Define Absorption, Storage and Elimination of vitamins?
Reading through this section you would realize that all fat-soluble vitamins undergo similar metabolic fate. They are absorbed along with fats from the small intestine. Bile is essential for the effective absorption of fats and therefore fat-soluble vitamins. The salts of bile acids (taurine and glycine derivatives of cholic acid) are the digestion promoting: constituents of bile. They are surface active agents (i.e. they lower the surface iencion and emulsify fats) and also activate the enzyme lipases. They combine will fat-soluble vitamins to form molecular components which are then absorbed. Further, all fat-soluble vitamins are stored in concentrated amounts in the liver. The main pathway of excretion is through the bile into small intestine and consequently faecal excretion. A detailed discussion on absorption, storage of each vitamin is presented later, within this section.