Roles of Vitamins in Diet

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Roles of Vitamins in Diet

Prepared by:

Shampa Roy : 1020523030

Saquib-E-Azam : 0930252520

Submitted to: Dr. Kazi Nadim Hasan(KNH)

Submission date:

Biology Assignment

Course: BIO103.6: Biology I; Spring 2011

Room: SAC 404

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Vitamins

Vitamins are organic compounds found in plants and animals and known as essential

nutrients for human beings. The name vitamin is obtained from "vital amines" as it was

originally thought that these substances were all amines. They cannot be made within the body, so must be present in the diet. Human body uses them for growth, function, energy,

tissue repair and waste removal. If a given vitamin is lacking, a characteristic set of symptoms will develop known as a deficiency disease.

Types of Vitamins

There are two categories of vitamins: water-soluble and fat-soluble vitamins. Water-

soluble vitamins, such as vitamins B, C and H need to be included in our daily diet as our

body does not store any excess of these vitamins. The excess is being excreted in theurine. Fat-soluble vitamins, such as vitamins A, D, E and K, are absorbed by the intestine

and transported to different parts of the body by the lymphatic system, which is part of

the immune system.

Characteristics of the vitamins• most of the vitamins have been artificially synthesized

• some of vitamins are soluble in water and others are fat-soluble

• some vitamins are synthesized in the body, for example some members of vitamin

B complex are synthesized by microorganisms in the intestinal tract)

• vitamins are partly destroyed and are partly excreted

• vitamins can be stored in the body to some extent, for example the fat-soluble

vitamins are stored in the liver and subcutaneous tissue

• vitamins can perform their work in very small quantities; hence, the total daily

requirement is usually very small

Why We Need Vitamins?

First of all vitamin is that component of a balanced diet which the human body generallycannot manufacture on its own. So you must consume vitamin directly in the form of

food or through supplements as tonic or pills. The whole process of assimilation of

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vitamins depends on ingestion of food. Once you have it as a part of your meal, say for

tomatoes, lemon, spinach and other stuffs, it is more helpful. Moreover you don't feel that

you are a patient and need to have medicines for cure. But if the deficit of a particular vitamin is high, then supplementary dose of vitamins have to be given to the body for a

particular period. The body's metabolism is also dependent on vitamins as on

carbohydrates, fats, minerals and other basic components of a complete diet. But beforeadding the vitamin list to our routine diet, let's understand the importance of vitamins in

life.

Role of Vitamins in Metabolism

Metabolism describes all of the chemical reactions that take place within the tissues. Each

part of the intricate process requires specific protein molecules called enzymes. Most of

these enzyme proteins rely on coupling with a vitamin coenzyme in order to become

active. You can see in the figure above that the vitamin, portrayed in light brown, seemsso insignificant compared to the four massive subunits of the protein enzyme. Its

presence is absolutely essential for the active enzyme to function. The vitamin helps

form what is called the active site of the enzyme. This is the exact location that themolecule to be acted upon (substrate) by the enzyme fits into the active enzyme. Because

most of the vitamins are water soluble, they have relatively short half-lives, from minutesto a few days. This means that they need to be replaced daily from either food intake or avitamin supplement.

Metabolism involves anabolism, or the building of small molecules into large molecules

to create all of the substances that are needed by the cells. It also involves catabolism, or

the breaking down of large molecules into small ones, so the cells have the energy thatthey need to work. Vitamins play a role in these reactions.

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Carbohydrate Metabolism

Vitamin B1, also called thiamin, has a crucial role in the metabolism of carbohydrates.

Enzymes, or proteins that speed up a reaction, sometimes use substances calledcoenzymes for help. Vitamin B1 in its coenzyme form of thiamin diphosphate is vital in

several of the steps of carbohydrate metabolism. Three different groups of enzymes musthave thiamin diphosphate so carbohydrates can be broken down to glucose within the

cells of the body.

