This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nutrition and Health, Subject name: Social & Preventive Medicine
Niacin deficiency cause - 
Select and explain. 
A. Pellagra, B. Scurvy, C. Rickets, D. Lathyrism
A: Pellagra
Answer: A: Pellagra 
Explanation: Ans. is 'a' i.e., Pellagra {Ref: Park 22nd/ep. 574]Niacino This vitamin differs from the other vitamins of the B-complex group in that an essential amino acids tryptophan serves as its precursor.o Another characterstic of niacin is that it is not excreted in urine as such, but is metabolised to two major methylated derivatives.N-methyl-nicotinamideN-methyl pyridoneso Niacin deficiency results in *Pellagra 'o Pellagra is identified by the presence of three 'D's - Diarrhea, Dementia, Dermatitis.