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Vitamin C


Average daily intake

PHC dosage

Hazardous level

men 51+

90 mg

110 mg

500 mg twice a day


women 51+

80 mg

110 mg; 128 (elderly, 45)

500 mg twice a day


 Index to all VITAMIN C pages: Vitamin C is found not only in plasma but in high millimolar concentrations in cells and tissues.  It is not a pro-oxidant at any dose taken orally.  A recent clinical trial in AJCN showed those taking the PHC dosage had 51% lower levels in their blood of the hazardous inflammation marker CRP, and they were happier! People with high cholesterol have impaired vascular function, hypertension, and vitamin C can provide significant benefit - doses of 500 mg twice a day lowers blood pressure by 10 points in mild hypertension.  Tea helps too, but probably by a different mechanism.  VC supplement use is associated with lower heart disease and cancer risk, and may reduce inflammation and CRP levels.  Balz Frei, head of LPI, believes the RDA and UL are too low.  Flavanoids from fruits and vegetables are fine, but not nearly as effective as vitamin C at trapping free radicals.  On the JAMA studies on hazards of vitamins C and E, LPI states unequivocally that those reports were interpreted inaccurately by the media.  In fact, many studies have "reported benefits for supplemental vitamins C and E in the prevention and treatment of heart disease and cancer." (Link: Vitamin C: Source: Linus Pauling Institute Research Newsletter Spring/Summer 2009; added 6/2009)

Vitamin: C, ascorbic acid

Daily Value: 90 mg

Maximum level approved by Food and Nutrition Board: 2,000 mg

Should you take it before surgery?

Average intake in US diet: 109 mg

Function: cosubstrate in hydroxylations requiring oxygen, especially the amino acids proline and lysine in the formation of collagen, of dopamine to the neurotransmitter norepinephrine, and perhaps many others. It affects functions of leukocytes and macrophages in the immune response, wound healing, and allergic reactions. It builds collagen, thus strengthens blood vessels, speeds wound healing, increases resistance to infection, aids iron utilization; antioxidant

Key research findings:

reduces symptoms of colds

reduces incidence of age-associated diseases

There is overwhelming evidence that vitamin C reduces your risk for a host of different diseases associated with aging, including cancer, heart attacks, atherosclerosis, cataracts, Alzheimer's disease, etc. This has been demonstrated through clinical trials and is based on sound scientific theory and experiments demonstrating reasonable mechanisms by which vitamin C works to prevent these diseases. Vitamin C works in the water soluble portion of the body to break free radical chain reactions. Vitamin C is also essential in regenerating vitamin E which works in the fat portion of the body. This includes all cell membranes. In addition to acting as a free radical trap, Vitamin C acts as a co-enzyme to produce collagen, which lines the arteries. Vitamin C prevents damage to these linings, and thereby prevents the deposition of cholesterol plaque which leads to heart disease. The first three papers by Bowry et al, Ingold et al, and Wayner et al are especially important because they demonstrate that vitamins C and E are the important antioxidants, not exogenous compounds like pycnogenol, ginseng, etc.


Here's a recent report touted in the popular press to get attention. The report claims that vitamin C causes arthritis.

J. Nutr 133: 3047-51 (Oct, 2003) "Our results demonstrate that vitamin C inhibits lipid peroxidation in HDL and preserves the antioxidant activity associated with this lipoprotein fraction." The main point of this paper is that vitamin C (water soluble), as well as vitamin E (fat soluble), are important to keep lipoproteins working properly to prevent development of plaque in your arteries. This is consistent with the value of taking vitamin C twice a day.

Bowry, VW, Ingold, KU, and Stocker, R, "Vitamin E in human low-density lipoprotein", Biochem J 288: 341-44 (1992) "Uptake of oxidatively modified low-density lipoprotein (LDL) by cells in the arterial wall is believed to be an important early event in the development of atherosclerosis. Because vitamin E is the major antioxidant present in human lipoproteins, it has received much attention as a suppressor of LDL lipid oxidation and as an epidemiological marker for ischaemic heart disease...reagents which reduce the alpha-tocopherol radical (i.e. vitamin C and ubiquinol-10) strongly inhibit lipid peroxidation in vitamin E-containing LDL."

