What Happens to Your Body When You Have a Vitamin A Deficiency?

November 2, 2025 •

4 min read

According to the World Health Organization, vitamin A deficiency remains the leading cause of preventable blindness in children globally. When you have a vitamin A deficiency, your body can experience a cascade of serious health issues impacting everything from your vision to your immune system.

Quick Summary

A lack of vitamin A can cause significant health problems, including night blindness, dry skin, and a compromised immune system. This nutrient is crucial for vision, immune function, and cell growth throughout the body. Severe deficiency can lead to permanent blindness and increased susceptibility to infections.

Key Points

Night Blindness: One of the earliest signs of a vitamin A deficiency is difficulty seeing in low-light conditions, which is caused by impaired pigment production in the retina.
Immune System Compromise: A lack of vitamin A weakens the immune system, leading to an increased risk of severe infections, especially respiratory issues and diarrhea.
Dry Skin and Hair: Vitamin A is essential for skin cell growth, so a deficiency can result in dry, rough, and scaly skin, and may also contribute to hair loss.
Severe Eye Damage: Untreated deficiency can progress to xerophthalmia (severe dry eye) and keratomalacia, which can cause permanent damage to the cornea and result in irreversible blindness.
Reproductive Problems: In both men and women, low vitamin A levels can lead to infertility, poor pregnancy outcomes, and impaired fetal development.
Growth Stunting in Children: For infants and children, a vitamin A deficiency can delay growth and development, impacting overall health and survival.

The Far-Reaching Effects of a Vitamin A Deficiency

Vitamin A is a fat-soluble nutrient crucial for numerous bodily functions, including maintaining healthy vision, a robust immune system, and proper organ function. Because the body cannot produce it, adequate dietary intake is essential. When intake or absorption is insufficient, the body’s stored reserves of vitamin A are gradually depleted, leading to a host of symptomatic issues that can become severe if left untreated.

Impact on Vision and Eye Health

One of the most well-known consequences of a vitamin A deficiency is its devastating effect on vision. The eye’s retina requires vitamin A to produce specific pigments necessary for light absorption and proper function, especially in low-light conditions.

Night Blindness (Nyctalopia): This is often the first symptom to appear. Individuals have trouble seeing in dim light or adjusting to darkness, which happens because the production of rhodopsin—a pigment critical for night vision—is impaired. This condition is usually reversible with treatment.
Xerophthalmia: As the deficiency progresses, the eyes can become extremely dry due to a lack of tear production, a condition known as xerophthalmia. The white of the eye and the cornea dry out and thicken, causing discomfort.
Bitot's Spots: Foamy, white or grayish patches of keratin can appear on the conjunctiva, which is a key indicator of advanced deficiency.
Keratomalacia and Corneal Ulcers: In the most severe cases, the cornea can soften, break down, and form open sores, leading to irreversible vision loss and permanent blindness.

Weakened Immune System

A vitamin A deficiency severely compromises the immune system, making the body more vulnerable to infections.

Impaired Immune Response: Vitamin A is vital for the proper function of various immune cells, including T cells and B cells. A deficiency can reduce the body’s ability to fight off common infections effectively.
Increased Infection Risk: Individuals with low vitamin A levels are more susceptible to respiratory infections, diarrhea, and measles. In fact, supplementation can significantly reduce the mortality risk in children with measles in regions where vitamin A deficiency is prevalent.
Compromised Epithelial Barriers: The vitamin helps maintain the health of epithelial tissues that line the respiratory, gastrointestinal, and urinary tracts, acting as a barrier against pathogens. Without enough vitamin A, these barriers are weakened, increasing the risk of infection.

Skin and Reproductive Health Issues

Beyond vision and immunity, vitamin A plays a crucial role in maintaining healthy skin and supporting reproductive functions.

Dry and Scaly Skin: The skin, an epithelial tissue, depends on vitamin A for cell growth and repair. A deficiency can lead to rough, dry, and scaly skin.
Follicular Hyperkeratosis (Phrynoderma): Hair follicles can become clogged with excess keratin, forming small, bumpy eruptions on the skin.
Infertility and Reproductive Problems: In both men and women, vitamin A is essential for reproductive health. Deficiency can lead to fertility issues and complications during pregnancy, potentially impacting fetal development.

Other Potential Effects

Growth and Development Delays: In children, inadequate vitamin A intake can stunt growth and slow bone development.
Anemia: A deficiency can lead to anemia, a condition where the body lacks enough healthy red blood cells to carry adequate oxygen to the body's tissues.
Hearing Impairment: Some research suggests a link between vitamin A deficiency and hearing loss, as the vitamin is important for the maintenance of inner ear tissue.

Comparison: Effects of Vitamin A Deficiency vs. Excess


Feature	Vitamin A Deficiency	Vitamin A Excess (Toxicity)
Effects on Vision	Night blindness, dry eyes, corneal damage, permanent blindness.	Blurred vision, double vision, and, in severe cases, brain swelling.
Skin Conditions	Dry, scaly skin, follicular hyperkeratosis (bumpy skin).	Dry, rough skin, hair loss, peeling skin, and sometimes a yellowish-orange discoloration (from excess beta-carotene).
Immune System	Weakened immunity, increased susceptibility to infections.	No direct benefits; can suppress immune function at very high doses.
Reproduction and Growth	Infertility, poor pregnancy outcomes, delayed growth in children.	Birth defects if consumed in high doses during pregnancy; retarded growth.
Neurological Effects	Lower cognitive function in children.	Headaches, dizziness, confusion, liver damage, and potential for coma.

Conclusion

A vitamin A deficiency is a serious health concern with systemic consequences that affect vision, immunity, skin, and reproductive health. While relatively rare in developed countries, it remains a public health issue in many developing regions, particularly affecting children and pregnant women. Early symptoms like night blindness are often reversible with treatment and dietary changes. However, prolonged deficiency can lead to irreversible damage, including blindness. Maintaining a balanced diet rich in vitamin A sources is the most effective way to prevent this deficiency, but supplementation is crucial in high-risk populations. Recognizing the signs and addressing the root cause promptly is key to preventing long-term complications and restoring overall health. For more on dietary requirements and food sources, consult the NIH Office of Dietary Supplements.

Frequently Asked Questions

The most common and earliest sign is night blindness, or nyctalopia, which is a person's inability to see well in dim light. This is a treatable and reversible condition in its early stages.

Infants, young children, and pregnant or breastfeeding women in developing countries are at the highest risk. Individuals with fat malabsorption disorders like cystic fibrosis, celiac disease, or chronic diarrhea are also vulnerable.

Yes, many symptoms, such as night blindness and dry skin, can be reversed with proper treatment, including dietary changes and supplementation. However, advanced corneal damage can lead to permanent blindness.

Foods rich in preformed vitamin A include liver, fish oil, eggs, and dairy products. Provitamin A carotenoids, converted to vitamin A by the body, are found in orange and yellow vegetables (carrots, sweet potatoes) and dark leafy greens (spinach).

The deficiency weakens the immune response by impairing the function of immune cells and damaging the protective epithelial linings of the respiratory and gastrointestinal tracts, making the body more susceptible to infections.

Yes, high intake of preformed vitamin A, especially from supplements, can cause toxicity with symptoms like headaches, dizziness, and liver damage. It's best to get most vitamin A from a balanced diet.

A doctor can diagnose a deficiency based on symptoms, a review of diet, and, if severe, a blood test to measure serum retinol levels.