Vitamin A and Carotenes

Vitamin A comes in 2 forms; Preformed vitamin A (essential but toxic in extreme amounts) and plant-form ("provitamin A") or Carotene (a safe, non-toxic form you may store up in great reserves and the body will convert to vitamin A as needed without any toxicity). There are dozens of different carotenes. Different carotenes have different benefits. Beta carotene is the most popular, however, studies indicate that a variety of different carotenes as found in green and yellow-orange plants work best as a team. These are a superior quencher of singlet free radicals (formed during exposure to radiation and during normal metabolism). In addition they are building blocks for your body's anti-tumor immune factors. They operate as communicators between cells to keep cells normalized and functioning properly and in unison. These carotenes and vitamin A also support a more vigorous production of several different disease-fighting cells. In studies, this has more than doubled the immune system's Candida kill rate, an especially important benefit for AIDS sufferers. Vitamin A and carotene have grabbed their share of headlines. "Miracle antioxidant", "The Immune Vitamin", "The Anti-infective Vitamin", "The Anti-wrinkle Vitamin", "Fountain of Youth for the Skin" and "The Anti-cancer Vitamin".

Vitamin A "The anti-wrinkle vitamin" is essential to the growth and repair of all body tissues. A lack of vitamin A is especially obvious as unhealthy skin (including acne and psoriasis) Vitamin A is critical to the health of the mucous membranes of the eyes, lungs, throat, nose, mouth, digestive tract, bladder, kidneys and reproductive systems. These membranes are often your first line of defense against invaders.

Vitamin A is also significant for reducing high cholesterol and production of hormones - important factors for quality and quantity of life.

Vitamin A is necessary to support strong digestion, the building and maintenance of bones and teeth, and for good eyesight, especially night vision - an important safety factor for driving at night. Plentiful vitamin A is required for healthy blood. Your body is creating millions of new blood cells as you read this. The creation of these and other cells requires RNA. Ribonucleic acid transmits the instructions of life within each cell. Vitamin A increases the rate at which new RNA is created, thus new cells can be created as fast or faster than old ones are being worn out or destroyed. When the replacement rate falls behind the needs, you age faster. When the replacement rate keeps up or surpasses the need, you age more slowly, perhaps heal old problems and even "de-age".

This is why carotene is so important. 5,000 iu (100% RDA) of vitamin A per day is a very safe level for everyone. Three or more times this amount can start leading to problems for some people. However, your body may require 20 times this amount when health is under attack. This huge gap should be filled safely with carotene. This way we can take enough to keep a safe and plentiful supply of vitamin A to put us together faster than we are falling apart. As benefits are most notable during wound healing, disease, pregnancy, after delivery and in older age. These nutrients are in especially critical demand in the body of a smoker.

Vitamin A/Carotene is considered to be a primary nutrient useful in virtually every nutritional strategy and supportive of optimal performance by any measure.

Vitamin A - Retinol

Vitamin A is actually a family of fat-soluble vitamins. Retinol is one of the most active, or usable, forms of vitamin A, and is found in animal foods such as liver and eggs. It can be converted to retinal and retinoic acid, other active forms of the vitamin A family. Some plant foods contain orange pigments called provitamin A carotenoids that the liver can convert to retinol. Beta-carotene is a provitamin A carotenoid found in many foods. Lycopene, lutein, and zeaxanthin are also carotenoids commonly found in food, but your body cannot convert them to vitamin A.

