thi·​a·​mine ˈthī-ə-mən How to pronounce thiamine (audio)
variants or thiamin
: a vitamin C12H17N4OSCl of the vitamin B complex that is essential to normal metabolism and nerve function and is widespread in plants and animals

called also vitamin B1

Example Sentences

Recent Examples on the Web Sweet corn is a good source of vitamin C, thiamine, folate, magnesium and potassium. Bethany Thayer, Detroit Free Press, 30 July 2022 Whole grains also provide important micronutrients, including vitamin E and various B vitamins such as riboflavin, thiamine, niacin, and folate, that offer critical support to digestion, the nervous system, and more, Caplan says. Christine Byrne, Outside Online, 14 Mar. 2019 Alzheimer’s disease have shown low thiamine levels. Dr. Keith Roach, oregonlive, 3 June 2022 Federal biologists point to the drop in alewives — and a subsequent healthy rise in thiamine levels in lake trout eggs., 2 Sep. 2021 Alewives carry high levels of an enzyme that triggers a thiamine deficiency in trout, which causes their eggs to either not hatch or induces deadly development problems in trout offspring., 2 Sep. 2021 The new research argues that an underlying cause of problems with the explorer’s heart and breathing was a thiamine deficiency. Livia Gershon, Smithsonian Magazine, 20 May 2021 The doctor ordered the missing minerals and admitted her to the hospital for a five-day course of high-dose thiamine replacement. New York Times, 3 Dec. 2020 Hoffman started the patient on intravenous thiamine even before the results of the testing came back. New York Times, 3 Dec. 2020 See More

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

Word History


thiamine alteration of thiamin, from thi- + -amin (as in vitamin)

First Known Use

1937, in the meaning defined above

Time Traveler
The first known use of thiamine was in 1937

Dictionary Entries Near thiamine

Cite this Entry

“Thiamine.” Dictionary, Merriam-Webster, Accessed 28 Nov. 2022.

Kids Definition



thi·​a·​mine ˈthī-ə-ˌmən How to pronounce thiamine (audio)
variants also thiamin
: a vitamin of the B complex that is necessary for normal metabolism and nerve function and is found in many plants and animals

called also vitamin B1

Medical Definition



thi·​a·​mine ˈthī-ə-mən, -ˌmēn How to pronounce thiamine (audio)
variants or thiamin
: a vitamin C12H17N4OSCl of the vitamin B complex that is an amino hydroxy quaternary ammonium water-soluble salt containing a thiazole ring and a pyrimidine ring, that occurs widely both free (as in the germs of cereals and hulls of grain) and combined (as in yeast and in animal tissues like liver, kidneys, and heart) but is usually synthesized commercially, that functions in the body as a cocarboxylase and is essential for carbohydrate metabolism and for normal functioning of the nervous system, and that is used in nutrition (as in vitamin preparations and in enriching flour and bread) and in medicine

called also vitamin B1

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