Why Does Vitamin B2 Deficiency Cause Angular Cheilitis?

November 26, 2025 •

3 min read

According to research, a significant portion of angular cheilitis cases can be attributed to poor nutrition. A deficiency in vitamin B2, also known as riboflavin, is a well-documented cause of this painful inflammatory condition, which manifests as cracks and sores at the corners of the mouth.

Quick Summary

A lack of vitamin B2 impairs cellular function and repair, compromising mucous membrane health and leading to angular cheilitis. This deficiency can result from insufficient dietary intake or malabsorption, and correction involves addressing the nutritional shortfall.

Key Points

Cellular Integrity: Vitamin B2 is essential for maintaining the health and structural integrity of skin and mucous membranes.
Compromised Repair: A lack of riboflavin impairs cellular repair, leading to the cracking and inflammation characteristic of angular cheilitis.
Opportunistic Infection: The cracked skin at the mouth corners becomes a breeding ground for yeast (Candida) and bacteria, complicating the condition.
Common Co-Symptom: Riboflavin deficiency often appears alongside other symptoms, such as glossitis (magenta tongue) and seborrheic dermatitis.
Simple Solution: Addressing the deficiency through diet and supplements is typically a straightforward and effective approach for this type of angular cheilitis.

The Essential Role of Vitamin B2 in Mucous Membrane Health

Vitamin B2, or riboflavin, is a water-soluble vitamin vital for overall health and maintaining healthy skin and mucous membranes. It's a precursor for FMN and FAD coenzymes, essential for metabolic processes like energy production and tissue repair. Insufficient riboflavin impairs these functions, negatively impacting rapidly regenerating tissues such as the mouth's skin and mucous membranes.

The Mechanisms Behind Angular Cheilitis

Riboflavin deficiency, or ariboflavinosis, weakens the integrity and repair of epithelial tissues. This causes inflammation and vulnerability in the skin at the mouth's corners. Saliva can keep the area moist, creating an environment ripe for opportunistic infections, commonly by Candida albicans fungus or Staphylococcus aureus bacteria. Adequate vitamin B2 supports cell turnover and tissue repair. Without it, the skin's barrier weakens, leading to dryness, irritation, and eventually cracking. This breakdown makes the area prone to infection, initiating angular cheilitis.

Symptoms and Diagnosis of Riboflavin Deficiency

Riboflavin deficiency symptoms progress from subtle to more pronounced oral and skin issues. Key signs include:

Painful cracks at the mouth corners (angular cheilitis)
Inflamed, magenta-colored tongue (glossitis)
Scaling lips (cheilosis)
Red, scaly skin patches (seborrheic dermatitis) around the nose, ears, and eyes
Eye symptoms like strain, light sensitivity, and itching

Diagnosis relies on clinical observation of symptoms. Urine tests or a trial of riboflavin supplements can confirm the deficiency, with symptoms typically improving within weeks of treatment.

Comparison of Angular Cheilitis Causes

Angular cheilitis can arise from various factors, often distinguishable by co-occurring symptoms:


Cause	Mechanism	Key Associated Symptoms (Beyond AC)	Diagnostic Indicators
Vitamin B2 Deficiency (Riboflavin)	Impaired cellular repair and metabolism compromises mucosal integrity, leading to cracks.	Glossitis (magenta tongue), seborrheic dermatitis, eye issues.	Clinical response to riboflavin supplementation; blood/urine tests.
Iron Deficiency	Impaired oxygen transport affects tissue health, making skin vulnerable.	Microcytic anemia (fatigue, pale skin), brittle nails (koilonychia).	Complete Blood Count (CBC) showing microcytic anemia.
B12/Folate Deficiency	Impaired DNA synthesis affects rapidly dividing cells, including skin.	Macrocytic anemia, neurological symptoms (numbness/tingling).	CBC showing macrocytic anemia; B12/folate level tests.
Fungal Infection (Candida)	Opportunistic infection thrives in moist, compromised skin at mouth corners.	Oral thrush (white patches in mouth), diaper rash in infants.	Swab culture of the lesion; poor response to nutritional treatment alone.
Poorly-fitting Dentures	Mechanical irritation and excess saliva trap moisture, promoting infection.	Denture stomatitis (redness under dentures).	Dental examination; observation of denture fit.

