Fat soluble vitamin: Vitamin E

Vitamins are divided into two groups: water-soluble (B-complex vitamins and C vitamins) and fat-soluble vitamins (A, D, E and K).

Vitamin E, of which there are four different forms (the tocopherol), is fat soluble. The tocopherols have the same name except with the prefix α-, β-, γ-, and ẟ- (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.

Vitamin E is the most powerful natural antioxidant and protecting vitamins A and C, red blood cells, and essential fatty acids from destruction.

Vitamin E is a known biological antioxidant able to quench the lipid peroxidation chain. Vitamin E activity is measured by activity of α-tocopherol equivalents, while β-tocopherol has lower activity.

About 60 percent of vitamin E in the diet comes from vegetable oil (soybean, corn, wheat germ, cottonseed, and safflower). This also includes products made with vegetable oil (margarine and salad dressing).
Fat soluble vitamin: Vitamin E

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.
Vitamin deficiency

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.
Characteristics of fat soluble vitamins

Fat soluble vitamins

Solubility characteristics divide the vitamins into two major classes: the water-soluble vitamins and the fat-soluble vitamins.

There are nine water-soluble vitamins and four fat-soluble vitamins. The fat soluble vitamins A, D, E and K are chemically similar and found in fats and oils of food.

Fat soluble vitamins in general carried in the blood by protein carriers, are stored in fat tissues, are needed in periodic doses and are more likely to be toxic when consumed in excess of need.

These vitamins are absorbed like dietary fat – with the assistance of bile acids. Once absorbed, the fat soluble vitamins enter the lymphatic system before circulating in the blood.

They are transported through the blood by lipoprotein because they are not soluble in water.

Excess fat soluble vitamins are stored in the liver and adipose tissue and remain there until needed. Fat soluble vitamins play diverse roles in the body.

Vitamins A and D may act somewhat like hormones, directing cells to convert one substance to another, to store this or to release that.

Other functions of vitamin A including maintenance of vision in dim light, maintenance of mucous membranes and healthy skin and involve in growth and development of bones.

Vitamin E flows throughout the body, preventing oxidative destruction of tissues. Vitamin E is considered essential for protection of cell structure, especially of red blood cells. Vitamin K is necessary for blood to clot.
Fat soluble vitamins

Classification of Vitamins

Classification of Vitamins
Classically, vitamins have been divided into two groups based on their solubilities in fat solvents or in water.

Thus, fat-soluble vitamins include A, D, E and K, while vitamin of the B-complex and C are classified water soluble.

Fat soluble vitamins are found in foodstuffs in association with lipids.

The fat soluble vitamins are absorbed along with dietary fats, apparently by mechanisms similar to those involve in fat absorption.

Conditions favorable to fat absorption, such as adequate bile flow and good micelle formation, also favor absorption of the fat-soluble vitamins.

Water soluble vitamins are not associated with fats, and alterations in fat absorption do not affect their absorption.

Three of the four fat-soluble vitamins (vitamins A, D and E) are well stored in appreciable amounts in the animal body. Except for vitamin B12, water soluble vitamins are not well stored, and excesses are rapidly excreted.

A continual dietary supply of the water soluble vitamins and vitamin K is needed to avoid deficiencies.

Fat-soluble vitamins are excreted primarily in the feces via the bile, whereas water soluble vitamins are excreted mainly in the urine.
Classification of Vitamins

Fat Soluble Vitamins

Fat Soluble Vitamins
Vitamins A, vitamin D, vitamin E and vitamin K are relatives that have two characteristics in common: All dissolve in fat, and all are stored in fatty tissues.

But like members of the family, they also have distinct personalities. One keeps the skin moist. Another protects bones. A third keeps reproductive organs purring happily. And the fourth enables to make us special proteins.

Vitamin A
Vitamin A is the moisturizing nutrient that keeps your skin and mucous membranes smooth and supple.