Vitamin A plays an important role in vision, bone growth, reproduction, cell division and differentiation. It maintains the surface linings of your eye and your respiratory, urinary, and intestinal tracts. When those linings break down, bacteria can enter your body and cause infection. The immune system helps prevent or fight off infections by making white blood cells that destroy harmful bacteria and viruses. Vitamin A may help lymphocytes, a type of white blood cell that fights infections, function more effectively. Vitamin A also may help prevent bacteria and viruses from entering your body by maintaining the integrity of skin and mucous membranes. Vitamin A is required for night vision, and for a healthy skin. It assists the immune system, and because of its antioxidant properties is great to protect against pollution and cancer formation and other diseases. It also assists your sense of taste as well as helping the digestive and urinary tract and many believe that it helps slow aging. It is required for development and maintenance of the epithelial cells, in the mucus membranes, and your skin, and is important in the formation of bone and teeth, storage of fat and the synthesis of protein and glycogen.

Although vitamin A is probably best known for promoting and maintaining healthy eyesight, it has other important functions as well. One of its major contributions is to improve the body's resistance to infection. It does this in part by maintaining the health of the skin, mucous membranes, and other surface linings (intestinal tract, urinary tract, respiratory tract) so that harmful bacteria and viruses can't get into your body. Another way that vitamin A boosts immunity is by enhancing the infection-fighting actions of the white blood cells called lymphocytes. Vitamin A is also vital to the growth of bones, the division of cells in your body, and to human reproduction.

Retinol, the most useful form of vitamin A, (along with retinal and retinoic acid) is a fat-soluble, antioxidant vitamin important in vision and bone growth. It is sometimes used in the treatment of severe acne. This is a compound synthesized from isoprene. Another form of retinol is retinyl palmitate. Retinyl palmitate is a more stable version of retinol, however, because the skin has to further break down retinyl palmitate, much higher concentrations are required to provide the similar benefits. When choosing between the two, it is better to go with the formula containing retinol rather than retinyl palmitate. Retinol is the immediate precursor to two important active metabolites: retinal, which plays a critical role in vision, and retinoic acid, which serves as an intracellular messenger that affects transcription of a number of genes. Retinol is one of the most active, or usable, forms of vitamin A, and is found in animal foods such as liver and eggs. Retinol is often called preformed vitamin A and can be toxic. This condition, called hypervitaminosis A can cause birth defects, liver abnormalities, and reduced bone mineral density that may result in osteoporosis. When toxic symptoms arise suddenly, which can happen after consuming very large amounts of preformed vitamin A over a short period of time, signs of toxicity include nausea and vomiting, headache, dizziness, blurred vision, and muscular uncoordination. For this reason, it is important to check your multivitamins to make sure that the source of vitamin A is not retinol or palmitate. All vitamin supplement products that contain any form of vitamin A must list vitamin A as the main ingredient on the label, even if it is all in the form of beta carotene, so do not be alarmed. Some multivitamins like Cooper Complete have labels that list the ingredient as "Vitamin A (as natural mixed carotenoids)". In such cases, you will have no need to worry. However, in some cases you may have to look at the "other ingredient" section of the label to determine what the product includes.

Beta-carotene is the molecule that gives carrots their orange colour. It is part of a family of chemicals called the carotenoids, which are found in many fruit and vegetables, as well as some animal products such as egg yolks. Beta carotene, as well as the other members of the carotenoid family, are precursors to vitamin A, meaning that they are transformed into the vitamin after entering the body. The metabolism of beta carotene is much different than that of retinol because the body can convert it into as much or as little of vitamin A as it needs. For this reason, you cannot ingest toxic levels of beta carotene. However, eating high levels of it may actually turn your skin an orange color! This provitamin A has been linked to a lower risk of cataracts, heart disease, and cancers, such as rectal cancer, melanoma, and bladder cancer. As a potent immune-system booster and a powerful antioxidant--it counters the effects of cell-damaging molecules called free-radicals--beta-carotene has an important role to play in human health. In addition to the numerous studies on beta-carotene's effectiveness for heart disease and cancer, researchers have been exploring the nutrient's potential for treating chronic fatigue syndrome, Alzheimer's disease, fibromyalgia, male infertility, and psoriasis. Interestingly, low levels of beta-carotene and other antioxidants have been linked to the development of cataracts, a clouding of the eye's lens that impairs vision.

