Iron deficiency, also known as anemia, is a condition that occurs when the body does not have enough iron. Iron is a mineral that is essential for many bodily functions, especially the production of hemoglobin. Hemoglobin is a protein in red blood cells that carries oxygen from the lungs to tissues and organs throughout the body. When iron levels are too low, the body cannot produce enough hemoglobin for red blood cells. This results in iron deficiency anemia, which can cause many symptoms and affect overall health.
How Common is Iron Deficiency?
Iron deficiency is the most common nutritional deficiency worldwide. It is estimated that 1.62 billion people, or 24.8% of the global population, suffer from anemia due to iron deficiency. Women, young children, and people with certain health conditions have an increased risk of developing iron deficiency.
In the United States, around 5% of women aged 12-49 years are iron deficient. Pregnant women are especially susceptible, with 18% developing iron deficiency anemia during pregnancy if they do not take iron supplements. Up to 12% of adolescent girls and women of childbearing age in the US are iron deficient.
Iron deficiency is also common in young children. Around 7% of US toddlers aged 1-2 years and 9% of all US children aged 1-5 years are iron deficient. Premature and low birth weight infants also have a higher risk of iron deficiency.
People with certain conditions like inflammatory bowel disease, celiac disease, kidney failure, and cancer are more likely to develop iron deficiency anemia. Blood loss from heavy menstrual periods, peptic ulcers, hemorrhoids, or colon polyps also increases the risk of deficiency.
How Does Iron Deficiency Develop?
The development of iron deficiency anemia occurs in stages:
- Stage 1 – Iron stores in the body become depleted. This stage is known as iron depletion.
- Stage 2 – Iron transport systems cannot keep up with iron demands. This leads to iron deficient erythropoiesis.
- Stage 3 – Hemoglobin levels fall and anemia develops due to insufficient iron for hemoglobin production.
In the first stage, the body’s stores of iron become depleted but blood levels remain normal. Iron is stored in the liver, spleen, and bone marrow. When these stores are used up, the body cannot supply enough iron for functions like oxygen transport.
The second stage occurs when transport systems cannot keep up with the iron needs of tissues and organs. Transferrin is a protein that transports iron in the bloodstream. When iron stores are low, transferrin levels decrease. This reduces the amount of iron that can be delivered to developing red blood cells in the bone marrow.
In the third stage, hemoglobin production slows and anemia sets in. Without adequate iron, fewer red blood cells can be manufactured and existing cells become smaller. This reduces the oxygen carrying capacity of blood, leading to the common symptoms of iron deficiency anemia.
What Are the Symptoms of Iron Deficiency?
The symptoms of iron deficiency anemia include:
- Fatigue and weakness
- Shortness of breath and chest pain
- Headaches
- Dizziness or lightheadedness
- Pale skin and lips
- Brittle nails
- Swollen tongue
- Cramps and tingling in the legs
- Restless leg syndrome
- Poor appetite
- Inflammation or soreness of the mouth
- Craving non-food items like dirt, clay, or ice
These symptoms occur because iron deficiency anemia reduces the amount of oxygen that can be delivered to cells throughout the body. Organs then cannot function properly when they do not get enough oxygenated blood.
Which Organs are Affected by Iron Deficiency Anemia?
When the body does not have sufficient iron levels to produce adequate red blood cells and hemoglobin, all body systems can be deprived of oxygen. The reduced oxygen supply affects many different organs and body systems:
Cardiovascular System
A lack of oxygen damages the heart muscle and forces it to pump harder to make up for the reduced oxygen carrying capacity of the blood. This can lead to an enlarged heart or heart failure over time. Iron deficiency increases risk for irregular heartbeats and other arrhythmias. Low iron is also associated with higher blood pressure and atherosclerosis.
Respiratory System
With reduced oxygen transport in the blood, tissues in the lungs do not get enough oxygen. This can cause shortness of breath from lack of oxygen even without physical exertion.
Nervous System
Iron deficiency anemia starves the nervous system of oxygen, leading to symptoms like headaches, lightheadedness, and mood changes. It may also impair cognitive function and brain development in infants and children. Restless legs syndrome is a common symptom of iron deficiency.
Digestive System
A lack of oxygen damages the cells lining the digestive tract. This can cause symptoms like soreness of the mouth and tongue, heartburn, nausea, and loss of appetite. Iron deficiency anemia increases risk for gastrointestinal infections.
Immune System
Iron deficiency impairs the function of immune cells, making people more susceptible to infections. Even mild iron deficiency that has not yet progressed to full-blown anemia can weaken the immune system.
Muscles and Bones
With decreased oxygen supply, iron deficiency can cause muscle weakness, fatigue, and bone problems. Anemia may increase risk of osteoporosis and stress fractures.
Skin, Hair, and Nails
The skin can take on a pale, waxy appearance when anemic from low iron. Hair may become thinner and more brittle. Nails also become brittle and concave with iron deficiency.
Kidneys
Anemia places stress on the kidneys by reducing oxygen supply. Iron deficiency harms the kidneys’ ability to filter waste from the bloodstream. This may accelerate chronic kidney disease.
Reproductive System
Iron deficiency anemia can reduce libido and fertility in men and women. It increases risk for maternal and perinatal complications during pregnancy. Iron deficiency anemia increases the chances of having a preterm delivery or low birth weight infant.
How is Iron Deficiency Anemia Diagnosed?
Iron deficiency anemia is diagnosed through blood tests. These may include:
- Complete blood count (CBC) – Measures levels of red blood cells, hemoglobin, and other blood components.
- Ferritin – Reflects the amount of iron stored in the body.
- Transferrin and total iron binding capacity (TIBC) – Measures blood levels of the iron transport protein transferrin.
