Vitamin C

Clinical Studies
References


Ascorbic acid is an antioxidant water-soluble vitamin. When you are under stress the adrenal glands are known to "gobble up" vitamin C, so it is beneficial to the body during times of stress when excess free radical production may occur. The general functions of vitamin C include aiding the production of "anti-stress" hormones and interferons (immune system proteins), being needed for the metabolism of folic acid, tyrosine and phenylalanine (amino acids) and as an essential component for collagen (protein component of ligaments, tendons and muscles) formation. Bioflavonoids help the absorption of vitamin C.

Vitamin C may be beneficial in athletic performance (for energy), bronchitis, bruising, burns, capillary fragility, common cold/sore throat, gingivitis (periodontal disease), glaucoma, heart attack, high cholesterol, infection, infertility (male), wound healing, asthma, atherosclerosis, autism, cataracts, diabetes, gastritis, immune function, influenza, iron-deficiency anemia, lead toxicity, pancreatic insufficiency, schizophrenia, skin ulcers and sprains and strains.

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Published Clinical Studies
Vitamin C


Raw and cooked vegetables, fruits, selected micronutrients, and breast cancer risk: a case-control study in Germany.

Adzersen KH, Jess P, Freivogel KW, Gerhard I, Bastert G.

Department of Gynecological Endocrinology and Reproductive Medicine.

In 1998-2000, a case-control study of breast cancer was conducted in Heidelberg, Germany. Three hundred ten consecutively recruited cases with primary breast cancer were matched according to 10-yr age groups to 353 controls with conditions unrelated to diet or endocrine disorders. Intake of raw vegetables, total vegetables, and whole-grain products was inversely associated with breast cancer risk (highest vs. lowest quartile adjusted odds ratio [OR] 0.51, 95% confidence interval [CI] 0.31-0.84; OR = 0.62, 95% CI = 0.38-1.02; and OR = 0.57; 95% CI = 0.34-0.95, respectively). Also, high intake of some selected vitamins and minerals possessing putative DNA-stabilizing properties displayed significant inverse risk associations. Adjusted ORs were as follows: vitamin C (OR = 0.49, 95% CI = 0.2-0.88), folate equivalents (OR = 0.47, 95% CI = 0.25-0.88), b-carotene (OR = 0.46, 95% CI = 0.27-0.80), zinc (OR = 0.35, 95% CI = 0.15-0.78), and copper (OR = 0.51, 95% CI = 0.31-1.03). In contrast, no significant association with risk was seen for an increased intake of fruits, cooked vegetables, fiber, calcium, manganese, or iron. In this population of German women, components of raw vegetables and some micronutrients appear to decrease breast cancer risk.

PMID: 14690788 [PubMed - in process]

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Effects of a combined micronutrient supplementation on maternal biological status and newborn anthropometrics measurements: a randomized double-blind, placebo-controlled trial in apparently healthy pregnant women.

Hininger I, Favier M, Arnaud J, Faure H, Thoulon JM, Hariveau E, Favier A, Roussel AM.

1LBSO, Faculte de Pharmacie, Universite Joseph. Fourier, La Tronche, France.

OBJECTIVE:: To investigate the possible beneficial effects of a micronutrient supplementation to apparently healthy pregnant women on maternal biological status and new born anthropometric characteristics. SETTING:: Departments of Obstetric of the University Hospital of Grenoble (France) and Lyon (France), Laboratoire of Biology of Oxidative Stress, UFR de Pharmacie. Grenoble (France). STUDY DESIGN:: Double-blind, randomized placebo-controlled intervention trial. SUBJECTS:: A total of 100 apparently healthy pregnant women were recruited at 14+/-2 weeks of gestation to delivery. At the end, they were 65 women to follow out the study. INTERVENTIONS:: Daily consumption over gestation of a miconutrients supplement or placebo. MAIN OUTCOME MEASURES:: Plasma micronutrient levels and oxidative stress parameters were measured in mothers at 14 and 38 weeks of gestation. New born's anthropometric characteristics were measured at delivery. RESULTS:: In the supplemented group, folic acid, vitamin C, E, B(2), B(6) and beta-carotene levels were higher than in the placebo group. Oxidative stress parameters were not different between the groups. Birth weights were increased by 10% and the number of low newborn weights (<2700g) decreased significantly when the mother received the supplementation. Maternal plasma Zn levels were positively correlated to the newborn heights. CONCLUSION:: A regular intake of a micronutrient supplement at nutritional dose may be sufficient to improve micronutrient status of apparently healthy pregnant women and could prevent low birth weight of newborn. SPONSORSHIP:: The supplement and placebo were supplied and the study was partially funded by BOIRON Pharmaceutical Company. European Journal of Clinical Nutrition (2004) 58, 52-59. doi:10.1038/sj.ejcn.1601745

PMID: 14679367 [PubMed - in process]

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Decreased levels of plasma vitamin C and increased concentrations of inflammatory and oxidative stress markers after stroke.

