 L-Ascorbic Acid Powder -
powdered Vitamin C
99+% purity with Certificate of Analysis
Vitamin C is a life enhancer that must be renewed every day. Its most well known effect is to stimulate immune function and protect patients from colds and flu-like symptoms. Other important properties of the vitamin are: (1) as an antioxidant - this is to protect tissues from tissue damage caused by free radicals; (2) to help the body repair damaged tissues or heal, promoting wound healing and is essential in the formation of collagen to protect against blood clotting and bruising. Vitamin C also acts as an antihistamine so it can be helpful for allergic-type problems, and helps to lower cholesterol. For its antioxidant effect and immune-stimulating function, Vitamin C has been found to protect against the harmful effects of pollution, prevents cancer and protects against infection.
40,000 mg. unit, $14.95 - DE 0005
Research Articles on L-Ascorbic Acid:
American diets may lack Vitamin C
Vitamin C is also known as ascorbic acid
How Safe Is Vitamin C?
Q & A With Dr. Andrew Weil
Carcinogenesis Bioassay of L-Ascorbic Acid
Vitamin C is also known as ascorbic acid, L-Ascorbic acid, dehydroascorbic acid and the antiscorbutic vitamin
Chemically, it is called L-xyloascorbic acid and L-threo-hex-2-uronic acid g-lactone. The very highest concentrations of vitamin C are found in the adrenal and pituitary gland. High levels are also found in liver, leukocytes, brain, kidney and pancreas. Most of the vitamin C is found in liver and skeletal muscle because of their relative size to the rest of the body. The best characterized function is the synthesis of collagen connective tissue protein at the level of hydroxylation of prolyl and lysyl residues of procollagen.
Vitamin C also plays important roles in the synthesis of neurotransmitters, steroid hormones, carnitine, conversion of cholesterol to bile acids, tyrosine degradation and metal ion metabolism. This vitamin also may enhance iron bioavailability. The role of ascorbic acid as a biological reducing agent may be linked to its prevention of degenerative diseases, such as cancer and cardiovascular diseases. Deficiencies: Severe ascorbic acid deficiency results in clinical scurvy which is characterized by swollen, bleeding gums, loosening of the teeth, capillary hemorrhaging, including bleeding into joints, tender and painful extremities, poor wound healing, weakness and fatigue, and psychological disturbances. Clinical uses: The only established use of vitamin C is in the prevention and treatment of scurvy. Studies investigating possible effects on wound healing, blood pressure, colds and immune function have often employed other antioxidants in addition to ascorbic acid and, in most cases, the results have been unremarkable, conflicting or inconsistent.
Diet recommendations: The Recommended Dietary Allowance (RDA) for adults is 60 mg/day in the US, but may range from 30-75 mg/day in other Western countries. Intakes of 75-95 mg/day are recommended for pregnant and lactating women. The RDA is 35 mg/day in infants and 40 mg/day in children, ages 1-3. About 10 mg/day is required to prevent scurvy.
Increased intake of vitamin C is recommended for stress situations such as trauma, infection, strenuous exercise, or elevated environmental temperatures. The requirement in smokers may be 100 mg/day.
Food sources: The best food sources of vitamin C are citrus fruits, berries, melons, tomatoes, potatoes, green peppers and leafy green vegetables. Vitamin C is sensitive to air, heat and water, so it can easily be destroyed by prolonged storage, overcooking and processing of foods.
Toxicity: Megadoses of vitamin C of 1000-2000 mg have commonly been associated with gastrointestinal disturbances (nausea, abdominal cramps and diarrhea). In general, Megadoses of vitamin C should be avoided in individuals with a history of renal stones due to oxalate formation or hemochromatosis or other diseases related to excessive iron accumulation. Excess vitamin C may predispose premature infants to hemolytic anemia due to the fragility of their red blood cells. In healthy individuals, it appears that Megadoses of vitamin C are well tolerated and not associated with any consistent adverse effects.
Recent research: Work continues to develop and define a useful function test for vitamin C status, such as activities of certain enzymes, white cell viability, or perhaps a test related to the immune response. Investigations continue into developing a better understanding of the role of vitamin C beyond preventing vitamin C deficiency. Some examples are establishing optimal or pharmacological uses of the vitamin and discerning its role as an antioxidant/pro-oxidant in human biology. Clinical studies also continue to define the role of vitamin C in cancer and in treating other human diseases.