Beta-carotene

Beta-carotene is a substance from plants that the body converts into vitamin A. It also acts as an antioxidant and an immune system booster. Beta carotene has two roles in the body. It can be converted into vitamin A (retinol) if the body needs more vitamin A. If the body has enough vitamin A, instead of being converted, beta carotene acts as an antioxidant which protects cells from damage caused by harmful free radicals. Other members of the antioxidant carotenoid family include cryptoxanthin, alpha-carotene, zeaxanthin, lutein, and lycopene. However, unlike beta-carotene, most of these nutrients are not converted to vitamin A in significant amounts.

Most beta-carotene in supplements is synthetic, consisting of only one molecule called all trans beta-carotene. Natural beta-carotene, found in food, is made of two molecules—all trans beta-carotene and 9-cis beta-carotene. Much of natural beta-carotene is in the all trans molecule form—the same as synthetic beta-carotene. Moreover, much of the 9-cis molecule found only in natural beta-carotene is converted to the synthetic molecule before it reaches the bloodstream. Also, absorption of 9-cis beta-carotene appears to be poor, though some researchers question this finding.

Despite the overlap between natural and synthetic forms, natural beta-carotene may possibly have activity that is distinct from the synthetic form. For example, studies in both animals and humans have shown that the natural form has antioxidant activity that the synthetic form lacks. Also, in one trial, pre-cancerous changes in people reverted to normal tissue with natural beta-carotene supplements, but not with synthetic supplements. Israeli researchers have investigated whether the special antioxidant effects of natural beta-carotene might help people suffering from asthma attacks triggered by exercise. People with asthma triggered by exercise were given 64 mg per day of natural beta-carotene for one week. In that report, 20 of 38 patients receiving natural beta-carotene were protected against exercise-induced asthma. However, because synthetic beta-carotene was not tested, the difference between the activity of the two supplements cannot be deduced from this report. Current research indicates that a diet rich in foods containing beta-carotene may reduce the risk of developing certain types of cancer and offers protect against heart disease. Beta-carotene offers protection against other diseases as well as some degenerative aspects of aging.

Beta-carotene is part of a large family of compounds known as carotenoids (which includes over 600 members such as lycopene and lutein). Carotenoids are widely distributed in fruits and vegetables and are responsible, along with flavonoids, for contributing the color to many plants (a rule of thumb is the brighter, the better). In terms of nutrition, beta-carotene’s primary role is as a precursor to vitamin A (the body can convert beta-carotene into vitamin A as it is needed). It is important to note that beta-carotene and vitamin A are often described in the same breath – almost as if they were the same compound (which they are not). Although beta-carotene can be converted to vitamin A in the body, there are important differences in terms of action and safety between the two compounds. Beta-carotene. like most carotenoids, is also a powerful antioxidant – so it has been recommended to protect against a variety of diseases such as cancer, cataracts and heart disease. The best food sources are brightly colored fruits and veggies such as cantaloupe, apricots, carrots (duh!), red peppers, sweet potatoes and dark leafy greens.

Orange yellow powder or reddish brown liquid. It can be added into food or medicine as yellow of orange yellow pigment.

Vitamin A Palmitate

Vitamin A Palmitate (retinyl palmitate, all-trans-retinyl palmitate) is known as a skin "normalizer." It acts as an antikeratinizing agent, helping the skin stay soft and plump. Clinical studies with vitamin A palmitate indicate a significant change in skin composition with increase in collagen, DNA, skin thickness, and elasticity. Vitamin A palmitate's stability is superior to retinol. Vitamin A palmitate is the preferred form of vitamin A because it is possible that RP patients may have problems converting beta carotene into vitamin A.

The activity of vitamin a palmitate in skin may depend on its conversion to retinoic acid. This conversion depends on the enzymatic cleavage of the ester bond in retinul palmitate, and on the skin's ability to ozidse retinol to retinoic acid. Non-specific esterase enzyme activity exists within the skin and it has been demonstrated that skin preparations can convert retinol to retinoic acid.

