, which inhibit non-heme iron absorption. These include dark leafy greens, brightly colored fruits, veggies, nuts, chocolate, lentils (if tolerated), and spices/herbs.
Consume dairy products with meals (if tolerated). Dairy products are rich in calcium, which is the only substance known to decrease both heme iron (found in animal products) and non-heme iron.
Limit supplemental vitamin C. Vitamin C in foods is acceptable.
Avoid sugar. It increases iron absorption by as much as four times in some cases.
Don't drink alcohol.
Don't take Betaine HCl
Don't eat fortified foods or supplements/multivitamins that contain iron.
Limit consumption of beef and lamb to two to three times per week. They are also high in heme iron.
Take apolactoferrin. Lactoferrin is the only natural substance known to remove iron that is stored in the body.
If iron is still high after initial attempts to lower it, then blood donation is an excellent way to reduce it. Donating blood is an incredible thing to do, even if you have no iron issues. It improves your health in numerous ways. Please read my post about it here.
If the iron level is very high, then donation is not the way to go because you can only donate every 56 days, and sometimes patients need to have blood taken two times per week until the iron is back to normal.
This post is intentionally vague with regards to diagnosis and treatment protocols. Iron metabolism is a complicated subject and should be diagnosed and treated professionally. You should call your doctor if you suspect you may have a problem or are just curious about your iron. Functional medicine practitioners are more likely to run the additional tests I mentioned today. You can find one here.