Vitamin A is also the vision vitamin, a constituent of 11-cis retinol, a protein in the rods (cells in the back of your eye that enable you to see even the lights are low) that prevents or slows the development of age related macular degeneration, or progressive damage to the retina of the eye, which can cause the loss of central vision (the ability to see clearly enough to read or do fine work).

Finally, vitamin A promotes the growth of healthy bones and teeth keeps your reproductive system humming and encourages your immune system to churn out the cells you need to fight off infection.
Fat Soluble Vitamins

Fat Soluble and Water Soluble Vitamins

Fat Soluble and Water Soluble Vitamins
Vitamins can be defined as essential organic micronutrients that are involved in fundamental functions of the body, such as growth, maintenance of health and metabolism. Because of these substances must be supplied wholly or partially by the diet. Although the clinician should be able to recognize the syndrome caused by a lack of the vitamin in the case of a deficiency, it is more relevant in this country of abundant and varied food supply for the nutrition professional to think in terms of what a specific vitamin does rather than what disease it [prevents. Unfortunately, at the present time it is often impossible to relate directly the function of the vitamin to its deficiency syndrome.

Vitamins for the most part are not related chemically and differ in their physiologic roles. The broad classifications of water soluble vitamins and fat soluble vitamins are made because of certain properties common to each group. For instance, absorption and transport of fat soluble vitamins are closely associated with the absorption and transport of lipids; optimal absorption requires the presence of bile slats, these vitamins can also be stored in body lipids, although the amounts stored varies widely among the four fat soluble vitamins.

The water soluble vitamins are handled quite differently by the body. Their absorption requires no formation of micelles and with the exception of cyanocobalamin (vitamin B12), they cannot be retained by the body for long periods. Any storage occurring, results from their binding to enzymes and transport proteins. Water soluble vitamins are excreted in the urine wherever plasma levels exceed renal thresholds.
Fat Soluble and Water Soluble Vitamins

Vitamins in General

Vitamins in General
20th century marks the most exciting era in the history of nutrition science. It was during this time that the discovery of vitamins or “accessory growth factors,” began. Researchers found that for life and growth animals required something more than a chemically defined diet consisting of purified carbohydrate, protein, and aft, the essential mineral, and water.

The first of these dietary essentials discovered was and antiberiberi substance isolated from rice polishing by Funk, a Polish biochemist. Because the substance was an amine and necessary for life, Funk gave it the name vitamine. Very shortly thereafter McCollum and Davis extracted a factor from butter fat that they called fat soluble A to distinguish it from the water soluble antiberiberi substance. These two essential factors became known as vitamine A and vitamine B. As each additional vitamin was discovered, it was assigned a letter; the e on vitamine was dropped to give the general name vitamin because only a few of the essential substances were found to be amines.

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. 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.
Vitamins in General

Vitamin K and Its Role in Our Body

Vitamin K and Its Role in Our Body
Vitamin K denotes a group of lipophilic, hydrophobic vitamins that are needed for the posttranslational modification of certain proteins. Chemically they are 2-methyl-1,4-naphthoquinone derivatives.

Vitamin K is fat soluble. It is essential for the synthesis of prothrombin, a compound involved in the clotting of blood. Cabbage, spinach, cauliflower, and liver are especially good sources of vitamin K, although moderate amounts are found in many other vegetables, as well, as in cereals.

Although vitamin K is a fat-soluble vitamin, the body stores very little of it and its stores are rapidly depleted without regular dietary intake. Perhaps, because of its limited ability to store vitamin K, the body recycles it through a process called the vitamin K cycle. The vitamin K cycle allows a small amount of vitamin K to function in the gamma-carboxylation of proteins many times, decreasing the dietary requirement.

The significant symptom of vitamin K deficiency in humans and in animals is the loss of the ability of the blood to clot which is, of course, a dangerous condition that can result in death whenever bleeding from cuts occurs. It is believed that humans ordinarily receive adequate amounts of vitamin K in the diet.
Vitamin K and Its Role in Our Body