Iron is an important mineral for healthy red blood cells. Without enough of it, you have a higher risk of developing anemia. However, it’s also possible to have an iron deficiency without anemia.

Anemia is when your level of red blood cells is too low, which can cause fatigue and weakness. Iron deficiency is the most common cause of anemia.Iron-deficiency anemia affects about 20% of people worldwide.

Iron is a mineral that your body needs to make healthy red blood cells. Without enough of it, your body can’t make enough red blood cells.

It’s also possible to have an iron deficiency without anemia, though it may eventually progress to anemia. One 2021 study estimates that iron deficiency without anemia is actually three times as common as iron-deficiency anemia.

Iron deficiency with and without anemia are preventable and treatable conditions. Let’s take a closer look at the signs and symptoms of iron deficiency without anemia, as well as who’s at risk and how it’s treated.

An iron deficiency can cause some of the same symptoms as iron-deficiency anemia. The only way to know for sure is through blood testing.

Common symptoms of iron deficiency include:

  • difficulty concentrating or focusing
  • feeling tired or lethargic
  • changes in your mood
  • feeling weak, especially when doing an activity

It’s a good idea to speak with a medical professional if you notice any of these symptoms. They can order blood tests to determine a possible cause. Blood tests will measure your iron levels and may also be able to determine if low iron levels have caused iron-deficiency anemia.

It may take several weeks for iron levels in your body to drop below normal. If there are multiple factors that affect your ability to get enough iron, your body’s iron stores may be used up more quickly.

Iron deficiency has different causes. Sometimes it’s a combination of factors.

Common causes of iron deficiency include:

  • low iron intake from food or supplements
  • increased iron needs
  • poor iron absorption

Some people are at greater risk of developing iron deficiency. This includes those who:

About ferritin and hemoglobin

Ferritin levels also play a role in iron deficiency. Ferritin is a storage form of iron. The World Health Organization (WHO) defines low iron as a ferritin level below 12 micrograms/L. There’s strong evidence that a ferritin level under 30 micrograms/L should be considered an iron deficiency.

A transferrin saturation test is also useful to see how much iron in the blood is bound to transferrin. Transferrin is a protein that helps bind and transport iron in the blood. A low transferrin saturation usually indicates iron deficiency.

Hemoglobin can also be affected by iron levels. Hemoglobin is a part of the red blood cell that carries oxygen. Your body needs iron to make hemoglobin. When hemoglobin levels are low, it means that your red blood cell levels are also low.

Iron deficiency without anemia may be diagnosed when ferritin is low but hemoglobin levels are in the typical range. On the other hand, iron-deficiency anemia is diagnosed if ferritin and hemoglobin are both low.

How much iron do you need each day?

Anyone who menstruates needs more iron due to monthly blood loss.

People ages 19 to 50 who menstruate need 18 milligrams (mg) of iron daily. Anyone who is pregnant or lactating may need additional iron. Everyone else needs 8 mg of iron daily. You can get iron from both plant and animal sources.

Some of the best sources of iron include:

  • iron-fortified breakfast cereal
  • oysters
  • pumpkin seeds
  • liver
  • lentils
  • sardines

Blood testing is the best way for iron deficiency to be diagnosed, with or without anemia.

The main blood tests that are used include ferritin and hemoglobin. Other tests might be done at the same time to find out more about the health of your red blood cells.

If your ferritin is low, but your hemoglobin is typical, you may have iron deficiency without anemia. If your hemoglobin level is also low, it means your red blood cell count is low. A doctor may then diagnose iron-deficiency anemia.

The first-line treatment for iron deficiency is usually dietary counseling and oral iron supplements. If your doctor recommends iron supplements, make sure you understand what type and dose to take.

Iron infusions are another option, but this is typically only done in more severe cases of iron-deficiency anemia.

Increasing iron intake from food may help, but this is most effective in those who don’t experience symptoms and don’t have any iron absorption issues. In many instances, dietary changes alone aren’t enough to raise iron levels into the healthy range.

You’ll likely need to have follow-up blood work done within 2 to 3 months of starting a supplement. This is a good timeline to recheck your iron levels to see if they are increasing.

If iron deficiency is not treated, the amount of iron in your body may continue to drop. Over time, this may affect your body’s ability to make red blood cells which could, ultimately, cause anemia.

An iron deficiency is when the levels of iron in your body are low. Iron deficiency is the most common cause of anemia, but an iron deficiency can also occur without anemia. Blood testing is the only way to know for sure.

Iron deficiency with and without anemia are both treatable conditions. Many people may be able to improve their levels within a few months with the right treatment.