Glycogen and Amino Acid Metabolism

The coenzyme form of vitamin B6 is called pyridoxal phosphate and approximately 80

percent of this coenzyme is in the muscles. Glycogen is the storage form of glucose, and

when this glycogen reserve has been used up, the vitamin B6 coenzyme is released so theliver can make glucose from amino acids. Amino acids are proteins, and the liver uses

amino acids to make glucose to meet the energy needs of the body. Pyridoxal phosphate

is also a coenzyme in the metabolism of amino acids.

Metabolism to Produce Energy

Vitamin B2 is also referred to as riboflavin. Flavin adenine dinucleotide, or FAD, and

flavin mononucleotide, or FMN, are the coenzyme forms of vitamin B2. The coenzyme

forms of niacin, which is also called vitamin B3, are nicotinamide adenine dinucleotide,

or NAD, and nicotinamide adenine dinucleotide phosphate, or NADP. All of thecoenzyme forms of vitamin B2 and niacin have roles in the metabolic processes that

provide energy for the cells. FAD and FMN both pass along electrons from one molecule

to another when the cell needs to make energy. NAD transfers electrons when the cell

breaks down large molecules for energy, while NADP transfers electrons whenever thecell needs to build large molecules. These metabolic processes are also called oxidation.

Fatty Acid and Cholesterol Metabolism

Pantothenic acid, or vitamin B5, has a role in metabolism because it forms part of asubstance called coenzyme A. Coenzyme A is crucial in the metabolism of fatty acids

and in the synthesis of cholesterol. It joins with a molecule called acetyl to form acetyl-

CoA. Acetyl-CoA will then join with other substances and form fats, or join with another acetyl-CoA as a beginning step in the formation of cholesterol. Because vitamin B5 is

found in so many foods, people rarely have deficiencies in this vitamin.

Gluconeogenesis

Gluconeogenesis refers to the metabolic process that makes glucose. Vitamin B7, alsocalled biotin, has a role in this process because it has the responsibility of transferring

carbon dioxide in several reactions that are part of making new glucose molecules.

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Sources, Roles and Deficiency Diseases of Each

Vitamin

Vitamin A

SourcesVitamin A is found in animal foods such as whole eggs, liver, milk, margarine, and

fortified ready-to-eat cereals. Also, Vitamin A is abundant in darkly colored fruits and

vegetables such as carrots, cantaloupes, sweet potatoes and spinach. Animal sources of vitamin A are well absorbed and used efficiently by the body. Plant sources of vitamin A

are not as well absorbed as animal sources.

Roles• Eye Health- Within the eye lies a complex neural/sensory processes that allow us

to see. Vitamin A is fundamentally involved in this process and is also involved in

maintaining the health of the cornea.

• Maintenance of Mucus Producing Tissue- Vitamin A is also indispensable for

the maintenance and regulation of growth of many types of cells in the body.Cells that produce mucus, a lubricating and protecting substance, are particularly

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sensitive to vitamin A status. These types of cells are found lining the digestive

tract and lungs and also in the eye’s cornea.

• Growth of Body- Vitamin A is also essential for normal growth and development

of the human body as a whole. It is now clear that vitamin A acts in certain cells

throughout the body at the genetic level. This means that some of the function of

vitamin A is related to its ability to interact with DNA and affect the manufactureof certain proteins. This seems to be very important in the proper development

and maintenance of various tissues throughout the body.

• Regulate the immune system-Vitamin A helps prevent or fight off infections bymaking white blood cells that destroy harmful bacteria and viruses. It also may

help lymphocytes, a type of white blood cell, fight infections more effectively.

Deficiency Diseases Night blindness (Xerophthalmia) is one of the first signs of vitamin A deficiency. It can

contribute to blindness by making the cornea very dry and damaging the retina and

cornea. Vitamin A deficiency diminishes the ability to fight infections, and cells lining

the lungs lose their ability to remove disease-causing microorganisms, contributing to pneumonia. Inadequate mucus secretion of cells lining the respiratory, digestive, urinary,

and reproductive tracts will greatly affect the function and health of these tissues as well.Dry, hard skin is an observable sign of a vitamin A deficiency.

