151. [The effect of VITAMIN C on the lipolytic activity in type-II diabetics with angiopathy].
Angiologia 1991 Mar-Apr;43(2):77-81
[Article in Spanish] Triana Mantilla ME, Simon Carballo R, Fernandez Montequin JI, Lima Santana B, Cardona Alvarez ME, Morejon Reinoso O Instituto de Angiologia y cirugia vascular, Ciudad de la Habana, Cuba.
Effects produced by different doses of Vit C (2, 3 and 4 gr/day) on lipoprotein and hepatic lipase activities were studied between a group of 35 ambulatory patients, men and women, affected by diabetes mellitus type II with macroangiopathy at lower limbs and/or food. The medium age of patients was 62 years, ranging from 44 to 82 years. Patients were aleatory divided into four groups. One from those four groups was treated with placebo, the other three received Vit C. In the group treated with 3 gr./day of Vit C we found a significant reduction and increase (p less than 0.05) of lipoprotein and hepatic lipase activities, respectively, when we compared outcomes before and after eight weeks of treatment with Vit C. By other hand, when we compared the different groups, we found a significant increase in the hepatic lipase activity in the same group, particularly between the patients whose plasmatic Vit C levels before treatment were reduced. We didn't found any significant change in the rest of parameters. Publication Types: Clinical trial Randomized controlled trial PMID: 2069272, UI: 91298485
152. Effect of Ascorbic acid on the intragastric environment in patients at increased risk of developing gastric cancer.
IARC Sci Publ 1991;(105):139-42
Reed PI, Johnston BJ, Walters CL, Hill MJ Lady Sobell Gastrointestinal Unit, Wexham Park Hospital, Slough, Berks, UK.
Ascorbic acid has been shown to decrease nitrosation in vivo, and epidemiological data suggest that the consumption of foods rich in this vitamin is associated with a reduced risk for gastric cancer. In order to study this suggestion further, fasting gastric juice samples were obtained from 62 high-risk patients (seven with atrophic gastritis, ten with pernicious anaemia, ten with partial gastrectomy, 21 with vagotomy and drainage and 14 with highly selective vagotomy), before, during four weeks' treatment with 1 g Ascorbic acid four times daily, and four weeks after treatment. Samples were analysed for pH, total and nitrate-reducing bacterial counts, nitrite and N-nitroso compounds. Treatment with Ascorbic acid lowered the median pH only in the vagotomized patients (p less than 0.001) but resulted in a reduction in median nitrate-reducing bacterial counts and in nitrite and N-nitroso compound concentrations in all groups, except for an increase in the nitrate-reducing bacterial count in atrophic gastritis patients and in nitrite in those with pernicious anaemia. These data suggest that treatment with a high dose of Ascorbic acid reduces the intragastric formation of nitrite and N-nitroso compounds. PMID: 1855837, UI: 91310115
153. The effects of short-term VITAMIN C on plasma bun, uric acid, cholesterol and triglyceride levels.
Acta Med Hung 1991;48(1-2):73-8
Beser E Department of Public Health, School of Medicine, Karadeniz Technical University, Trabzon, Turkey.
The effects of daily 0.5 g VITAMIN C on plasma urea nitrogen, uric acid, cholesterol and triglyceride levels were recorded over a period of one month. There was a significant reduction in plasma cholesterol level (P less than 0.05). There was no significant effect of VITAMIN C on plasma urea nitrogen, uric acid and triglyceride levels (P greater than 0.05). It was a placebo-controlled trial. The research and control groups were formed of 105 and 47 volunteer university students, respectively. In these groups the mean ages were 20 +/- 0.33 (mean +/- S.E.M.) and 20 +/- 0.49 years, respectively. Mean body mass indices were 22.2 +/- 0.13 and 22.3 +/- 0.19 kg/m2, respectively. Publication Types: Clinical trial Controlled clinical trial PMID: 1813860, UI: 92262203
154. Effect of VITAMIN C on histamine bronchial responsiveness of patients with allergic rhinitis.
Ann Allergy 1990 Oct;65(4):311-4
Bucca C, Rolla G, Oliva A, Farina JC Dpt. di Scienze Biomediche e Oncologia Umana, Universita di Torino, Italy.
The effect of acute oral administration of 2 g VITAMIN C on bronchial responsiveness to inhaled histamine in 16 patients with allergic rhinitis was compared with placebo on two consecutive days in a double-blind, crossover design. The PC15FEV1 was significantly increased one hour after treatment with VITAMIN C but not after placebo.
