Abstract
This chapter covers a short review of the vitamin discovery period, followed by a discussion of the vitamins as nutritional supplements for poultry diets. These organic molecules perform within a complex metabolic system, and function in catalytic, developmental, and protective roles. Research in recent years suggests vitamins also play a pivotal role in the intestinal microbiome and “gut health” and may have direct effects on the establishment of a more desirable microbial population. Rapid changes in poultry genetics requires modifications in fortification rates, especially when less feed is required to attain these improvements. A survey on the vitamin fortification rates of broiler feeds in the U.S. is also included for discussion and comparison with a similar 1993 survey and the National Research Council. Some vitamins showed a wider disparity in fortification levels than others.