|  | Vitamin C
|
Jarrow Formulas  |
| |
| |
|
Carlson Laboratories Inc  |
| |
| |
|
Natural Factors  |
| |
| |
|
Nutrition Now  |
| |
| |
|
Nature's Way  |
| |
| |
|
All One  |
| |
| |
|
NOW Foods  |
| |
| |
|
Ultimate Nutrition  |
| |
| |
|
American Health  |
| |
| |
|
Childlife  |
| |
| |
|
Nature's Answer  |
| |
| |
|
Nutricology  |
| |
| |
|
Nutricology  |
| |
| |
|
Dynamic Health Laboratories  |
| |
| |
|
Avalon Organics  |
| |
| |
|
Avalon Organics  |
| |
| |
|
Avalon Organics  |
| |
| |
|
Avalon Organics  |
| |
| |
|
Jason Natural  |
| |
| |
|
DermaPro  |
| |
| |
Vitamin C (ascorbic acid)
Vitamin C, or ascorbic acid, has many vital functions within the body. It has a role in the metabolism of amino acids, most likely as a coenzyme. It facilitates the conversion of folic acid (folate) to its active form, folinic acid. Vitamin C also has a vital part in cellular respiration. But by far the most well-known role of vitamin C is its essentiality in the formation of collagen and other fibrous tissue. Collagen is the main supportive protein of skin, tendon, bone, teeth, cartilage, and connective tissue. The structural and functional integrity of capillary walls depends on vitamin C. Whenever tissue has to grow, develop, or repair itself after injury, a collagenous intracellular matrix must be set down to hold everything together. If vitamin C is not present in adequate quantities, this matrix is not set down, or it is incompletely constructed. A prolonged deficiency of the vitamin will deteriorate structures already present. So just about all the tissues in the body depend on vitamin C for proper growth, development, and maintenance.
Vitamin C is absorbed from the small intestine, circulated in the blood, and stored in the tissues. The adrenals, pituitary gland, thymus, and corpus luteum contain higher amounts than other tissue. Metabolically active tissue also contains higher than normal amounts.
Vitamin C concentrations are usually highest in the adrenal glands. When the organism is stressed in any way, vitamin C is mobilized from the glands, as well as from other tissues, and higher amounts of it appear in the urine. This is an indication that vitamin C plays an important role in the body's ability to withstand stress. Vitamin A-deficient rats lose the ability to synthesize vitamin C, and their adrenal glands malfunction. Vitamin C supplementation restores normal adrenal function, however. In humans, many of the symptoms of vitamin C deficiency (scurvy) are identical to those of adrenal insufficiency: fatigue, muscle weakness, digestive disorders, and reduced ability to tolerate stress.
Vitamin C is also an antioxidant, which means it helps protect cells and tissues from damaging oxidation. This fact alone could account for vitamin C's usefulness in the treatment of many diseases, since researchers are finding out more and more how really large a role oxidation plays in the disease process. Stimulation of muscle tissue raises the tissue requirements for vitamin C, because exercised muscle uses the vitamin at an increased rate. This may, in part, explain why vitamin C deficiency produces muscle weakness.
First, it's important to understand that the RDA for vitamin C is supposed to be the amount that will prevent the development of scurvy in normal people. By "scurvy," the scientists who set the standard mean the acute form. But many doctors and researchers feel that scurvy can occur with a more insidious development of symptoms, or that localized scurvy can occur in certain areas or tissues of the body, resulting in a whole range of possible disorders. There is enough evidence to convince several scientists and doctors that "chronic, latent scurvy is prevalent" in modern society. This means that vast numbers of people are not getting enough vitamin C to help build their resistance to diseases either as minor as bleeding gums and easy bruising, or as devastating as cancer and heart disease.
Many factors can contribute to a vitamin C deficiency or an increased need for the vitamin. For example, vitamin C deficiencies have been found in people who don't like "acid" foods. Smokers, as a rule, have lower tissue levels of vitamin C than nonsmokers. Smoking is known to directly deplete the vitamin C levels. This depletion could be one factor in smokers' higher death rate from cancer and heart disease.
Vitamin C levels are lower than normal in people with liver disease, a deficiency which can result in an increase in the toxicity of medications used to treat the disease. Hyperthyroid patients also tend to have lower than normal tissue levels of vitamin C.
Several medications can cause a vitamin C deficiency. Among them are: adrenal corticosteroids (which can actually induce scurvy symptoms); estrogen-containing medications such as oral contraceptives and menopausal medications; barbiturates; and tetracycline. Aspirin can increase urinary excretion of vitamin C by a factor of three.