155. Ascorbic acid: effect on ongoing iron absorption and status in iron-depleted young women.
Am J Clin Nutr 1990 Apr;51(4):649-55
Hunt JR, Mullen LM, Lykken GI, Gallagher SK, Nielsen FH US Department of Agriculture, ARS, Grand Forks Human Nutrition Research Center, ND.
The effect of Ascorbic acid on iron retention from a diet with predicted low iron bioavailability (containing minimal meat and Ascorbic acid) was investigated in iron-depleted premenopausal women. Eleven women were depleted of storage iron (indicated by serum ferritin) through a combination of diet (5.0 mg Fe/2000 kcal for 67-88 d) and phlebotomy. They then consumed a diet containing 13.7 mg Fe/2000 kcal, supplemented with placebo or Ascorbic acid three times daily (1500 mg total) with meals for 5.5 wk. Ascorbic acid improved apparent iron absorption (balance method) [38 +/- 2% (means +/- SEM) vs 27 +/- 2%]. Ascorbic acid also improved hemoglobin, erythrocyte protoporphyrins, and serum iron but not hematocrit, serum ferritin, iron-binding capacity, or transferrin saturation. In iron-depleted women consuming a diet with predicted poor iron availability, Ascorbic acid supplementation enhanced body iron retention for 5.5 wk. Publication Types: Clinical trial Controlled clinical trial PMID: 2321571, UI: 90209952
156. Effect of a single oral dose of Ascorbic acid on body temperature and trace mineral fluxes in healthy men and women.
J Am Coll Nutr 1990 Apr;9(2):150-4
Johnston CS Department of Family Resources and Human Development, Arizona State University, Tempe 85287.
Several metabolic changes characteristic of the acute-phase response were examined in healthy men and women following a single 1 g dose of Ascorbic acid. Utilizing a placebo-controlled, double-blind protocol, oral body temperatures were recorded in rested, fasted subjects (0900 hr) prior to the consumption of 1 g L-Ascorbic acid or placebo (n = 10/group). Temperatures were recorded hourly for the next 8 hours, and again the next morning in the rested, fasted state (0900 hr). Blood samples, collected at 0, 4, and 24 hours post-dose, were analyzed for plasma ascorbate, iron, and zinc. Mean oral body temperature was significantly elevated 2 hours post-dose in the experimental subjects compared to controls (+0.7 degrees F, p = 0.03). In the vitamin-dosed subjects, mean plasma ascorbate rose 32% over the control value after 4 hours (1.11 +/- 0.08 and 0.84 +/- 0.06 mg/100 ml, ns). Serum iron levels were similar in the two groups at 0 and 4 hours post-dose, but at 24 hours post-dose mean serum iron of the vitamin-dosed subjects fell to 73% of that recorded for the control subjects (77 +/- 8 and 105 +/- 10 micrograms/100 ml, p = 0.04). Plasma zinc levels were similar for both groups at 0, 4, and 24 hours post-dose. These data indicate that ascorbate administration, at a level commonly supplemented in the US diet, elicits several host metabolic responses similar to those observed following exposure to infectious or inflammatory agents. These metabolic changes are most likely due to the reducing potential of the vitamin and may factor in the reported prophylactic success of VITAMIN C supplementation. Publication Types: Clinical trial Controlled clinical trial PMID: 2110943, UI: 90250219
157. Effects of smoking and/or VITAMIN C on crevicular fluid flow in clinically healthy gingiva.
Quintessence Int 1990 Mar;21(3):191-5
The purpose of this study was to (1) compare crevicular fluid flow in smokers and nonsmokers with clinically healthy gingiva; (2) compare crevicular fluid flow of smokers in the areas physically exposed to smoke (maxillary lingual) to that in areas not physically exposed to smoke (maxillary buccal); and (3) compare crevicular fluid flow in smokers and nonsmokers before and after 1 month of (500 mg) twice daily VITAMIN C supplementation. All sampled areas were required to exhibit clinical health for all measurements (gingival, plaque, and bleeding indices at 0). Ten smoking (at least one pack a day) and ten nonsmoking male dental students were subjects of the study. Areas sampled were midbuccal and midlingual of teeth 3, 5, 12, and 14. Smokers were found to have significantly less crevicular fluid flow than did nonsmokers. Lingual areas of smokers showed no significant difference from buccal areas in crevicular fluid flow. One month of (500 mg) twice daily VITAMIN C supplementation resulted in a significant decrease in crevicular fluid flow in smokers and nonsmokers. The effect of tobacco smoke on clinically healthy gingiva may be a physiologic result of vasoconstriction rather than a physical irritation.
158. High dose antioxidant supplementation to MS patients. Effects on glutathione peroxidase, clinical safety, and absorption of selenium.
