Niacin, also known as vitamin B3 and nicotinic acid, like any other B vitamin helps the body to convert food into energy. It is not stored in the body and any excess of this vitamin is excreted in urine, so we need to consume it daily. Besides this, niacin plays an important role in maintaining skin and nerves healthy. High doses of niacin can improve cholesterol levels.
Deficiency of this vitamin can lead to pellagra. This disease is rare in industrialized nations but it is still public health problem in some poor countries.
Considering that the best sources of niacin are fish, chicken and turkey, pork, and some types of mushrooms, juice recipes are usually low in this vitamin, so you need to get your daily dose of niacin from other sources.