Multiple choice Which of the following is the result of deficiency of niacin? Beriberi Scurvy Pellagra Rickets Reveal answer Fill a bubble to check yourself C Correct answer Explanation Pellagra is the classic deficiency disease of niacin, characterized by the four Ds: dermatitis, diarrhea, dementia, and death. Beriberi is caused by thiamin deficiency, scurvy by vitamin C deficiency, and rickets by vitamin D deficiency.