Ingold, KU, Bowry, VW, Stocker, R, and Walling, C, "Autoxidation of lipids and antioxidantion by alpha-tocopherol and ubiquinol in homogeneous solution and in aqueous dispersions of lipids: Unrecognized consequences of lipid particle size as exemplified by oxidation of human low density lipoprotein", PNAS USA 90: 45-49 (1993)

"ascorbate is an extremely effective antioxidant for LDL containing alpha- tocopherol...alpha-tocopherol in LDL can be regenerated from its radical by ascorbate; in the absence of ascorbate and coenzyme Q10 (ubiquinol-10), the alpha-tocopherol in LDL acts as a chain-transfer agent rather than as a radical trap" Wayner, DD, Burton, GW, Ingold, KU, Barclay, LRC, and Locke, SJ, "The relative contributions of vitamin E, urate, ascorbate and proteins to the total peroxyl radical-trapping antioxidant activity of human blood plasma", Biochim. Biophys Acta 924: 408-19 (1987)

"It is shown that contributions from urate (35-65%), plasma proteins (10-50%), ascorbate (0-24%) and vitamin E (5-10%) to Total Radical Trapping [ability] account for all of the peroxyl radical-trapping antioxidant activity in the majority of the samples [of six freshly

prepared and 45 frozen human plasma samples]... The modes of action of all of these

plasma antioxidants and possible interactions between them are discussed, with particular

emphasis on the abilities of the water-soluble antioxidants to regenerate or spare the only

lipid-soluble antioxidant, vitamin E."

Levine, M, et al, "In situ kinetics: an approach to recommended intake of vitamin C", Methods in Enzymol 281: 425-437 (1997) "The Optimum requirement of vitamin may be greatly in excess of the accepted physiological requirement", "vitamin C concentration would appear to have no adverse consequences except perhaps in those rare patients who have iron overabsorption" "the possibility of adverse effects of ascorbate at 1000 mg is probably of little consequence. It remains possible that there are other advantages of higher doses of ascorbate, either as unabsorbed vitamin C in the gastrointestinal tract or as excess vitamin C in the urinary exretion system."

Curhan, GC, Willett, WC, Rimm, EB, and Stampfer, MJ, "A prospective study of the intake of vitamins C and B6, and the risk of kidney stones in men", J Urol 155: 1847-51 (1996) "We conducted a prospective study of the relationship between the intake of vitamins C and B6 and the risk of symptomatic kidney stones in a cohort of 45,251 men 40 to 75 years old with no history of kidney calculi...For vitamiin C the age-adjusted relative risk for men consuming 1,500 mg daily or more compared to less than 250 mg daily was 0.78...After adjusting for other potential stone risk factors the relative risks did not change significantly."

Blanchard, J., Tozer, T.N., and Rowland, M., "Pharmacokinetic perspectives on megadoses of ascorbic acid", Am. J. Clin. Nutr. 66: 1165-71 (1997). [see also editorial with it, Barry Shane] [this paper reflects the opposite view on vitamin C dose. Note dramatic inconsistencies in Table 1. Gladys Block disagrees with paper conclusions] "The analysis indicates that both saturable gastrointestinal absorptionh and nonlinear renal clearance act additively to produce the ceiling effect in plasma concentrations. As a consequence of this ceiling effect, there is no pharmacokinetic justification for the use of megadoses of ascorbic acid"

Levine, M. and Wang, Y., PNAS Dec 9, referred to in Holden, C., "Vitamin C: Bacterial Antidote", Science 278: 2061 (1997) "Scientists have found that vitamin C may serve as just such a shield to save a key type of

immune cell from self-annihilation..[neutrophils] produce oxidants that puncture a bacterium's cell walls, then the neutrophils engulf the disabled bug....neutrophils may avoid poisoning themselves by absorbing extra ascorbic acid"

Enstrom, JE, Kanim, L.E., and Klein, M.A., "Vitamin C intake and mortality among a sample of the United States population", Epidemiol. 3: 194-202 (1992) 11,348 noninstitutionalized U.S. adults age 25-74 years from NHANES I followed for 10 years.