Sanchez-Moreno C, Dashe JF, Scott T, Thaler D, Folstein MF, Martin A.

Nutrition and Neurocognition Laboratory, Jean Mayer USDA-Human Nutrition Research Center on Aging, Boston, Mass 02111, USA.

BACKGROUND AND PURPOSE: Inflammatory response is a critical component of the complex pathophysiological response to stroke. Vitamin C has been shown to have important roles in cell performance and vascular function. In this study, we compared the nutritional status and levels of inflammatory markers between stroke cases and controls and assessed which antioxidant was associated with levels of inflammatory markers and oxidative stress among cases and controls. METHODS: We evaluated the nutritional status and measured plasma levels of vitamins C and E, uric acid, serum levels of C-reactive protein (CRP), the cytokines tumor necrosis factor-alpha and interleukin-1beta, intercellular adhesion molecule-1 (ICAM-1) and chemokine monocyte chemoattractant protein-1 (MCP-1), prostaglandins PGE2 and PGI2, and 8-isoprostanes (8-epiPGF2alpha) for 15 patients with ischemic stroke within 2 to 5 days after stroke onset and for 24 control subjects. RESULTS: Stroke patients had significantly lower plasma levels of vitamin C than did controls. Among stroke patients, CRP was significantly elevated, as were the ICAM-1, MCP-1, and 8-epiPGF2alpha, but the prostaglandins PGE2 and PGI2 were significantly reduced. Interestingly, vitamin C concentration was significantly inversely correlated with the levels of CRP and 8-epiPGF2alpha among stroke patients, and 8-epiPGF2alpha was significantly associated with the levels of CRP. Uric acid was also elevated among stroke patients. CONCLUSIONS: Lower vitamin C concentration, higher serum levels of inflammatory (CRP, ICAM-1, MCP-1) and oxidative stress (8-epiPGF2alpha) markers, and lower PGI2 and PGE2 concentrations among stroke patients indicate the presence of an inflammatory response associated with stroke.

PMID: 14671251 [PubMed - in process]

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Reduction of C-reactive protein levels through use of a multivitamin.

Church TS, Earnest CP, Wood KA, Kampert JB.

The Cooper Institute, Dallas, Texas 75230, USA. tchurch@cooperinst.org

PURPOSE: Elevated C-reactive protein levels are associated with the risk of cardiovascular disease and diabetes. We examined whether multivitamins reduce C-reactive protein levels. METHODS: We performed a post hoc subgroup analysis of a 6-month, randomized, double-blind, placebo-controlled trial. Patients (n = 87; mean age, 53 years) for whom frozen plasma samples were available; who did not have an inflammatory condition at baseline; and who were not hospitalized, taking antibiotics, smoking, or starting statin therapy during the study were included. C-reactive protein and plasma vitamin levels were measured at baseline and 6 months. RESULTS: At 6 months, C-reactive protein levels were significantly lower in the multivitamin group than in the placebo group (between-group difference = -0.91 mg/L; 95% confidence interval: -1.52 to -0.30; P= 0.005). The reduction in C-reactive protein levels was most evident in patients who had elevated levels (> or =1.0 mg/L) at baseline. Of the six vitamins measured (C, E, B(6), B(12), folate, and beta carotene), only vitamin B(6) (baseline: r = -0.31, P= 0.003; 6 months: r = -0.29, P= 0.006) and vitamin C (baseline: r = -0.25, P= 0.02) were inversely associated with C-reactive protein level. CONCLUSION: In a post hoc analysis of a randomized, double-blind, placebo-controlled study, multivitamin use was associated with lower C-reactive protein levels. Other similarly formulated multivitamins may yield comparable results.

PMID: 14693322 [PubMed - in process]

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Effects of vitamin C on high blood pressure induced by salt in spontaneously hypertensive rats.

Nishikawa Y, Tatsumi K, Matsuura T, Yamamoto A, Nadamoto T, Urabe K.

