principles of nutrition by nhi (vitamins)

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Vitamins

Vitamins are special chemicals found in food.

Vitamins

Vita = Life

Amine = Containing Nitrogen

The First Vitamin Discovered Contained Nitrogen

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Vitamins

OrganicEssential NutrientsRequirements Minute (Small)Perform Specific Functions

GrowthReproductionMaintenance of Health and Life

Vitamins are organic substances which the body require in small amounts to perform specific functions that promote growth, normal metabolism, reproduction and normal maintenances of health and life.

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Vitamins

Vitamins Differ from Energy-Yielding Nutrients such as Carbohydrate, Proteins and Fat

Structure

Function

Food Contents

Vitamins do not supply energy but are essential to metabolic activities and help in the utilization to the proximate principles.They are also involved in the utilization of the major nutrients like proteins, CHO & fats.

Vitamins Similar to Energy-Yielding Nutrients: Carbohydrate, Protein and Fat

Vital to Life

Organic

Vitamins

Vitamins

Available in Foods

OrganicDestructible:

Light: Riboflavin (B2)

Oxygen: Vitamin C

Heat : Thiamin (B1) and Vitamin C

Vitamins

Solubility:Hydrophilic: (Water-Soluble)

Carbohydrate, Protein

Vitamins B and C

Hydrophobic: (Fat-Soluble)Fat

Vitamins A, D, E, K

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Precursors

Provitamins Inactive Vitamin Form

Chemically Changed to Active Form of Vitamins

Substances that occur in foods which are not themselves vitamins, but are capable of conversion into vitamins in the body e.g; carotens are the pro-vitamin of vitamin A.

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Riboflavin-Vitamin B2

FunctionsCoenzymes FMN and FAD

Energy Metabolism

Supports Normal Vision

Supports Skin Health

Food Sources

Vitamin is a precursor of two enzymes—Flavin-mononucleotide & Flavin adenine di-nuleotied.Release of energy from foods as it effects growth and cellular metabolismNeeds in normal vision and may help against cataract.Sources– Milk, eggs, organ meat, mushrooms, shellfish, cereals and pulses.

Riboflavin-Vitamin B2

Deficiency DiseaseAriboflavinosis

Deficiency SymptomsSkin RashCracks and Redness of MouthSensitivity to Light

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Niacin-Vitamin B3

FunctionsCoenzymes NAD and NADP

Energy Metabolism

Nervous System

Digestive System

Food Sources

NAD & NADP- are the active form of niacin named as nicotinamide adenine dinucleotide and nicotinamide adenine dinucleotide phosphate.-These coenzymes are involved in more than 50 different metabolic reactions.-Extracts energy from CHO and glucose.-proper nervous system functioning.Sources- Organ meats, liver, poultry, fish, milk, eggs, wheat germ, whole wheat, yeast.

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Niacin-Vitamin B3

Deficiency DiseasePellegra

Deficiency Symptoms

-A clinical condition due to niacin deficiency, characterized as 3Ds.-Weakness, irritability, burning tongue as the mucous membrane of the mouth is inflamed.-High doses results in irritation of the gastrointestinal tract.

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Biotin

Food Sources

Originally called vitamin H.Egg, liver, kidney, yeast, pulses, nuts, chocolates, cauliflower and green vegetables.

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Biotin

FunctionsCoenzyme

Energy Metabolism

Fat Synthesis

Amino Acid Metabolism

Glycogen Synthesis

--Biotin coenzyme participate in the metabolism of fat and CHO in the synthesis of fatty acids and amino acids.--Helps metabolize proteins, fats and CHO & thus helps to produce energy in body cells.--Assists in the synthesis of FA.--Incorporate AA into proteins & help with the formation of DNA & RNA.

Biotin

Deficiency SymptomsLoss of Appetite and Nausea

Abnormal Heart Action

Depression

Muscle Pain and Weakness

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Pantothenic Acid-Vitamin B5

Food Sources

Sources– Whole grain cereals, vegetables, peanuts, cheese, eggs-yolk, organ meats.

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Pantothenic Acid-Vitamin B5

FunctionsCoenzyme A

Energy Metabolism

This vitamin is a constituent of co-enzyme A and is present in all living matter.Important for cellular metabolism of CHO & fats to release energy.

Pantothenic Acid-Vitamin B5

Deficiency Symptoms

Insomnia

Fatigue

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Pyridoxine-Vitamin B6

FunctionsCoenzymes PLP and PMPAmino Acid MetabolismFatty Acid MetabolismConverts Tryptophan to Niacin

Food Sources

Pyridoxine and its co-enzymes have a wide variety of metabolic functions especially—-AA metabolism and its transportation.-Production of antibodies, RBC, synthesis and functioning of both DNA & RNA.- Fish, poultry, egg yolk, soya- bean, bananna, potatoes, cauliflower.

Pyridoxine-Vitamin B6

Deficiency DiseaseAnemia (small-cell type)

Due to the deficiency of B6 , the RBCs are pale and small and the Anemia is said to be Hypochromic and Microcytic.

