What are the functions of vitamin A?

A fat-soluble nutrient, vitamin A, also known as retinol, has many important functions. Vitamin A is converted to light sensitive pigments in receptor cells of the retina, the light sensitive layer of the eye.

Vitamin A is also required for healthy reproduction and lactation. Vitamin A helps form and maintain healthy teeth, mucous membranes, skeletal and soft tissues and skin. It supports cell growth, immune function, fetal development, and vision. It is also known as retinol because it produces the pigments in the retina of the eye.

Vitamin A helping human body's natural defense against illness and infection (the immune system) work properly. Scientists claim that vitamin A is ‘the anti-infective vitamin,’ enabling body surfaces to act as a barrier to invading micro-organism and toxins.

One of its physiological functions is the formation and maintenance of epithelial tissue, which contributes to the body immune system. Epithelial cells (those cells present in the lining of body cavities and in the skin and glands) require vitamin A.

Provitamin A carotenoids, β -carotene is an antioxidant. Antioxidants protect cells from damage caused by substances called free radicals.

Free radicals are believed to contribute to certain long-term diseases and also play a role in aging Lack of vitamin A in the diet will result in the drying up of the body cells which could lead to dermatitis, dry hair or night blindness.

Good sources of vitamin A (retinol) include: cheese, eggs, oily fish, fortified low-fat spreads, milk, yoghurt, and liver. Vitamin A is also available in dietary supplements. It most often comes in the form of retinyl acetate or retinyl palmitate (preformed vitamin A), beta-carotene (provitamin A) or a combination of preformed and provitamin A.
What are the functions of vitamin A?

Vitamin content in apple juice

Apple fruit juices are commonly consumed for their refreshing attribute, nutritive values. Fruit juice contain several important therapeutic properties that may reduce the risk of various diseases and health benefits.

Apple juices rich with vitamin A and vitamin C. A high percentage of the vitamin A in apples is concentrated in their skins. Therefore, the apple juice with highest vitamin A content will be the apple juice from unpeeled, organically grown apples that are juiced with their skin on.

Vitamin A helps ward off colds and other infections and promotes growth. It also keeps the eyes in good condition, and prevents night blindness.

The fresh apple juice is very rich sources of vitamin C, but canned juice normally contains very high amount of ascorbic acid as compared to fresh juice.

The vitamin C content of fresh juice from both peeled and unpeeled apples helps prevent colds flu, and intestinal infections. Vitamin C also act as a body normalizer and is essential in keeping bones and teeth sound.

Vitamin C is necessary for the body to form collagen, cartilage, muscle, and blood vessels, and aids in the absorption of iron.

Other than that apple juice also contributes some vitamin K. It is very necessary for the body to promote blood clotting.
Vitamin content in apple juice

Major nutrient and chemical compound in fruit juice

Fruit juice is important in human nutrition for beyond its use as a refreshing source of liquid. Many fruits contain a variety of minor ingredients, particularly vitamins and minerals, as well as carbohydrates which are the predominant solid component.

Although fruit contains small amounts of protein and fat, these are not important ingredients of juices.

Nutrients frequently consumed in sub-optimal concentrations by humans are protein, calcium, iron, vitamin A, thiamin (vitamin B1), riboflavin (vitamin B2) an ascorbic acid (vitamin C). Some of these nutrients occur in higher concentrations in fruit juices than in other foods. There is experimental evidence that indicates that ascorbic acid of natural origin is apparently superior to that of synthetic origin.

It has been established that the above phenomenon is caused by the presence of certain flavonoids compounds in fruit juice that influence blood circulation, increasing the permeability and elasticity of capillaries.

This action is known as vitamin P activity, but the flavonoids showing this property are not classified as vitamins, because there several substances with is activity and no serious deficiency diseases occur if they are not consumed.

There are indications that these flavonoids have a useful protective action, in particular against some respiratory diseases, but they are readily decomposed in the body, and it is impossible to maintain an effective concentration.

Apart from the more obvious benefits of fruit juice, such as being a source of potassium, it contains other substances that have or are claimed to have useful pharmacological activity. Sorbitol, which occurs in many fruit juices, has a laxative effect.

Several components with antioxidant activity are found in fruit juices. These are including ascorbic acid, tocopherols (vitamin E), beta carotene and flavonoids. Beta carotene has antioxidant activity that can quench the singlet oxygen that can induce precancerous cellular changes.

