Question

) In Chapter 8 (The Water Soluble Vitamins), section 8.1 (What are Vitamins) discusses Absorption, Storage and Excretion of Vitamins, both water- and fat-soluble. How readily a vitamin can be absorbed and utilized by the body is called its _________________________. Fat-soluble vitamins require ________ in the diet for absorption while water soluble vitamins, which include all B vitamins and vitamin ______, dissolve in water and depend on energy-requiring transport systems or need to be bound to specific molecules in the GI tract in order to be absorbed in the small intestine. Once absorbed into the blood, vitamins must be transported to the cells, mostly by being bound to _________________________ for transport. Fat soluble vitamins, which include vitamins ______, ________, _________ and _______ are incorporated into ___________________ for transport from the intestine. With the exception of vitamin B12, the water-soluble vitamins are easily excreted from the body in the urine. In contrast, fat-soluble vitamins are stored in the ___________ and ____________ and cannot be excreted in the urine. Therefore it takes longer to develop a deficiency of fat-soluble vitamins when no longer provided in the diet. Because they are not stroed to any great extent, supplies of water-souble vitamins are rapidly depleted and must be consumed regularly in the diet, even though it may take more than a few days to develop deficiency symptions, even if absent from the diet.

Answer 1

How readily a vitamin can be absorbed and utilized by the body is called its bioavailability. Fat soluble vitamin require fat in the diet for aborption (The aborption of fat soluble vitamin is helped by bile which is produced by liver) while water soluble vitamins, which include all B vitamin and Vitamin C that dissolve in water and depend on energy requiring transport system and need to be bound to specific molecules in the GI tract in order to be absorbed in the small intestine.Once absorbed in the blood, vitamins must be transported to the cells, mostly by being bound to protein for transport. Fat soluble vitamins, which include vitamins A, Vitamin D, Vitamin E and Vitamin K are incorporated into bile for transport from the intestine. With the exception of vitamin B12, the water soluble vitamins are easily excreted from the body in the urine. In contrast fat soluble vitamins are stored in the liver and the fatty tissues and cannot be excreted in the urine. Therefore it takes longer to develop a deficiency of fat soluble vitamins when no longer provided in diet.