"The relation of the standardized mortality ratio (SMR) for all causes of death to increasing

vitamin C intake is strongly inverse for males and weakly inverse for femalies. Among those

with the highest vitamin C intake, males have an SMR of 0.65 for all causes, 0.78 for all cancers,

and 0.58 for all cardiovascular diseases; females have an SMR of 0.90 for all causes, 0.86 for all

cancers, and 0.75 for all cardiovascular diseases [vs. an SMR of 1.0 for all U.S. whites.]"

Reduced risk of developing condition over 10 year period

Condition All U.S. Men+vit C Women+vit C

Death 0% 35% 10%

Cancer 0% 22% 14%

Heart disease 0% 42% 25%

McAlindon, T. E., Jacques, P., and Felson, D.T., "Do antioxidant micronutrients protect against the

development and progression of knee osteoarthritis?", Arthritis and Rheum. 39: 648-56 (1996)

Framingham study, 640 people. "A 3-fold reduction in risk of osteoarthritis progression was found

for [those with higher vitamin C intakes]. Those with high vitamin C intake also had a reduced risk

of developing knee pain." "A reduction in risk of osteoarthritis progression was seen for beta

carotene and vitamin E intake, but was less consistent."

Jacques, P.F., et al, "Long-term vitamin C supplement use and prevalence of early age-related lens

opacities", Am J Clin Nutr. 66: 911-6 (1997)

"Use of vitamin C supplements for at least 10 years was associated with a 77% lower prevalence

of early lens opacities [leading to cataracts] and a 83% lower prevalence of moderate lens

opacities..."Women who consumed vitamin C supplements for less than 10 years showed no

evidence of a reduced prevalence of early opacities." In other words, you need to start taking our

product ASAP, and keep taking it for the rest of your life to get the maximum benefit as you

become older.

McAlindon, T.E., et al, "Do antioxidant micronutrients protect against the development and progression of

knee osteoarthritis?", Arthritis Rheum. 39: 648-56 (1996 )

"Cumulative damage to tissues, mediated by reactive oxygen species, has been implicated as a

pathway that leads to many of the degenerative changes associated with aging. We hypothesized that

increased intake of antioxidant micronutrients might be associated with decreased rates of

osteoarthritis (OA) in the knees... CONCLUSION: High intake of antioxidant micronutrients,

especially vitamin C, may reduce the risk of cartilage loss and disease progression in people with


Stahelin, H.B., K. F. Gey, M. Eichholzer, E. Ludin, F. Bernasconi, J. Thurneysen, and G. Brubacher

"Plasma antioxidant vitamins and subsequent cancer mortality in the 12-year follow up of the

prospective Basel Study", Am. J. Epidem. 133:766-75 (1991)2,974 men. "low levels of vitamin C

increased the risk of stomach cancer (RR=2.38) and gastrointestinal cancer (RR=2.46) in older

subjects... The authors conclude that low plasma levels of antioxidant vitamins are associated with

an increased risk of subsequent cancer mortality."

Heitzer, T.H., Just, H., and Munzel, T., "Antioxidant Vitamin C Improves Endothelial Dysfunction in

Chronic Smokers", Circulation 94: 6-9 (1996)

"vitamin C markedly improves endothelium-dependent responses in chronic smokers. This

observation supports the concept that endothelial dysfunction in chronic smokers is at least in part

mediated by enhanced formation of oxygen-derived free radicals."