Vitamin B1

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SourcesVitamin B1 (Thiamine, Thiamin) is found most abundantly in foods such as cereal grains

(wheat germ, whole wheat) and meats (pork, fish). Good sources also include peas, beans, enriched flour, and peanuts.

RolesVitamin B1 (Thiamine, Thiamin) helps the body convert carbohydrates into energy and is

necessary for the heart, muscles, and nervous system to function properly. Additionally, it

aids in digestion, especially of carbohydrates, increases urine formation, maintains

normal red blood count, improves circulation, and promotes healthy skin. It also reducesfatigue, increases stamina, and prevents premature ageing and senility by increasing

mental alertness. Similar to other B vitamins, it is more potent when combined with other

B vitamins rather than used separately.

Deficiency DiseasesDeficiency is more a problem in alcoholics and people with malabsorption conditions.Beriberi, a nutritional disorder caused by deficiencies in Vitamin B1 (Thiamin, Thiamin)

is characterized by impairment of the nerves and heart. Typical symptoms include loss of

appetite, digestive irregularities, and a feeling of numbness and weakness in the limbsand extremities. Left untreated, a gradual degeneration of the long nerves will occur,

beginning in the legs, and then the arms, followed by atrophy of muscle and loss of

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reflexes. Also, infants breastfed by mothers deficient in Vitamin B1 (Thiamine, Thiamin)

may lead to rapidly progressing heart failure.

Vitamin B2

SourcesVitamin B2 (riboflavin) occurs abundantly in whey (the watery part of milk), egg whites,and meat. It is also present in leafy green vegetables, whole grains, and enriched grains.

RolesVitamin B2 (riboflavin) is an essential nutrient for growth and general health. It is mainlyknown to function as part of metabolic systems concerned with the oxidation of

carbohydrates, fats, and miscs. It is also involved in a number of chemical reactions

throughout the body and is essential for normal tissue maintenance. Other uses include

aiding in digestion, preventing constipation, promoting healthy skin, hair, and nails,strengthening the mucous lining of the mouth, lips, and tongues, and playing an important

role in the health of the eyes. Vitamin B2 (Riboflavin) is also sensitive to light, and can be destroyed if food is sun-dried. Normal cooking does not destroy this vitamin;

however, losses may occur in the excess water if the food is boiled.

Deficiency Diseases

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Vitamin B2 (riboflavin) deficiency can be characterized by symptoms such as reddening

of the lips with cracks at the corners, inflammation of the tongue, inflammation of the

mucous membranes of the mouth, scaly inflammation of the skin, fatigue, dizziness,nervous tissue damage, and retarded growth in infants or children. Ocular disturbances

may also exist, such as vascularization of the eyeball with eyestrain, abnormal intolerance

to light, eye redness, eye fatigue, or a dry, sandy feeling in the eyes.

Vitamin B3

Sources

Vitamin B3 (niacin) foods include chicken, fish, lean meat, milk, eggs, and various organmeats such as liver, heart and kidney. Plant sources include wholegrain products, leafy

green vegetables, legumes, broccoli, tomatoes, carrots, dates, nuts, seeds, fortifiedcereals, asparagus, and avocados.

RolesVitamin B3 (niacin) play an important role in proper blood circulation, ensures that the

nervous system functions properly, maintains the normal functions of the gastro-intestinaltract, and metabolizes miscs and carbohydrates properly. It also helps to maintain healthy

skin and dilates the blood vessels to increase the flow of blood to the peripheral capillary

system. Finally it is also used in the synthesis of sex hormones and can be used to treatschizophrenia and enhance memory.