Reviews: Gershoff, S.N. (1993) Vitamin C (ascorbic acid): new roles, new requirements? Nutr. Rev. 51: 313-326 Diplock, A.T. (1995) Safety of antioxidant vitamins and b-carotene. Am. J. Clin. Nutr. 62: 1510S-1516S.
TR-247 Carcinogenesis Bioassay of L-Ascorbic Acid (Vitamin C) (CAS No. 50-81-7) in F344/N Rats and B6C3F1 Mice (Feed Study) Chemical Formula: C6H8O6 - 3D Structure
L-Ascorbic acid is essential for many physiologic functions in animals and humans, mostly biochemical reactions involving oxidation. L-Ascorbic acid is approved for use as a dietary supplement and chemical preservative by the US Food and Drug Administration and is on the FDA's list of substances generally recognized as safe. L-Ascorbic acid may be used in soft drinks as an antioxidant for flavor ingredients, in meat and meat-containing products, for curing and pickling, in flour to improve baking quality, in beer as a stabilizer, in fats and oils as an antioxidant, and in a wide variety of foods for vitamin C enrichment. L-Ascorbic acid may also find use in stain removers, hair waving preparations; plastics manufacture, photography, and water treatment.
A carcinogenesis bioassay of L-Ascorbic acid (>97% pure) was conducted by administering diets containing 25,000 or 50,000 ppm L-Ascorbic acid to groups of 50 F344/N rats and 50 B6C3F1 mice of each sex for 103 weeks. Controls consisted of 50 untreated rats and untreated mice of each sex. Fifty-thousand ppm is the highest dose recommended for chronic studies. Survival of dosed and control female rats and of dosed and control female mice were comparable. Survival of high-dose male rats was slightly greater than that of the controls (P=0.087). Survival of high-dose male mice was significantly greater (P=0.009) than that of the controls.
Throughout most of the study, mean body weights of dosed female rats and dosed female mice were lower than those of the controls. Final body weights were comparable among groups, except for the high-dose female rats (<13%); marginal differences (<8%) were observed for low-dose female rats and for dosed female mice (8%-11%). Food consumption was equivalent among groups. Most observational differences were confined to the female rat. The incidence of low-dose female rats with undifferentiated (mononuclear-cell) leukemia's (control, 6/50, 12%; low-dose, 17/50, 34%; high-dose, 12/50, 24%) was significantly higher (P<0.02) than that in controls. These tumors were not considered to be related to administration of L-Ascorbic acid because they did not occur in the female high-dose group at incidences significantly greater (P>0.07) than those in the controls, the trend test was not significant (P>0.07), and no increases were observed for male rats. Under the conditions of this bioassay, L-Ascorbic acid was not carcinogenic for male and female F344/N rats or male and female B6C3F1 mice.
Synonym: vitamin C Report Date: March 1983 Target Organs & Incidences from 2-year Studies Levels of Evidence of Carcinogenicity: Male Rats: Negative Female Rats: Negative Male Mice: Negative Female Mice: Negative NTIS# PB83-201194
American diets may lack Vitamin C
By Ann Quigley
NEW YORK, Aug 17 (Reuters) -- Arizona State University researchers found '`surprisingly high rates'' of vitamin C deficiency in a group of American middle class patients attending a healthcare facility for routine health exams. Blood tests showed that 30% of 494 study participants were vitamin C depleted, and 6.3% suffered from the more severe condition, vitamin C deficiency, according to a report published in the Journal of the American College of Nutrition.
``If a physician examined these (vitamin C deficient) people,'' lead author Dr. Carol Johnston, told Reuters Health, ''it is very likely they would have found some of the early indications of scurvy.'' Scurvy, a disease caused by vitamin C deficiency, is thought to be rare in modern societies with year-round access to fresh fruits and vegetables. The early symptoms of scurvy include tiredness, weakness, irritability, weight loss, and vague muscle aches.
Although the researchers did not obtain dietary data on the study subjects, those who were vitamin C deficient and vitamin C depleted were probably not eating enough fruits and vegetables that are high in vitamin C, said Johnston. Fresh produce with high levels of the vitamin include oranges, grapefruits, broccoli, cauliflower, and cabbage.
``If you are just eating apples, bananas, green beans and lettuce, that's not going to do it,'' said Johnston. ``They are the most commonly consumed and they literally have no vitamin C. Potatoes have a little bit. I think french fries are probably keeping people over the edge of having a problem.''
