Vitamins.docVIP

Vitamins Introduction The word vitamin comes from the Latin word vita, means life. Vitamins are organic compounds of low molecule weight. They are necessary for keeping natural physiological function, especially for intracellular specific metabolism. They can’t be synthesized in the body. They are not the material of the tissue. They exist in natural food in different form. They can’t supply energy. “vitamins have been defined as organic compounds which are required in minute amounts to maintain normal health of organisms”. Classification of Vitamins FAT SOLUBLE A D E K WATER SOLUBLE B1- Thiamine B2 - Riboflavin B3 – Niacin B5 – pantothenic acid B6 –Pyridoxine B8 – biotin B 9-Folic acid B12 -CyanoCobalamin C vitamin (ascorbic acid) Water soluble Vitamins Water soluble (hydrophilic): B vitamins and vitamin C o??found in watery compartments of food o??moves directly into the blood after being absorbed o??can travel freely in the blood o?freely circulate in watery compartments of the bodys cells O?regulated and excreted when in excess by the liver easily – are less likely to have toxic effects when ingested in large amounts Fat soluble Vitamins Fat soluble (hydrophobic) Vitamins A, D, E, and K o???found in fats and oils of food o need fat for their absorption o????carried through the lymph to the blood o????many times require proteins for transportation in the blood o????trapped in cells associated with fat o?? less readily excreted - tend to stay in fat storage sites –can build up to toxic levels with serious and potentially fatal results Vitamin A VITAMIN A :- Is widely distributed in animal and plant foods From animals –pre-formed –Retinal, retinol, retinoic acid From plants – pro-formed – Carotenoids Must be converted to retinoid form Intestinal cells can split carotene in two (molecules of retinoids) Found in plant products Dietary Sources of Vitamin A pre-formed vitamin A:meat, liver dairy products PRO-FORM VITAMIN A