10/03/2024 | Press release | Distributed by Public on 10/03/2024 17:38
Key takeaways:
Iron-deficiency anemia (IDA) occurs when low levels of iron in the body leads to low blood counts.
IDA is more common among people with any type of blood loss, increased iron needs, or reduced iron absorption. Examples include women who menstruate or are pregnant, children, and people with gastrointestinal conditions.
The main treatment for IDA is oral iron supplements. More severe cases may require intravenous iron infusions.
Iron is an essential building block of red blood cells. These are the cells that carry oxygen to all your muscles and organs. But if you have low stores of iron, it can start to affect your ability to make red blood cells. This is called iron-deficiency anemia (IDA).
Iron deficiency is a common nutritional deficiency in the U.S. It can make people feel tired, have trouble thinking, and affect their mood. And if not treated, it can lead to anemia and serious health issues. So it's important to know the signs and how it's diagnosed. This way, you can get the treatment you need to feel better.
Anemia is a general term that means there are not enough red blood cells in the body. Iron-deficiency anemia means these low blood counts are caused by low levels of iron. Many different things can cause anemia, but iron deficiency is the most common cause.
Is your ferritin low? The first sign of iron deficiency is a low ferritin level. But many healthcare professionals don't think to check it.
Iron supplements: There are a few guidelines to keep in mind if you need to take iron supplements. Our guide will walk you through the basics.
Iron-rich foods: One of the best ways to prevent iron deficiency is with a balanced, nutritious diet. These iron-rich foods can help keep you strong.
There are a few different ways you can measure the amount of iron and red blood cells in the body. (We explain this in more detail in the testing section.) But it's helpful to know that when someone develops iron deficiency, their blood counts are not affected right away. It takes time for the general progression of iron deficiency to affect blood counts:
When iron deficiency is mild, the first thing to decrease is ferritin. Ferritin is a protein in the body that stores iron.
As iron stores get more depleted, less iron binds to transferrin. Transferrin is the protein that transports iron through the blood.
When iron deficiency becomes more severe, the number of red blood cells eventually starts to decrease.
So in many ways, anemia is a sign of more advanced iron deficiency.
The symptoms of iron-deficiency anemia can vary a lot from person to person. Someone with IDA may have few or even no symptoms. And other people with low ferritin - even before iron deficiency progresses to true anemia - may notice pretty significant changes in how they feel.
Symptoms of low iron (or low ferritin) include:
Fatigue and low energy
Headaches
Trouble concentrating
Changes in mood
As iron-deficiency anemia develops, additional signs and symptoms include:
Shortness of breath
Heart palpitations or a fast heartbeat
Cravings for ice
Feeling more cold than normal
Paleness or increased bruising
Loss of appetite or nausea
Brittle nails or hair loss
The most common causes of low iron levels are:
Decreased iron consumption in the diet
Decreased iron absorption through the gut
Increased need for iron, such as during pregnancy
Blood loss
Blood loss can happen for many different reasons. But some of the more common reasons are:
Heavy menstruation
Bleeding from the stomach or intestine, like from a stomach ulcer
Recent surgery
Frequent blood donation
In general, iron deficiency in the U.S. is more common in young children and women of reproductive age.
More specifically, the risk factors for iron-deficiency anemia include:
Heavy menstrual bleeding
Pregnancy or lactation
Strict vegetarian or vegan diet, or diets low in iron-rich foods
Cancer in the esophagus, stomach, small bowel, or colon
Peptic ulcer disease
Celiac disease
Crohn's disease
A history of gastric bypass surgery or intestinal surgery
Medications, like tetracycline, antacids, or nonsteroidal anti-inflammatory drugs (NSAIDs)
Iron-deficiency anemia can also happen in infants and children. Infants who are born prematurely are at risk for IDA. And children who drink more than 16 oz to 24 oz a day of cow's milk are also at higher risk of developing IDA. This happens because cow's milk interferes with iron absorption from other foods. It can also irritate the gastrointestinal (GI) tract, which causes bleeding.
To have a diagnosis of iron-deficiency anemia, you need to have lab tests that show both:
Low red blood cell counts (anemia)
Low iron stores (iron deficiency)
There are a few different tests that are all related to red blood cells. And they all can help diagnose anemia. These tests are a standard part of any complete blood count test (CBC):
Red blood cell count (RBCs): the actual number of red cells in your blood
Hematocrit (Hct): the concentration of red cells in your blood
Hemoglobin (Hgb): this measures the amount of hemoglobin, the protein in a red blood cell that holds onto oxygen
Mean corpuscular volume(MCV): the average size of your red blood cells
The normal ranges for these tests are listed below. So any levels below these are suggestive of anemia. When it comes to iron-deficiency anemia, healthcare professionals pay close attention to the hemoglobin (Hgb) test and the mean corpuscular volume (MCV) specifically.
Women |
Men |
|
RBCs |
4.2 to 5.4 million cells/μL |
4.6 to 6.2 million cells/μL |
Hct |
36% to 48% |
40% to 54% |
Hgb |
12 to 16 g/DL |
13 to 18 g/DL |
MCV |
80 to 100 µm3 |
80 to 100 µm3 |
Newborns and children, depending on their age, have different normal ranges from adults.
