ni·​a·​cin ˈnī-ə-sən How to pronounce niacin (audio)
: 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

Example Sentences

Recent Examples on the Web Some research suggests that taking niacin supplements may help with ED. Amber Smith, Discover Magazine, 15 Jan. 2023 Cow's milk, the most common type of milk found in many households, has healthy vitamins and nutrients like calcium, vitamin D, niacin and protein, according to U.S. Health News. Mythili Devarakonda, USA TODAY, 29 Dec. 2022 Leading the pack is ground venison, which is a lean protein packed with vitamins B12, B6, niacin, and riboflavin. Dallas News, 21 Dec. 2022 The cooling gel phase contains hyaluronic acid and peptides to deeply hydrate skin, while the cream phase contains niacin and vitamin B3 to strengthen the delicate area. Anamaria Glavan, Allure, 22 Dec. 2022 Particularly, brown rice offers 19% of the DV for magnesium, 87% of the DV for manganese, 21.3% of the DV for selenium and 32.5% of the DV for Vitamin B3 (AKA niacin). Good Housekeeping, 5 Dec. 2022 Anchovies are on par with salmon and tuna as one of the fish with the highest amounts of omega-3s per serving, and are a good source of protein, niacin and vitamin B12. Casey Barber, CNN, 12 Dec. 2022 Innosupps T-Drive is formulated with a variety of highly effective ingredients, including tribulus terrestris, boron, fenugreek, epimedium, and coleus forskohlii as well as zinc, niacin, magnesium, and vitamin D3. The Salt Lake Tribune, 8 Nov. 2022 Each serving is loaded with creatine, L-citrulline, niacin, and a blend of B-vitamins. The Salt Lake Tribune, 28 Oct. 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'niacin.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History


nicotinic acid + -in entry 1

First Known Use

1942, in the meaning defined above

Time Traveler
The first known use of niacin was in 1942

Dictionary Entries Near niacin

Cite this Entry

“Niacin.” Dictionary, Merriam-Webster, Accessed 8 Feb. 2023.

Kids Definition


ni·​a·​cin ˈnī-ə-sən How to pronounce niacin (audio)
: 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


ni·​a·​cin ˈnī-ə-sən How to pronounce niacin (audio)
: 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

More from Merriam-Webster on niacin

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