Whatever the nutritional interest, it should be noted that changes occur during storage, particularly to the minor components of juices and particularly under adverse conditions (e.g., light, increasing temperature, time)
Major nutrient and chemical compound in fruit juice

The importance of vitamin K

In 1929, Henrik Dam of Denmark discovered vitamin K. Vitamin K is a fat soluble vitamin has been implicated in both cardiovascular and bone health.

Vitamin K is needed for the production of prothrombin which is necessary for blood clotting. The blood clotting process involves the participation of a number of vitamin K dependent plasma proteins. They include factors II (prothrombin), XII (pro-convertin), IX (Christmas factor) and X (Stewart factor) and proteins C, S, Z and M.

It is also essential for bone formation and repair; it is necessary for the synthesis of osteocalcin, the protein in bone tissue on which calcium crystallizes. Consequently, it may help prevent osteoporosis.

The importance of the availability of sufficient vitamin K for the rate of carboxylation became evident when it was shown that osteocalcin circulating in the blood of normal volunteers only reach full carboxylation when vitamin K supplements were given.

Vitamin k plays important role in the intestine and aids in converting glucose into glycogen for storage in the liver, promoting healthy liver function.

It may increase resistance to infection in children and help prevent cancers that target the inner linings of the organs. It aids in promoting longevity.
The importance of vitamin K

Vitamin D from natural sources

Very few naturally occurring foods are rich in vitamin D. Typically animal foods contain cholecalciferol, while plant foods contain ergocalciferol. Some food items that naturally contain small amounts of vitamin D include oil fish such as salmon, mackerel and blue fish. Cod liver oil is the best source of vitamin D.

Liver meat is another source of abundant vitamin D. For vegetarians or vegans, all edible mushrooms have some content of vitamin D2 and ergosterol, which becomes activated with UVB exposure.

The two basic substances with vitamin D activity D2 and D3, occur only in yeast and fish liver oils. Vitamin D is also presents in small quantities in vegetables, meat and egg yolk.

The main food sources are those to which crystalline vitamin D has been added. Milk, because it is commonly used, has proved to be the most practical carrier. In United States fluid milk is voluntary fortified with 400 IU per quart of vitamin D.

The most efficient source of the vitamin D is not a food at all, but exposure to sunlight, which transforms a related pro-vitamin substance in the skin into a substance which the kidney can change into active vitamin D.

Sunlight provides 90 to 100% of the requirement for most people who are exposed to adequate sunlight. Vitamin D3 is synthesized in human skin from 7-dehydrocholesterol following exposure to ultraviolet B radiation with wavelength 290 to 320 nm.

Like other fat soluble vitamins, the sunlight activated pro-vitamin D can be stored away in the liver.
Vitamin D from natural sources

Causes and effects of vitamin deficiency

Vitamins play an integral and an almost central role in human health and wellbeing. Significantly, the vitamins were discovered not by their presence in the diet but because of their absence.

Deficiency of vitamins may arise due to: inadequate dietary intake, decreased absorption, increased need and impaired unitization.

A lack of most of the vitamins known to be required by human resulted in typical clinical syndromes or symptoms that can be cured by adding the necessary vitamin to the diet.

Deficiency of fat soluble vitamins results in night blindness, skeletal deformation, haemorrhages and hemolysis. Deficiencies of water soluble vitamins produce beriberi, glossitis, pellagra, microcytic anaemia, megaloblastic anemia and scurvy.

Since most of the water soluble vitamins are component or enzymes, their deficiency leads to blocks in metabolic reactions. This negative approach to the function of the vitamins is a useful tool in research.

The investigator obtains some clues to the metabolic role of nutrients when he observes the functional failures that result when the nutrient is absent from the diet.
Causes and effects of vitamin deficiency

What are antimetabolites?

Certain compounds similar in structure to the vitamin molecule (or to the portion of the molecule containing the active site) can replace the vitamin by attaching themselves to the enzyme. These substances are called ‘antimetabolites’ or ‘metabolic antagonists’. They block the normal action of the co-enzyme and in effect, result in cellular deficiency of the vitamin.

The antimetabolite is a chemical substance which is shaped like the substrate. In other words, it is a structural relative or analogue of the substrates. Probably for this reason it also is able to combine with the active center of the enzyme.

Certain other antimetabolites exhibit anti-vitamins activity because they are capable of blocking biosynthesis of the coenzyme molecule; such compounds may or may not resemble the vitamin in structure.

