Dietary sources of thiamine include beef, brewer's yeast, legumes (beans, lentils), milk, nuts, oats, oranges, pork, rice, seeds, wheat, whole-grain cereals, and yeast. In industrialized countries, food made with white rice or white flour is often enriched with thiamine.Thiamine is used as part of a treatment for metabolic disorders and thiamine deficiency symptoms, as well as in alcoholics.It has been studied for other uses, but conclusions are lacking at this time.n industrialized countries, food made with white rice or white flour is often enriched with thiamine. Thiamine is used as part of a treatment for metabolic disorders and thiamine deficiency symptoms, as well as in alcoholics. It has been studied for other uses, but conclusions are lacking at this time.