<prompt> What amount of tryptophan produces 1 gm of niacin?40 mg50 mg60 mg70 mg  <response>: Ans. c 60mg. Ref. Harper, Biochemistry, 26th ed., 258NIACIN Vitamin B3 Niacin is derived from tryptophan using vitamin B6; 1 mg of niacin is formed from 60 mg of tryptophan. Niacin is constituent of NAD, NADP used in redox reactions. Niacin deficiency results in Pellagra; The symptoms of Pellagra are the 4 Ds:- Diarrhea,- Dermatitis Necklace sign,- Dementia and- Death Pellagra can be caused by:- Hartnup disease tryptophan absorption,- Malignant carcinoid syndrome tryptophan metabolism, and- INH vitamin B6.AMINO ACID DERIVATIVES1TryptophanNiacin NADNADP1 mg of niacin is formed from 60 mg of tryptophan; Synthesis requires B6.Serotonin Melatonin2PhenylalaninePhenylalanine tyrosine dopa dopamine Norepinephrine epinephrinePhenylalanine tyrosine dopa melanin.Phenylalanine tyrosine thyroxine3Histidine Histamine By decarboxylation.4Glycine Porphyrin and haem Purines Creatine totally made-up of glycine arginine methionine; mnemonic--GAM Glutathione totally made up of glycine cystine glutamate; mnemonic--GCG5ArginineCreatinine, Urea, Nitric oxide6MethionineCholine7GlutamateGABA glutamate decarboxylase--requires B6.Glutathione 