In either case, a condition similar to true vitamins deficiency is produced. Antimetabolites are useful in producing experimental vitamin deficiencies, especially those deficiency that developed slowly from dietary restriction alone.

Antimetabolites also useful adjuncts in delineating the biochemical pathways in which the vitamin is involved, and in relating metabolic disturbances to symptoms of deficiency.

The use of vitamin metabolites created new opportunities for inducing a studying many aspects of s wide range and variety of malformations and fortuitously led to an avenue of human studies.

A variety of antagonists of vitamins, hormones and cell metabolites had been synthesized after Donald Woods of Oxford University discovered in 1940 that sulfonamides exerted their antibacterial action by antagonizing the role of 4-aminobenzoic acid, a growth factor for  bacteria. Such antagonists were described as antimetabolites.
What are antimetabolites?

Nutrition of onion

The onion is a biennial (a plant that lives for 2 years); it stores food in the bulb during the first year, and it flowers in the second year. Onion when cut gives a characteristics strong odour.

Onions are low in calories and in most nutrients. However, they not only provide flavor in cooking, but also are a source of health promoting phytochemicals such as quercetin and alluim, both considered to be helpful in preventing cardiovascular disease and cancer.

Onion is an important spice as well as well commercial vegetable. The nutritive value of onion bulbs varies from variety to variety.

Average composition per 100 g of bulb is as follows:
*Moisture 86.0 g
*Carbohydrate 10.9 g
*Protein 1.4 g
*Fiber 0.8 g
*Potassium 180 mg
*Sulfur 70.0 mg
*Phosphorus 44.0 mg
*Calcium 32.0 g
*Chlorine 25 mg
*Magnesium 16 mg
*Sodium 7 mg
*Iron 9.7 mg
*Thiamine 0.06 mg
*Riboflavin 0.01 mg
*Niacin 0.4 mg
*Vitamin C 28 mg,
*Carotene 660 ug

A serving contains 60 calories and has no fat and cholesterol. Onion is a source of energy and acts as a stimulant, increases vigor and vitality.

It also acts as an expectorant and diuretic, normalizes the heart beat prevents flatulence and dyspepsia. Eating at least half an onion a day is reported to reduce the risk of stomach cancer by 50%.
Nutrition of onion

Vitamins content of dairy milk

Vitamins are organic chemicals required by the body in trace amounts but which cannot be synthesized by the body.

The vitamins found in milk include vitamins A, D, E and K, ascorbic acid, thiamin, riboflavin, niacin, panthotenic acid, pyridoxine, folic acid, and cyanocobalamin.

Fat-soluble vitamins A, D, E and K are located in the milk fat component of milk. Cow’s milk is generally well pigmented with carotene, the precursor of vitamin A. About 11% to 50% of total vitamin A activity in milk is derived from carotenoids, the specific proportion depending on the breed and feed of the cow and season of year, among other factors.

Ruminant derived all the water soluble vitamins via synthesis by rumen microbial flora, but are dependent on an exogenous supply of the fat soluble vitamins.

The quantities of water soluble vitamins and of vitamin K in milk are little affected by feed, season, breed or stage of lactation, whereas the quantities of vitamins D and E are influenced by feed.

Dairy milk contains more vitamin B than soy milk. It has 8 types of vitamin B, compared to soy milk which contains 7 types, but lacking in vitamin B12.

All the vitamins appear to be well absorbed from milk products and make important contributions to human diets.
Vitamins content of dairy milk

Roles of coenzyme Q10 in human body

Coenzyme Q10 is a vitamin substance naturally found in all parts of the body the action of which resembles that of vitamin E. It may be an even more powerful antioxidant. It is also called ubiquinone.

Coenzyme Q10 is a fundamental ingredient in the energy production that keeps those trillions of cells running smoothly. A shortage of coenzymes Q10 translates into an energy crunch, with cell running on weak batteries. It aids circulation, stimulates the immune system, increases tissue oxygenation, and has vital anti-aging effects.

Besides generating energy, coenzyme Q10 is one of the body’s most powerful antioxidants. It protects body against radicals, the destructive molecular fragments that cause accelerated aging and degenerative diseases.

Coenzyme Q10 is especially well-known for its ability to prevent cellular damage during and following a heart attack (myocardial ischemia and reperfusion).