Reilly, M., Delanty, N., Lawson, J.A., and FitzGerald, G.A., "Modulation of Oxidant Stress In Vivo in

Chronic Cigarette Smokers", Circulation 94:19-26 (1996)

"Elevated levels of [oxidant stress] in smokers may be modulated by quitting cigarettes and

switching to nicotine patches or by antioxidant vitamin therapy."

King, G., Beins, M., Larkin, J., Summers, B., and Ordman, A.B., "Rate of Excretion of Vitamin C in

Human Urine", AGE 17:87-92 (1994)

"The conclusion is that two conditions are necessary to elevate vitamin C excretion continuously:

a dose of at least 500 mg and a dose every 12 hr. This is substantially higher than the U.S.

recommended daily allowance and more frequent than administration being used in clinical trials."

Levine, M. , Conry-Cantilena, C., Wang, Y., Welch, R.W., and Cantilena, L.R., "Vitamin C pharmacokinetics

in healthy volunteers: Evidence for a recommended dietary allowance," PNAS USA 93: 3704-9 (1996)

A $3 million clinical trial by the National Institutes of Health conducted after our research was

published and patented confirms that a 500 mg dose is necessary for urinary excretion and body

saturation with vitamin C. "At single doses of 500 mg and higher, bioavailability declined and the

absorbed amount was excreted."

Niedzwiecki, A., MacEvilly, C. and Pauling, L., "Effect Of Megadoses Of Vitamin C On Plasma Risk

Factors For Heart Disease And Structural Changes In Guinea Pig Aortas", AGE 23rd Annual Meeting, pg.

6 (1993)

Animals that make vitamin C naturally do not get heart disease. Risk factors for heart disease

correlate with low vitamin C intake. It is required to form blood vessel walls, responsible for

4-hydroxyproline found in collagen in wall lining. Vitamin E prevents LDL oxidation. In a 1992

study by Engstrom, doses over 250 mg/day lowered heart disease in men by 50%, in women by 30%.

Only 20% of Alzheimer's is genetic [and thus vitamin C can help protect against environmental

factors responsible for the other 80% of risk].

Bazzarre, T. L., "Effects of vitamin C supplementation among male smokers and non-smokers", Nutr

Reports Intl 33:711-721 (1986)

Double-blind study of 59 non-smokers, 24 smokers; 45% of American males have significant

atherosclerosis by 25 years of age, smoking increases one's risk. "Ascorbic acid supplementation has

significantly reduced cholesterol in some but not all hypercholesterolemic populations." "Total

cholesterol was higher among individuals with low ascorbic acid status than adequate ascorbic acid


Burr, M.L. , Bates, C.J., Goldberg, G. and Butland, B.K., "Vitamin C and Cholesterol in the Elderly", Human

Nutrition: Clinical Nutrition 39C, 387-88 (1985)

"Large doses of vitamin C may affect blood cholesterol, but the amount commonly obtained in the

diet is unlikely to be an important determinant of total or HDL cholesterol"

Block, G., "Vitamin C gets a little respect", Science 254:374-76 (1991)

"Block points to a growing body of information about the role antioxidant - including vitamin C may

play in chronic diseases such as cancer, heart disease, even AIDS..." "Vitamin C is a good

antioxidant, well-suited to reducing those nasty substances [cigarette smoke and smog] before they

can do their oxidative damage." "the substance is apparently nontoxic, even in large doses, [so] why

not play it safe and take a lot?" " Balz Frei, now at the Harvard School of Public Health,

human plasma to oxidative substances and found that vitamin C protects LDL from oxidation."

"Raxit Jariwalla and Steve Harakeh of the Linus Pauling Institute...have found that vitamin C also

inhibits HIV infection of cultured cells..."