A low Hgb and low MCV suggest iron-deficiency anemia. But in order to test if iron deficiency is causing your anemia, a healthcare professional will also check your iron levels. Like blood counts, there are a few different tests that can measure iron in your body:
Ferritin: the amount of ferritin in your blood, the protein that stores iron. This is often the first test a healthcare professional looks at when diagnosing iron deficiency. It will be low.
Transferrin saturation: the percentage of iron in your blood that's bound to transferrin, the protein that transports iron. This is below normal in IDA.
Total iron-binding capacity(TIBC): the amount of iron that your blood can potentially carry. Most of the time, a transferrin saturation can replace this test.
Iron: the amount of iron in your blood. Surprisingly, this test result is not used to make the diagnosis of IDA. The above tests are more helpful.
Every lab uses a different cutoff for normal values. But if you're looking at your results, the report should indicate if your level is normal, high, or low. When it comes to iron-deficiency anemia, healthcare professionals pay close attention to the ferritin and transferrin saturation. The table below summarizes the typical results for someone with IDA.
Test |
Iron deficiency |
Ferritin |
Less than 30 ng/mL |
Transferrin saturation |
Less than 20% |
Total iron-binding capacity |
Above normal |
Iron |
Below normal |
To treat iron-deficiency anemia, most healthcare professionals prescribe oral iron supplements. There are many types of iron supplements, but the most commonly prescribed supplements are:
Ferrous fumarate
Ferrous sulfate
In some cases, people need intravenous (IV) iron. This might be the case if someone's iron levels are extremely low, or if they're experiencing more severe symptoms. IV iron may also be better for someone who cannot take iron by mouth.
Response to iron therapy can be seen in as little as 2 weeks. But most people will need to continue taking iron supplements for several weeks or even a few months. Your healthcare team will monitor your treatment with blood work. Depending on the cause of your iron deficiency, you may be able to stop taking supplements once your blood counts and iron levels are normal.
Oral iron supplements should be taken on an empty stomach, if possible. This is because there are some foods that may interfere with iron absorption. Iron should not be taken with:
Milk
Eggs
Tea or coffee
There's some data to support the idea that orange juice can actually increase iron absorption, so taking iron supplements with a glass of orange juice is OK.
Certain medications can also interfere with iron absorption such as:
Antacids
Calcium supplements
Zinc supplements
Proton pump inhibitors
Levothyroxine
Levodopa
People should take iron supplements either 2 hours before or 4 hours after taking these medications.
Side effects of oral iron supplementation include:
Abdominal discomfort
Nausea
Diarrhea
Black, green, or tarry stools
Taking too much iron can cause mild to severe adverse effects - from nausea to multisystem organ failure, seizures, and even death. So it's important to always take iron supplements as prescribed. Talk with your healthcare team if you're having side effects from them.
Finally, it's important to note that fatal overdoses have been reported in children. Iron supplements should be safely stored so children cannot get ahold of them.
While iron-rich foods are usually not enough to treat IDA, they can help prevent iron deficiency. Iron-rich foods include both animal and plant-based foods. But iron from animal-based food is more easily absorbed.
Examples of iron-rich foods include:
Meat (especially organ meat, like liver)
Eggs
Seafood
Raisins
Prunes
Spinach
Broccoli
Beans and lentils
Fortified breads and cereals
Iron plays a major role in many metabolic processes of the body. So the consequences of iron-deficiency anemia can be wide-ranging and include:
Worsening heart disease
Increased risk of infection
Complications during pregnancy
Physical and cognitive difficulties in children
Restless leg syndrome
Most people with iron-deficiency anemia have very few or no symptoms. But if symptoms appear quickly, you should get emergency help right away. These symptoms include:
A rapid heartbeat (over 100 beats per minute, even at rest)
Intense dizziness
Fainting
Abnormal or heavy bleeding
Chest pain
Difficulty breathing
Confusion or altered consciousness
The only way to know for sure if you have iron-deficiency anemia is to see a healthcare professional for blood tests. But there are a few signs you may notice at home that can be a clue. In addition to the symptoms listed above - like fatigue and hair loss - anemia can make your skin paler than usual. People also can sometimes tell their gums or the inside of their eyelids look pale.
Certain medications can interfere with the absorption of iron. If you take these medications on a regular basis over a long period of time, they can cause your iron levels to drop. Examples include:
Antacids that contain calcium, magnesium, or aluminum
NSAIDs and aspirin
Certain antibiotics
Ulcer medications, like cimetidine or famotidine
Proton pump inhibitors
Researchers don't know for sure why iron deficiency is associated with cravings to chew ice. Some hypothesize that chewing ice increases mental alertness. Others suggest it may help soothe tongue inflammation, which can happen with iron deficiency. But no one knows for sure.
Iron deficiency is a common condition in the U.S., and it's one of the most common causes of anemia. It's more common among women who menstruate, or who are pregnant. If you're experiencing new symptoms like fatigue or hair loss, talk with your primary care provider about testing for IDA. Untreated iron-deficiency anemia can have significant health consequences. But once diagnosed, iron-deficiency anemia can be easily treated with oral iron supplements.
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