Riboflavin (Vitamin B2)

Riboflavin in Whole Blood

Clinical Information

Riboflavin helps release energy from foods. It is a cofactor in the mitochondrial respiratory chain1. Its most important biologically active forms are flavin adenine dinucleotide (FAD) and flavin mononucelotide (FMN) which act as electron carriers in redox reactions 2. It is readily degraded by light 2.

Signs and Symptoms of Deficiency or Toxicity

Manifestations of inadequate intakes of vitamin B2 include sore throat, lesions in the lips and corners of the mouth, magenta tongue3. However, these classical symptoms are not specfic to riboflavin deficiency 4. Severe deficiency can impair body production of niacin 2.

Riboflavin deficiency typically arise from inadequate dietary intake and arises within days 2. It is largely confined in developing countries 4.

Toxicity of water-soluble vitamins is unlikely 4.

Biomarker and Methods of Analysis


Riboflavin status may be measured both from the blood and urine.

Riboflavin in whole blood provides an indication of tissue saturation and long term riboflavin status and is a more practical approach to determining riboflavin status 5.

Supplementation Guide

No established clinical guidelines for supplementation.

No upper limit established due to absence of toxicological basis 7.

No known clinical relevant interactions with medications 8.

Food Sources

Milk and dairy products, meat (especially offal) and fatty fish, cereals, and dark green leafy vegetables 2.

(1) Huskisson E, Maggini S, Ruf M. The role of vitamins and mineral in energy metabolism and well-being. The Journal of International Medical Research 2007; 35: 277-289
(2) Powers HJ. Riboflavin (vitamin B-2) and health. American Journal lf Clinical Nutrition 2003; 77:1352-1360.
(3) Mayo Clinic Medical Laboratories. (n.d.). Test Catalog. Riboflavin (Vitamin B2), Plasma. Retrieved from https://www.mayomedicallaboratories.com/test-catalog/Clinical+and+Interpretive/42363
(4) Sriram K and Lonchyna VA. Micronutrient supplementation in adult nutrition therapy: Practical considerations. Journal of Parenteral and Enteral Nutrition 2009; 33(5): 548-562.
(5) McAuley E, McNulty H, Hughes C, Strain SS, Ward M. Ribflavin status, MTFHR genotype and blood pressure: current evidence and implicatons for personalized nutrition. The Proceedings of the Nutrition Society, 2010. 10 pp.
(6) Graham JM, Peerson JM, Haskell MJ, Shrestha RK, Brown KH, Allen LH. Erythrocyte ribflavin for the detection of ribflavin deficiency in pregnant Nepali Women. Clinical Chemistry 2005; 51:2162-2165. Retrieved from: https://naldc.nal.usda.gov/download/8731/PDF
(7) Hathcock , John H. Safety of Vitamin and Minral Supplements. Safe Levels Identified by Risk Assessment. April 2004.
(8) Office of Dietary Supplements- National Institutes of Health. (n.d.) Riboflavin. Fact Sheet for Health Professionals. Retrieved from https://ods.od.nih.gov/factsheets/Riboflavin-HealthProfessional/