Vinson, J. A., and Bose, P., "Comparative Bioavailability to Humans of Ascorbic Acid Alone or in a Citrus

Extract", Am. J. Clin. Nutr. 48:601 (1988)

"Ascorbic acid in citrus extract was found to be more bioavailable than ascorbic acid alone in human

subjects" [argument for natural vs. synthetic vitamin C]

Block, G., "Vitamin C, cancer, and aging", Age 16:55-58 (1993)

"Numerous epidemiological studies have found that persons with lower intake of antioxidant

nutrients... have a higher risk of almost every type of cancer" "Among white men 65-74 in the US,

15% have blood ascorbate levels below ...the normal boundary of 'normal'. Among black men of that

age, 25% have levels below [normal]."

Jialal, I. and Grundy, S. M., "Preservation of the Endogenous Antioxidants in Low Density Lipoprotein by

Ascorbate But Not Probucol During Oxidative Modification", J. Clin. Invest. 87:597-601 (1991)

"Several lines of evidence indicate that the oxidative modification of low density lipoproteins (LDL)

may provide an important link between plasma LDL and the genesis of atherosclerotic lesion.

Ascorbate is an important water-soluble, chain-breaking antioxidant in humans." "ascorbate

...preserves the endogenous antioxidants in the LDL"

Zannoni, V., "Study Says Vitamin C May Prevent Cirrhosis", Ann Arbor News, A2 (11 Oct 1986)

Report on this Prof. of Pharmacology, at University of Michigan Medical School reported

"relatively large doses of vitamin C - such as 500 mg per day ...over a long period may help protect

people from ...cirrhosis of the liver."

Jacques, P.F. and Chylack Jr., L.T., "Epidemiological Evidence of a Role for the Antioxidant Vitamins and

Carotenoids in Cataract Prevention", Am J. Clin Nutr. 53: 352S-5S (1991)

In a study of 77 people and 35 controls, "Low vitamin C intake was associated with an increased risk

of cataract"

Davies, M.B., Austin, J., and Partridge, D.A.., Vitamin C: Its Chemistry and Biochemistry, Cambridge,

Royal Society of Chemistry, 1991, pg.7-25.

Vitamin C strengthens collagen. Current standard for vitamin C varies even for government

recommendations: United Kingdom 30 mg/day, US 60 mg/day, Soviet Union 90 mg/day

Roig, M.G., Rivera, Z.S., and Kennedy, J.F., "L-ascorbic acid: an overview", Int. J. Food. Sci. Nutr., 44:

59-72 (1993)

Vitamin C strengthen collagen. Vitamin C reduces cancer risk.

Block, G., " Vitamin C, Cancer and Aging", Age, 16: 55-8 (1993)

Vitamin C reduces cancer risk. Taking an optimal dose of vitamin C could be extremely beneficial

to health

Marwick, C.:, "Cancer institute takes a look at ascorbic acid", JAMA, 264:1926 (1990)

Vitamin C reduces cancer risk. "Of [cancer studies], 33 had evidence of statistically significant


Burr, M.L. , Bates, C.J., Goldberg, G. and Butland, B.K., "Vitamin C and Cholesterol in the Elderly", Human

Nutrition: Clinical Nutrition 39C, 387-88 (1985)

Vitamin C reduces risk of heart attacks and cholesterol

Kimura, H., Yamada, Y., and Morita, Y., "Dietary ascorbic acid depresses plasma and low density

lipoprotein lipid peroxidation in genetically scorbutic rats", J. Nutr., 122: 1904-9, (1992)

Vitamin C reduces risk of heart attacks and cholesterol damage to circulation. The lipid peroxide

concentration in plasma LDL and liver was significantly elevated in ...rats fed the ascorbic acid-free

diet. Supplementing the diet with 300 mg ascorbic acid/kg kept those concentrations within the

normal ranges.."

