Vitamin C

Deficiency and toxicity: For most purposes, vitamin C, or ascorbic acid, in its many forms of use is nontoxic. It is not stored appreciably in our body, and most excess amounts are eliminated rapidly through the urine. However, amounts over 10 grams per day that some people use and some doctors prescribe are associated with some side effects, though none that are serious. Diarrhea is the most common and usually is the first sign that the body's tissue fluids have been saturated with ascorbic acid. Most people will not experience this with under 5–10 grams per day, the amount that is felt to correlate with the body's need and use. Other side effects include nausea, dysuria (burning with urination), and skin sensitivities (sometimes sensitivity to touch or just a mild irritation). Hemolysis (breakage) of red blood cells may also occur with very high amounts of vitamin C. With any of these symptoms, it is wise to decrease intake.

There is some concern that higher levels of vitamin C intake may cause kidney stones, specifically calcium oxalate stones, because of increased oxalic acid clearance through the kidneys due to vitamin C metabolism. This is a rare case, if it does exist, and I personally have not seen, nor do I know any doctors who have seen, kidney stone occurrence with people taking vitamin C. Only people who are prone to form kidney stones or gout should give this any thought. If there is concern, supplementing magnesium in amounts between half and equaling that of calcium intake (which should be done anyway with calcium supplementation) would reduce that risk, at least for calcium-based stones. I usually suggest using a buffered vitamin C preparation with calcium and magnesium, which alleviates this concern.

As far as deficiency problems go, the once fairly common disease called scurvy is very rare these days. However, early symptoms of scurvy or vitamin C deficiency are more likely in formula-fed infants with little or no C intake or in teenagers or the elderly who do not eat any fresh fruits and vegetables. Smokers with poor diets and people with inflammatory bowel disease more often have lower vitamin C blood levels. Other people commonly found to be low in ascorbic acid include alcoholics, psychiatric patients, and patients with fatigue.

The symptoms of scurvy are produced primarily by the effects of the lack of ascorbic acid on collagen formation, causing reduced health of the tissues. The first signs of depletion may be related to vitamin C's other functions as well, where deficiency could lead to poor resistance to infection and very slow wound healing. Easy bruising and tiny hemorrhages, called petechiae, in the skin, general weakness, loss of appetite, and poor digestion may also occur. With worse deficiency, nosebleeds, sore and bleeding gums, anemia, joint tenderness and swelling, mouth ulcers, loose teeth, and shortness of breath could be experienced. During growth periods, there could be reduced growth, especially of the bones. The decrease in collagen may lead to bone brittleness, making the bones more fragile. The progression and health of the teeth and gums are also affected. In breastfeeding women, lactation may be reduced. With the elderly, vitamin C deficiency could enhance symptoms of senility. The bleeding that comes from capillary wall fragility may lead to clotting and increased risk of strokes and heart attacks.

An important note is that many medical problems have been found to be associated with low blood levels of vitamin C. These problems include various infections, colds, depression, high blood pressure, arthritis, vascular fragility, allergies, ulcers, and cholesterol gallstones.

Most of these symptoms and problems can be easily avoided with minimal supplementation of vitamin C or a diet well supplied with fresh fruits and vegetables. Since the average diet has much less vitamin C than that of our ancestors, it is important for us to be aware of our ascorbic acid intake.

Requirements: The RDA for adults is considered to be 60 mg. We need only about 10–20 mg. to prevent scurvy, and there is more than that in one portion of most fruits or vegetables. Infants need 35 mg.; about 50 mg. between ages one and fourteen and 60 mg. afterward are the suggested minimums. During pregnancy, 80 mg. are required; 100 mg. are needed during lactation. Realistically, between 100–150 mg. daily is a minimum dosage for most people.

Vitamin C needs, however, are increased with all kinds of stress, both internal (emotional) and external (environmental). Smoking decreases vitamin C levels and increases minimum needs. Birth control pills, estrogen for menopause, cortisone use, and aspirin also increase ascorbic acid requirements. Both nicotine and estrogen seem to increase copper blood levels, and copper inactivates vitamin C. In general, though, absorption of vitamin C from the intestines is good. Vitamin C (as ascorbic acid) taken with iron helps the absorption of iron (and many minerals) and is important in treating anemia, but the iron decreases absorption of the ascorbic acid. Overall, it is probably best to take vitamin C as it is found in nature, along with the vitamin P constituents (discovered later)—the bioflavonoids, rutin, and hesperidin. These may have a synergistic influence on the functions of vitamin C, although there is no conclusive research on humans to support this theory.

