Understanding the Signs: What are the symptoms of a B2 deficiency?

October 7, 2025 •

3 min read

While severe riboflavin deficiency, also known as ariboflavinosis, is rare in developed countries, it is still a potential health concern, especially for certain at-risk populations. Understanding what are the symptoms of a B2 deficiency can help in early detection and intervention.

Quick Summary

A vitamin B2 (riboflavin) deficiency can cause cracked lips, a swollen magenta tongue, skin inflammation, and eye problems like light sensitivity. It may also lead to fatigue and anemia, often occurring alongside other B-vitamin deficiencies.

Key Points

Angular Cheilitis: One of the most common signs is painful cracks and sores at the corners of the mouth.
Magenta Tongue (Glossitis): A tell-tale symptom is an inflamed, swollen tongue that appears a purplish-red or magenta color.
Skin Inflammation: Deficient individuals may experience seborrheic dermatitis, presenting as red, greasy, scaly patches on the face or other areas.
Eye Sensitivity: Ocular symptoms like photophobia (light sensitivity), eye fatigue, and blurred vision are frequently reported.
Associated with Other Deficiencies: Riboflavin deficiency often coexists with other B-vitamin deficiencies due to shared dietary causes or malabsorption issues.
Easily Treatable: Once diagnosed, the condition is easily corrected with dietary changes and oral riboflavin supplements.

Vitamin B2, or riboflavin, is an essential water-soluble vitamin vital for energy production, metabolism, and antioxidant defense. When the body lacks sufficient amounts, ariboflavinosis can develop, although it's uncommon in areas with fortified foods. Risk factors include certain diets, medical conditions, and lifestyle choices. Symptoms can be non-specific, highlighting the importance of recognizing key indicators.

The many faces of ariboflavinosis: What are the symptoms of a B2 deficiency?

Riboflavin deficiency symptoms often affect the mouth, throat, skin, and eyes. They develop gradually and vary in severity, reflecting riboflavin's role as a cofactor for numerous metabolic enzymes.

Oral and mucosal symptoms

Common and often visible signs include:

Angular cheilitis: Painful cracks at the corners of the mouth.
Cheilosis: Dry, cracked, and inflamed lips.
Glossitis: A swollen, inflamed tongue, often magenta in color.
Sore throat: Inflammation of oral and throat membranes.

Skin symptoms

Deficiency can lead to dermatological issues:

Seborrheic dermatitis: Red, greasy, scaly patches, typically around the nose, ears, eyelids, and genitals.
Dry skin: Skin may become dry and itchy.

Eye symptoms

The eyes are sensitive to riboflavin levels:

Photophobia: Increased light sensitivity.
Eye fatigue and blurred vision: Tiredness in the eyes and potentially blurred vision in severe cases.
Itchy, watery, and red eyes: Inflammation can cause discomfort and redness.
Cataracts: Chronic, severe deficiency may increase cataract risk.

General systemic symptoms

Broader health issues can include:

Fatigue and weakness: Feeling constantly tired due to reduced cellular energy.
Anemia: Normochromic-normocytic anemia can result from impaired iron metabolism.
Hair loss: May also be observed.

Why a B2 deficiency happens

Contributing factors include:

Inadequate dietary intake: A diet low in riboflavin-rich foods.
Malabsorption disorders: Conditions like Crohn's or celiac disease hindering nutrient absorption.
Alcoholism: Interferes with B vitamin absorption and use.
Increased demand: Higher requirements in pregnancy, lactation, or with certain medical conditions.
Genetic defects: Rare conditions affecting riboflavin transport and metabolism.

