Vitamin E

VITAMINS

INTRODUCTION:

Here are some key points about vitamins.

•    There are 13 known vitamins.
•      Vitamins are either water-soluble or fat-soluble.
•     Fat-soluble vitamins are easier for the body to store than water-soluble.
•      Vitamins always contain carbon, so they are described as "organic.

VITAMIN E:

INTRODUCTION:

·         Vitamin E is found naturally in some foods, added to others, and available as a dietary supplement. “Vitamin E” is the collective name for a group of fat-soluble compounds with distinctive antioxidant activities .

·         Naturally occurring vitamin E exists in eight chemical forms (alpha-, beta-, gamma-, and delta-tocopherol and alpha-, beta-, gamma-, and delta-tocotrienol) that have varying levels of biological activity . Alpha- (or α-) tocopherol is the only form that is recognized to meet human requirement.

SUBTYPES OF VITAMIN E :

The term vitamin E describes a family of eight fat-soluble molecules with antioxidant activities: four tocopherol isoforms (α-, β-, γ-, and δ-tocopherol) and four tocotrienol isoforms (α-, β-, γ-, and δ-tocotrienol) . Only one form, α-tocopherol, meets human vitamin E requirements . In the human liver, α-tocopherol is the form of vitamin E that is preferentially bound to α-tocopherol transfer protein (α-TTP) and incorporated into lipoproteins that transport α-tocopherol in the blood for delivery to extrahepatic tissues. Therefore, it is the predominant form of vitamin E found in the blood and tissues . In addition, α-tocopherol appears to be the form of vitamin E with the greatest nutritional significance, such that it will be the primary topic of the following discussion.

CHEMICAL NAME OF VITAMIN E :

TOCOPHEROL AND TOCOTRIENOL.

STRUCTURE OF VITAMIN E AND SUBTYPES:

DIETARY SOURCES OF VITAMIN E :                

Vitamin E is also found naturally in such foods as:

·         vegetable oils such as sunflower, safflower, canola, and olive;

·         seeds and nuts such as sunflower seeds, almonds, hazelnuts, and peanuts;

·         wheat germ.

·         some green leafy vegetables, although it is present in small amounts.

RECOMmenDEDINTAKE :

The recommended dietary allowance (RDA) for vitamin E is 15 milligrams (or 22.4 International Units, or IU) for people over age 14, according to the National Institutes of Health (NIH). Women who are breastfeeding may need a little more vitamin E, so the RDA for lactating women is 19 mg (28.4 IU). Doses below 1,000 mg (1,500 IU) seem to be safe for most adults.

For infants up to age 6 months, the RDA is 4 mg (6 IU), and the RDA is 5 mg (7.5 IU) for ages 6 month to one year. From ages 1 to 3 years old, 4 to 8 years old and 9 to 13 years old, the RDAs for vitamin E are 6 mg (9 IU), 7 mg (10.4 IU) and 11 mg (16.4 IU), respectively, according to the NIH.

Recommended Dietary Allowances (RDAs) for Vitamin E (Alpha-Tocopherol)
Age	Males	Females	Pregnancy	Lactation
0–6 months*	4 mg (6 IU)	4 mg (6 IU)
7–12 months*	5 mg (7.5 IU)	5 mg (7.5 IU)
1–3 years	6 mg (9 IU)	6 mg (9 IU)
4–8 years	7 mg (10.4 IU)	7 mg (10.4 IU)
9–13 years	11 mg (16.4 IU)	11 mg (16.4 IU)
14+ years	15 mg (22.4 IU)	15 mg (22.4 IU)	15 mg (22.4 IU)	19 mg (28.4 IU)

PHYSIOLOGICAL ROLE OF VITAMIN E :

Following are the main biological role of vitamin E;

·         Including sources of vitamin E in your diet brings many benefits.

·         As a fat-soluble nutrient, vitamin E functions mainly as an antioxidant, which means it helps protect cells from damage caused by unstable molecules called free radicals.

·         "It protects cells from damage, and it might aid in lowering [the risk of] a variety of health problems, from heart disease to cancer, and possibly even dementia," Somer told Live Science.

·         In addition to providing cell protection, vitamin E is vital to a functioning immune system. As a powerful antioxidant, it helps cells fight off infection.

·         This vitamin also helps protect eyesight. A 2015 study by the Department of Epidemiology and Health Statistics of the Qingdao University Medical College found that vitamin E intake and high serum-tocopherol levels were linked to a decreased risk of age-related cataracts.

