Niacin deficiency causes ?

Ans. is 'b' i.e., Diarrhea Deficiency of niacin (and tryptophan) causes pellagra which is characterized by 3 Ds, i.e. dermatitis, diarrhea and dementia. Pellagra is common in people consuming maize and sorghum (jowar) as their staple foods. These two are poor in niacin and tryptophan, and rich in leucin. Excess of leucine inhibits the conversion of tryptophan into niacin.