Addressing and Preventing Riboflavin-Induced Angular Cheilitis

Addressing the Deficiency

Addressing riboflavin deficiency involves increasing dietary intake and often, supplementation. A healthcare provider might recommend a course of oral riboflavin. Since other B vitamin deficiencies can coincide, a B-complex supplement may be suggested.

Dietary Interventions

Preventing deficiency long-term requires a diet rich in riboflavin. Good sources include:

Dairy (milk, cheese, yogurt)
Meat (especially liver)
Eggs
Leafy green vegetables (spinach)
Fortified cereals and grains

Managing Local Symptoms

Managing local symptoms, alongside treating the deficiency, is crucial for comfort and preventing secondary infections. This includes:

Keeping the affected area dry and protected with a barrier cream.
Using topical antifungal or antibiotic creams if infection is present.
Avoiding irritants like spicy food or harsh toothpaste.

Conclusion

Vitamin B2 deficiency causes angular cheilitis by impairing the repair of skin at the mouth's corners, making it susceptible to cracking and infection. Recognizing symptoms and addressing the deficiency with diet and supplements can effectively treat and prevent this condition. A diet rich in riboflavin is key to avoiding this uncomfortable issue.

Key Takeaways

Impaired Cellular Repair: Vitamin B2 (riboflavin) is crucial for cellular energy production and tissue repair. A deficiency compromises the integrity of mucous membranes, making the corners of the mouth vulnerable to damage.
Weakened Skin Barrier: Lack of riboflavin leads to a weakened skin barrier, causing dryness, scaling, and the characteristic cracking and fissuring of angular cheilitis.
Increased Infection Risk: The cracks provide an entry point for opportunistic fungal and bacterial infections, such as Candida and Staphylococcus, which can worsen the condition.
Associated Symptoms: Riboflavin deficiency often presents with other signs, including a magenta tongue (glossitis), skin rashes (seborrheic dermatitis), and eye sensitivity.
Treatment is Effective: Addressing the deficiency through diet and supplements is typically a straightforward and effective treatment for this type of angular cheilitis.
Local Symptom Management: Protecting the affected area with barrier creams and avoiding irritants can help manage pain and prevent secondary infections.
Outbound Link: For more information on nutritional deficiencies, the National Institutes of Health provides detailed resources on dietary supplements.

Frequently Asked Questions

Vitamin B2, or riboflavin, plays a crucial role in maintaining healthy skin and mucous membranes by aiding in cellular energy production, antioxidant protection, and tissue repair. A deficiency impairs these processes, leaving the skin vulnerable.

When vitamin B2 is deficient, the body cannot effectively repair epithelial tissues. This compromises the skin barrier at the mouth corners, leading to dryness, inflammation, and painful cracks, which can then become infected.

Yes, other nutritional shortfalls can also cause or contribute to angular cheilitis, including deficiencies in iron, vitamin B12, and folic acid. A comprehensive evaluation is often necessary to pinpoint the exact cause.

Excellent food sources of vitamin B2 include dairy products, eggs, lean meats (especially liver), green leafy vegetables, and fortified grains and cereals.

Yes, angular cheilitis can have multiple causes. Other common factors include fungal or bacterial infections, excess saliva from poor-fitting dentures, dry mouth, and conditions like diabetes or inflammatory bowel disease.

With proper intervention to address the deficiency through supplementation and dietary changes, most people see significant improvement in riboflavin-induced angular cheilitis within 1-2 weeks, though complete healing may take longer depending on severity.

If a secondary fungal or bacterial infection is present, a healthcare provider may prescribe a topical antifungal or antibiotic cream. For simple dryness, a protective barrier cream like petroleum jelly can help. However, it's essential to address the underlying riboflavin deficiency for a more complete resolution.