·         Vitamin E plays an important role in the production of hormone-like substances called prostaglandins, which are responsible for regulating a variety of body processes, such as blood pressure and muscle contraction. Also, a 2015 study published by the U.S. National Library of Medicine found that vitamin E aids in muscle repair after exercise.

·         People with Crohn's disease, cystic fibrosis or an inability to secrete bile from the liver into the digestive tract may need to take water-soluble, supplemental forms of vitamin E to avoid digestive problems, according to the NIH.

THE EMERGING BENEFITS OF VITAMIN E:

MECHANISM OF ACTION OF VITAMIN E IN BODY:

·       AS PREVENTING OSTEOCLASTOGENESIS;

Mechanism of action of vitamin E in preventing osteoclastogenesis. Vitamin E affects osteoclastogenesis via three distinct mechanisms. Firstly, it inhibits COX-2 activity and subsequently PGE2 level. It also decreases IL-1 level and thus preventing IL-1-mediated RANKL expression. Secondly, vitamin E induces upregulation in antioxidant enzymes in bone and acts as a free radical scavenger itself, thus abolishing ROS-mediated RANKL signaling. Lastly, vitamin E also abrogates downstream signaling pathways leading to osteoclastogenesis even with or without affecting the expression level of signaling molecules.

·       ANTIOXIDANT ACTIVITY OF ALPHA-TOCOPHEROL;

Alpha-tocopherol’s main role inside the body is to act as an antioxidant. Alpha-tocopherol is lipid-soluble, so it mostly exerts its antioxidant effects on parts of the cell that are also lipid-soluble, such as the cell membrane, an important part of the cell that is made of lipids. Because cell membranes are made of lipid molecules, they are vulnerable to oxidation by free radicals, which can lead to cell death. Alpha-tocopherol plays a very big role in protecting cell membranes by donating its own electrons to free radicals in order to neutralize them. Although alpha-tocopherol loses its antioxidant activity once it donates an electron, other antioxidants like vitamin C can restore alpha-tocopherol’s antioxidant properties.

·       ALPHA TOCOTRIENOL INHIBITS 12-LOX;

The same researchers found that alpha-tocotrienol not only protects nerve cells by reacting with free radicals directly, but can also prevent free radicals from forming. Alpha-tocotrienol can prevent excessive oxidative damage by inhibiting an enzyme called 12-lipoxygenase (12-LOX), an effect independent of its antioxidant properties. Increased levels of glutamate around the nerve cells cause activation of 12-LOX within the cells, which when activated leads to a cascade of events that lead to production of free radicals and an influx of calcium ions into the nerve cells. These events eventually lead to nerve cell death. Alpha-tocotrienol inhibits 12-LOX from setting off this cascade by binding to it close to its active site. The active site is the spot where an enzyme would normally bind to other molecules, or substrates, in order to set off a reaction in the cell. 12-LOX normally binds to a molecule called arachidonic acid to set off the above-mentioned cascade of events. By binding close to the active site, alpha-tocotrienol prevents 12-LOX from binding arachidonic acid and setting off the reactions that would eventually lead to nerve cell death.

DEFICIENCY DISORDERS:

REASON FOR DEFICIENCY:

Vitamin E deficiency can be the result of an underlying condition. Many conditions prevent your body from being able to adequately absorb fats, including fat-soluble nutrients like vitamin E.

This includes:

•          chronic pancreatitis
•         cholestasis
•          cystic fibrosis
•          primary biliary cirrhosis
•          Crohn’s disease
•          short bowel syndrome

In some cases, vitamin E deficiency results from a rare genetic condition known as ataxia. This condition is neurologically based and affects muscle control and coordination. It’s most likely to develop in children between the ages of 5 and 15.

SYMPTOMS OF DISORDER:

Following are the vitamin e deficiency symptoms:

•          difficulty with walking or coordination
•          muscle pain or weakness
•          visual disturbances
•          general unwellness

TREATMENT:

Supplements may cause complications, so it’s best to eat a healthy diet that includes many foods rich in vitamin E.

DIET:

You can find vitamin E in a wide range of foods. These include:

•     nuts and seeds, such as almonds, sunflower seeds, peanuts, and              peanut butter
•    whole grains
•     vegetable-based oils, especially olive and sunflower
•     leafy vegetables
•      egg

SUPPLEMENTATION :

Some of the medications that may be affected include:

•         anticoagulants
•          antiplatelets
•          simvastatin
•         niacin
•          chemotherapy drugs
•          radiotherapy drugs

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