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VITAMINS

VITAMINS. Vijayalakshmi. INTRODUCTION. organic molecules with wide variety of capacities prominent function - cofactors for enzymatic reactions generally cannot be synthesized by mammalian cells Vitamins are usually supplied in the diet or in dietary supplements

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VITAMINS

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  1. VITAMINS Vijayalakshmi

  2. INTRODUCTION • organic molecules with wide variety of capacities • prominent function - cofactors for enzymatic reactions • generally cannot be synthesized by mammalian cells • Vitamins are usually supplied in the diet or in dietary supplements • necessary for our growth, energy, and general well-being

  3. HISTORY • Ancient Egyptians recognized night blindness • 1747-Scottish naval surgeon James Lind discovered the unknown nutrient (vitamin C) in citrus foods prevented scurvy

  4. 1753- Lind published his Treatise on the Scurvy 1860- Louis Pasteur demonstrated that microscopic organisms can cause diseases 1880- Christian Eijkman vitamin-deficiency conditions in animals on an experimental basis 1905- Julius Friedenwald and John Ruhräh Beri-Beri is probably of microbic origin

  5. 1906- Frederick Hopkin's - foods contain a small amount of “growth factors” 1911- Casimir Funk discovered what he termed "vitamines" 1919- “Eat and Be Healthy”, Virgil MacMickle, M.D., of Portland “ chemical substances of which the body is composed are similar to those of the foods which nourish it. They are made up of the same chemical elements...the body can only get these from foods...”

  6. FUNCTIONS • Digestion • Converting food into energy • Cell division and growth • Tissue repair • Transporting oxygen and wastes in the circulation • Immunity

  7. FUNCTIONS • Mental alertness • Making hormones • Reproduction • Protecting the body from poisons • Neutralizing the harmful by-products of metabolism such as free radicals

  8. CLASSIFICATION

  9. VITAMIN A • Vitamin A consists of three biologically active molecules,retinol, retinaland retinoic acid • Retinol - “sticky” and light sensitive • Provitamin A carotenoids– converted to retinol by the body ex- Beta (b)-carotene

  10. Sources • milk, cheese, cream, liver, kidney, cod and halibut fish oil milk, • Beta carotene - carrots, pumpkin, sweet potatoes, winter squashes, cantaloupe, pink grapefruit, apricots, broccoli, spinach and most dark green leafy vegetables

  11. FUNCTIONS-VISION

  12. Immunity- maintains integrity of skin and mucosal cells - Development and differentiation of WBC- by Retionic Acid - activation of t-cells requires all-trans RA binding Growth and Development-embryonic development Regulation of expression of gene for growth hormone Red blood cell production DEFICIENCIES: Night Blindness- Bitot’s spot, Xeropthalmia infectious disease – Diarrhea, respiratory diseases

  13. VITAMIN D • synthesized only when exposed to sunshine. • Converted to active form, 1a,25-dihydroxyvitamin D • The 1a,25-dihydroxyvitamin D acts as a hormone, and has a specific nuclear receptor

  14. SOURCES • Sunlight(PRIMARY) • MILK PRODUCTS:Cheese, butter, margarine, cream, fortified milk • SEA FOODS :fish, oysters • fortified cereals.

  15. FUNCTIONS: Calcium metabolism Vitamin D endocrine system - D3 bounds to vitamin D-binding protein and transported to liver - converted to 25-OH-D3 or calcidol (inactive) - increase exposure of sunlight – increase blood level of calcidol - hydroxyled to 1,25-OH-D3 or calcitriol - parathyroid hormone released Vitamin D receptor – Vitamin D Receptor to Retinoic Acid X Receptor to form heterodimer-interacts with DNA Vitamin D Responsive Elements- change in transcription of a nearby gene.

  16. Cell differentiation- proliferation - psoriasis - the proliferation of skin cells called keratinocytes - identification of VDR in keratinocytes led to the use of creams containing analogs of calcitriol in the treatment of severe cases of psoriasis. Immunity – WBC recognizes Antigens - Autoimmune disease - Immune responses are mediated by T-Cells DEFICIENCIES: Rickets Osteomalacia

  17. VITAMIN K • The K vitamins exist naturally as K1 (phylloquinone) in green vegetables • K2 (menaquinone) produced by intestinal bacteria • K3 is synthetic menadione.

  18. SOURCE • Spinach, cauliflower and other green leafy vegetables • chief source of vitamin K is synthesis by bacteria in the large intestine

  19. FUNCTIONS Coagulation (clotting) - ability to bind Ca2+ required foractivation of the 7 “vitamin k-dependent” clotting factor in the coagulation cascade Factors II , VII, IX,X make up the core Protein Z enhances the action of thrombin by promoting association with phospholipids Protein C and S control cascade Vitamin k-dependent factors synthesized in liver Bone mineralization – Osteocalcin – Osteoblasts- regulated by active form of vitamin D or calcitriol.

  20. DEFICIENCIES • Liver disease • Poisoning with vitamin K antagonists • Hemorrhagic disease of the newborn results from vitamin K deficiency in human infants • Increased risk of fractures or reduced bone density may result from inadequate intake of vitamin K

  21. VITAMIN E • Describes a family of 8 alpha, beta, gamma, delta and 4 tocotrienols • Alpha tocopherol is the only vitamin E that is actively maintained in human body found in tissues and blood • Maintains integrity of cell membrane and protects fats from oxidation

  22. SOURCES: Vegetable oils, nuts, egg yolk, Parmesan, chickpeas, wheat germ, oatmeal, olives,carrots, parsnips, red peppers, green leafy vegetables, sweet potatoes, tomatoes, sweet corn DEFICIENCIES: Sever malnutrition Genetic defects Fat malabsorption Neurological symptoms VITAMIN E

  23. THIAMIN B1 RIBOFLAVIN B2 NIACIN B3 PANTOTHENIC ACID B5 VITAMIN B6 VITAMIN B

  24. NIACIN • found in fish,poultry, meat, nuts and eggs • Niacin is required for the synthesis of of the active form of vitamin B3 NICOTINAMIDE ADENINE DINUCLEOTIDE • Deficiency disease is pellagra

  25. VITAMIN B6 • PYIDOXAL, PYRIDOXAMINE and PYRIDOXINE • Protein metabolism • Deficiencies are rare and usually related to overall deficiency of all the B-complex vitamins.

  26. VITAMIN C • derived from glucose via the uronic acid pathway • extracted from plant sources such as rose hips, blackcurrants or citrus fruits • easily oxidised in air

  27. SOURCES • Broccoli, Brussels sprouts, cauliflower, cabbage, mange tout, green leafy vegetables, red peppers, chilies, watercress, parsley, blackcurrants, strawberries, kiwi fruit, guavas, citrus fruit.

  28. VITAMIN C FUNCTIONS: • synthesis of collagen, neurotransmitter, norepinephrine • protects indispensable molecules • regenerate other antioxidants such as vitamin E DEFICIENCY: • Scurvy

  29. THANK YOU

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