What is the leading cause of anemia worldwide?

November 22, 2025 •

4 min read

Globally, anemia remains a significant public health issue, with nearly one in four people affected. The World Health Organization and other research bodies have repeatedly confirmed that dietary iron deficiency is the leading cause of anemia worldwide, particularly in low-income settings.

Quick Summary

Dietary iron deficiency is the primary global cause of anemia, with other major contributing factors including nutritional deficits, infectious diseases like malaria, and chronic illnesses. Vulnerable groups, such as young children and women of reproductive age, are most affected.

Key Points

Iron Deficiency is Primary Cause: Dietary iron deficiency is globally the most common cause of anemia, particularly affecting vulnerable populations.
Regional Variations Exist: While iron deficiency is widespread, other causes like malaria and hemoglobinopathies are significant in specific geographic regions, especially sub-Saharan Africa and South Asia.
High-Risk Groups: Young children and women of reproductive age are the most affected demographics globally due to high iron demands and blood loss.
Beyond Diet: Infectious diseases, chronic conditions, and genetic disorders are also major drivers of anemia, requiring targeted interventions.
Health Consequences: Anemia can lead to severe fatigue, impaired cognitive development in children, and adverse pregnancy outcomes if left untreated.
Requires Multi-Faceted Strategy: Combating anemia effectively involves improving nutrition, controlling infections, and managing underlying chronic diseases.

Iron Deficiency: The Primary Culprit

Dietary iron deficiency is recognized by major global health organizations as the single most common cause of anemia on a global scale. Iron is a crucial component of hemoglobin, the protein in red blood cells that transports oxygen throughout the body. When iron intake or absorption is inadequate, the body cannot produce enough healthy red blood cells, leading to microcytic, hypochromic anemia. This issue is particularly pronounced in low- and middle-income countries due to insufficient access to iron-rich foods, but it remains a widespread problem even in developed nations.

Why is Iron Deficiency so Widespread?

Several factors contribute to the high prevalence of iron deficiency worldwide:

Inadequate Diet: Many populations, especially in developing countries, rely on diets with low iron content or poor iron bioavailability. Diets low in meat, poultry, and fish (heme iron sources) are at a higher risk.
Parasitic Infections: Soil-transmitted helminths like hookworm are a major cause of chronic blood loss and subsequent iron deficiency in tropical regions.
Blood Loss: For women, heavy menstrual bleeding is a common cause of iron loss. Gastrointestinal bleeding from ulcers, gastritis, or infections can also deplete iron stores.
Increased Demand: Pregnancy and rapid growth during infancy and adolescence significantly increase iron requirements. If not met through diet or supplementation, deficiency and anemia can develop.
Malabsorption: Conditions like celiac disease or surgical procedures like gastric bypass can impair the body's ability to absorb iron from food.

Other Major Causes and Regional Variations

While iron deficiency is the most common cause globally, anemia is a complex condition with a multifaceted etiology. The relative importance of different causes varies considerably by geographic location, age, and socioeconomic status.

Key Contributing Factors to Anemia Globally:

Infections: Infections are a major driver of anemia, especially in regions with a high burden of infectious diseases. For example, malaria is a significant cause of anemia, particularly in sub-Saharan Africa, by destroying red blood cells and impairing nutrient absorption. HIV and tuberculosis can also contribute.
Genetic Red Blood Cell Disorders: Inherited conditions, such as thalassemia and sickle cell disorders, cause abnormal red blood cell production or premature destruction, leading to anemia. These conditions are especially prevalent in certain parts of Africa, South Asia, and the Mediterranean.
Chronic Diseases: Anemia of chronic disease or inflammation is common in people with long-term conditions like cancer, kidney disease, rheumatoid arthritis, and inflammatory bowel disease. Inflammation can disrupt the body's ability to use iron effectively.
Vitamin Deficiencies: Besides iron, other nutritional deficiencies are significant causes. A lack of vitamin B12 or folate, which are vital for red blood cell production, can cause megaloblastic or macrocytic anemia.

