What Is Iron Deficiency Anemia Secondary to Inadequate Dietary Iron Intake?

People with anemia have a lower-than-normal level of red blood cells (RBCs) in their blood. It can cause headaches, weakness, fatigue, and many other symptoms. It can also lead to long-term health problems if not treated.

Without enough iron, your body will make fewer RBCs or will produce smaller RBCs than normal. This leads to iron deficiency anemia secondary to inadequate dietary iron intake. In other words, the anemia is caused by not getting enough iron from the foods you eat.

There are many causes of anemia, but iron deficiency is the most common. According to the World Health Organization (WHO), iron deficiency is the top nutritional disorder in the world. Research suggests that as many as 80 percent of people in the world don’t have enough iron in their bodies. It also suggests that as many as 30 percent of people have anemia due to prolonged iron deficiency.

Iron deficiency anemia can be very mild at first and symptoms may go unnoticed. According to the American Society of Hematology, most people don’t realize they have anemia until it’s found in a routine blood test.

As iron deficiency gets worse, symptoms can include:

  • fatigue
  • weakness
  • pale skin
  • shortness of breath
  • dizziness
  • headaches
  • brittle nails
  • fast heartbeat
  • strange cravings for ice or dirt, called pica
  • cold hands and feet
  • tingling or a crawling-feeling in the legs

Iron deficiency is the most common nutritional deficiency in the United States. It’s also the most common cause of anemia. Iron deficiency anemia secondary to inadequate dietary iron intake is caused by consuming a diet low in iron-rich foods. The best source of iron in foods is from meat, fish, beans, and foods fortified with additional iron.

There are many reasons why you may not be getting enough iron in your diet. The following groups of people are at a higher risk of having a diet low in iron:

  • vegetarians or vegans who don’t replace meat with other iron-rich food
  • people with an eating disorder
  • people who are poor or homeless and do not have easy access to food
  • people who live in urban “food deserts,” where healthy, affordable food is not available
  • elderly people who do not eat a complete or diverse diet
  • young children who drink a lot of cow’s milk, as cow’s milk is low in iron
  • people on a weight loss diet
  • people who eat a diet low in fruits, vegetables, and meat
  • people who consume excessive amounts of daily caffeine
  • people who regularly take antacids

Your doctor can diagnose anemia with several different blood tests.

Complete Blood Count (CBC) Test

This is usually the first test your doctor will use. A CBC test measures the amounts of all components in your blood. These components include:

  • red blood cells, RBCs
  • white blood cells, WBCs
  • hemoglobin
  • hematocrit, the percentage of total blood volume that is made up of RBCs
  • platelets, the component of blood that helps blood clot

The CBC test provides information about your blood that’s helpful in diagnosing iron deficiency anemia, including:

  • hematocrit levels
  • hemoglobin levels
  • size of your RBCs

In iron deficiency anemia, hematocrit and hemoglobin levels are low and RBCs are usually smaller than normal in size.

A CBC test is often performed as part of a routine physical examination because it’s a good indicator of your overall health. It may also be performed routinely before surgery.

Other Tests

Your doctor can usually confirm anemia with a CBC test. But they might order other blood tests to identify the severity of your anemia and how to treat it. They may also examine your blood under a microscope to provide more information, including:

  • iron level in your blood
  • RBC size and color: RBCs are pale when they are deficient in iron.
  • ferritin levels: Ferritin helps with iron storage in your body. Low levels of ferritin indicate low iron storage.
  • total iron-binding capacity: People with an iron deficiency have a large amount of a protein transferrin that isn’t properly transporting iron.

If you’re eating a poor diet, it’s likely you are also deficient in other vitamins and minerals. Your doctor may order several other blood tests to determine if you’re deficient in anything else. This may include blood tests for folic acid and vitamin B-12 deficiency.

Most cases of anemia caused by iron deficiency are mild and do not cause complications. However, if iron is not added back into your diet, it can lead to other health problems.

Anemia forces your heart to pump more blood to compensate for the low amount of oxygen. Heart failure or an enlarged heart muscle may occur if the iron deficiency is not reversed.

In pregnant women, severe cases of iron deficiency can cause a child to be born prematurely or with a low birth weight. Most pregnant women take iron supplements as part of their prenatal care to prevent this from happening.

Infants and children severely deficient in iron may experience a delay in their growth and development. They may also be more susceptible to infections.


Iron tablets can help restore iron levels in your body. You may need to take iron supplements for several months. Iron supplements may cause constipation or stools that are black in color. Plant-based iron supplements may be tolerated more easily and cause less digestive symptoms.

If your doctor determines that you’re deficient in other vitamins and minerals, they may also prescribe other vitamins or a multivitamin.


You should eat a diet high in iron-rich foods and vitamin C to prevent low blood-iron levels. Mothers should make sure to feed their babies either breast milk or iron-fortified infant formula. Iron-fortified infant cereals are also available when babies are ready to start eating solid foods.

Diets high in red meat, dark leafy vegetables, dried fruits and nuts, iron-fortified cereals, or bread can help treat or prevent iron deficiency. Foods high in iron include:

  • meat, such as lamb, pork, chicken, and beef
  • beans, including soybeans
  • pumpkin and squash seeds
  • leafy greens, such as spinach
  • raisins and other dried fruit
  • tofu
  • eggs
  • seafood, such as clams, sardines, shrimp, and oysters
  • iron-fortified cereals

Vitamin C helps your body absorb the iron you eat. If you’re taking iron tablets, your doctor might suggest taking the tablets along with a source of vitamin C. Foods high in vitamin C include:

  • citrus fruits, such as oranges, grapefruit, strawberries, kiwis, guava, papaya, pineapple, melons, and mangos
  • broccoli
  • red and green bell peppers
  • Brussels sprouts
  • cauliflower
  • tomatoes
  • leafy greens

Vegetarians and vegans should make sure they’re eating enough beans, tofu, dried fruits, spinach, and other dark vegetables. They should incorporate iron-fortified foods into their diet regularly. According to the National Institutes of Health’s Office of Dietary Supplements, vegetarians who don’t eat animal products may need nearly twice as much iron on a daily basis as people who eat animal products. This is because iron from plant foods may not be absorbed as easily or completely as iron found in animal products, such as meat.

Nutritional Counseling

Your doctor may also refer you to a dietitian or nutritionist. These specialists are trained in healthy eating. A dietitian can help make sure you are getting all the necessary vitamins and minerals from the foods you eat.

People with an eating disorder may need to speak with a nutritionist to discuss long-term treatment options.

Blood Transfusions

In severe cases, a blood transfusion can replace iron quickly. This procedure involves receiving blood through an intravenous (IV) line inserted into a blood vessel.

Iron deficiency anemia secondary to inadequate dietary iron intake is a common condition. It’s easy to detect and treat through dietary changes and supplements.