Vitamin B3, also called niacin, is one of the water-soluble B vitamins. The term niacin refers to ‘nicotinic acid’ and ‘nicotinamide’ (also called niacinamide). Both are used to form the coenzymes. Since nicotinic acid can also be synthesized in humans from the amino acid tryptophan, it does not qualify as a vitamin provided that an adequate dietary supply of tryptophan is available.
A sufficient intake of vitamin B3 (niacin) is important as it helps the body to convert food into glucose, used to produce energy produce macromolecules, including fatty acids and cholesterol DNA repair and stress responses. The European Food Safety Authority (EFSA), which provides scientific advice to assist policy makers, has confirmed that clear health benefits have been established for the dietary intake of niacin (vitamin B3) in contributing to: normal energy-yielding metabolism; the normal function of the nervous system; the maintenance of normal skin and mucous membranes; normal psychological functions; the reduction of tiredness and fatigue.
Cancer Some preliminary study results have indicated that increased consumption of vitamin B3 (niacin), along with other micronutrients, might be associated with a decreased incidence of mouth and throat cancer. Diabetes Some evidence suggests that vitamin B3 (nicotinamide) might help to delay the time individuals with type 1 diabetes would need to take insulin.
In developed countries, where vitamin B3 deficiency is rare, alcoholism is the prime cause of deficiency. Symptoms of mild deficiency include indigestion, fatigue, canker sores, vomiting, and depression.
Yeast, liver, poultry, lean meats, nuts and legumes contribute most of the niacin obtained from food. In cereal products (e.g., corn, wheat), niacin is bound to certain components of the cereal and is thus not bioavailable. The amino acid tryptophan contributes as much as two thirds of the niacin activity required by adults in typical diets. Important food sources of tryptophan are meat, milk and eggs.