Deficiency DiseasesLong term deficiency of vitamin B3 (niacin) can lead to pellagra. The disease starts with

sunburn-like eruptions on the skin when exposed to sunlight, with other symptoms

including diarrhea, dementia, swollen red tongue, and irritability. Other symptoms of more minor deficiency typically include fatigue, loss of appetite, low blood sugar,

dizziness, headaches, insomnia, and canker sores.

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Vitamin B5

SourcesVitamin B5 (pantothenic acid) foods include pork, beef, fish, egg yolk, poultry, and

especially organ meats such as liver, heart, and kidney. Plant sources include wholewheat, whole grains, legumes, mushrooms, broccoli, cauliflower, nuts, enriched cereals,

oranges, and strawberries.

RolesVitamin B5 (pantothenic acid) is abundant in many foods and also produced by intestinal

bacteria. It plays a major role in the metabolism of carbohydrates, fats and miscs and also

in the synthesis of amino acids and fatty acids. This vitamin plays an essential role inmany of the vital functions of the body such as red blood cell production, hormone

production, adrenal gland stimulation, and immune system functionality. Vitamin B5

(pantothenic acid) also acts as an anti-stress agent, increases vitality, wards off infections,and speeds up recovery from illness.

Deficiency DiseasesTypical symptoms of vitamin B5 (pantothenic acid) deficiency include fatigue, nausea,

cardiac instability, depression, muscular weakness, cramps. Nervous system disordersmay include tingling hands, numbness, headaches, headaches, and insomnia. Factors thancan contribute to this deficiency include allergies, stress, too much processed foods,

alcohol, and caffeine.

Vitamin B6

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Sources

Most natural food sources come from non-meat sources such as brown rice, whole wheat,

rye, buck wheat, wheat bran, avocados, bananas, cantaloupe, cabbage, lentils, soybeans,and seeds. Meat sources also include beef liver, chicken, ground beef, ham, shrimp, and

tuna.

RolesVitamin B6 (Pyridoxine) is necessary for the body to absorb vitamin B12, zinc and

produce hydrochloric acid, magnesium, antibodies, and red blood cells. It maintains

healthy brain function. It is also a coenzyme involved in metabolizing misc,carbohydrates, fats, and selenium and promotes the synthesis of nucleic acids. Other

functions include controlling nausea during pregnancy, treating degenerative diseases,

maintaining the health of the skeletal system, improving skin disorders, and relieve thesymptoms of carpal tunnel syndrome.

Deficiency DiseasesExcess Vitamin B6 (Pyridoxine) is usually excreted by the body, and can be destroyed by

food processing and alcohol. For this reason, deficiency is quite common. Deficiency

symptoms include low blood sugar, increased infections, anemia, insomnia, tooth decay,kidney stones, morning sickness, excess PMS, skin rashes, sore mouth, dry skin, and

nervousness.

Vitamin B9

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Sources

Common plant sources for vitamin B9 (folic acid, folate) include asparagus, Brussels

sprouts, cabbage, cantaloupe, green leafy vegetables, citrus fruits, lentils, carrots,apricots, melons, wheat germ, fortified grain products, and whole wheat. Animal sources

include egg yolk and calf liver.

RolesVitamin B9 (folic acid, folate) is essential for the division of body cells, the formation of

red blood cells, the production of nucleic acids, and for normal growth and development.

It maintains vital systems like the nervous system, the intestinal tracts, and the sexorgans. Experts also agree that vitamin B9 (folic acid, folate) can reduce the risk of birth

defects; it regulates embryonic and fetal development of nerve cells and prevents neural-

tube defects.

Deficiency Diseases

Deficiency in vitamin B9 (folic acid, folate) can cause some forms of anemia, digestive problems, nervous problems, sore / red tongue, diarrhea, impaired memory, insomnia,

confusion, reduced immunity, and paleness.

Vitamin B12

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Sources

Vitamin B12 (cobalamin, cyanocobalamin) is required in small amounts and only found

in animal foods. Common sources include blue cheese, dairy products, sardines, oysters,mackerel, liverwurst, milk, yogurt, eggs, and kidneys.

