Niacin deficiency presents with Pellagra. Which vitamin is Niacin?

• A. Vitamin B3 (Niacin)
• B. Vitamin B6
• C. Vitamin B2
• D. Vitamin B1

Answer: (A)

Niacin is Vitamin B3. It forms the coenzymes NAD+ and NADP+ that are essential for many oxidation–reduction reactions in energy metabolism and other cellular processes. Without enough niacin, these redox reactions falter, leading to pellagra, the disease classically described by dermatitis, diarrhea, and dementia. Other B vitamins are different: thiamine is B1, riboflavin is B2, and pyridoxine is B6, each with distinct roles. So the vitamin referred to as niacin is Vitamin B3.