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Folate-Folic Acid-Folacin

Functions

DNA Synthesis

New Cell Formation

Food Sources

Sources– Spinach, liver, peas, sweet potato, bean sprout, wheat germ, soya flour, milk, fruits.

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Folate-Folic Acid-Folacin

Deficiency DiseaseAnemia (large-cell type)

Deficiency SymptomsDiarrhea

Depression/Mental Confusion

-Deficiency leads to impaired RBC production.-Megaloblastic anaemiaIf the maturation of the RBCs in the bone marrow is impaired by lack of Folic acid or Vitamin B12, the cells which enter the blood stream are irregular in size and shape, but usually on average larger than normal. Such anemia is orthochromic and megalocytic. It is usually referred to as Megaloblastic Anemia.

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Cobalamin-Vitamin B12

FunctionsCoenzymes

New Cell Synthesis

Fatty Acids

Amino Acids

Maintain Nerve Cells

Bulk of body stores of vitamin B12 is in the form of coenzyme B12.

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Cobalamin-Vitamin B12

Food Sources

This vitamin has cyanide group and cobalt group. From animal foods like goat liver, fish, eggs & milk.

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Cobalamin-Vitamin B12

Deficiency DiseasePernicious Anemia

Deficiency SymptomsFatigueDegeneration of Peripheral NervesHypersensitivity

Variations in the size and shape of the blood cells.Results in peripheral neuropathy. Loss of mental energy, depression, tingling, numbness, diminished or absent sensation in extrimities.

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Ascorbic Acid-Vitamin C

FunctionsCollagen Synthesis

Antioxidant

Amino Acid Metabolism

Absorption of Iron

Resistance to Infection

Also helps to maintain healthy blood vessels.

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Ascorbic Acid-Vitamin C

Food Sources

Amala, guava, oranges, all citrious fruits, dark green leafy vegetables, tomatoes, etc.

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Ascorbic Acid-Vitamin C

Deficiency DiseaseScurvy

Deficiency Symptoms

--General manifestation of scurvy are fever, rapid pulse, and susceptibility to injection and wound healing is delayed.--Bleeding gums, common cold, delayed wound healing.--Gastrointestinal disturbances, dysuria, skin sensitivity.

Fat Soluble Vitamins

Fat-Soluble Vitamins

Fat Soluble Vitamins: A, D, E, K

*Differ From Water-Soluble Vitamins

Found in Fat and Oily Parts of FoodsInsoluble in WaterLymphatic System

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Fat Soluble Vitamins: A, D, E, K

*Differ From Water-Soluble Vitamins

Greater Risks for ToxicityStored in Liver and Adipose TissueNot Readily Excreted

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Vitamin A and Beta-carotene

First Fat-Soluble Vitamin RecognizedBeta-Carotene, Precursor to Vitamin AThree Forms of Vitamin A (Retinoids)

Retinol (an Alcohol)

Retinal (an Aldehyde)

Retinoic Acid (an Acid)

Circulates in the plasma with the specific retinol binding protein. This combination is called halo-RBP.

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Beta Carotene as an Antioxidant

Protects the Body Against DiseaseFree Radicals

Heart Disease

Cancer

Arthritis

Cataracts

-Encourages immune system to produce the cells you need to fight off infection and promotes rapid recovery.-As anti-oxidant and may aid in reducing the risk of cancer.-Also promotes the growth of healthy bones.

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Retinol-Vitamin A

FunctionsVision

Maintenance of Cornea

Mucous Membranes

Skin, Bone, and Tooth Growth

Food Sources

-It is a vision vitamin.-Keeps skin and mucous membranes smooth and supple.-Promotes the growth of bones and teeth.-Sources- Eggs, liver, fish liver oil, milk and milk products & green leafy vegetables.

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Retinol-Vitamin A in Vision

CorneaTransportation of Light Energy Nerve Impulses at RetinaSupports Growth of Bones

Remodeling of Bone

-It may be affected in severe vitamin A deficiency. It becomes dull and then corneal scar occurs.-Takes part in the formation of bony matrix.

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Retinol-Vitamin A

Deficiency DiseaseHypovitaminosis A

Deficiency Symptoms

Changes in the eyes like night blind ness, xeropthalmia, skin changes ,effects the mucous membrane of the respiratory tract, alimentary tract and genito-urinary tract.Toxicity– Fatigue, loss of appetite, nausea, vomiting, weight loss, irritability, cracking lips, dry skin and hair loss, swelling over long bones.

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Retinol-Vitamin A Deficiency

Vitamin A Stores: 90% in LiverAdequate ProteinVitamin A Food Sources

Global Nutrition ProblemNight Blindness100 Million Children with Deficiency

In liver it is stored in the form of retinyl esters.

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Calciferol-Vitamin D

Significant SourcesFood

Sunlight

Also called Sun shine vitamin. Skin prepares vitamin D in the presence of sunlight.

