Vitamin B3, is a water-soluble vitamin, it is also known as niacin or vitamin PP due to its action against pellagra ("pellagra preventive factor"), a once widespread disease caused by deficiency of this vitamin. Pellagra spread among the populations that made exclusive use of sorghum or corn polenta, extremely widespread in Italy between the 18th and 19th centuries and exclusively in the northern areas. At the beginning of the 20th century, scientists discovered that the pathology was due to an insufficient intake of a factor (precisely niacin) which was identified only in 1937. Pellagra was in fact also caused by the lack or lack of absorption of vitamin PP. The major natural sources of vitamin B3 are peanuts, white meat (especially turkey), red meat, and beef liver. In fish, this vitamin is found mainly in anchovies, tuna, sardines, swordfish and salmon, apart from bran, whole grains and their derivatives contain them in good quantities, just as milk and cheese are rich in this vitamin.Niacin is a micro-nutrient necessary for cellular respiration, helps in the metabolism of carbohydrates, fats and proteins, promotes circulation thanks to its vasodilating effect and also affects skin health. It supports the functioning of the nervous system, enhancing memory and cognitive abilities, participating in the physiological secretion of bile and stomach fluids, exerting a beneficial effect on the activity of gastrointestinal mucosa. In the medical field, it is known to reduce cholesterol levels in the blood where it has long been used and recommended as one of the first interventions together with dietary and lifestyle changes, or as an adjunct to specific therapies.In the past, niacin was prescribed as a supplement to lower LDL and triglyceride levels and was not yet considered an effective way to increase HDL levels ("good" cholesterol). Numerous studies have shown all the benefits of niacin to increase the "good cholesterol", an element of fundamental importance for our cardiovascular protection, as it transports the "bad" cholesterol present in the body towards the liver so that it is removed, just like a true "sweeper" of the arteries. It is important to consider that having low levels of HDL therefore means having an alarm bell that signals us about increased chances of having heart diseases or disorders. This important action, combined with good efficacy in lowering LDL and triglycerides, makes niacin a weapon of first intervention for the physiological balance of cholesterol, which should preferably be accompanied by adequate eating habits and physical activity.This precious vitamin also supports adequate brain function: it seems to protect against Alzheimer's and other age-related brain diseases that have a cognitive deficit. Niacin is an aid in preventing impotence or erectile dysfunction, as it acts as a vasodilator.Unfortunately there are some side effects of niacin that cause many people to stop taking it. The most common side effect is hot flashes or skin rashes with annoying urticaria-like itching, followed by tingling, diarrhoea and headaches. This is not a nuisance, that is dangerous or harmful to health, but many people who take niacin supplements find it unbearable and stop taking them. Discomfort that should be temporary sometimes becomes very less tolerable and in fact is often debilitating.To overcome this obnoxious inconvenience, several companies have however wanted to produce a supplement based on niacin, but in the form of "inositol esanicotinate", which is a special form of niacin (the exanicotinic acid ester of meso-inositol), which allows users to enjoy the benefits of this vitamin without having to bear the potential side effects of niacin.In this form, niacin has good bio-availability and is absorbed intact by the stomach, where it is hydrolysed into free nicotinic acid and inositol, resulting in a slower, more gradual release, which can be defined as "less violent" in the bloodstream, avoiding the disturbances listed above and promoting the positive effects of this important vitamin.