Niacin - What is it

https://medlineplus.gov/ency/article/002409.htm

Niacin is a type of B vitamin. It is water-soluble, which means it is not stored in the body. Water-soluble vitamins dissolve in water. Leftover amounts of the vitamin leave the body through the urine. That means you need a regular supply of such vitamins in your diet.

Function

Niacin helps the digestive system, skin, and nerves to function. It is also important for converting food to energy.