In their report, the researchers also note that the ``poor vitamin C status of some of our subjects may be related in part to smoking.'' Previous studies have shown that smokers need over 200 milligrams of the vitamin daily to maintain blood levels comparable to those of nonsmokers consuming the recommended daily allowance of the vitamin.
``Efforts should be made to further establish the prevalence of poor vitamin C status in the US population and to delineate the clinical significance of below normal plasma vitamin C concentrations,'' conclude the research team.
SOURCE: Journal of the American College of Nutrition 1998;17:366-370.
Vitamin C seen as helpful in preventing chronic lung disease
One of the largest studies of its kind in China reveals that vitamin C may help prevent chronic obstructive pulmonary disease (COPD). The results from three recent Western studies also suggest that vitamin C may lower the risk of obstructive emphysema, chronic bronchitis, and other forms of chronic lung disease. COPD is a major cause of death and disability in the US and other countries. Smoking greatly increases the risk of COPD. Since only about 15% of smokers develop the disease, however, other factors also appear to come into play.
The new report details how a team of researchers studied a group of more than 3,000 people living in 69 rural counties in China. The researchers measured the subjects' lung function, tested levels of vitamin C in their blood, and gave them questionnaires that asked, among other things, whether they had breathing problems or had ever smoked. The researchers also analyzed the diets of about half of the group. Individuals who consumed a diet rich in vitamin C and who had relatively high levels of the vitamin in their blood, had better lung function, and consequently, a lower risk of COPD than those with lower intakes and blood levels of the vitamin. Among those with a vitamin C-rich diet, variations in dietary intake of other vitamins, including vitamins E and A, beta carotene and other carotenes, were not associated with variations in lung function.
These findings provide support that the observed effect is more likely to be due to vitamin C per se, rather than due to other nutrients, noted the investigators. As for how much vitamin C is recommended, the study was unclear outside of showing that the higher the intake of vitamin C, the better the lung function. Those in the study averaged about 151 milligrams of vitamin C per day, about 50% more than the US average. The USDA suggests that most adults consume 60 mg of the vitamin daily. (From American Journal of Epidemiology 1998;148:594-599)
Copyright © 1998 EGW Publications
How Safe Is Vitamin C?
Q & A with Dr. Andrew Weil
QUESTION: Several months ago, the results of carefully planned and carried-out research on human subjects at the National Institutes of Health suggested that the RDA for vitamin C should be increased to 200 milligrams/day. Daily intake of more than 800 or 1,000 milligrams may actually be harmful, according to the study. Why have you chosen to stick with your recommendation of 1,000 to 2,000 milligrams/day in the face of these findings? (Harry Glass)
ANSWER: The doses I suggest are actually very modest doses, compared to those recommended by the ultimate vitamin C enthusiast, the late Linus Pauling. He took 18,000 milligrams of vitamin C a day. I wouldn't go quite that far, but I do recommend 1,000 milligrams twice a day at minimum. We get vitamin C from fruits and vegetables, and we need more of it when exposed to toxins, infection, and chronic illness. If you eat an unhealthy diet or have increased cancer risks for any reason, I'd go up to 2,000 milligrams three times a day. The best form to take is soluble powder. I recommend a non-acidic form, because it's easier on your teeth and stomach. Avoid those chewable tablets packed with sugar, too. I've never seen any toxicity from vitamin C. The only problem that large doses commonly cause is bowel intolerance: flatulence and diarrhea. If this happens, you should just cut back to a more comfortable dose. You can also trigger a deficiency by taking large doses then stopping suddenly, because the body gets lazy about absorbing it.
The NIH studied absorption of vitamin C in the blood, not its effects on immune function or its ability to counteract degenerative disease. The problem the researchers encountered in doses of about 1,000 milligrams had to do with high production of oxalate, which can spur kidney stones in some people. A magnesium supplement a day can help deter kidney stones.
Some of the advantages of vitamin C, such as the strengthening of blood vessels and connective tissue, do not occur at the levels recommended by the NIH. Vitamin C has been linked to denser bones, lowered risk of heart attack, and improved asthma. I don't view vitamin C as a cure for all illnesses, but I do believe we have yet to discover all of its benefits.
The US government comes up with recommended daily allowances from the perspective of preventing deficiencies like scurvy, so the numbers are going to be on the low end. I'm looking at vitamins quite differently. Rather than just minimal nutritional requirements, I view vitamins as natural therapeutic agents with a variety of beneficial effects, which is why I consistently recommend more than the RDAs. |
