Riboflavin (B2) is a yellowish-green fluorescent compound that is water soluble and derived from ribose sugar. It is involved in many oxidation-reduction reactions as part of the coenzymes FMN and FAD. Good dietary sources include plant foods like rice, pulses, and green vegetables, as well as animal foods like liver, eggs, and milk. Riboflavin deficiency can cause cracks at the corners of the mouth, a smooth purple tongue, scaly skin rashes, and corneal vascularization of the eyes.

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2. B2
RIBOFLAVIN
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Riboflavin (B2)
It is also called as beauty vitamin.
 it is yellowish green fluorescent compound
soluble in water.
The word riboflavin is derived from 2 sources
ribose – means many ribose sugar found in
several vitamins
flavin – yellow.
 It is widely involved in oxidation-reduction
reaction.

7. Structure & function

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Sources
• Plant :
 Rice
 Bajra
 Pulses- soybeans
 Vegetables – spinach
cauliflower
 brinjal
• Animals:-
 liver of sheep
 eggs
 Mutton
 Prawn
 milk

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Absorption & excretion
It is readily absorbed from intestinal tract
It is carried to tissue of the body &
incorporated into the cell enzymes.
It is stored in liver, kidney & heart.
Excretion – urine & sweat

12. BIOCHEMICAL FUNCTIONS OF
RIBOFLAVIN:
A- Biochemical role of FMN as a coenzyme
1. FMN as a part of redox potential
2. FMN is a coenzyme for L-amino acid
oxidases:

13. 3. FMN being a part of Cut. C reductase
4. FMN also accepts 2H+
from NADH+H+
5. FMN is a coenzyme for Warburg’s yellow
enzyme [a component of respiratory
chain]

14. B- FAD is a coenzyme for the following
enzyme:
Like FMN, FAD is also is a part of
mitochondrial respiratory chain

15. 1. D-aminoacid oxidases: The enzymes
catalyze reaction similar to L-aminoacid
oxidases but with FAD as coenzyme.
2. Aldehyde oxidase
3. Acyl-CoA dehydrogenase of the β
oxidation of fatty acids

16. 4. Succinate dehydrogenase, an enzyme of
citric acids cycle and converts succinate
to fumarate in mitochondria
5. Xanthine oxidase present in milk, small
intestine, kidney converts purine bases to
uric acid

17. 6. Glucose oxidase prepared from fungi
7. Glycine oxidase which oxidative
deaminates glycine to glyoxylic acid and
ammonia

18. Riboflavin-B2
Involved in energy metabolism; part of two
co- enzymes,FMN and FAD
Participate in citric acid cycle and beta
oxidation and electron transport
Remove ammonia during deamination of
some amino- acids

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Daily requirement
Men – 1.5mg
women – 1.2 mg
Pregnancy and lactation – 2 to 2.3 mg .
Children – 1.3mg.

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Functions
It is essential for normal growth.
Metabolism – It is involved in the metabolism
of carbohydrates, fat & proteins.
Digestion – it helps in digestion
Nervous system – it helps in proper
functioning of Nervous system

21. RIBOFALVIN IMPORTANCE

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Deficiency
Ocular changes-
it consists of corneal vasodilatation,
superficial & interstitial keratitis.
Skin & nails –
it may also result in dull or oily hair. Oily
skin, premature wrinkle on face.

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Deficiency
sore throat
cheliosis
glossitis
seborrheic dermatitis
anemia

25. SYMPTOMS OF RIBOFLAVIN
DEFICIENCY
• Stomatitis
• Anemia
• Swollen and dark tongue
• Angular chelosis: cracks in corners of
mouth and lips

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• Chapping &
fissuring of lips
CHEILOSIS
GLOSSITIS
• Inflammmed
• Red beefy tongue

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SEBORRHEIC DERMATITIS
 Red, scaly, itchy rashes
seen on
• scalp
• sides of nose
• eyebrows
• eyelids
• skin behind ears, middle of
chest

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Oral manifestation
Tongue:- in severe cases the tongue becomes
glazed & smooth due to complete atrophy of
the papillae.
Lips:- becomes red & shiny because of
desquamation of epithelium.

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Management
Riboflavin 25,000 to 50,000 mcg is given
daily in divided doses.

31. VITAMIN B2 (Riboflavin)
SOURCES:
 Yeast
 Whole grain
 Dry beans and pea
 Green vegetables
RDA: 1.5-1.8 mg/day in adults
FUNCTIONS:
In two active forms FMN and FAD serves as coenzyme in various reactions
DEFICIENCY
 Cheilosis-fissuring at angle of the mouth
 Glossitis-tongue smooth and purplish
 Seborrhagic Dermatitis:scaly,greasy,desquamation
 Eyes: corneal vascularization
Chronic alcoholics are susceptible to deficiencies.