Pellagra is caused by deficiency of which vitamin-

.Ans. is 'b' i.e., B3 o Pellagra is Caused by Deficiency of Tryptophan & Niacin. The VitaminsVitaminFunctionsDeficiency DiseaseLipid-solubleA Retinol, b-caroteneVisual pigments in the retina; regulation of gene expression and cell differentiationNight blindness, xerophtalmia; keratinization of skinD CalciferolMaintenance of calcium balance; enhances intestinal absorption of Ca2+ and mobilizes bone mineral; regulation of gene expression and cell differentiationRickets = poor mineralizetion of bone; osteomalacia = bone demineralizatinE Tocopherols, tocotrienolsAntioxidant, expecially in cell membrances; signalingExtremely rare--serious neurologic dysfunctionK Phylloqinone: menaquinonesCoenzyme in formation of y-carboxyglutsmste in enzymes of blood clotting and bone matrixImpaired blood clotting, hermorrhagic diseaseWater-solubeB1 ThiaminCoenzyme in pyruvate and a-ketoglutarate dehydrogenases, and transketolase; regulates Cl channel in nerve conductionPeripheral nerve damage (beriberi) or central nervous system lesions (Wemicke-Korsakoff syndrome)B2 RiboflavinCoenzyme in oxidation and reduction reactions (FAD and FMN); prosthetic group of flavoproteinsLesions of comer of mouth, lips and tongue, seborrheic dermatitisNiacin Nicotinic acid nicotinamideCoenzyme in oxidation and reduction reactions, functional part of NAD and NADP; role in intracellular calcium regulation and cell signalingPellagra--photosensitive dermatitis depressive psychosisB6 Pyridoxine, pyridoxal, pyridoxamineCoenzyme in transmination and decarboxylation of amino acids and glycogen phosphorylase; modulation of steroid hormone actionDisorder of amino acid metabolism, convulsionsFolic acidCoenzyme in transfer of one-carbon fragmentsMegaloblastic anemiaB12 CobalaminCoenzyme in transfer of one-carbon fragments and metabolism of folic acidPernicious anemia = megaloblastic anemia with degeneration of the spinal cordPantothenic acidFunctional part of CoA and acyl carrier protein: fatty acid synthesis and metabolismPeripharal nerve damage (nutritional melagia or "burning foot syndrome")H BiotinCoenzyme in carboxylation reactions in gluconeogenesis and fatty acid synthesis; role in regulation of cell cycleImpaired and carbohydrate metabolism dermatitisC Ascorbic acidCoenzyme in hydroxylation of proline and lysine in collagen synthesis; antioxidant; enhances absorption of ironScurvy--impaired wound healing, loss of dental cement, subcutaneous hemorrhage