Retinyl palmitate is the easiest retinoids to formulate topically in the over-the-counter moisturizers. Topical application of retinyl palmitate is a pragmatic strategy for loading the skin with retinol (vitamin A). Cosmetic formulations containing retinyl palmitate are substantially more stable than those containing retinol. Furthermore, retinyl palmitate readily penetrates into the epidermis and dermis. In vitro measurements of retinyl palmitate’s percutaneous absorption indicate that 18% of retinyl palmitate, topically applied in acetone, penetrates human skin within 30 hrs. Percutaneous absorption of retinyl palmitate in currently marketed cosmetic products may be still greater due to the considerable efforts of cosmetics formulators to maximize the effectiveness of products containing retinyl palmitate and retinol. Studies indicate that absorbed retinyl palmitate is readily hydrolyzed to retinol by cutaneous esterases. In addition, skin contains the enzymes required for further metabolism of retinol to retinaldehyde and retinoic acid, and some studies have shown that levels of retinoic acid in the skin can increase following topical application of retinyl palmitate or retinol.

Molecular Formula: C₃₆H₆₀O₂

Vitamin A Acetate

Light yellow, fine granular powder. Individual particles contain all-trans-Vitamin A Acetate finely dispersed in a starch coated matrix of gelatin, sucrose and corn starch. BHT is added as an antioxidant.

Molecular formula: C₂₂H₃₂O₂

Vitamin A produces astonishing leukemia cure rate, even without chemotherapy

New research conducted at the University of Texas M. D. Anderson Cancer Center shows that vitamin A cures as many as 33% of patients with a rare form of leukemia -- without using chemotherapy. In the study, the vitamin A was being delivered inside "bubbles of fat" to enhance bioavailability. Out of 34 patients participating in the trial, an astonishing 10 remained cancer-free after five years, despite receiving no chemotherapy.

So what's the real story here? Researchers are calling this form of vitamin A a "drug," which seems odd, since it's just vitamin A. Perhaps they don't want to admit that a vitamin is better than chemotherapy for curing cancer. And this is definitely a cure -- that term is even being used by the researchers here. To take a group of cancer patients and watch them remain cancer-free for five years is nothing short of astonishing, especially since they were only taking one vitamin. Imagine how well they'd do if they also consumed chlorella (a strong anti-cancer superfood), spirulina (another superfood containing phytochemicals known to destroy breast cancer tumors), graviola (an Amazonian herb known for its powerful ability to destroy cancer cells), licorice root (a more popular anti-cancer herb) and other health-promoting foods and supplements. With the help of this collection of health-promoting substances, the cure rate could have easily risen to 75% or more.

Still, that's just a guess. Organized medicine isn't really interested in studying things that don't generate profits, and herbs and superfoods certainly fall into that category. But it is exciting to see vitamin A having such a dramatic, positive impact on patients with leukemia who might otherwise be subjected to chemotherapy. And perhaps someday these researchers will have the courage to admit that it's a vitamin, not a drug, that's working the healing magic here.

Overview:

A biological agent -- a drug that wraps vitamin A inside bubbles of fat -- used without chemotherapy appears to offer as many as one-third of patients with a rare form of leukemia an opportunity for a long-term, disease-free future, say researchers at The University of Texas M. D. Anderson Cancer Center.

Researchers say the findings, presented at the annual meeting of the American Society of Clinical Oncology, provide the proof that biologic drugs can work in patients with acute promyelocytic leukemia (APL), and opens the door to development of such agents for more common forms of leukemia.

"This is the first time we have seen patients with an acute leukemia potentially cured without use of chemotherapy," says the study principal investigator, Elihu Estey, M.D., a professor in the Department of Leukemia.

Source: http://www.news-medical.net/view_article.asp?id=2248