Niacin, also known as vitamin B3 or nicotinic acid, is a water soluble vitamin which is a vital component of the human diet. Like other water soluble vitamins, the body expresses excess niacin, meaning that a continuous supply needs to be consumed. Common sources of niacin, along with other healthy vitamins and minerals, are meats, wheat germ, dairy products, and yeast. Under rare situations, a patient may need to take a niacin supplement. Caution should be used when adding niacin to the diet, however, as an excess can be harmful.

The substance was discovered by chemists who were working with nicotine. When nicotine was oxidized, it produced nicotinic acid. As the chemists explored the properties of the substance, they realized that it had potential health applications. Since nicotinic acid is found in substances which do not contain nicotine, a new name was chosen to distinguish it from nicotine. Allegedly, niacin is a portmanteau of nicotinic acid vitamin. Further research on niacin showed that it played a crucial role in many biological functions, either in a pure form or in the form of chemicals derived from it.

In addition to reducing bad cholesterol and elevating good cholesterol, niacin also contributes to the regulation of a number of bodily processes, including metabolism and cell repair, in the form of derivatives which are created in the body through biosynthesis. Niacin also appears to reduce triglyceride levels in the blood. A deficiency of niacin, called pellagra, can lead to skin conditions, susceptibility to cold, dementia, and diarrhea. Excess of niacin can also lead to health problems, so supplemental niacin should only be taken under medical supervision.

Pure niacin is a white, water soluble powder. Most people get enough niacin from a balanced diet which includes foods with plentiful amounts of it. Women require around 14 milligrams of niacin each day, and men need slightly more, 16 milligrams. Over 20 milligrams a day can bring on skin rashes, liver damage, and changes in the body's natural insulin levels. If a patient is diagnosed with pellagra, a doctor may prescribe niacin supplements. These supplements are typically taken with food to increase absorption.

Many people do not eat balanced diets, either because they lead busy lifestyles or because they are unaware of the basic needs of the human body. Vitamin deficiency can lead to health problems further down the line, and patients should consult their doctors about nutritional needs. The needs of the body change with age, and reviewing your diet with a doctor may help to determine whether or not you need to alter your diet or consider taking supplemental vitamins for health.