Comparison of B-vitamin deficiency symptoms

B-vitamin deficiencies often overlap. Here's a comparison of common symptoms:


Symptom	B2 (Riboflavin)	B1 (Thiamin)	B12 (Cobalamin)
Oral Manifestations	Cracked lips (cheilosis), sores at mouth corners (angular cheilitis), magenta tongue (glossitis), sore throat.	Can cause soreness and inflammation of the mouth and tongue, but not typically magenta.	Sore, inflamed tongue, typically red, not magenta. Mouth sores can occur.
Neurological Issues	Peripheral neuropathy (numbness/tingling) can occur in severe, chronic cases.	Beriberi (nerve, muscle, and heart problems), Wernicke-Korsakoff syndrome (confusion, memory loss).	Neurological issues including numbness, tingling, difficulty walking, and cognitive changes.
Skin Problems	Seborrheic dermatitis (greasy, scaly patches), dermatitis around mouth/nose.	No specific skin rash linked to deficiency.	Pale or jaundiced skin and fatigue due to megaloblastic anemia.
Eye Issues	Photophobia, blurred vision, eye fatigue, cataracts in severe cases.	Eye problems (e.g., nystagmus) can occur in Wernicke-Korsakoff syndrome.	Visual disturbances due to optic nerve damage.
Anemia	Normochromic-normocytic anemia.	Not typically associated with anemia.	Megaloblastic anemia (large, immature red blood cells).

Diagnosis, treatment, and prevention

Diagnosis

A healthcare professional diagnoses ariboflavinosis based on physical examination, symptoms, and dietary history. Improvement with riboflavin supplements can help confirm the diagnosis. Laboratory tests like measuring urinary riboflavin may also be used.

Treatment

Treating riboflavin deficiency is usually simple, involving increased intake through diet or supplements.

Oral supplements: Often recommended, with dosages varying based on severity.
Other B-vitamins: A B-complex supplement may be suggested as other B deficiencies often coexist.
Dietary changes: Increasing riboflavin-rich foods is advised.
Intravenous administration: Used in severe cases or with malabsorption.
Address underlying causes: Managing any contributing medical conditions is crucial.

Prevention

A balanced diet rich in riboflavin is the best prevention.

Include riboflavin-rich foods: Incorporate dairy, eggs, lean meats, organ meats, leafy greens, mushrooms, almonds, and fortified grains.
Consider dietary restrictions: Individuals on vegan or restrictive diets may need fortified foods or supplements.
Protect food from light: Store riboflavin-sensitive foods like milk in opaque containers.

Conclusion

Ariboflavinosis is rare but a risk for some groups. Recognizing what are the symptoms of a B2 deficiency, especially oral, skin, and eye signs, is vital for early detection. Prevention is best achieved through a balanced diet. If a deficiency is suspected, consult a healthcare provider for diagnosis and treatment, which may include supplementation.

Visit the NIH Office of Dietary Supplements for more information on Riboflavin.

Frequently Asked Questions

A vitamin B2 deficiency is most commonly caused by inadequate dietary intake, but it can also be triggered by malabsorption disorders, alcoholism, increased bodily demands (like during pregnancy), and some medications.

Yes, a riboflavin deficiency is considered rare in countries where diets are generally adequate and many foods are fortified. However, it can affect specific populations, such as alcoholics, vegans, and individuals with malabsorption issues.

Diagnosis is typically based on a clinical evaluation of symptoms, dietary history, and sometimes confirmed with a therapeutic trial of riboflavin supplements. In some cases, laboratory tests like measuring urinary riboflavin levels can be used.

Good sources of riboflavin include dairy products (milk, cheese, yogurt), eggs, lean meats (especially organ meats like liver), green leafy vegetables (spinach, broccoli), and fortified grains.

Treatment usually involves increasing dietary intake of riboflavin-rich foods or taking oral supplements. In severe cases or for malabsorption issues, healthcare providers might recommend higher doses or intravenous administration.

Symptoms can begin to resolve relatively quickly with proper treatment. For instance, oral lesions may start to heal within a few weeks of consistent supplementation.

Yes, riboflavin deficiency can affect the eyes by causing symptoms such as photophobia (light sensitivity), eye fatigue, blurred vision, and, in severe cases, cataracts.