Is It Common to Be Low in Vitamin A? Understanding Deficiency Risk

October 19, 2025 •

3 min read

According to the World Health Organization (WHO), vitamin A deficiency affects an estimated 190 million children under five in low-income countries, making it the leading cause of preventable childhood blindness worldwide. The question of is it common to be low in vitamin A? depends largely on geographic location and underlying health factors.

Quick Summary

Vitamin A deficiency is widespread in developing regions, primarily due to insufficient dietary intake, but is rare in wealthier nations. It is most common in young children and pregnant women globally, though it can also result from specific malabsorption disorders in developed countries. Symptoms range from night blindness and dry eyes to frequent infections and delayed growth.

Key Points

Global vs. Regional Prevalence: While very rare in developed countries like the U.S., vitamin A deficiency is a common and severe public health problem in developing nations.
Primary Causes: Globally, the main cause is insufficient dietary intake, often due to economic limitations and diets high in vitamin A-poor staple foods. In developed countries, underlying health conditions causing malabsorption are the key culprits.
High-Risk Groups: Young children and pregnant women, especially in developing countries, are at the highest risk due to increased nutritional demands. Individuals with chronic conditions like cystic fibrosis, Crohn's disease, and liver disorders are also vulnerable.
Early Symptoms: The first and most common symptom is night blindness, which is difficulty seeing in low light. This can progress to permanent blindness if untreated.
Immune System Impact: Deficiency weakens the immune system by compromising mucosal barriers, leading to a higher frequency and severity of infections, particularly respiratory and gastrointestinal illnesses.
Source Bioavailability: Preformed vitamin A from animal sources (e.g., liver, eggs) is highly bioavailable, while provitamin A carotenoids from plants (e.g., carrots, spinach) have lower and more variable absorption.
Treatment and Prevention: Prevention involves a balanced diet rich in vitamin A sources and fortified foods. Treatment for established deficiency typically involves dietary adjustments and supplementation under medical guidance.

Vitamin A is a crucial fat-soluble micronutrient involved in vision, immune function, reproduction, and cell growth. It is found in two main dietary forms: preformed vitamin A (retinol, from animal products) and provitamin A carotenoids (like beta-carotene, from plants). The body utilizes preformed vitamin A efficiently, while conversion of carotenoids is less efficient.

The Global Prevalence of Vitamin A Deficiency

Vitamin A deficiency (VAD) is a significant public health issue, especially in developing countries. Limited access to varied, nutrient-rich foods and diets high in vitamin A-poor staples contribute to this. Infectious diseases also worsen VAD by hindering absorption and increasing vitamin A needs. The most severe impacts are seen in young children and pregnant women. VAD is a major cause of preventable childhood blindness and increases mortality from infections.

Why Deficiency is Rare in Developed Countries

In developed nations like the United States, VAD is uncommon. This is due to greater access to diverse vitamin A-rich foods, including fortified options. When VAD occurs in these areas, it's typically due to underlying health issues.

Conditions Affecting Vitamin A Absorption in Developed Countries

Certain medical conditions can impede vitamin A absorption or use, even with adequate intake. These include:

Chronic diarrhea.
Malabsorptive disorders such as celiac disease, Crohn's disease, and cystic fibrosis, which impair fat absorption crucial for vitamin A.
Pancreatic or liver disease, affecting vitamin A metabolism and storage.
Bariatric surgery, which can reduce nutrient absorption.
Alcoholism, impairing liver function and vitamin A metabolism.

Recognizing the Symptoms of Deficiency

VAD symptoms vary in severity and often develop gradually. Night blindness, difficulty seeing in low light, is typically the first sign. Progression can lead to more serious issues.

Spectrum of Vitamin A Deficiency Symptoms

Ocular issues: Beyond night blindness, VAD can cause dry eyes (xerophthalmia) and potentially permanent blindness. Bitot's spots, white patches on the eyes, may also appear.
Increased infections: VAD weakens the immune system's mucosal barriers, leading to more frequent and severe respiratory and gut infections.
Skin problems: Dry, scaly skin (hyperkeratosis) can occur as vitamin A is vital for skin cell health.
Growth and development: In children, VAD can hinder growth and development.
Fertility issues: VAD can contribute to problems with reproduction.

Dietary Solutions and Considerations

A balanced diet is essential for preventing VAD, with consideration for the two types of dietary sources.

Comparison of Preformed vs. Provitamin A Sources


Feature	Preformed Vitamin A (Retinol)	Provitamin A Carotenoids
Sources	Animal products like liver, eggs, milk, and cheese	Plant-based foods like sweet potatoes, carrots, spinach, and cantaloupe
Absorption	Highly efficient absorption (~70-90%)	Efficiency varies, influenced by food and fat intake
Toxicity Risk	Higher risk of toxicity with excessive intake	Very low risk of toxicity; high intake may cause benign skin discoloration
Bioavailability	High bioavailability	Must be converted by the body, which can be less efficient

Consuming fat with plant carotenoids enhances absorption. Cooking vegetables can also increase beta-carotene bioavailability. Supplementation may be needed for severe deficiency or malabsorption under medical supervision.

Conclusion

While the prevalence of low vitamin A levels depends significantly on geography and socioeconomic factors, it remains a critical global health concern, particularly affecting children and pregnant women in low-income areas. In developed countries, VAD is infrequent but can affect individuals with chronic malabsorptive diseases, liver issues, alcoholism, or those who have had certain surgeries. Prompt diagnosis and intervention through diet or supplementation are crucial to prevent the severe health consequences of vitamin A deficiency.

This content is for informational purposes only and does not constitute medical advice. Consult with a healthcare professional for diagnosis and treatment.

Frequently Asked Questions

No, vitamin A deficiency is very rare in the general population of the United States and other developed countries due to widespread availability of vitamin A-rich foods and fortified products.

Individuals at risk in developed countries are typically those with health conditions that impair nutrient absorption, such as cystic fibrosis, celiac disease, liver disease, or those who have undergone bariatric surgery.

The most common and earliest sign of a vitamin A deficiency is night blindness, or nyctalopia, which causes difficulty seeing in dim light or darkness.

For most people with a mild deficiency, increasing intake of vitamin A-rich foods can resolve the issue. However, severe deficiencies or those caused by underlying malabsorption may require supervised supplementation.

Good sources of preformed vitamin A include liver, eggs, milk, and cheese. Provitamin A carotenoids are found in orange and green leafy vegetables like sweet potatoes, carrots, and spinach.

Yes, excessive intake of preformed vitamin A, especially from high-dose supplements, can lead to toxicity (hypervitaminosis A). This risk is much lower with provitamin A carotenoids from food sources.

A doctor can test for a deficiency by measuring serum retinol levels in the blood. This is typically done if symptoms like night blindness are present.