Any condition which results in an increase in blood levels of copper can also increase the need for vitamin C. Many people are not aware that considerable copper can enter the body through water which is piped through copper plumbing. Apparently, vitamin C is involved in the detoxification of excess levels of copper.
Where is Vitamin-C found?
The richest natural sources of vitamin C are citrus fruits and their juices, strawberries, cantaloupes, raw vegetables-especially peppers, parsley, broccoli, cauliflower, kale, Brussels sprouts, turnip greens, cabbage, tomatoes, potatoes, and bean sprouts. Vitamin C levels in these items vary according to how they're grown, stored, and prepared. The amount of sunlight determines vitamin C content, more sunlight producing more of the vitamin. Furthermore, vitamin C is vulnerable to oxidation, so storage can expose it to considerable losses. Since the vitamin is water-soluble, steaming for prolonged periods, washing, soaking, and canning result in severe losses. Storage of citrus juice at warm temperatures results in almost total loss of vitamin C content.
Who is likely to be deficient of vitamin c?
Although scurvy (severe vitamin C deficiency) is uncommon in Western societies, many nutritionally oriented doctors believe that most people consume less than optimal amounts. Fatigue, easy bruising, and bleeding gums are early signs of vitamin C deficiency that occur long before frank scurvy develops. Smokers have low levels of vitamin C and require a higher daily intake to maintain normal vitamin C levels.
How much to take
Doctors of natural medicine often recommend 500 to 1,000 mg per day. Most research uses levels that do not exceed 1,000 mg per day. However, even greater levels (up to 10,000 mg per day) are not uncommon. In terms of heart disease prevention, as little as 100 to 200 mg of vitamin C might be adequate.
In contrast, current vitamin C researchers believe that 200 mg per day gets close to raising blood levels in healthy people about as high as they will go, and that supplementing more results in an excretion level almost identical to intake, meaning that more vitamin C does not stay in the body. This suggests that levels above 200 mg per day may prove to be superfluous for healthy people. The same kinds of studies that have ascertained that 200 mg is approximately correct for healthy people have not yet been done with sick individuals.
Side effects
Some individuals develop diarrhea after as little as a few thousand milligrams of vitamin C per day, while others are not bothered by ten times this amount. However, high levels of vitamin C can deplete the body of copper-an essential nutrient. People should be sure to maintain adequate copper intake at higher intakes of vitamin C. Copper is found in many multivitamin/mineral supplements. Vitamin C probably increases the absorption of iron, although this effect is mild. Vitamin C helps recycle the antioxidant vitamin E.
It has been suggested that people who form kidney stones should avoid vitamin C supplements because vitamin C can convert into oxalate and increase urinary oxalate. Initially, these concerns were questioned because the vitamin C converted to oxalate after urine had left the body. However, using newer methodology that rules out this problem, recent evidence shows that as little as 1 gram of vitamin C per day can increase the urinary oxalate levels in some people, even those without a history of kidney stones; In one case, 8 grams per day of vitamin C led to dramatic increases in urinary oxalate excretion and kidney stone crystal formation causing bloody urine. Until more is known, people with kidney stones or a history of stone formation should not take large amounts (1 gram per day) of supplemental vitamin C. Significantly lower amounts (100 to 200 mg per day) appear to be safe.
Copyright © VitaminDeal.com
|
*These statements about Vitamin C have not been evaluated by the Food and Drug Administration. Vitamin C is not intended to diagnose, treat, cure, or prevent any disease.
Recently Viewed Items
|
|
 |
|
Subscribe to VitaminDeal Weekly Promotions
|
|
Bookmark VitaminDeal.com and Share with Friends
The information provided on this site is for informational purposes only and is not meant to
substitute for advice provided by a healthcare professional. The information provided should not
be used for diagnosing, treating or prescribing medication for treatment of a disease or health-related condition.
You should carefully read all information provided in product packaging and follow the appropriate directions for use.
If you have or suspect that you have a medical problem, promptly contact your healthcare professional.
All models 18 years of age or older at the time of depiction.
Custodian of Records (18 U.S.C. 2257)
Copyright © 2002-2009 VitaminDeal.com. Designated trademarks and brands are the property of their
respective owners.
Questions? Comments? Please contact us.
VitaminDeal.com Privacy Policy
Tel: 1-626-363-9830 Toll Free: 1-877-332-5798
|
|
|
|
Vitamin C
| |
