niacin

noun

ni·​a·​cin ˈnī-ə-sən 

: an acid C₆H₅NO₂ of the vitamin B complex found widely in animals and plants and used especially against pellagra

also : nicotinamide

called also nicotinic acid

Examples of niacin in a Sentence

Recent Examples on the Web

The Allure-editor favorite is formulated with conditioning ingredients like niacin (vitamin B3) and hyaluronic acid. —Angela Trakoshis, Allure, 4 June 2025

Peanuts are low in carbs, high in unsaturated fats, and a good source of many vitamins and minerals, including vitamin E, niacin, and thiamine. —Nancy Lebrun, Verywell Health, 2 May 2025

The bottom line: The first phase of the trial was small — just five patients who took mushrooms, and four who took niacin. —Andrew Keatts, Axios, 25 Mar. 2025

Asparagus is a nutrient-dense food that provides a host of important vitamins and minerals such as calcium, magnesium, phosphorus and niacin — plus nearly two grams of both protein and dietary fiber in only about seven stalks, per the U.S. Department of Agriculture. —Daryl Austin, USA TODAY, 13 Mar. 2025

Word History

Etymology

nicotinic acid + -in entry 1

First Known Use

1942, in the meaning defined above

Rhymes for niacin

• myosin
• actomyosin
• tropomyosin

Kids Definition

niacin

noun

ni·​a·​cin ˈnī-ə-sən 

: an acid of the vitamin B complex that is found widely in plants and animals and is used especially against pellagra

called also nicotinic acid

Medical Definition

niacin

noun

ni·​a·​cin ˈnī-ə-sən 

: a crystalline acid C₆H₅NO₂ that is a member of the vitamin B complex occurring usually in the form of a complex of niacinamide in various animal and plant parts (as blood, liver, yeast, bran, and legumes) and is used especially to lower LDL and triglyceride levels in the blood and to treat pellagra

called also nicotinic acid