Global Anemia Etiology Comparison


Cause	Mechanism	Affected Populations	Regional Variation	Contribution to Anemia YLDs (2021)
Dietary Iron Deficiency	Inadequate iron for hemoglobin production	All age groups, particularly children and women	Widespread, but highest in low-income settings	66.2%
Hemoglobinopathies & Hemolytic Anemias	Abnormal red blood cell structure/destruction	Hereditary; high prevalence in certain regions	Africa, South Asia, Mediterranean	13.6-16.1%
Malaria	Red blood cell destruction and inflammation	Children and adults in endemic areas	Concentrated in sub-Saharan Africa	Significant in endemic regions
Other Nutritional Deficiencies	Lack of B12, folate, or vitamin A	Poorly nourished populations, certain medical conditions	Widespread, but linked to malnutrition	Contributes to overall burden
Infectious Diseases (NTDs)	Chronic blood loss or malabsorption	Populations with poor sanitation and hygiene	High prevalence in low-income regions	Variable
Anemia of Chronic Disease	Inflammation inhibiting iron use	Elderly, those with chronic illnesses	More common in higher SDI regions	Increases with age

Impact on At-Risk Populations

The burden of anemia is not evenly distributed across the population. Young children, women of reproductive age, and pregnant women face the highest risks and most severe consequences. In infants and young children, iron deficiency can lead to irreversible cognitive and developmental delays. For pregnant women, anemia increases the risk of premature birth, low birth weight, and maternal mortality. Adolescent girls and women are vulnerable due to monthly menstrual blood loss and the increased demands of pregnancy. These disparities highlight the critical need for targeted public health interventions.

Addressing the Problem

Preventing and treating anemia requires a multifaceted approach that considers both the primary cause and local context. Key strategies include:

Dietary Interventions: Promoting consumption of iron-rich foods, including meat, legumes, and dark leafy greens. Combining iron sources with vitamin C-rich foods enhances absorption.
Micronutrient Supplementation: Providing iron and folic acid supplements to high-risk groups like pregnant women and infants.
Food Fortification: Adding iron to staple foods like flour and cereals is a cost-effective way to improve iron intake across entire populations.
Infection Control: Implementing measures to prevent and treat infectious diseases like malaria and hookworm is crucial in endemic areas.
Improved Healthcare Access: Early screening, diagnosis, and treatment of underlying medical conditions that cause anemia are vital.

Conclusion

While many factors contribute to the burden of anemia, dietary iron deficiency is unequivocally the leading cause globally. Its impact disproportionately affects vulnerable populations, including women and children, with significant health and socioeconomic consequences. Effective strategies to combat anemia must focus on improving nutrition through diet and supplementation, alongside addressing other significant regional causes such as infectious diseases and inherited conditions. A holistic and integrated public health approach is essential to make meaningful progress toward reducing this pervasive health problem. You can learn more about global anemia initiatives at the World Health Organization's website.

Frequently Asked Questions

Anemia is a major global health concern, affecting nearly one in four people, according to recent studies. Its prevalence is highest among children and women of reproductive age.

Iron deficiency is the condition where the body lacks sufficient iron stores. Iron deficiency anemia is a more advanced stage where the lack of iron has become severe enough to cause a low red blood cell count and low hemoglobin, resulting in anemia.

Infectious diseases like malaria cause anemia by destroying red blood cells faster than they can be replaced. Other infections, such as hookworm, can cause anemia through chronic blood loss or by impairing nutrient absorption.

Childhood anemia, particularly if caused by iron deficiency, has been linked to long-lasting negative effects on brain health. This can result in developmental delays, lower IQ, and impaired learning capacity.

Preventing iron deficiency anemia involves eating a diet rich in iron. Good sources include red meat, poultry, fish, legumes, iron-fortified cereals, and dark green leafy vegetables. Pairing these with foods high in vitamin C (like citrus fruits) helps enhance iron absorption.

The most at-risk groups globally include young children, pregnant women, and menstruating adolescent girls and women. People with chronic illnesses, intestinal disorders, and those living in areas with high infectious disease burdens are also at increased risk.

Yes, inherited red blood cell disorders like thalassemia and sickle cell anemia are significant causes of anemia in certain parts of the world. They cause abnormalities in hemoglobin or the structure of red blood cells.