Laboratory of Food Science and Nutrition, College of Nutrition, Koshien University, 10-1 Momijigaoka, Takarazuka 665-0006, Japan. nishizen@nike.eonet.ne.jp

By breeding and feeding salt to spontaneously hypertensive rats (SHR) continuously over a long period (until 60 wk old), rats with systolic blood pressures (SBP) of over 270 mmHg were prepared. It was studied whether or not supplying large amounts of vitamin C (200 mg/rat/d) over this period might bring any beneficial effect to blood pressure. Moreover, physico-chemical studies were performed to measure the components and enzymes in the blood and urine at 53 and 60 wk-old, and biochemical studies on vitamin C were also carried out in this experiment. Male (14 rats: 7 wk-old, 100-105 g) and female (15 rats: 7 wk-old, 95-100 g) SHR were divided into three groups and bred continuously for 53 wk. The A group rats were given salt (2.5 g/100 g of diet), the B group rats were given salt and vitamin C (500 mg/100 mL of drinking water), and the C group rats were controls. The results showed almost the same tendencies between male and female rats. The body weights of the SHR in groups A and B were slightly lower than group C. The amount of food intake in groups A and B was almost the same as group C. The amount of water intake was, in the order from highest to lowest, group A, B and C. The SBP of group A rats exhibited the highest value among the three groups. The SBP of group B rats given vitamin C simultaneously with the salt resulted in a low blood pressure level close to that of the controls (group C). Furthermore, the DBP (diastolic blood pressure) also reflected the antihypertensive effect of vitamin C as well. The heartbeat of the rats was highest in group A, and was comparable to the value in the rats receiving vitamin C simultaneously with salt. For the tests on occult blood and protein in the urine, group A rats showed strong positive reactions, whereas the group B and C rats had decreased results for both tests. The organ weights of the liver, stomach, spleen, adrenal gland and kidneys per 100 g rat body weight were not different among the three groups. The values for the bilirubin content, and the enzyme activities of ALT and AST in the blood showed to be the highest in the male rats of group A. The values from the group B rats decreased near to the normal value like the control group. Vitamin C was found to decrease the blood pressure in SHR, and also to work effectively to protect liver and kidney functions even under the condition of very high blood pressure, as high as 250 mmHg.

PMID: 14703303 [PubMed - in process]

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Effect of orange and apple juices on iron absorption in children.

Shah M, Griffin IJ, Lifschitz CH, Abrams SA.

Section of Neonatology, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.

OBJECTIVE: To measure iron absorption in children from meals containing apple juice or orange juice so as to determine if iron absorption will be greater with orange juice because of its higher ascorbic acid content than apple juice, a noncitrus fruit juice that US children reportedly prefer. DESIGN: On 2 successive days, children consumed identical meals that included apple juice on one day and orange juice on the other, in random order. The meals were labeled with iron-57 on one day and iron-58 on the other. Iron absorption was measured from red blood cell incorporation of the iron stable isotopes 14 days later. SETTING: Nutrition research institute in a major metropolitan medical center. PATIENTS: A total of 25 healthy children, 3 to 6 years of age, were recruited, of whom 21 (11 male and 10 female) completed the study.Intervention Identical meals served with orange juice and apple juice were given on consecutive days, in a balanced randomized design. MAIN OUTCOME MEASURES: Iron absorption measured by established stable isotope methods. RESULTS: Median iron absorption from the meal ingested with apple juice was 7.17% (mean +/- SD, 9.48% +/- 9.68%). Median iron absorption from the meal ingested with orange juice was 7.78% (9.80% +/- 6.66%; P =.44). Iron absorption from the meal that included apple juice was significantly correlated with serum ferritin concentration (P =.02); iron absorption from the meal that included orange juice tended to correlate with serum transferrin receptor concentration (P =.051). CONCLUSIONS: As children absorb iron well from a meal that includes either orange or apple juice, a preference for apple juice does not pose a concern with regard to the prospect of iron-deficiency anemia, which remains a significant health problem in the United States.

Publication Types:

  • Clinical Trial
  • Randomized Controlled Trial


PMID: 14662581 [PubMed - indexed for MEDLINE]

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Antioxidant vitamins and mortality in older persons: findings from the nutrition add-on study to the Medical Research Council Trial of Assessment and Management of Older People in the Community.

Fletcher AE, Breeze E, Shetty PS.

Centre for Ageing and Public Health, London School of Hygiene and Tropical Medicine, United Kingdom. astrid.fletcher@lshtm.ac.uk

BACKGROUND: Older persons are at risk of both poor nutrition and increased oxidative stress. Plasma ascorbate concentrations fall with increasing age, and concentrations of other antioxidants may also be reduced. OBJECTIVE: The goal was to examine the association between antioxidants and mortality in older persons. DESIGN: We randomly selected persons aged 75-84 y from the lists of 51 British family practitioners taking part in a randomized trial of assessment of older persons. A total of 1214 participants provided a blood sample and were interviewed about their usual diet with the use of a food-frequency questionnaire. Statistical analyses were based on deaths after a median of 4.4 y of follow-up, and hazard ratios were estimated for quintiles of dietary or blood antioxidants. RESULTS: We found strong inverse trends for blood ascorbate concentrations with all-cause and cardiovascular disease mortality, which were only marginally reduced after adjustment for confounders or supplement use. Those in the lowest fifth (< 17 micromol/L) had the highest mortality, whereas those in the highest fifth (> 66 micromol/L) had a mortality risk nearly half that (hazard ratio = 0.54; 95% CI: 0.34, 0.84). Similar results were found after the exclusion of those subjects with cardiovascular disease or cancer at baseline (hazard ratio = 0.51; 0.28, 0.93). In fully adjusted models, there was no evidence for an influence of alpha-tocopherol, beta-carotene, or retinol on total mortality. Dietary antioxidants measured by the food-frequency questionnaire were not associated with all-cause or cardiovascular disease mortality. CONCLUSION: Low blood vitamin C concentrations in the older British population are strongly predictive of mortality.