Uchida, K., Nomura, U., and Takase, H., "Effect of vitamin C depletion on serum cholesterol and lipoprotein

levels in ODS (od/od) rats unable to synthesize ascorbic acid", J. Nutr. 120: 1140-7 (1990)

Vitamin C reduces risk of heart attacks and high cholesterol. "vitamin C deficiency delays low

density lipoprotein metabolism and produces hypercholesterolemia in ... rats"

Blanchard, J., Conrad, K.A., and Watson, R.R., "Comparison Of Plasma, Mononuclear And

Polymorphonuclear Leukocyte Vitamin C Levels In Young And Elderly Women During Depletion And

Supplementation", Eur. J. Clin. Nutr. 43: 97-106 (1989)

Vitamin C may boost immune system function

Chavance, M., Herveth, B., and Fournier, C., "Vitamin Status, Immunity And Infections In An Elderly

Population", Eur. J. Clin. Nutr. 43: 927-35 (1989)

Vitamin C may boost immune system function. "subjects with a high vitamin E plasma concentration

had fewer infections during the past 3 years"

Vallance, S., "Platelets, Leukocytes And Buffy Layer Vitamin C After Surgery", Hum. Nutr. 40c: 35-41


Vitamin C may boost immune system function

Vojdani, A., and Ghoneum, M., "In vivo Effect Of Ascorbic Acid Enhancement Of Human Natural Killer

Cell Activity", Nutr. Res.13: 753 (1993)

Vitamin C may boost immune system function. "ascorbic acid is a potent immunomodulator and its

effect in enhancement of natural killer cell cytotoxicity may explain one mechanism by which

ascorbic acid exerts its probable anti cancer activity."

Harman, D., "Free Radical Theory of Aging: Current Status", in Lipofuscin-1987: State of the Art, edited

by Zs.-Nagy, I., New York, Elsevier, 1988, pg. 3-21.

Taking an optimal dose of vitamin C could be extremely beneficial to health. Free radical diseases

include atherosclerosis, cancer, hypertension, osteoarthritis, cataract, Parkinson's disease, diabetes

mellitus type 1, Alzheimer's, and others.

Cameron, E, and Pauling, L., Cancer and Vitamin C, Camino Books, Philadelphia, 1993, pg. 103-7.

Dr. Linus Pauling suggests taking megadoses up to 16 g per day.

Blanchard, J., K.A. Conrad, and Garry, P.J., "Effects Of Age And Intake On Vitamin C Disposition In

Females", Eur. J. Clin. Nutr.,44: 447-460 (1990)

"While the current recommended dietary allowance (RDA) for vitamin C is 60 mg in the United

States it is recognized that higher daily intakes may be necessary to achieve a saturation of 'deeper'

body pools... many believe that doses of vitamin C considerably higher than the RDA may provide

for 'optimal' health."

Burns, John J. et al. "Third Conference on Vitamin C", Annals of the New York Academy of Sciences Vol.

498, (1987), including:

Rivers, Jerry M. "Safety of High-level vitamin C Ingestion", pp. 445-454. No danger of oxalate

stones or iron overload. "large doses [above 5 g] should not result in increased oxalate formation

since the metabolic turnover of the vitamin is limited"

Hallberg, L. et al. "Is there a physiological role of vitamin C in Iron Absorption?", pp. 324-332. "do

you hypothesize that with large dose of vitamin C you may have an iron overload? I would not think

so because...the more iron you have in stores the lower the extra iron is being absorbed."



Blanchard, J. et al, "Comparison of plasma, mononuclear, and polymorphonuclear leucocyte vitamin C

levels in young and elderly women during depletion and supplementation", Eur J Clin Nutr 43: 97-106


"There were no age-related differences in the levels of vitamin C ..."

Curz, A., et al "Longitudinal changes in the intake of vitamins and minerals of elderly Europeans", Eur J

Clin Nutr 50: S77-85 (1996)

658 elderly men and 731 elderly women born 1913-18: "A significant decrease in the median

intake of vitamin B1, B2, B6, C or iron was observed..."

