What happen when you don't get enough niacin?

When you don't get enough niacin (vitamin B3), it can lead to a deficiency known as pellagra. Symptoms of pellagra include dermatitis, diarrhea, dementia, and, if left untreated, can be fatal. Niacin is essential for energy metabolism and the health of the skin, digestive system, and nervous system. A deficiency is often associated with inadequate dietary intake, chronic Alcoholism, or certain medical conditions.