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The Vitamins

Fat Soluble Vitamins Water Soluble Vitamins. Prepared by: Mona Abo Hasera. The Vitamins. Vitamins are micronutrients Very small amounts are needed by the body (>1 gm) Very small amounts are contained in foods. Vitamins are essential. The roles they play in the body are very important.

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The Vitamins

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  1. Fat Soluble Vitamins Water Soluble Vitamins Prepared by: Mona Abo Hasera The Vitamins

  2. Vitamins are micronutrients • Very small amounts are needed by the body (>1 gm) • Very small amounts are contained in foods. • Vitamins are essential. • The roles they play in the body are very important. • Most vitamins are obtained from the foods we eat. • Some are made by bacteria in the intestine • There is no perfect food that contains all the vitamins in the right amount. • Vitamins are non-energy producing • They do not contain kcalories. • Vitamins are classified according to how soluble they are in fat or water. Characteristics of Vitamins

  3. Fat Soluble Vitamins vs. Water Soluble Vitamins

  4. A, D, E, K Fat-Soluble Vitamins

  5. found in fats and oils • require bile for absorption • enter the lymph, then the blood • held and stored in fatty tissues • Needed in small amounts • may reach toxic levels • not readily excreted Fat-Soluble Vitamins

  6. Vitamin A • 3 forms in the body • retinol • retinal • retinoic acid • collectively known as retinoids Retinol, the alcohol form Retinal, the aldehyde form Retinoic acid, the acid form Cleavage at this point can yield two molecules of vitamin A* Beta-carotene, a precursor

  7. Vitamin A • precursor: beta-carotene • derived from plant foods • can split and form retinol in intestine and liver

  8. vision • maintain epithelial tissue and skin • support reproduction and growth • Immune system • Bone development Vitamin A function

  9. Vitamin A • deficiency • infectious disease • pneumonia, measles, diarrhea • keratinization • dry, rough, scaly skin • night blindness

  10. Vitamin A Sources • Beta-carotene • Dark leafy green vegetables, spinach, broccoli • Deep orange veggies • Carrots, pumpkin, squash, sweet potato • Deep orange fruits • Apricots, cantaloupe

  11. Retinol • Fortified milk, butter cheese, cream • Fortified margarine • Eggs • Liver

  12. body can make • from sunlight • precursor made from cholesterol • production occurs in liver and kidney • diseases can affect activation Vitamin D

  13. part of the bone-making/maintenance team • maintains blood concentrations of Ca & P • Mineralization of bones • raises blood calcium and phosphorus by increasing absorption from digestive tract • withdrawing calcium from bones • stimulating retention by kidneys • deficiencies • ultimately creates a calcium deficiency • rickets, osteomalacia function Vitamin D

  14. sources • fortified food: milk, margarine, cereals, beef, eggs • sun • storage from the summer does not last the winter Vitamin D

  15. Vitamin E • antioxidant • defender against free radicals • polyunsaturated fatty acids • may reduce the risk of heart disease • deficiencies • rare • erythrocyte hemolysis

  16. widespread in food • easily destroyed by heat processing Vitamin E

  17. aids in blood clotting and bone mineralization • deficiency causes hemorrhagic disease • sources • made by bacteria in GI tract • absorbed and stored in liver Vitamin K

  18. liver is also high in vitamin K

  19. Table 10-1, p. 326

  20. B complex , c water-Soluble Vitamins

  21. The B-complex vitamins are often associated with giving a person more energy. This is due to the fact that these vitamins each play different roles with energy metabolism in the body. When they are present in the body, they allow energy to be used more readily by the body. • Since these vitamins are water soluble, they are not stored in the body like fat soluble vitamins. They dissolve in water and are excreted from the body in urine. Therefore, it is important to consume foods rich in these vitamins each day in order to fulfill the body’s need. Water soluble vitamins

  22. B Complex Vitamins • Co-enzymes (activate enzymes) • Found in the same foods • Single deficiency rare • Act together in metabolism • Metabolic pathways used by protein, carbohydrate, and fat

  23. Thiamin (B1) • Riboflavin (B2) • Niacin (B3) • Pantothenic Acid • Biotin • Pyridoxine (B6) • Folate • Vitamin B-12 B Complex Vitamins

  24. B Complex Primary Functions • Energy metabolism • Thiamin (B-1), Riboflavin (B-2), Niacin (B-3), Pyridoxine (B-6), Biotin, Pantothenic Acid • Red blood cell synthesis • Folate, B12 • Homocysteine metabolism • Folate, B12, B6

  25. Vitamin C • Synthesized by most animals (not by humans) • Decrease absorption with high intakes • Excess excreted

  26. Functions of Vitamin C • Reducing agent (antioxidant) • Iron absorption (enhances) • Synthesis of collagen • Immune functions • Does not prevent colds, but may reduce duration of symptoms by a day • Wound healing

  27. Vitamin C Deficiency: History of Scurvy • Vitamin C (ascorbic acid) deficiency leads to scurvy, a disease characterized by weakness, small hemorrhages throughout the body that cause gums and skin to bleed, and loosening of the teeth. Sailors that were out at sea for months on end would often develop scurvy unless the captain had the foresight to pack limes and other citrus fruits.

  28. Scurvy Deficient diet for 20-40 days Fatigue, pinpoint hemorrhages Bleeding gums and joints. Hemorrhages Associated with poverty; macrobiotic diet Deficiency of Vitamin C

  29. Scurvy Scorbutic Rosary Follicular Hemorrhages

  30. Citrus fruit Potato Green pepper Cauliflower Broccoli Strawberry Romaine lettuce Spinach Easily lost through cooking Sensitive to heat Sensitive to iron, copper, oxygen Food Sources of Vitamin C

  31. Vitamin C Excess • Hemochromatosis • Vitamin C enhances iron absorption • Oxalate kidney stones • Erodes tooth enamel

  32. Vitamin C Deficiency • In the U.S., deficiency is seen mostly in alcoholic persons with poor diets and older persons who eat poorly (no fresh fruits and vegetables)

  33. Determination of Vitamin C (Ascorbic Acid) Concentration by a Redox Titration with Potassium Iodate (KIO3)

  34. Principle 1. KIO3 is used as a titrant and it is added to an ascorbic acid solution that contains a strong acid and potassium iodide (KI). 2. KIO3 reacts with KI, liberating molecular iodine (I2): KIO3 + 5KI + 6H+ → 3I2 + 6K+ + 3H2O (1) C6H8O6 + I2 → C6H6O6 + 2I- + 2H+ (2) Experiment

  35. 1. Pipette 25 ml of the provided ascorbic acid solution into a 250 ml conical flask, 2. Add  4 ml of 2M HCl, 3. Add  5 ml of potassium iodide (KI) solution and 3 ml starch solution. 4. Then titrate with the standard potassium iodate (KIO3) solution until the solution turns intense blue. Write down the standard potassium iodate (KIO3) solution volume. 5. Pipette 25 ml of an unknown ascorbic acid sample, a kind of juice, into a 250 ml conical flask, then follow the same procedure of steps 1-4 and write down the volume of the standard KIO3 solution determine the concentration (mol/ml) of ascorbic acid in the selected sample. Procedure

  36. procedure

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