VITAMINS

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VITAMINS

• Vijayalakshmi

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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

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HISTORY

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

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• 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

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• 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...

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FUNCTIONS

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

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FUNCTIONS

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

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CLASSIFICATION
Water soluble Fat soluble
  Thiamin (B1)   Riboflavin (B2)   Niacin (B3)   Pantothenic acid (B5) Pyridoxine (B6) Biotin, Folic acid   Cobalamin (B12) Ascorbic acid Vitamin A Vitamin D Vitamin E Vitamin K
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VITAMIN A

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

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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

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FUNCTIONS-VISION
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• 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- Bitots spot, Xeropthalmia
• infectious disease Diarrhea, respiratory
  diseases

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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

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SOURCES

• Sunlight(PRIMARY)
• MILK PRODUCTSCheese, butter, margarine, cream,
  fortified milk
• SEA FOODS fish, oysters
• fortified cereals.

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• 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.

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• 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

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VITAMIN K

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

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SOURCE

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

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• FUNCTIONS
• Coagulation (clotting)
• - ability to bind Ca2 required for activation
  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.

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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

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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

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VITAMIN E

• 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

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VITAMIN B

• THIAMIN B1
• RIBOFLAVIN B2
• NIACIN B3
• PANTOTHENIC ACID B5
• VITAMIN B6

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TYPE FUNCTION SOURCE DEFICIENCY
B1 Thiamin pyrophosphate Coenzyme non coenzyme function Whole grains, cereals, legumes nuts, lean pork, yeast BERI-BERI
B2 Flavin mononucleotide Flavin adenine dinucleotide Oxidation-reduction (redox) reactions Antioxidant functions liver, eggs, cheese, milk and cereals damage to eyes, mouth, and genitals
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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

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VITAMIN B6

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

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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

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SOURCES

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

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VITAMIN C

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

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