How many people are affected by vitamin A deficiency?

January 10, 2026 •

5 min read

According to a 2023 study, 333.95 million children and adolescents across 165 low- and middle-income countries were affected by vitamin A deficiency (VAD) in 2019, highlighting its extensive global impact.

Quick Summary

Vitamin A deficiency affects millions globally, particularly children in low-income nations. Prevalence remains high in regions like Sub-Saharan Africa and South Asia, causing severe health complications including blindness.

Key Points

Millions Affected: Hundreds of millions of children and adolescents are impacted by vitamin A deficiency (VAD) globally, especially in low-income countries.
Children are the Most Vulnerable: VAD disproportionately affects young children, and is the leading cause of preventable childhood blindness worldwide.
Regional Disparity: The highest prevalence of VAD is found in low socio-demographic index (SDI) regions, with a particularly heavy burden in Sub-Saharan Africa and South Asia.
Serious Health Consequences: VAD can cause night blindness, increase the risk of infectious diseases, stunt growth, and can be fatal in severe cases.
Preventative Measures: Strategies to combat VAD include supplementation programs, food fortification, and promoting dietary diversity.
Persistent Morbidity: While VAD-related mortality has decreased, the burden of associated morbidities remains a significant challenge, especially in low-SDI countries.

The Widespread Prevalence of Vitamin A Deficiency

Vitamin A deficiency (VAD) is a serious public health issue, impacting millions, particularly in developing countries. While overall VAD mortality has seen a decline due to interventions, the burden of associated morbidities persists, particularly in low-income regions. The most significant impact is observed among young children and pregnant women who have heightened nutritional needs and often have limited access to adequate vitamin A intake.

Global Statistics Reveal a Disproportionate Burden

Data from recent studies paint a clear picture of VAD's unequal distribution. The prevalence is dramatically higher in regions with low socio-demographic indices (SDI). These populations are typically the most vulnerable due to poverty, limited access to diverse food sources, and inadequate healthcare.

Children Under Five: The Most Vulnerable Group

Young children are disproportionately affected by VAD, which is the leading cause of preventable childhood blindness worldwide.

In 2019, 333.95 million children and adolescents were affected by VAD in 165 LMICs.
The highest prevalence is found in children aged 0–5 years. In 2019, the prevalence of VAD in this age group within LMICs was 19.53%.
Estimates suggest that between 250,000 and 500,000 vitamin A-deficient children become blind every year, with half of them dying within 12 months.

Pregnant and Lactating Women

This group is also highly susceptible due to increased nutrient requirements during pregnancy and lactation. VAD during pregnancy can lead to night blindness and increased mortality risk for both the mother and child.

Over 7 million pregnant women in the developing world are estimated to be vitamin A deficient.
Pregnant women with VAD face a higher risk of adverse outcomes, including increased mortality.

Geographical Hotspots

VAD is most prevalent in certain geographical areas, where a combination of poor diet, limited healthcare, and high infectious disease rates compound the problem. The World Health Organization (WHO) identifies the most affected regions based on public health significance.

Sub-Saharan Africa: This region carries a particularly heavy burden, with some studies indicating the highest prevalence rates globally. In 2019, Sub-Saharan Africa accounted for a large share of VAD cases in children.
South Asia: This region also has a very high prevalence of VAD, with countries like Bangladesh and India historically reporting high rates, particularly among preschool children.

Underlying Causes of VAD

Several factors contribute to vitamin A deficiency, often acting in concert to create a cycle of malnutrition and poor health.

Inadequate Diet: A primary cause is a diet lacking in vitamin A-rich foods, including animal products (like meat, eggs, and dairy) and provitamin A sources from plants (like carrots, sweet potatoes, and green leafy vegetables).
Infections and Diseases: Frequent infections, especially diarrheal and respiratory illnesses, can interfere with vitamin A absorption and metabolism, exacerbating deficiency.
Malabsorption Issues: Conditions like celiac disease, cystic fibrosis, chronic diarrhea, and liver disorders can impair the body's ability to absorb and utilize vitamin A.
Poverty and Socioeconomic Status: Limited access to nutrient-rich foods and healthcare in low-income settings is a major driver of VAD.

Signs and Symptoms of Deficiency

Recognizing the signs of VAD is crucial for early intervention. Symptoms range from mild visual impairment to severe, life-threatening complications.