There are ten common substances designated coenzyme Qs, but coenzyme Q10 is the only one found in human tissue. Deficiencies of coenzymes Q10 have been linked to periodontal disease, diabetes and muscular dystrophy. Supplemental has ability to counter histamine and therefore beneficial for people with allergies, asthma or respiratory disease.

Coenzyme Q10 is used by many health care professional. To treat anomalies of mental function, such as those associated with schizophrenia and Alzheimer’s disease. It is also benefiting in fighting obesity, candidiasis, multiple sclerosis and diabetes.

Orally it is used therapeutically in the treatment of various cardiovascular disorders, including angina pectoris, hypertension, high blood cholesterol and congestive heart failure.
Roles of coenzyme Q10 in human body

Vitamin A in cow's milk

All-trans retinol is the main form of vitamin A present in milk, the cis isomer of retinol being sometimes observed in a very low amount in cow’s milk.

The amount of vitamin A in milk varies with the carotene content of the feed. Normally, vitamin A potency is highest when the cow is on succulent pastures in the spring and lowest when the cow is hay-fed during the winter season.

The vitamin A potency of milk can be increased to a level that approaches summer milk by feeding rations high in carotene content.

Concentrations of vitamin A and carotenoids in milk are also dependent on animal species. Indeed caprine milk is richer (30%) in retinol and conversely beta-carotene is 30% higher in cow’s milk than goat’s milk.

Guernsey milk contained more carotene than preformed vitamin A, Jersey approximately equal proportions whereas the Holstein milk the carotene constituted approximately 30 percent and the vitamin A, 70 percent of the total biological active vitamin A.
Vitamin A in cow’s milk

The importance of ascorbic acid

Ascorbic acid was recognized as early as 1734 as the factor in fresh fruit and vegetables that prevent the development of scurvy.

Ascorbic acid or vitamin C is required for the formation of intercellular substances in the body, including dentine, cartilage, and the protein network or bone. Hence, it is important in tooth formation, the healing of broken bones, and the healing of wounds.

It may be important to oxidation –reduction reactions in the body and to the production of certain hormones.

In the brain, ascorbic acid may perform important functions related to the metabolism and release of several neurotransmitter.

Vitamin C is not only an important nutrient but is also used as an antioxidant in various foods.

Vitamin C recharges fat soluble vitamin E and water soluble glutathione, allowing them, to be reused many times.

Tomato juice, if it has been processed properly, is a fair source of this vitamin. Green peppers, cabbage, broccoli, and sprout are excellent to good sources of vitamin C, while other vegetables such as peas, spinach, and lettuce are good to fair sources. Many fruit contain fair amounts of vitamin C.

Overdoses of vitamin C induce perspiration, nervous tension, and lowered pulse rate.
The importance of ascorbic acid

What are bioflavonoids?

Flavonoids or bioflavonoids are natural products widely distributed in the vegetable kingdom and currently consumed in large amounts in the average Western diet.

One called vitamin P, bioflavonoids are a group of natural substances in fruits, vegetables, flowers and grains. Fruit sources include lemons, grape fruit, oranges and to a lesser extent, limes. Other fruit sources are apricots, cherries, grapes, blackcurrant, plums, blueberries, blackberries, pears, and papayas.

They are water soluble. While they often appear as constituents of vitamin C, they are not present in synthetic forms of the vitamin.

Since most of them have a yellow. Orange color they are referred to as flavonoids, derived from the Latin word ‘flavus’ for yellow.

Some of the better-known flavonoids are hesperidin, rutin, naringin, according to the Foods & Nutrition Encyclopedia. Citrin is a flavone found primarily in citrus fruit. Hesperidin is a bioflavonoid found in the skins and peels of citrus fruits. Rutin occurs in buckwheat.
What are bioflavonoids?

Vitamins in Fruits

Fruits and vegetables provide excellent sources of nutrients, such as protein, vitamins, minerals and fiber as well as non-nutrient phytochemical such as sulfur-containing compounds.

Vitamins are organic nutrients that are usually required in small quantities. They play various roles in biochemical reactions in cells within the body.

Fresh fruits and vegetables contribute about 91% of vitamin C, 48% of vitamin A, 27% of vitamin B6, 17% of thiamin and 15% of niacin to Americans diet.

