Good sources of niacin include meats, fish, legumes and some nuts. In many foods, such as cereals, niacin is of low bioavailability. However, it remains endemic in India as well as parts of China and Africa where corn is a staple, so called cereal pellagra. Other causes of pellagra include prolonged tx. The most characteristic sign is a pigmented rash occurring in sun-exposed areas.
Color is generally similar to a sunburn, although in chronic cases it make take on a darker color.
Changes in the GI tract are associated with vomiting or diarrhea and the tongue takes on a bright red color. Neurologic manifestations include anxiety, insomnia, and in more severe cases, disorientation and delusions. Death occurs within 4 to 5 years if untreated. Treatment is with po niacin or nicotinamide 50 mg 10 times per day.