Dror, Y. et al, "Estimation of vitamin needs-riboflavin, vitamin B6, and ascorbic acid-according to blood

parameters and functional-cognitive and emotional indices in a select well-established group of elderly in

a home for the aged in Israel", J Am Coll Nutr 15: 481-88 (1996)

ave. age over 80 "vitamin needs... (mg/day) of >150 for ascorbic acid, >3 for riboflavin, >3 for

vitamin B6"- elderly need >150 mg/day of vitamin C

Hellenbrand, W. et al, "Diet and Parkinson's disease", Neurology 47: 644-50 (1996)

"Our results suggest that if antioxidants play a protective role in [Parkinson's], the amounts

provided by diet alone are insufficient."- vitamin C lower in those with Parkinsons

Khaw, K. Woodhouse, P., "Interrelation of vitamin C, infection, haemostatic factors, and cardiovascular

disease", BMJ 310: 1559-63 (1995)

96 people, ages 65-74, "vitamin C may protect against cardiovascular disease through an effect

on...factors...through the response to infection"- study of 96 elderly; high vitamin C (increase of

60 mg) protective for both respiratory infection and heart disease.

Kushi, L. H. et al, "Dietary Antioxidant Vitamins and Death from coronary artery disease in

postmenopausal women", NEJM 334: 1156-62 (1996)

- 34,486 women for 7 years. Ave. age - 61 yr old

intake (healthiest quartile)

vit A carotenoids vit E vit C

17,500 IU 11,160 IU 10 mg 194 MG

Healthiest levels among those women taking supplements

vit A , 1-5000 iu; vit E more than 250 iu; vit C, more than 1 g

plasma beta-carotene rises 24-48 hrs after ingestion - vitamin C not correlated with risk of heart

disease in 34,486 post-menopausal women

McAlindon, T.E. et al, "Do antioxidant micronutrients protect against the development and progression

of knee osteoarthritis?", Arthritis Rheum 39: 648-56 (1996)

"A 3-fold reduction in risk of osteoarthritis progression was found for [those with the highest]

vitamin C intake...High intake of antioxidant micronutrients, esp. vitamin C, may reduce the risk

of cartilage loss and disease progression in people with osteoarthritis" - High intake of vitamin C

may reduce the risk of osteoarthritis progression

van der Wielen, R. P. , et al, "Nutritional status of elderly female nursing home residents: the effect of

supplementation with a physiological dose of water-soluble vitamins", Eur J Clin Nutr 49: 665-74 (1995)

supplementation of 42 women over 60 in nursing homes. "50% of the daily dietary

recommendation of water-soluble vitamins" "significantly improved the concentrations of

thiamin and pyridoxal, increased body weight and decreased serum homocysteine" - dietary

supplements improved vit C in elderly

van der Wielen, R. P. , et al, "Dietary intakes of energy and water-soluble vitamins in different categories

of aging", J Gerontol 51: B100-7 (1996)

"Dietary intakes of [thiamin, riboflavin, B6, and C] were below the minimum requirements in

almost half of the nursing home residents" - dietary intakes below RDAs in half of nursing home


Watson, R. R. and Leonard, T.K., "Selenium and vitamins A, E, and C: Nutrients with cancer prevention

properties," J. Am. Diet. Ass 86: 505-10 (1986)

Table 1: conservative recommendations for levels of possible

cancer prevention toxicity

A 12,500 25,000

E 200-800 IU safe

C 1,000 mg safe

selenium 50-200 mcg 200 mcg*

*not recommended as safe because of severe toxicity with high doses

- take 1,000 mg per day to prevent cancer - safe

Gale, CR, et al, "Vitamin C and risk of death from stroke and coronary heart disease in cohort of elderly

people," BMJ 310: 1563-66 (1995)

"In elderly people vitamin C concentration, whether measured by dietary intake or plasma

concentration of ascorbic acid, is strongly related to subsequent risk of death from stroke"- 20

year study of 730 men and women, mortality from stroke was highest in those with lowest vit C

status, but no correlation with risk of coronary heart disease - high vit C reduced risk by 60%


HemilÑ H, "Vitamin C supplementation and common cold symptoms: problems with inaccurate reviews",

Nutrition 12: 804-9 (1996).

