This chapter helps in understating the role of vitamins for proper functioning of the body. Vitamins are defined as organic substances present in minute amounts in natural foodstuffs that are essential to normal metabolism, and the lack of which causes deficiency diseases. All natural vitamins are organic food substances found only in living things. With few exceptions, the body cannot manufacture or synthesize vitamins. Vitamins can be classified according to chemical and physical properties, such as whether they are soluble in aqueous solution or lipid solvents. Those vitamins that are soluble in lipid solvents (vitamins A, D, E, and K) are absorbed and transported by conventional lipid transport processes. For water-soluble vitamins, respective solubility coefficients are major factors that dictate the availability and ease of absorption. Within physiological ranges of intake, active processes are usually involved in the absorption of water-soluble vitamins. Vitamins in foods are often present as cofactors or in highly modified forms. Pancreatic and intestinal cell-derived enzymes are required to initiate normal uptake in absorption. Nucleosidases, phosphatases, and peptidases act as key factors in processing cofactors to vitamins.
|Original language||English (US)|
|Title of host publication||Clinical Biochemistry of Domestic Animals|
|Number of pages||36|
|State||Published - 2008|
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)