Vitamin B3 (Niacin)

USE: Niacin is an important B vitamin that helps protect against cardiovascular disease and also supports cognitive function, the nervous system and the digestive tract. Niacin protects your heart by lowering blood levels of "bad" LDL cholesterol and preventing the accumulation of arterial plaque. Your digestive system, nervous system and brain need niacin to function properly. Niacin also helps your body make new DNA, and it helps your body use insulin efficiently to control blood sugar levels. It's often used to treat ateriosclerosis (coronary heart disease, or hardening of the arteries), arthritis, diabetes and acne, aswell as metal disorders like dementia, schizophrenia and psychosis. 
SOURCE: Niacin is found in red meat, liver, kidneys, chicken, turkey, fish and dairy. Salmon and tuna are especially high in niacin, but be careful with consumption of these fish because they can contain high levels of mercury and other pollutants. Vegetables that have a high niacin content include crimini mushrooms, which should be eaten raw for the maximum nutritional benefit. Green leafy vegetables are good sources, as are tomatoes and asparagus. Coffee also contains high levels of niacin. To get the most nutritional benefit from your vegetables, eat them raw or lightly steamed.