Vitamin B1 is important for nervous system function, musculature, cardiovascular health, and normal growth and development. The essential co-enzyme also aids in metabolizing carbohydrates, and it helps to regulate the appetite. Dietary sources of this important vitamin include flour, brewer's yeast, beans, pork, salmon, soybeans, and wheat germ.

Urea is the end product of nitrogen metabolism in most mammals, and it was the first animal metabolite to be isolated in crystallized form. In 1773, scientists discovered that urea releases ammonia when heated, and in 1828, urea was the first organic compound to be synthesized from inorganic materials.