"Studies carried out since then have consistently found that vitamin C (> or = 1 g/d) alleviates

common cold symptoms, indicating that the vitamin does indeed have physiologic effects on

colds. However, widespread conviction that the vitamin has no proven effects on the common

cold still remains. Three of the most influential reviews drawing this conclusion are considered

in the present article. Two of them are cited in the current edition of the RDA nutritional

recommendations as evidence that vitamin C is ineffective against colds. In this article, these

three reviews are shown to contain serious inaccuracies and shortcomings, making them

unreliable sources on the topic"

Kibak, P. "Vitamins C and E may counter effects of oxygen-free radicals on arteries", Press release,

American Heart Association (see article in White Paper)

"When volunteers consumed 800 units of vitamin E and one gram of vitamin C with the meal,

the blood vessels widened about 18% - about as much as expected"

Johnston, C.S. and Luo, B., "Comparison of the absorption and excretion of three commercially available

sources of vitamin C", J Am Diet Assoc 94: 779-84 (1994)

"vitamin C from Ester-C or in association with bioflavonoids was not more bioavailable than

simple ascorbic acid"

Schorah, CJ, et al, "Total vitamin C, ascorbic acid, and dehydroascorbic acid concentrations in plasma of

critically ill patients," Am J Clin Nutr 63: 760-5 (1996)

"[vitamin C was measured] in critically ill patients in whom the excessive generation of reactive

oxygen species could compromise antioxidant defense mechanisms. Median

concentrations...were less than 25% of the values found in healthy control subjects and in

subjects in two other disease groups (diabetes, gastritis)...The findings indicate that antioxidant

defenses could be considerably compromised in these very sick patients."

Carr, AB, Einstein, R, Lai, LYC, Martin, NG, and Starmer, GA, "Vitamin C and the common cold: using

identical twins as controls", Med. J. Aust. 2: 411-12 (1981)

1 g vitamin C per day+multivitamin, 125 pairs of twins "Vitamin C had no significant effect

except for shortening the average duration of cold episodes by 19%"

Curhan, GC, Willett, WC, Rimm, EB, and Stampfer, MJ, "A prospective study of the intake of vitamins

C and B6, and the risk of kidney stones in men", J Urol 155: 1847-51 (1996)

"We conducted a prospective study of the relationship between the intake of vitamins C and B6 and

the risk of symptomatic kidney stones in a cohort of 45,251 men 40 to 75 years old with no history

of kidney calculi...For vitamiin C the age-adjusted relative risk for men consuming 1,500 mg daily

or more compared to less than 250 mg daily was 0.78...After adjusting for other potential stone risk

factors the relative risks did not change significantly."

Anderson, TW, "Large-scale trials of vitamin C", in Burns, John J. et al. "Third Conference on Vitamin

C", Annals of the New York Academy of Sciences Vol. 498, (1987), pg 498-503

"to test widely publicized claims of Professor Linus Pauling that...the regular intake of 1 g of

vitamin C per day would lead to 45% fewer colds and 60% fewer days of sickness....we found

that among the 818 subjects ...those receiving [4 g per day during the first 3 days of any

illness]...those receiving the vitamin experienced 30% fewer days indoors or off work"

Vojdani, A., and Ghoneum, M., "In vivo effect of ascorbic acid on enhancement of hmuna natural killer

cell activity", Nutr. Res. 13: 753-64 (1993)

"We conclude that ascorbic acid is a potent immunomodulator and its effect in enhance of NK

cytotoxicity may explain one mechanism by which ascorbic acid exerts its probable anti cancer


Anderson, TW, Reid, DBW, and Beaton, GH, "Vitamin C and the common cold: a double-blind trial",

CMA Journal 107: 503-9 (1972)

"1 g of vitamin C per day substantially reduces the frequency and duration of 'colds'" "30%

fewer total days of disability"

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