A vitamin — one of the B group, also called vitamin B1. Your body needs a small amount of it every day to turn the food you eat into energy, and to keep the nerves and heart working properly. Your body cannot store much of it, so you have to keep taking it in through food: pork, beans, nuts, seeds, and whole grains are the usual sources. Also, in many countries white rice and white flour have it added back in, because the processing strips it out. If someone goes without it for long enough, they get an illness called beriberi, which damages the nerves and the heart; this used to be common in places where polished white rice was almost the whole diet. You will meet the word mostly on food packets, vitamin bottles, and in health writing — it is a technical word, not a conversational one. Note the spelling: both thiamin and thiamine are correct and you will see both, often on the same shelf. American food labelling tends to prefer thiamin; thiamine is more common in British and medical writing.

硫胺素、維生素 B1（台灣包裝上多半直接寫「維生素 B1」或「維他命 B1」；「硫胺」「硫胺素」是化學名，比較少在日常出現）。