The following fruits are important contributors (based on their vitamin content and the amount consumed) to the supply of indicated vitamins in the U.S diets:

Vitamin A: apricot, peach, cherry orange, mango, papaya, persimmon, pineapple, cantaloupe, watermelon

Folate: strawberries, oranges, grapefruits

Pantothenic acid: plums

Vitamin C: strawberry, orange, grapefruit, kiwifruit, pineapple, banana, apple, cantaloupe, blackcurrant

Niacin: peach, banana, orange, apricot, plum

Riboflavin: banana, peach, orange, apple, avocado

Thiamin: orange, banana, grapefruit, apple

People who consume diets high in fruits have a lower risk for cardiovascular disease, most cancer types, diabetes and all-cause mortality. It is often assumed that vitamin in fruits are responsible for the protective effects of these foods.
Vitamins in Fruits

General characteristics of fat soluble vitamins

The fat soluble vitamins A, D, E and K are found in the fats and oils of food. Unlike water soluble counterparts, these vitamins are absorbed like dietary fat, with the assistance of bile acids.

Unlike water soluble vitamins, fat soluble vitamins are circulated away from small intestine in the lymph via chylomicrons before eventually entering the blood either as components of lipoproteins or bound to transport proteins.

Once absorbed, these vitamins are stored in the lover and fatty tissues until the body needs them.

The risk of toxicity from vitamin A and D is greater that that of vitamin E and K. A toxic affect from vitamin D can be seen when one consumes only ten times the body’s need. In contrast, consuming just three times the body’s need for vitamin A can lead to toxicity.

Fat soluble vitamins play diverse roles in the body. Vitamins A and D act somewhat like hormones, directing cells it convert one substance to another to store this or to release that.

Fat soluble vitamins typically found in fatty portions of foods, and they easily destroyed by heat and light.
General characteristics of fat soluble vitamins

What are vitamins?

Vitamins have been defined as organic substances present in minute amounts in natural foodstuffs that are essential to normal metabolism and lack of which in the diet causes deficiency diseases.

Vitamins are required in trace amounts in the diet for health, growth and reproduction.

As the chemical structure of the vitamin became known through its isolation and synthesis; it was given a chemical name. When the chemical name was assigned, it was assumed that the name applied to one substance with one specific activity.

Some of the vitamins occur in foods in a form known as precursors or provitamin. Once inside the body, these are transformed chemically to one or more active vitamin forms.

Now it is evident that a vitamin may have a variety of functions and that vitamin activity may be found in several closely related compounds known as vitamers. An excellent example of this is vitamin A, which has several seemly unrelated functions and encompasses not only retinol but also retinal and retinoic acid.

The vitamins can further classified into two classes: fat soluble and water soluble. Soluble confers vitamin many of their characteristics. It determines how they are absorbed into and transported by the bloodstream.

The fat soluble vitamins are represented by vitamins A, D, E, and K absorbed and transported by conventional lipid transport.

For water-soluble vitamins, respective solubility coefficients are major factors that dictate the availability and ease of absorption.
What are vitamins?

Food sources of niacin (vitamin B3)

Niacin (nicotinic acid) is one of vitamin B. This compound is part of an enzyme system regulating reduction reactions in the body.

It is also a compound that dilates blood vessels. Deficiency of niacin causes pellagra (a disease that causes diarrhea, dermatitis, nervous disorders, and sometimes death).

In general, niacin is widespread in foodstuff. Cereals seeds, meat and fish are good food sources of niacin, which converts trigonelline.

All foods containing complete protein, such as the above mentioned, and also milk and eggs, are good source of the precursor of niacin, tryptophan. Tryptophan an amino acid present in some of these foods, can be converted to niacin in the body.

Lean meat, poultry, and peanuts are good sources of both niacin and tryptophan, as are beans, peas, other legumes, most nuts, and several whole grain or enriched cereal products.

The niacin vitamers in foods include nicotinic and nicotinamide, which occur in limited quantities in the free form, and their coenzymes, nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate.
Food sources of niacin (vitamin B3)

Vitamins as antioxidants in processed foods

Oxidation, a series of chemical reactions yielding undesirable and products (off odors, colors, and flavors), may occur in many fruits and vegetables and foods high in fat and oil during exposure to air, light, heat, heavy metals, certain pigments or alkaline conditions.

Enzymatic browning may occur in some fruits and vegetables, particularly apples, banana, peaches, pear, and potatoes, which contain phenolase enzymes. Enzymatic browning is the rapid, enzyme-mediated conversion of plant phenolic compounds into dark polyphenolic polymers.

When these fruits and vegetables are cut or sliced and exposed to air, the phenolases catalyze oxidation of phenolics compounds to ortho-quinone compounds, which then polymerize, forming brown pigments.