Biol Trace Elem Res 1990 Feb;24(2):109-17
Mai J, Sorensen PS, Hansen JC Department of Neurology, Arhus Kommunehospital, Denmark.
High-dose antioxidant supplementation has recently been recommended for multiple sclerosis (MS) patients. This study tests the clinical safety, the glutathione peroxidase (GSH-px) activity, and the absorption of selenium during such supplementation. Eighteen MS patients were given 6 tablets especially made for this study, equivalent to 6 mg sodium selenite, 2 g VITAMIN C, and 480 mg vitamin E a day for five wk. GSH-px, which was lower than in non-MS controls before the start of treatment, increased fivefold during 5 wk of treatment. Side effects were scarce. Ten MS patients were subjected to a 24-h selenium absorption study after ingestion of 2 active tablets, equivalent to 2 mg sodium selenite. Selenium, which was low initially, increased 24% during the first 3 h and then stabilized. It is concluded that the tested antioxidant treatment seems to be safe and that MS patients have low GSH-px, which may be increased by the tested antioxidant treatment.
159. Effects of multivitamin/mineral supplementation, at nutritional doses, on plasma antioxidant status and DNA damage estimated by sister chromatid exchanges in lymphocytes in pregnant women.
Int J Vitam Nutr Res 1999 Nov;69(6):396-402
Park E, Wagenbichler P, Elmadfa I
Institut fur Ernahrungswissenschaften, Wien.
The purpose of this study was to evaluate the effect of multivitamin/mineral-supplementation during pregnancy on plasma levels of antioxidants and sister chromatid exchange (SCE) rate--an indicator of damage to DNA. A controlled, semi-randomized, prospective trial was performed comparing the supplement group, who received multivitamin/mineral tablet once daily for 10 weeks, to the control group. Plasma levels of antioxidants and SCE in lymphocytes were measured initially (20 wk gestation) and at the end of the intervention (34 wk gestation). In the control group, SCE rates increased significantly at 34 wk gestation compared to 20 wk gestation, whereas there was no change in the supplement group. Plasma retinol, beta-carotene and ascorbate decreased significantly in the control group. In the supplement group, a significant increase in plasma beta-carotene (55.6%), coenzyme Q10 (40.2%), folic acid (15.9%) and zinc (24.2%) was observed after 10 weeks of supplement. Increased plasma levels of antioxidants in the supplement group could not decrease SCE rates, however, they could prevent an increase in SCE rates which may be induced by reactive oxygen species generated from the enhanced steroid hormones in the last trimester, suggesting that multivitamin/mineral-supplement during pregnancy may prevent DNA damage due to the altered hormonal profile.
160. Effect of ascorbic acid dose taken with a meal on nitrosoproline excretion in subjects ingesting nitrate and proline.
Nutr Cancer 1998;31(2):106-10
Mirvish SS, Grandjean AC, Reimers KJ, Connelly BJ, Chen SC, Morris CR, Wang X, Haorah J, Lyden ER
Eppley Institute for Research in Cancer, University of Nebraska Medical Center, Omaha 68198, USA.
We determined the dose of ascorbic acid (ASC) given to subjects with a standard 400-calorie meal that inhibited N-nitrosoproline (NPRO) formation when we gave 400 mg of nitrate one hour before and 500 mg of L-proline with the standard meal. Volunteers consumed their normal US diets but restricted their intakes of nitrate, proline, NPRO, and ASC. NPRO and N-nitrososarcosine (NSAR) were determined in the 18-hour urines by methylation followed by gas chromatography-thermal energy analysis. Mean NPRO yields were 10.7, 41.9, 33.2, 22.3, and 23.1 nmol for groups of 9-25 subjects taking proline alone, proline + nitrate, and proline + nitrate + 120, 240, and 480 mg of ASC, respectively. There was a significant trend to lower NPRO yields as the ASC dose was raised. These results correspond to inhibitions by ASC of 28%, 62%, and 60%, respectively. Pairwise comparison showed that each group taking ASC formed significantly less NPRO than the group given only proline + nitrate. Mean NSAR yields were 9.0 nmol when proline alone was taken and 16.9-24.0 nmol when proline + nitrate + ASC was taken, with no trend to increase as the ASC dose was raised. However, NPRO and NSAR yields in individual urines were correlated with each other. We concluded that 120 mg of ASC taken with each meal (360 mg/day) would significantly reduce in vivo nitrosamine formation, similar to tests by Leaf and co-workers (Carcinogenesis 8, 791-795, 1987) in which the reactants were taken between meals. The inhibitory dose of ASC may be < 120 mg/meal when doses of nitrate and proline are not taken.