What is the source of vitamin A deficiency?

January 11, 2026 •

3 min read

According to the World Health Organization, vitamin A deficiency (VAD) affects more than half of all countries, particularly impacting young children and pregnant women in low-income regions. The source of vitamin A deficiency is not limited to poor dietary intake but also involves complex factors affecting the body's ability to absorb, store, and utilize this crucial fat-soluble nutrient.

Quick Summary

This article explores the primary causes of vitamin A deficiency, focusing on insufficient dietary intake, poor absorption due to various health conditions, and increased bodily demands. It outlines the specific factors contributing to this prevalent nutritional problem.

Key Points

Dietary Intake: The most common source of vitamin A deficiency is inadequate consumption of vitamin A and beta-carotene-rich foods, especially in developing regions.
Fat Malabsorption: Conditions like celiac disease, cystic fibrosis, and Crohn's disease disrupt fat absorption, thereby impeding the uptake of fat-soluble vitamin A.
Liver Disease: The liver stores most of the body's vitamin A, so diseases such as cirrhosis can significantly interfere with storage and release.
Increased Physiological Needs: Pregnant women, breastfeeding mothers, and rapidly growing children require more vitamin A, placing them at higher risk of deficiency.
Infectious Diseases: Illnesses like measles and chronic diarrhea can deplete vitamin A stores and worsen deficiency by reducing absorption.
Alcohol Abuse: Chronic alcoholism negatively impacts vitamin A absorption and metabolism, leading to severe depletion of hepatic reserves.
Zinc and Protein Deficiencies: These are often associated with vitamin A deficiency, as they are necessary for vitamin A absorption and transport proteins.

Primary Sources of Vitamin A Deficiency

Vitamin A deficiency (VAD) can arise from two main categories of causes: inadequate intake from dietary sources and issues with the body's ability to absorb, store, or metabolize the vitamin. While the former is the most common cause globally, especially in developing nations, the latter is a significant factor in wealthier, industrialized countries.

Dietary Insufficiency

Dietary factors are the leading cause of VAD worldwide, particularly in populations where access to vitamin A-rich foods is limited. This problem is widespread in many low-income and middle-income countries, particularly in parts of Africa and South-East Asia.

Lack of Access to Nutrient-Rich Foods: Diets heavily reliant on unfortified staple foods like white rice, which contain no beta-carotene, are a major contributor. In these regions, populations may lack access to a variety of fruits, vegetables, and animal products rich in vitamin A.
Low Fat Intake: As a fat-soluble vitamin, vitamin A requires dietary fat for proper absorption. In areas of chronic malnutrition or poverty, diets are often low in fat, further hindering the body's ability to absorb the limited vitamin A available.
Strict Vegan or Restrictive Diets: While plant-based foods contain provitamin A carotenoids, the body's conversion rate to active vitamin A (retinol) is significantly less efficient than absorbing preformed vitamin A from animal sources. Vegans and those on highly restrictive diets must ensure adequate consumption of foods rich in provitamin A to prevent deficiency.

Malabsorption and Underlying Medical Conditions

Even with adequate dietary intake, certain health issues can interfere with vitamin A's absorption and metabolism, leading to a deficiency.

Fat Malabsorption Syndromes: Conditions that impair the absorption of dietary fats can drastically reduce vitamin A uptake. These include:
- Celiac disease: An autoimmune disorder damaging the small intestine's lining.
- Cystic fibrosis: Affects the pancreas, reducing the enzymes needed for digestion.
- Crohn's disease and other Inflammatory Bowel Diseases (IBD): Cause chronic intestinal inflammation.
- Chronic diarrhea: Leads to increased nutrient excretion.
Liver and Pancreatic Disorders: Since the liver is the main storage site for vitamin A, any disease affecting its function, such as cirrhosis or chronic liver disease, can impair storage and release. Pancreatic insufficiency also disrupts the production of enzymes required for absorption.
Bariatric Surgery: Surgical procedures that alter the digestive tract to reduce fat absorption can lead to fat-soluble vitamin deficiencies, including vitamin A.

Increased Requirements and Infections

Certain life stages and illnesses increase the body's demand for vitamin A, depleting its stores if not met by higher intake.

Infants, Children, and Pregnant/Lactating Women: These groups have higher nutritional needs for rapid growth and development. Breastfeeding infants from vitamin A-deficient mothers are particularly vulnerable.
Infectious Diseases: Infections like measles and diarrheal diseases can exacerbate VAD. They can interfere with absorption, reduce appetite, and increase metabolic demand for vitamin A. Measles, in particular, can cause a rapid and significant drop in vitamin A levels.
Alcoholism: Chronic alcohol consumption is a well-documented cause of VAD. It interferes with vitamin A absorption and storage in the liver, leading to depleted hepatic stores.

Comparison of Major VAD Sources


Feature	Dietary Insufficiency	Malabsorption Disorders	Chronic Alcoholism
Primary Mechanism	Inadequate intake of vitamin A-rich foods.	Impaired intestinal absorption of fat-soluble vitamins.	Interferes with absorption and depletes liver storage.
Common Affected Groups	Young children, pregnant women, populations in developing countries.	Individuals with celiac disease, cystic fibrosis, IBD, or post-bariatric surgery.	Long-term heavy alcohol drinkers.
Socioeconomic Factor	Often linked to poverty and food insecurity.	Can affect individuals regardless of income level, though underlying conditions are key.	Can be a factor in any socioeconomic group.
Treatment Focus	Increasing consumption of vitamin A-rich foods and supplementation.	Managing the underlying medical condition and high-dose supplementation.	Addressing alcohol use disorder alongside nutritional therapy.

Conclusion

While a diet lacking in vitamin A is the most common and widespread cause of deficiency, particularly in resource-poor settings, it is crucial to recognize the other significant factors involved. Underlying medical conditions that impede nutrient absorption, heightened bodily requirements during growth and illness, and lifestyle factors such as chronic alcoholism can all serve as sources of vitamin A deficiency. Addressing this complex issue requires a multi-pronged approach involving public health initiatives, medical management of underlying conditions, and promoting dietary diversity, as outlined by organizations like the World Health Organization. Understanding the specific source of the deficiency is the first step toward effective prevention and treatment, ensuring better health outcomes for affected individuals. https://www.who.int/data/nutrition/nlis/info/vitamin-a-deficiency

Frequently Asked Questions

The main cause of vitamin A deficiency globally is inadequate dietary intake, particularly in low-income regions where staple diets lack sufficient vitamin A-rich fruits, vegetables, and animal products.

Several health conditions can cause vitamin A deficiency, including fat malabsorption syndromes like celiac disease and cystic fibrosis, liver disorders such as cirrhosis, and inflammatory bowel diseases like Crohn's disease.

Infants and children are at higher risk due to their rapid growth and developmental needs, as well as the limited vitamin A reserves they inherit if their mothers were deficient. High rates of infection in developing areas further exacerbate this risk.

Yes, chronic alcoholism is a known cause of vitamin A deficiency. It impairs the liver's ability to store and utilize vitamin A and disrupts its metabolism.

Because vitamin A is a fat-soluble vitamin, adequate dietary fat is necessary for its absorption. Low-fat diets or conditions that hinder fat digestion can significantly reduce the amount of vitamin A the body can absorb.

Deficiencies in other nutrients, notably zinc and protein, can contribute to VAD. Zinc is essential for the transport of vitamin A from the liver, and protein is needed to synthesize the carrier proteins.

Yes, infectious diseases, especially those causing chronic diarrhea or measles, can increase the body's demand for vitamin A and lead to poor absorption, worsening an existing deficiency.