Publication Types:

  • Clinical Trial
  • Randomized Controlled Trial


PMID: 14594788 [PubMed - indexed for MEDLINE]

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References

  1. Kaufmann PA, Gnecchi-Ruscone T, di Terlizzi M, et al. Coronary heart disease in smokers: vitamin C restores coronary microcirculatory function. Circulation 2000;102:1233-8.

  2. Zhang S, Hunter DJ, Forman MR, et al. Dietary carotenoids and vitamins A, C, and E and risk of breast cancer. J Natl Cancer Inst 1999;91:547-56.

  3. Ascherio A, Rimm EB, Hernan MA, et al. Relation of consumption of vitamin E, vitamin C, and carotenoids to risk for stroke among men in the United States. Ann Intern Med 1999;130:963-70.

  4. Labriola D, Livingston R. Possible interactions between dietary antioxidants and chemotherapy. Oncology 1999;13:1003-8.

  5. Halperin EC, Gaspar L, George S, et al. A double-blind, randomized, prospective trial to evaluate topical vitamin C solution for the prevention of radiation dermatitis. Int J Radiat Oncol Biol Phys 1993;26:413-6.

  6. Dwyer JH, Merz NB, Shirocre AM, et al. Progression of early atherosclerosis and intake of vitamin C and vitamin E from supplements and food. The Los Angeles Atherosclerosis Study. 41st Annual Conference on Cardiovascular Disease Epidemiology and Prevention - Abstract P77. Circulation 2001;103:1365d.

  7. Pannelli F, La Rosa F, Saltalamacchia G, et al. Tobacco smoking, coffee, cocoa and tea consumption in relation to mortality from urinary bladder cancer in Italy. Eur J Epidemiol 1989;5:392-7.

  8. Slattery ML, West DW, Robison LM. Fluid intake and bladder cancer in Utah. Int J Cancer 1988;42:17-22.

  9. Tribble DL. AHA Science Advisory. Antioxidant consumption and risk of coronary heart disease: emphasis on vitamin C, vitamin E, and beta-carotene: A statement for healthcare professionals from the American Heart Association. Circulation 1999;99:591-5.

  10. McKevoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.

  11. Cohen HA, Neuman I, Nahum H. Blocking effect of vitamin C in exercise-induced asthma. Arch Pediatr Adolesc Med 1997;151:103-9.

  12. Micromedex Healthcare Series. Englewood, CO: MICROMEDEX Inc.

  13. Salonen JT, Nyyssonen K, Salonen R, et al. Antioxidant Supplementation in Atherosclerosis Prevention (ASAP) study: a randomized trial of the effect of vitamins E and C on 3-year progression of carotid atherosclerosis. J Intern Med 2000;248:377-86.

  14. Yokoyama T, Date C, Kokubo Y, et al. Serum vitamin C concentration was inversely associated with subsequent 20-year incidence of stroke in a Japanese rural community : the shibata study. Stroke 2000;31:2287-94.

  15. Gale CR, Martyn CN, Winter PD, Cooper C. Vitamin C and risk of death from stroke and coronary heart disease in cohort of elderly people. BMJ 1995;310:1563-6.

  16. Alster TS, West TB. Effect of topical vitamin C on postoperative carbon dioxide laser resurfacing erythema. Dermatol Surg 1998;24:331-4.

  17. Slivka A, Kang JO, Cohen G. Ascorbic acid. N Engl J Med 1986;315:708-9.

  18. Daniel TA, Nawarskas JJ. Vitamin C in the prevention of nitrate tolerance. Ann Pharmacother 2000;34:1193-7.

  19. Hodby ED, Hirsh J, Adeniyi-Jones C. The influence of drugs upon the anticoagulant activity of heparin. Can Med Assoc J 1972;106:562-4.

  20. Watanabe H, Masaaki K, Ohtsuka S, et al. Randomized, double-blind, placebo-controlled study of the preventative effect of supplemental oral vitamin C on attenuation of development of nitrate tolerance. J Am Coll Cardiol 1998;31:1323-9.