Thiamine, also known as thiamin or vitamin B₁, is a vitamin found in food, and manufactured as a dietary supplement and medication. Food sources of thiamine include whole grains, legumes, and some meats and fish. 

Thiamine supplements are generally well tolerated.Allergic reactions, including anaphylaxis, may occur when repeated doses are given by injection Thiamine is in the B complex family. It is an essential micronutrient, which cannot be made in the body.Thiamine is required for metabolism including that of glucose, amino acids, and lipids

Thiamine was discovered in 1897, was the first vitamin to be isolated in 1926, and was first made in 1936.  It is on the World Health Organization's List of Essential Medicines, the safest and most effective medicines needed in a health syste Thiamine is available as a generic medication, and as an over-the-counter drug.The wholesale cost in the developing world (as of 2016) is about US$2.17 per one gram vial.In the United States a month's supply of a multivitamin containing thiamine is less than US$25.