- Reticulocyte hemoglobin – Tests for inadequate hemoglobin levels in new red blood cells.
Doctors also consider medical history and symptoms when diagnosing iron deficiency anemia. They look for possible causes like blood loss or malnutrition. More medical testing may be ordered to pinpoint the cause of low iron if it is not obvious from blood work and evaluation of symptoms.
How is Iron Deficiency Anemia Treated?
Treatment for iron deficiency anemia aims to increase iron levels and improve symptoms. Treatment may include:
- Oral iron supplements – Iron tablets or liquids containing ferrous sulfate, ferrous gluconate, ferric citrate, or iron polysaccharide complexes. High-dose supplements typically improve iron levels and anemia faster than low doses.
- Parenteral iron – Iron injected directly into the vein intravenously. Used when oral supplements are not tolerated or absorption is impaired.
- Dietary changes – Eating more iron-rich foods from sources like red meat, eggs, leafy greens, nuts, seeds, legumes, iron-fortified cereals and breads.
- Vitamin C supplements – Vitamin C aids iron absorption, so supplements are recommended.
- Blood transfusions – Used in severe anemia that cannot be corrected quickly with iron therapy.
Treatment focuses on addressing the underlying cause of iron deficiency, if possible. This may involve surgical removal of sources of bleeding or gastrointestinal disorders preventing iron absorption. Lifestyle changes like avoiding excess stress and getting enough sleep also help recovery.
Most people begin to feel relief from iron deficiency anemia within a few weeks after starting treatment. Adsorption and transport of iron to tissues takes some time. It may take up to 6 months for iron stores and red blood cell levels to return to normal.
Are There Complications From Iron Deficiency Anemia?
When left untreated, iron deficiency can cause both short-term and long-term complications:
- Impaired brain function – Iron is needed for proper brain development and function. Untreated iron deficiency in infants and children can lead to cognitive, motor, and behavioral impairments.
- Weakened immune system – Increased infections from the reduced ability to fight off foreign pathogens.
- Poor pregnancy outcomes – Higher risk of preterm birth and low birth weight babies.
- Restless legs syndrome – Unpleasant crawling, tingling, or burning sensations in the legs that are worse during rest.
- Brittle, spoon-shaped nails – Dry and brittle nails that curve inward.
- Hair loss – Temporary patchy hair loss or thinning while anemic.
- Angina or heart failure – Reduced oxygen can damage the heart muscle and its ability to pump.
- Growth and development issues – Impaired growth in infants and children from effects on the endocrine system.
These potential complications demonstrate the importance of diagnosing and treating iron deficiency anemia early. Reversing it quickly reduces the chances of short and long-term problems.
Are Organ Damage or Failure Caused by Anemia Reversible?
The reduced oxygen supply from iron deficiency anemia can damage organs over time. Effects on some organ systems are temporary and improve with treatment. However, some damage may become permanent if anemia is severe or long-standing.
Here is the reversibility of damage by organ system:
| Organ System | Reversibility of Damage |
|---|---|
| Cardiovascular | May be permanent damage to the heart muscle leading to lifelong complications. |
| Respiratory | Lung changes are typically reversible with treatment. |
| Nervous | Some neurocognitive effects can persist but generally improve with iron therapy. |
| Digestive | GI damage is usually temporary and reverses with treatment. |
| Integumentary (Skin, hair, nails) | Skin, hair, and nail changes are reversible. |
| Reproductive | Most reproductive effects are temporary but some infertility may persist. |
| Musculoskeletal | Muscle and bone effects typically resolve and do not cause permanent damage. |
| Kidneys | Kidney function can improve but some chronic impairment may remain. |
The key to reducing permanent organ damage is early detection and prompt treatment of iron deficiency. The longer anemia goes untreated, the higher the likelihood of lifelong complications, especially in the cardiovascular system.
How Can Iron Deficiency Anemia Be Prevented?
Iron deficiency anemia is usually preventable through a combination of dietary measures, supplementation, and screening for those at high risk:
- Eat iron-rich foods – Consume adequate meat, seafood, plants, iron-fortified foods.
- Include vitamin C – Eat foods high in vitamin C to enhance iron absorption.
- Avoid excess tea and coffee – Tea and coffee contain compounds that interfere with iron absorption.
- Take prenatal vitamins – Pregnant women should take prenatal vitamins with iron.
- Give iron drops to infants – Iron supplementation is recommended for breastfed babies from 4-6 months.
- Screen high-risk groups – Check ferritin levels periodically in those susceptible like menstruating women.
- Treat underlying conditions – Manage issues leading to blood loss or poor absorption.
Raising awareness of iron deficiency anemia, improving diets, and increasing access to supplements can help prevent low iron levels on a population scale.
Conclusion
Iron deficiency anemia is a common condition affecting around 25% of people globally. When the body cannot produce enough red blood cells and hemoglobin due to low iron, oxygen delivery to tissues is impaired. This oxygen deprivation damages many organs and bodily systems.
The cardiovascular, respiratory, nervous, digestive, integumentary, reproductive, musculoskeletal, and renal systems can all be impacted. Effects may include heart failure, lung problems, neurocognitive issues, GI irritations, skin/hair/nail changes, complications during pregnancy, muscle weakness, and kidney dysfunction.
Prompt diagnosis and treatment is key to reversing damage and preventing complications. While some effects like heart and nervous system changes may persist, most organ dysfunction is temporary if iron deficiency anemia is corrected quickly. Maintaining adequate iron intake through diet and screening those at high risk are important prevention strategies.
Understanding how low iron can impact the body allows for earlier intervention and better long-term health outcomes.