RolesVitamin B12 (cobalamin, cyanocobalamin) is needed for the body to form red blood

cells, thereby helping to prevent anemia. It is also used to metabolize fats, miscs, and

carbohydrates. Additionally, it is essential for a healthy nervous system, and plays a role

in nucleic acid metabolism, and the formation of RNA and DNA. Other uses includeimproving concentration, memory and balance, and also detoxifying cyanides and

tobacco smoke.

Deficiency DiseasesSome common "enemies" of vitamin B12 (cobalamin, cyanocobalamin) include water,

alcohol, sunlight, and sleeping pills; it is also not well absorbed through the stomach.Common deficiencies include fatigue, nerve damage, weakness in the arms and legs,

shortness of breath, depression, poor memory bruising, sore tongue, nausea, and brain

damage.

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Vitamin C

Sources

Many foods are rich in vitamin C (ascorbic acid). Plant sources include citrus fruits, black

currants, broccoli, Brussels sprouts, cabbage, green peppers, mangos, papayas, potatoes,

spinach, strawberries, tomatoes, and watercress. It is best to eat these vegetables andfruits fresh or raw when possible.

RolesVitamin C (ascorbic acid) is one of the most common and important vitamins found in

many fruits and vegetables. It promotes healthy capillaries, bones, tissue, gums, and teeth

as well as helping to heal wounds and burns. Right before a cold, it is advised to take

more vitamin C (ascorbic acid) to decrease the intensity and duration, and also toencourage immune activity. It can also be used to aid iron absorption, treat anemia, treat

urinary tract infections, form collagen, and increase calcium absorption. Additional

benefits include reducing cholesterol, preventing some forms of cancer, reduce symptoms

of arthritis, and reduce the toxic effect of alcohol and drugs.

Deficiency DiseasesThe most common ailment of vitamin C (ascorbic acid) deficiency is scurvy, which is

characterized by swollen gums, loss of teeth, bleeding gums, bleeding under skin, muscle

weakness, tiredness, and depression. Other symptoms include lowered immune activity, bruising, anemia, and various skin problems.

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Vitamin D

Sources

Vitamin D is common in fortified milk and dairy products, especially butter. It is also

found in cod-liver oil, herring, mackerel, salmon, sardines, and tuna.

RolesVitamin D is fat soluble so that it can be stored in the body and also produced by

exposure to sunlight. This production occurs through a chemical reaction of the sun withvarious skin oils, which is then absorbed into the body.

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Figure: Vitamin D Metabolism

The primary function of vitamin D is for bone growth, repair, and hardening though theabsorption of minerals such as calcium, magnesium, iron, zinc, and phosphorus. It also

treats post-operative muscle contraction, promotes normal growth and development of

children, and is necessary for the health of bones and teeth. Other uses include regular kidney function, and helping the body assimilate vitamin A.

Figure: Vitamin D in Calcium Absorption

Deficiency DiseasesThings that contribute to vitamin D deficiency include little exposure to sunlight and

living in highly polluted areas. The most common symptom of deficiency is rickets, a

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childhood disease characterized by bent or bowed legs, malformations of joint or bones,

late tooth development, or weak muscles. The adult form is called Osteomalacia, and is

characterized by pain in the ribs, brittle bones, and muscle weakness.

Vitamin E

Sources

Most vitamin E food sources come from plants like asparagus, broccoli, corn, spinach,walnuts, almonds, nuts, peanuts, wheat germ, and fortified cereals. Animal sources

include butter and eggs.

RolesSince vitamin E is fat soluble, it can be stored in the body, but not as efficiently as others.

