What are the diagnostic tests for Riboflavin (Vitamin B2) deficiency?

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Last updated: April 11, 2025 • View editorial policy

From the Guidelines

Testing for vitamin B2 (riboflavin) deficiency is typically done through blood tests that measure levels of FAD (flavin adenine dinucleotide) or erythrocyte glutathione reductase activity coefficient (EGRAC), and should be ordered by a healthcare provider when there is clinical suspicion of deficiency, as stated in the ESPEN micronutrient guideline 1.

Importance of Testing

Testing for vitamin B2 deficiency is crucial because riboflavin plays vital roles in energy production, cellular function, and metabolism of other B vitamins. The body cannot store large amounts of B2, making regular dietary intake necessary. Deficiencies are relatively rare in developed countries but can occur in those with poor diets, alcoholism, certain chronic diseases, or who take medications that interfere with riboflavin absorption.

Preparation and Procedure

To prepare for testing, patients should continue their normal diet unless instructed otherwise by their healthcare provider. No fasting is typically required, though certain medications may affect results, so it is essential to inform the doctor about all supplements and medications being taken.

Treatment

After diagnosis, treatment involves riboflavin supplements, usually 5-10 mg daily until levels normalize, then a maintenance dose if needed, as recommended by the ESPEN micronutrient guideline 2. Vitamin B2 deficiency testing is important for identifying individuals who require supplementation to prevent or treat deficiency-related symptoms, such as cracked lips, inflammation of the tongue, sore throat, skin disorders, or eye problems like sensitivity to light.

At-Risk Populations

Certain populations are at a higher risk of vitamin B2 deficiency, including those with malabsorption, thyroid dysfunction, diabetes, renal disease, alcoholism, and pregnant or lactating women, as well as the elderly, according to the ESPEN micronutrient guideline 3. Regular monitoring of riboflavin status is not required, but assessment of riboflavin status can be necessary when there is clinical suspicion of deficiency, as stated in the guideline 1.

From the Research

Testing for Vitamin B2 Deficiency

  • Vitamin B2, also known as riboflavin, plays a crucial role in various bodily functions, including energy metabolism and antioxidant potential 4, 5.
  • Deficiency in riboflavin can lead to a range of health issues, including cheilosis, angular stomatitis, glossitis, seborrheic dermatitis, and severe anemia with erythroid hypoplasia 6.
  • Subclinical deficiency may be more widespread, but often goes undetected due to the rarity of riboflavin biomarker measurements in human studies 6.

Diagnosis and Detection

  • Riboflavin transporter deficiencies can present with weakness, cranial nerve deficits, sensory symptoms, feeding difficulties, and respiratory difficulties, which can be caused by a sensorimotor axonal neuropathy and cranial neuropathy 7.
  • Biochemical abnormalities may be absent, and diagnosis can only be made or rejected by molecular analysis of all genes 7.
  • Treatment with oral supplementation of riboflavin is lifesaving, and should be started immediately if a riboflavin transporter deficiency is suspected, without awaiting molecular diagnostics results 7.

Health Implications

  • Riboflavin deficiency has been linked to various health issues, including anemia, hypertension, cancer, hyperglycemia, diabetes mellitus, and oxidative stress 4, 5.
  • Riboflavin may also exert neuroprotective effects in some neurological disorders, such as Parkinson's disease, migraine, and multiple sclerosis 4.
  • The role of riboflavin in preventing a wide array of health diseases, including migraine, anemia, cancer, and oxidative stress, has been highlighted in recent studies 5.

References

Guideline

espen micronutrient guideline.

Clinical Nutrition, 2022

Guideline

espen micronutrient guideline.

Clinical Nutrition, 2022

Guideline

espen micronutrient guideline.

Clinical Nutrition, 2022

Research

Riboflavin in Human Health: A Review of Current Evidences.

Advances in food and nutrition research, 2018

Research

Riboflavin and health: A review of recent human research.

Critical reviews in food science and nutrition, 2017

Research

Causes and Clinical Sequelae of Riboflavin Deficiency.

Annual review of nutrition, 2023

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.