Overview of Iron Deficiency

Iron deficiency is the most common cause of nutritional deficiency in the world. It usually stems from a lack of dietary iron, but medical illnesses can cause iron deficiency as well. It can cause subtle, slowly worsening effects, such as anemia (low red blood cell count) and learning delays in children.

Iron deficiency can be detected with blood tests. Eating a diet rich in iron, taking supplements, and intravenous (IV) iron replacement can help bring your iron to an optimal level. Sometimes, iron deficiency anemia may require treatment with a blood transfusion to restore red blood cell (RBC) count.


Iron deficiency causes a variety of symptoms, typically due to the anemia. Common symptoms include fatigue and feeling cold. Many people do not get medically evaluated for these symptoms, often ignoring them. But it is important to see your doctor if you are feeling run down, lacking in energy, or prone to feeling cold.

There are a number of other symptoms that can develop as a result of iron deficiency, including:

  • Headaches or migraines
  • Lightheadedness
  • Trouble concentrating
  • Moodiness and irritability
  • Pica—a craving for eating ice or non-food items, such as metal or dirt
  • Generalized weakness
  • A rapid heart rate
  • Shortness of breath
  • Restless legs when trying to sleep
  • Prone to infections
  • Glossitis—an inflamed, red, tongue
  • Dry hair and/or nails

Iron deficiency can affect you differently depending on your age and health. For example, it can affect the development of a growing baby born to a woman who was iron deficient during pregnancy. It can cause learning problems when it affects children. And it is more likely to cause shortness of breath if you have heart failure or pulmonary disease.


Iron deficiency can affect anyone at any age. There are some risk factors that can make you more prone to developing iron deficiency, such as:

  • Pregnancy
  • Chronic bleeding—such as from a gastrointestinal (GI) ulcer or cancer
  • Malnutrition
  • Menstruation
  • Being a vegetarian
  • Malabsorption—trouble absorbing food due to a GI illness
  • Gastric bypass surgery

Why Iron Deficiency Affects the Body

Iron is a mineral that forms the heme portion of hemoglobin. Hemoglobin is a protein inside RBCs that binds to oxygen. You need oxygen for energy. When you become low in iron, your oxygen delivery throughout your body can be impaired, making you feel tired, headachy, irritable, and cold.

The exact reason why iron deficiency causes some of its effects—such as glossitis and pica is not completely clear.


If you complain of fatigue and other symptoms of iron deficiency, your doctor may consider this nutritional deficiency to be the cause of your problem.

Iron deficiency is not usually detected based on a physical examination. Many of the signs, such as a rapid heart rate and dry hair, occur at a relatively late stage and can be caused by other medical problems as well. Some people may have pale fingers or toes, but this sign occurs with a number of other medical conditions too.

Blood Test

Blood tests are usually the most common method of identifying iron deficiency. A complete blood count (CBC) is a fairly common screening test that measures your (RBC) count, the size and shape of your RBCs, and your hemoglobin. CBC also measures your white blood cells (WBCs), which can be a reflection of some illnesses that cause iron deficiency (such as lymphoma and leukemia).

Iron deficiency can be detected by several values measured with a CBC, including:

RBC count reference ranges are:

  • 4.2 to 5.4 million/mcL for women
  • 4.7 to 6.1 million/mcL for men
  • 4.1 to 5.5 million/mcL for children

Microscopic examination of the RBCs can assess their shape and size. Iron deficiency is associated with a low or normal concentration of RBCs, which are each normal or small in size.

Hemoglobin test reference ranges are:

  • 12.0 to 15.5 gm/dl for women
  • 13.5 to 17.5 gm/dl for men
  • 11 to 16 g/dl for children
  • 11 to 12 g/dl for pregnant women

With iron deficiency, you may have a low hemoglobin concentration.

Iron tests are not standard, but you may have this test if your doctor is concerned about low iron levels. A normal iron level ranges from 15 to 30 ug/L, but this value should be assessed based on a number of factors. For example, pregnant women should have an iron level closer to 30 ug/L. If you have had GI bleeding, then a change in your iron level is a sign that you could be having recurrent bleeding.

Interventional Tests

You may need to have one or more interventional diagnostic tests to evaluate the cause of your iron deficiency. Since GI bleeding is a fairly common cause of iron deficiency, a digital rectal examination, colonoscopy, or endoscopy may be necessary. A rectal examination can identify blood, and colonoscopy or endoscopy can find where the bleeding is coming from.