Fruits and vegetables must be blanched and pretreated prior to pressing, in order to inactivate the enzyme. 

Oxidation in lipids (autoxidation) and in fat and oil containing foods, on the other hand, occurs as a result of the susceptibility of fatty acids (building blocks of fats and oils) to oxidations and subsequent formation of reactive compounds referred to as “free radicals”.

The free radicals promote the development of a series of chemical reactions which lead to the production of off-flavors, colors, odors, and rancidity.

Some oxidations have more than one function. For example, ascorbic acids may function as a free-radical chain terminator, and oxygen scavenger, or a metal chelator. Under certain conditions, it may act as a promoter for oxidation.

Due to increasing concern over the potential toxicity and safety of some phenolic antioxidants, the replacement of synthetic antioxidants by ‘safe, natural’ antioxidants such as vitamins E and C flavonoids and other plant phenolic has received considerable attention.

Vitamin E compounds are reported to effectively inhibit lipid oxidation in foods and biological systems.
Vitamins as antioxidants in processed foods

The role of vitamin B Complex in human body

The vitamins consist of a group of water-soluble vitamins that include B1 (thiamin), B2 (riboflavin), B1 (niacin and niacinamide), B6 (pyridoxine), B12 (cobalamin), folic acid, pantothenic acid, biotin, choline, inositol and PABA (para-aminobenzoic acid).

The grouping of these compounds under the term B complex is based upon their common source their close relationship in vegetable and animal tissues and their functional relationships.

The B vitamins help to maintain the health of the nerves, skin, eyes, hair, liver and mouth and well as healthy muscle tone in the gastrointestinal tract and proper brain function.

Each vitamin has its own unique biological role to play and its own properties. B vitamin also work together in the body and many of them are found in the same foods.

They act as coenzymes, helping enzymes to react chemically with other substances and are involved in energy production.

They may be useful for alleviating depression or anxiety as well.

The B vitamins are most plentiful in whole grains such as wheat, rice, oats, and rye; and liver. They are also found in green leafy vegetables, meats, poultry, fish, eggs, nuts and beans.

Since the B vitamin work best as a team, it’s important to take a B-complex supplement when taking additional amounts of any single B vitamin. They are also vital in the metabolism of carbohydrates, fats and protein in the body. The B vitamins are important for antibody production and red blood cells.

While B vitamins are an important part of the diet and are needed to help avoid many health conditions, there is not enough scientific evidence to determine if B vitamins can reduce the risk of cancer.
The role of vitamin B Complex in human body

Why is vitamin E important?

Vitamin E was discovered and characterized as a fat soluble nutritional factor during reproductive studies with rats. This observation was published in1922 by Herbert McLean Evans and Katharine Scott Bishop. 

That supplement, vitamin E (alpha-tocopherol), was eventually isolated from wheat germ oil in 1936. There are four different forms of tocopherol. The tocopherols have the same name except with the prefix alpha-, beta-, gamma-, and delta- (the first four letters of the Greek alphabet).

The four compounds are closely related, with some difference in the molecular weight and in the position and number of certain molecular constituents.

Vegetable oils and lipid rich plants products (e.g. nuts, seeds, grains) are the main dietary sources of vitamin E.

In Western diets, vitamin E intakes derives mainly from fats and oils contained in margarine, mayonnaise, salad dressing and desserts and also from fortified food such as breakfast cereals, milk and fruit juices. 

Function of Vitamin E
The vitamin is an antioxidant that serves to prevent the oxidation of some body components, such as unsaturated fatty acids, and is necessary for reproduction. This vitamin involved in several biological processes such as immunity, protection against tissue damage such as heart and nerve, reproduction, growth and development.

Vitamin E also slows the aging process, probably delaying the onset of such conditions as cataracts and wrinkles. And it helps heal or alleviated many minor health complaints – including everything from burns to menopausal hot flashes.

Vitamin E deficiency 
A primary deficiency of vitamin E is rare; deficiency is usually associated with diseases of fat malabsorption such as cystic fibrosis.

Without vitamin E, the red blood cells break open and spill their contents, probably due to oxidation of the polyunsaturated fatty acids in their membranes.

Muscular dystrophy is another equally important consequence of vitamin E deficiency. Skeletal, cardiac and smooth muscles and peripheral vascular system need vitamin E for their functioning.
Why is vitamin E important?