Excess amounts are excreted in urine, so it is considered to be non-toxic. Considered to

be an antioxidant, it also slows down aging, improves immunity in the body, heals theskin, and promotes normal growth and development. It also works as anti-blood clotting

agent and promotes normal red blood cell formation. During pregnancy, it can reduce the

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risk of a miscarriage and can also improve fertility. In males, it protects against prostate

cancer as well as reduces the risk against fatal first myocardial infarction.

Deficiency DiseasesDeficiency symptoms can include lethargy, inability to concentrate, reproductive

problems, muscle degeneration, red blood cell degeneration, nerve dysfunction, andvarious forms of anemia. Similar to other vitamins, vitamin E is also very susceptible to

food processing. Smokers and pregnant women should take vitamin E supplements.

Vitamin H

Sources

Animal sources of vitamin H (biotin) include liver, chicken, clams, eggs, mackerel,salmon, and tuna. Plant sources include wholegrains, nuts, unpolished rice, oatmeal,

almonds, green peas, lentils, mushrooms, peanuts, walnuts, and soybeans.

RolesBiotin or Vitamin H is a water soluble product found in many foods and also synthesized by intestinal bacteria. It is necessary for normal growth and development, aids in the

formation of fatty acids, and is required for the metabolism of miscs, carbohydrates, and

fats. It is also promotes the growth and health of sweat glands, nerve glands, skin, hair,

blood cells, sex glands, and bone barrow.

Deficiency DiseasesSome common enemies of vitamin H (biotin) include food processing, alcohol, sulfur drugs, estrogen, and egg whites. Long term use of antibiotics can also have a detrimental

effect, as the body's natural bacteria that produces biotin is also destroyed. Deficiency

symptoms include depression, eczema, fatigue, impairment of fat metabolism, nausea,loss of muscular reflexes, dermatitis, pale tongue, hair loss, and anemia.

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Vitamin K

Sources

Most sources of vitamin K (phytonadione) are found in plant foods such as alfalfa,

broccoli, leafy green vegetables, Brussels sprouts, green tea, wholegrains, and tomatoes.Animal sources include yogurt, liver, cheddar cheese, and egg yolks.

RolesVitamin K (phytonadione) is fat-soluble vitamin, so deficiency rarely occurs. The bacteria located in the small intestine produces it, and yoghurt, which encourages "good"

bacteria growth in the small intestine, can be a contributing factor towards preventing

vitamin K (phytonadione) deficiency. The primary function is for the body to form

prothrombin, which is required for blood clotting. It also promotes healthy bones, prevents hemorrhagic disease of the newborn, and promotes normal growth.

Deficiency DiseasesVitamin K (phytonadione) can result in hemorrhaging throughout the body including

nosebleeds, postoperative bleeding, blood in the urine or eye, intestinal bleeding due to blood clotting problems. It can also cause miscarriages, colon problems, and

osteoporosis.

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Inference :

Vitamins are needed for growth and good health. The vitamins we need are found in the

food you eat. It's important to eat a balanced diet that includes fruits and vegetables.

Some food is enriched. This means that vitamins were added. For example, bread and

milk are enriched. Some people also take vitamin pills.Vitamins are chemical compounds. They are nutrients for the human body that are

contained within food substances. Vitamins control the chemical reactions within the

body to convert food into energy and living tissue. They help the body use the energynutrients, maintain normal body tissue, act as a regulator, and are only needed in small

amounts.

There are a total of thirteen needed vitamins, four that are produced in the body itself.Biotin, pantothenic acid, and vitamin K are made in the human intestine and usually in

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adequate amounts to meet the body's needs. Sunlight on the skin surfaces can produce

sufficient amounts of vitamin K. The remaining vitamins must be supplied in the daily

diet.Each vitamins meets specific body needs that one of the other compounds cannot

substitute or act for instead. However the lack or deficiency of one of them can

sometimes interfere with another vitamins function. If a vitamin deficiency continues,the person can incur a related disease such as beriberi, pellagra, rickets, and scurvy.

Conversely, too much of some vitamins brings on a toxic condition.

Roles of Vitamins in Diet

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