Calciferol-Vitamin D from the Sun

Natural Exposure to SunlightSun Imposes No Risk of Toxicity

Prolonged Exposure Degrades the Vitamin D Precursor

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Calciferol-Vitamin D from the Sun

Ultraviolet Rays of the SunDark Skinned People Prone to Rickets

Deficiency More Likely in Elderly

Vitamin D Fortified Foods or Supplements

-as it reduces the production of vitamin D.-Osteomalacia is more common in adults. The calcium deficiency results in de-mineralization of bones.-should be taken carefully.

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Calciferol-Vitamin D

FunctionsRaises Blood Calcium and Phosphorus

Hormone

Organs: Intestines, Kidneys, Bones

Stimulates Absorption from GI Tract

Bone Growth

Maintain the blood (plasma) Ca & P levels.Acts like a hormone.Vitamin D main site of action is in the small intestine where promotes Ca & P absorption from the gut & also has direct action on the gut.Raises concentration of plasma Ca & P to promote bone deposition.

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Calciferol-Vitamin D

Deficiency DiseaseRickets

OsteomalaciaDeficiency Symptoms

Deformity of the weight bearing bones, knock knees, bowing of legs.Loss of bone mineral.Pain in bones.

Excessive thirst, diarrhea, nausea, weakness & headach.

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Tocopherol-Vitamin E

1922, Discovery in Vegetable Oils Anti sterility Factor = TocopherolCompound Named Vitamin E

Alpha BetaGamma Delta

Alpha-Tocopherol is the most common and the most active of the seven mentioned forms.

Tocopherol-Vitamin E

Food Sources20% = Vegetable Oils

20% = Fruits and Vegetables

15% = Grain Products

Animal Fats: Meat and Milk Fat Contain Little or No Vitamin E

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Tocopherol-Vitamin E

FunctionsAntioxidant

Stabilization of Cell Membranes

Regulation of Oxidation Reactions

Protection of PUFA

Protection of Vitamin A

-Natural antioxident. It helps to reduce oxidation of lipid membranes, USFA & breakdown of other nutrients by oxygen.-Protect the cell membrane destruction.-It reacts with free radicals & oxidizing agents.-Found in cell membrane that contain PUFA. It inhibits the reaction involving oxygen.-It protects both vitamin A & carotene from oxidation.

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Vitamin E as an Antioxidant

OxidationTransformation of Energy Fuels to ATP

Oxidation of Polyunsaturated Fatty Acids

Protection of Lungs

Air Pollutants (Nitrogen or Ozone)

Protects Red Blood Cells

-prevents the oxidation of USFA-protects lungs from oxidative damage from environmental substances.-protects RBC membrane from oxidative damage.

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Tocopherol-Vitamin E Deficiency

Rare in HumansFat Malapsorption

Cystic FibrosisCauses of Vitamin E Deficiency

Erythrocyte Hemolysis

Deficiency– low fat diet, malabsorption syndrome or after gastric surgery.RBC hemolysis occur more easily in vitamin E deficiency.

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Vitamin K

Blood Clotting

“K” = Danish Word Koagulation (Coagulation or Clotting)

13 Different Proteins and CalciumVitamin K Essential Synthesis of Protein

Calcium andthromboplastin(a phospholipid)

from blood platelets

Vitamin K

PrecursorProthrombin(an inactive

protein)

Thrombin(an activeenzyme)

Fibrinogen(a solubleprotein)

Fibrin(a solid

clot)

Blood-Clotting Process

Originally called Koagulation vitamin.

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Vitamin K

Significant SourcesFood

Non-Food

Bacteria in GI

Bacterial Synthesis

K1 is the naturally occurring form of vitamin K.Bacteria in GI synthesis vitamin K. Normal synthesis is inhibited by the intake of oral antibiotics– K2 vitamin.

Vitamin K

FunctionsBlood-Clotting Synthesis

Bone Growth

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Vitamin K Deficiency

Deficiency is RareBile Production

Diarrhea

Malabsorption Diseases (Crohn’s)

Sulfa Drugs

Antibiotics

Bile production is impaired if there is sever damage to liver as secretion of bile salts is necessary for normal absorption of vitamin K.In steatrrhoea, ulcerative colitis fats are not absorbed effectively, bleeding due to vitamin K deficiency may occur.Sulfa drugs and antibiotics spoils the GI bacterial flora.

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Vitamin K Deficiency

Surgery: Blood Clotting Time CheckedNewborn Babies: Sterile Digestive Tract

Vitamin K-Producing Bacteria

Plasma Prothrombin Concentrations

Hemorrhagic Disease

New born babies has sterile GI tract for about a week & hence a low blood prothrombin level.Due to prolonged antibiotic therapy, prevents the growth of intestinal bacteria.Deficiency of vitamin K produces a lowered prothrombin time.Vitamin K deficiency involves abnormal bleeding as in nose bleeding and internal hemorrhage which can be sever.