Vitamin C is the most commonly consumed nutrient supplement and is available in tablets, both fast-acting and time-released, in chewable tablets, in powders and effervescents, and in liquid form. It is available as ascorbic acid, L-ascorbic acid, and various mineral ascorbate salts, such as sodium or calcium ascorbate. One of my favorite formulas, which was developed by Stephen Levine at Nutricology in San Leandro, California, is a buffered powder made from sago palm that contains 2,350 mg. of vitamin C per teaspoon, along with 450 mg. of calcium, 250 mg. of magnesium, and 99 mg. of potassium. It gets into the body quickly and is very easy on and often soothing to the stomach and intestinal lining. The potassium-magnesium combination can often be helpful for fatigue, and this formula is a good vehicle for fulfilling calcium needs.

Vitamin C works rapidly, so the total amount we take over the day should be divided into multiple doses (four to six) or taken as a time-released tablet a couple of times a day. When increasing or decreasing vitamin C intake, it is best to do so slowly because our body systems become accustomed to certain levels. Some nutritionists describe a problem of rebound scurvy in infants, especially when a high amount is taken by the mother during pregnancy but then the infant gets very little after birth and so suffers some deficiency symptoms. I have seen nothing confirming this in the literature. Overall, though, it is probably wise to reduce vitamin C intake slowly after taking high amounts, rather than to drop abruptly.

My basic suggestion for vitamin C use is about 2–4 grams per day with a typical active and healthy city lifestyle. Based on previous levels in our native diets, Linus Pauling feels that the optimum daily levels of vitamin C are between 2,500 and 10,000 mg. Clearly, requirements for vitamin C vary and may be higher according to state of health, age (needs increase with years), weight, activity and energy levels, and general metabolism. Stress, illness, and injuries further increase the requirements for ascorbic acid. Many authorities suggest that we take at least 500 mg. of vitamin C daily to meet basic body needs.

During times of specific illnesses, especially viral infections, doctors who use megadose vitamin C treatment suggest at least 20–40 grams daily, some of it intravenously. Vitamin C has been used safely and effectively in dosages of 10 grams or more dripped slowly (over 30–60 minutes) into the blood to reach optimum tissue levels before excretion, so as to bathe the cells in vitamin C. Some doctors prescribe what is called "bowel tolerance" daily intake of vitamin C—that is, increasing the oral dose until diarrhea results and then cutting back. This level can vary greatly from a few grams to 100 grams or more. The claim is that our body knows what we need and will respond by changing the water balance in the colon when we have had enough. Physician Robert Cathcart has used vitamin C this way in his practice for years to treat many problems, with claimed good success; yet, I do not have the experience to make an adequate conclusion. This practice does, however, add further mystery to the vitamin C controversy. More research is definitely needed regarding ascorbic acid, and new discoveries will likely be made.

Staying Healthy With Nutrition
© Elson M. Haas, M.D.

Source: http://www.healthy.net/

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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 drugs used to treat the disease. Hyperthyroid patients also tend to have lower than normal tissue levels of vitamin C.

Several drugs can cause a vitamin C deficiency. Among them are: adrenal corticosteroids (which can actually induce scurvy symptoms); estrogen-containing drugs such as oral contraceptives and menopausal drugs; 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.

Vitamin C is available in supplemental form in a wide range of doses, from a few milligrams to more than one gram (1000 mg.). Vitamin C tablets advertised as "natural" or "rose hips" or "acerola" should be carefully examined before purchase. These forms of vitamin C are usually composed of some synthetic vitamin C with the addition of small quantities of acerola berry or rose hips. There's nothing wrong with "synthetic" vitamin C. It's produced by the fermentation of glucose, basically the same way it's produced in nature. However, "natural" vitamin C tablets are often sold for many times the price of the same strength tablet labeled plainly "ascorbic acid." Vitamin C is also available as sodium ascorbate.

Vitamin C is also available in pure powdered form, which is by far the least expensive way to obtain the vitamin.

Where is it 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 ?

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.

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