The vitamins differ from carbohydrates, fats, and proteins in the following way:
Structure : vitamins are individual units ; they are not linked together
Function: vitamins do not yield usable energy when broken down; they assist the enzymes that release energy from carbohydrates, fats, and proteins
Food contents: the amounts of vitamins people ingest daily from foods and the amounts they require are measured in micrograms or milligrams, rather than grams