Vitamin B1 (C12H17N4OS; aka thiamin or thiamine) is employed in biosynthesizing certain neurotransmitters. All living organisms require thiamin, but only bacteria, fungi, and plants can make it themselves. Animals must obtain B1 from their diet.
Thiamin is available in a wide variety of foods in low concentrations. Whole grains, oatmeal, flax, sunflower seeds, asparagus, kale, cauliflower, potatoes, oranges, and eggs are relatively high in thiamin.