Vitamin B2 (Riboflavin)

Vitamin B2 is also known as Riboflavin. The prime role of this vitamin is to help with energy production at a cellular level. Deficiency of vitamin B2 mainly causes cervical cancer and migraine headache. It can also help in preventing acne, muscle cramps, burning feet syndrome, carpal tunnel syndrome, and few blood disorders like congenital methemoglobinemia and red blood cell aplasia. Vitamin B2 is concentrated in major organs like liver, kidneys and heart. It helps process nutrients in the cardiovascular system through aerobic energy production and helps to keep cells in good health.

Riboflavin or vitamin B2 is an essential nutrient in human nutrition and plays a key role in the production of energy. Vitamin B2 is needed to process amino acids and fats, activate vitamin B6 and folic acid, and help convert carbohydrates into the fuel the body runs on. Under some conditions, vitamin B2 can act as an antioxidant. Vitamin B2 is an intermediary the transfer of electrons in the cellular oxidation-reduction reactions which generate energy from protein, carbohydrate and fat. The riboflavin coenzymes are also important for the transformation of vitamin B6 and folic acid into their respective active forms, and for the conversion of tryptophan into niacin. Riboflavin is involved in energy production as part of the electron transport chain that produces cellular energy.


Riboflavin functions as a coenzyme, meaning that it is required for enzymes (proteins) to perform normal physiological actions. Specifically, the active forms of riboflavin flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) function as cofactors for a variety of flavoprotein enzyme reactions:

  • Flavoproteins of electron transport chain, including FMN in Complex I and FAD in Complex II
  • FAD is required for the production of pyridoxic acid from pyridoxal (vitamin B6) by pyridoxine 5′-phosphate oxidase
  • The primary coenzyme form of vitamin B6 (pyridoxal phosphate) is FMN dependent
  • Oxidation of pyruvate, α-ketoglutarate, and branched-chain amino acids requires FAD in the shared E3 portion of their respective dehydrogenase complexes
  • Fatty acyl CoA dehydrogenase requires FAD in fatty acid oxidation
  • FAD is required to convert retinol (vitamin A) to retinoic acid via cytosolic retinal dehydrogenase
  • Synthesis of an active form of folate (5-methyltetrahydrofolate) from 5,10-methylenetetrahydrofolate by Methylenetetrahydrofolate reductase is FADH2 dependent
  • FAD is required to convert tryptophan to niacin (vitamin B3)
  • Reduction of the oxidised form of glutathione (GSSG) to its reduced form (GSH) by Glutathione reductase is FAD dependent

For the molecular mechanism of action see main articles Flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD)


Sources of riboflavin include organ meats (liver, kidney, and heart) and certain plants such as almonds, mushrooms, whole grain, soybeans, and green leafy vegetables. The richest sources of riboflavin include organ meats such as liver, kidney and heart. Milk, yeast, cheese, oily fish, eggs and dark green leafy vegetables are also rich sources. Flour and cereals are enriched with riboflavin. Riboflavin is stable when heated but will leach into cooking water. It is easily destroyed by light, and foods stored in clear containers will lose their riboflavin content in a short period of time. Because riboflavin is destroyed by exposure to light, foods with riboflavin should not be stored in glass containers that are exposed to light. Bread and cereals are often fortified with riboflavin. Because riboflavin is destroyed by exposure to light, foods with riboflavin should not be stored in glass containers that are exposed to light.


• Infant 0-6 months                    0.3 mg
• Infant 6-12 months                    0.4 mg
• Children 4-8 years                     0.6 mg
• Children 9-13 year                     0.9 mg
• Boys 14-18 years                        1.3 mg
• Girls 14-18 year                           1 mg

• Men 19 years and older              1.3 mg
• Women 19 years and older       1.1 mg
• Pregnant women                            1.4 mg
• Breast feeding women                1.6 mg


The normal value of plasma vitamin B2 (riboflavin) is 1-19 µg/L.


Blood Biochemistry


Higher Level indicates:

• Itching
• Numbness
• Burning or prickling sensation
• Yellow or orange urine
• Sensitivity to light

Lower level indicates:
• Migraine headache
• Cataracts
• Lactic acidosis in people with acquired immunodeficiency syndrome.
• Cervical cancer
• Carpal tunnel syndrome
• Rosacea
• Vaginitis
• Acne
• Muscle cramps
• Weak immune system
• Early aging
• Weak hair
• Unhealthy skin
• Canker sores
• Alzheimer’s disease