3Riboflavin (B2)It is also called as beauty vitamin. it is yellowish green fluorescent compoundsoluble in water.The word riboflavin is derived from 2 sourcesribose – means many ribose sugar found inseveral vitaminsflavin – yellow. It is widely involved in oxidation-reductionreaction.
10Absorption & excretionIt is readily absorbed from intestinal tractIt is carried to tissue of the body &incorporated into the cell enzymes.It is stored in liver, kidney & heart.Excretion – urine & sweat
BIOCHEMICAL FUNCTIONS OFRIBOFLAVIN:A- Biochemical role of FMN as a coenzyme1. FMN as a part of redox potential2. FMN is a coenzyme for L-amino acidoxidases:
3. FMN being a part of Cut. C reductase4. FMN also accepts 2H+from NADH+H+5. FMN is a coenzyme for Warburg’s yellowenzyme [a component of respiratorychain]
B- FAD is a coenzyme for the followingenzyme:Like FMN, FAD is also is a part ofmitochondrial respiratory chain
1. D-aminoacid oxidases: The enzymescatalyze reaction similar to L-aminoacidoxidases but with FAD as coenzyme.2. Aldehyde oxidase3. Acyl-CoA dehydrogenase of the βoxidation of fatty acids
4. Succinate dehydrogenase, an enzyme ofcitric acids cycle and converts succinateto fumarate in mitochondria5. Xanthine oxidase present in milk, smallintestine, kidney converts purine bases touric acid
6. Glucose oxidase prepared from fungi7. Glycine oxidase which oxidativedeaminates glycine to glyoxylic acid andammonia
Riboflavin-B2Involved in energy metabolism; part of twoco- enzymes,FMN and FADParticipate in citric acid cycle and betaoxidation and electron transportRemove ammonia during deamination ofsome amino- acids
19Daily requirementMen – 1.5mgwomen – 1.2 mgPregnancy and lactation – 2 to 2.3 mg .Children – 1.3mg.
20FunctionsIt is essential for normal growth.Metabolism – It is involved in the metabolismof carbohydrates, fat & proteins.Digestion – it helps in digestionNervous system – it helps in properfunctioning of Nervous system
29Oral manifestationTongue:- in severe cases the tongue becomesglazed & smooth due to complete atrophy ofthe papillae.Lips:- becomes red & shiny because ofdesquamation of epithelium.
30ManagementRiboflavin 25,000 to 50,000 mcg is givendaily in divided doses.
VITAMIN B2 (Riboflavin)SOURCES: Yeast Whole grain Dry beans and pea Green vegetablesRDA: 1.5-1.8 mg/day in adultsFUNCTIONS:In two active forms FMN and FAD serves as coenzyme in various reactionsDEFICIENCY Cheilosis-fissuring at angle of the mouth Glossitis-tongue smooth and purplish Seborrhagic Dermatitis:scaly,greasy,desquamation Eyes: corneal vascularizationChronic alcoholics are susceptible to deficiencies.