<Li> Sulfur for three amino acids and therefore many proteins (skin, hair, nails, liver, and pancreas) </Li> <P> Many elements are required in trace amounts, usually because they play a catalytic role in enzymes . </P> <P> Vitamin deficiencies may result in disease conditions . Excess of some vitamins is also dangerous to health (notably vitamin A), and animal nutrition researchers have managed to establish safe levels for some common companion animals . Deficiency or excess of minerals can also have serious health consequences . </P> <P> Though not really a nutrient as such, an entry for ash is sometimes found on nutrition labels, especially for pet food . This entry measures the weight of inorganic material left over after the food is burned for two hours at 600 ° C. Thus, it does not include water, fibre, and nutrients that provide calories, but it does include some nutrients, such as minerals </P>

What is the only product that comes from an animal that has substantial carbohydrates