What deficiency disease results from a lack of niacin?

Pellagra is the deficiency disease that results from a lack of niacin, also known as vitamin B3. Niacin plays a critical role in various metabolic processes in the body, particularly in the conversion of carbohydrates, fats, and proteins into energy. It is also essential for the synthesis of DNA and the functioning of the nervous system.

The symptoms of pellagra are often referred to as the "three D's": dermatitis, diarrhea, and dementia. These symptoms arise due to weakened cellular processes related to energy metabolism and skin health, which are directly affected by niacin deficiency. In historical contexts, pellagra was prevalent among populations with diets low in niacin and tryptophan (an amino acid that the body can convert to niacin), particularly in areas where corn was a staple food without proper preparation methods that enhance niacin bioavailability.

Understanding the distinct symptoms and biochemical roles of niacin clarifies why pellagra is specifically linked to this deficiency, while the other conditions listed are caused by deficiencies of other nutrients. For instance, scurvy results from a lack of vitamin C, beriberi is caused by a deficiency in thiamine (vitamin B1), and macrocytic anemia is typically linked to a deficiency in vitamin