Ocular Symptoms: Night blindness is often an early sign. As the deficiency progresses, it can lead to xerophthalmia (dry eyes), Bitot's spots (foamy patches on the conjunctiva), and ultimately, keratomalacia (softening of the cornea) and permanent blindness.
Increased Infection Risk: Vitamin A is vital for a healthy immune system. Deficiency can compromise the body's ability to fight off infections, leading to more frequent and severe episodes of measles, diarrhea, and respiratory illnesses.
Growth and Development Issues: VAD can stunt growth and hinder proper development in children.
Skin and Hair: Symptoms can include dry, rough skin and hair loss.

Prevention Strategies and Their Effectiveness

Numerous strategies are employed globally to combat VAD, with varying levels of success depending on the context. A multi-pronged approach is often the most effective.

Comparison of VAD Prevention Methods


Strategy	Description	Target Population	Effectiveness	Challenges
Supplementation	Administering high-dose vitamin A capsules biannually to vulnerable groups	Infants and children under five, pregnant women	Rapidly boosts vitamin A levels and reduces mortality significantly	Requires robust distribution programs, potential for coverage gaps, storage issues
Food Fortification	Adding vitamin A to staple foods like cooking oil, sugar, or flour	Whole populations, particularly those reliant on certain staples	Broad reach, sustained intake over time, does not require behavioral change	Requires government oversight and fortification infrastructure, potential for inadequate intake
Dietary Diversification	Promoting cultivation and consumption of vitamin A-rich foods (e.g., orange-fleshed sweet potatoes)	Individuals and communities in affected areas	Sustainable, promotes overall nutrition, empowers communities	Requires significant behavioral and agricultural changes, cultural acceptance issues

The Long-Term Consequences

Without intervention, the long-term consequences of VAD are devastating. In addition to permanent blindness and increased mortality, chronic deficiency can lead to a higher incidence of infectious diseases and overall developmental issues. The cycle of malnutrition and infection can trap individuals and entire communities in poverty, impacting health and economic productivity. Sustained efforts are necessary to maintain adequate vitamin A levels in vulnerable populations to prevent these serious outcomes.

Conclusion: The Path Forward

Vitamin A deficiency continues to affect hundreds of millions globally, with children in low-income countries bearing the heaviest burden. While significant progress has been made in reducing VAD-related mortality through supplementation, challenges remain in addressing persistent morbidity and ensuring consistent coverage. A combination of supplementation, fortification, and dietary strategies, along with addressing the root causes of poverty and infection, is crucial for eliminating VAD as a public health problem and securing a healthier future for all. For more information on vitamin A deficiency, visit the World Health Organization website.

Why We Need to Continue the Fight

The fight against VAD is far from over. Gaps in data, particularly at the national level in many LMICs, hinder targeted efforts. Disparities between regions and countries remain stark, emphasizing the need for continued funding, research, and intervention. Over 40% of LMICs still face a significant public health concern from VAD, indicating that while progress has been made, sustained global effort is vital to protect the most vulnerable populations.

Frequently Asked Questions

In 2019, an estimated 333.95 million children and adolescents in 165 low- and middle-income countries were affected by vitamin A deficiency (VAD). This corresponds to about 14.7% of the paediatric population in those regions.

The most vulnerable groups are young children (6–59 months of age) and pregnant and lactating women in low-income countries. These groups have higher nutritional demands and often have limited access to diets rich in vitamin A.

VAD is a public health problem in more than half of all countries, but it is especially concentrated in Sub-Saharan Africa and South-East Asia. Regions with low socio-demographic indices bear the greatest burden.

The most common symptoms include night blindness, dry eyes (xerophthalmia), Bitot's spots (foamy patches on the eyes), and an increased susceptibility to infections. In severe cases, it can lead to permanent blindness.

The primary causes are inadequate dietary intake of vitamin A-rich foods, malabsorption due to chronic diseases like celiac disease or liver disorders, and frequent infections, such as diarrhea, that interfere with absorption.

Significant global improvements in VAD-related mortality have been observed, largely due to successful supplementation programs for children under five. However, reductions in VAD-related morbidity have been more modest, especially in low-SDI countries.

Vitamin A deficiency is the leading cause of preventable childhood blindness worldwide. An estimated 250,000–500,000 children become blind every year due to VAD, with many dying shortly after.

Prevention involves a combination of strategies, including large-scale supplementation programs, food fortification (adding vitamin A to staples like flour or oil), and promoting the consumption of nutrient-rich foods through dietary diversification.