Your CBC may show WBC alterations suggestive of lymphoma or leukemia. If there is a high chance that you could have one of these conditions, you may need to have a bone marrow biopsy, which can assess the shape and appearance of your WBCs.


If you have iron deficiency, you will need prompt treatment. Your iron level can be brought up slowly with diet, or more rapidly with medication. You should not take supplements without your doctor's advice, as iron supplementation can cause side effects.

Additionally, if an illness has caused your iron deficiency, you will need treatment for that illness.

Dietary Sources of Iron


Chicken and potatoes in skillet
Melanie Defazio/Stocksy United

Beef, chicken, lamb, pork, and turkey are good sources of iron. Meat contains heme iron, which is easier for the body to absorb, meaning you get more of the iron from these foods.


dapan photography/Moment/Getty Images

Shrimp, clams, and oysters contain the same heme iron as meat, which is easily absorbed.


Pho Soup Bowls Being Prepared
Enrique Díaz / 7cero / Getty Images

Tofu is a great source of protein with a good amount of iron. Avoid tofu with added calcium as this can decrease the absorption of iron.


Healthy Eating, Variety of legumes, beans and soybeans
mikroman6 / Getty Images

In addition to being a great source of protein, beans (including pinto beans, black beans, lentils, and kidney beans) are also a good source of iron.

Broccoli and Bok Choy

Bok Choy
Tom Baker/EyeEm/Creative RF/Getty Images

Broccoli and bok choy are good sources of iron, and they contain vitamin C, which helps your body absorb iron from your diet.


Close-Up Of Tomatoes On Market Stall For Sale
Fabio Pagani / EyeEm / Getty Images

Vegetables such as green, leafy vegetables, green beans, and tomatoes are good sources of iron. Tomato juice is one of the few juices containing iron.

Dried Fruits

Dried apricots and raisins sultanas at the market
by IAISI / Getty Images

Dried apricots, peaches, prunes, and raisins contain iron. Prune juice is also a source of iron.


mixe of various nuts background above closeup
R.Tsubin / Getty Images

Most nuts, including cashews, hazelnuts, pistachios, and almonds contain iron.

Pumpkin Seeds

Pumpkin Seeds
John Carey/Photolibrary/Getty Images

Raw pumpkin seeds, also called pepitas, are a great plant source of iron. If you are going to roast them, avoid excessive heat because that can decrease the amount of iron in them. Consider using them as a salad topping.

Breads and Cereals

Bowl bran sticks cereal
tirc83 / Getty Images

In the United States and other countries, flours are fortified with vitamins and minerals including iron. You can identify these products by looking for enriched flour on the ingredient list. Fortified foods include bread, cereal, pasta, and other grains. In general, cereals with bran in them have more iron than others cereals.

Fruit helps you absorb iron.

Alexey Kopytko / Getty Images

Although they technically do not contain iron, fruits rich with vitamin C (oranges, lemons, limes, watermelon, kiwi) help you absorb iron from your diet better. So, include them with your iron-rich foods for a better result.

Interestingly, calcium, which is present in dairy products, can interfere with your ability to absorb iron. So if you don't eat much red meat, it is a good idea not to consume meat and dairy in the same meal.

Dietary Supplements

It is generally advised to avoid iron supplements unless they are prescribed by a doctor. If you need to take iron supplements, be sure to take them at the recommended dose, and only for the weeks or months that your doctor recommends.

Prenatal vitamins contain iron because pregnant women need extra iron. Iron supplements can uncomfortable constipation, so be sure to talk to your doctor about how you can safely manage your constipation, especially if you are pregnant.

Iron toxicity results in liver failure, heart failure, arthritis, and a number of other serious problems, and if you have a medical illness (such as cancer or liver failure) you could have difficulty metabolizing nutrients like iron, making you more prone to toxicity.

Medical or Surgical Intervention

You may need more serious intervention for iron deficiency. Sometimes, iron deficiency is extreme, or excessive blood loss can be a major problem.

If you can't consume food or supplements by mouth or if your body can't absorb iron due to malabsorption, then you would need an intramuscular (IM) injection or IV supplementation.

A blood transfusion may be necessary if you are severely anemic. And surgical repair of a bleeding polyp, ulcer, or cancerous lesion is often necessary to manage a harmful disease and to stop blood loss.

A Word From Verywell

Iron deficiency is a fairly common cause of low energy. You can usually prevent and reverse iron deficiency by consuming iron in your diet.

If you become low in iron, you might just need to adjust your diet. But if you have a medical cause of your low iron, be sure to follow up on your treatment, because diet alone will not solve the problem.

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