ascorbic-acid and Respiratory-Tract-Diseases

Vitamin C is used in modern medicine supplements for treatment of various disorders associated with oxidative stress, inflammation and immune dysregulation. In this review article, experimental and clinical results regarding the effects of vitamin C on respiratory immunologic, and allergic diseases are reviewed. Various databases and appropriate keywords are used to search the effect of vitamin C on respiratory diseases until the end of May 2022. Books, theses and articles were included. These studies assessed the effects of vitamin C on respiratory disorders including asthma, chronic obstructive pulmonary disease (COPD), lung infection and lung cancer. Vitamin C showed relaxant effect on tracheal smooth muscle via various mechanisms. The preventive effects of vitamin C were mediated by antioxidant, immunomodulatory and anti-inflammatory mechanisms in the experimental animal models of different respiratory diseases. Some clinical studies also indicated the effect of vitamin C on lung cancer and lung infections. Therefore, vitamin C could be used a preventive and/or relieving therapy in respiratory diseases.

Topics: Animals; Ascorbic Acid; Asthma; Lung Neoplasms; Pneumonia; Pulmonary Disease, Chronic Obstructive; Respiratory Tract Diseases; Vitamins

Maternal smoking during pregnancy is the largest preventable cause of abnormal in-utero lung development. Despite well known risks, rates of smoking during pregnancy have only slightly decreased over the last ten years, with rates varying from 5-40% worldwide resulting in tens of millions of fetal exposures. Despite multiple approaches to smoking cessation about 50% of smokers will continue to smoke during pregnancy. Maternal genotype plays an important role in the likelihood of continued smoking during pregnancy and the degree to which maternal smoking will affect the fetus. The primary effects of maternal smoking on offspring lung function and health are decreases in forced expiratory flows, decreased passive respiratory compliance, increased hospitalization for respiratory infections, and an increased prevalence of childhood wheeze and asthma. Nicotine appears to be the responsible component of tobacco smoke that affects lung development, and some of the effects of maternal smoking on lung development can be prevented by supplemental vitamin C. Because nicotine is the key agent for affecting lung development, e-cigarette usage during pregnancy is likely to be as dangerous to fetal lung development as is maternal smoking.

Topics: Animals; Antioxidants; Ascorbic Acid; Asthma; Child; Disease Models, Animal; Epigenesis, Genetic; Female; Humans; Infant, Newborn; Lung; Nicotine; Nicotinic Agonists; Pregnancy; Prenatal Exposure Delayed Effects; Respiratory Tract Diseases; Smoking; Tobacco Smoke Pollution

Malnutrition is a major cause of morbidity and mortality in developing countries and nutrition plays a critical role in both acute and chronic respiratory conditions. Inadequacies in the nutritional requirements of a developing lung in utero and in early life can compromise the respiratory system integrity and result in poor lung function, reduced protection against infections, greater likelihood of acute illnesses in childhood and chronic illness in adulthood. Nutritional interventions harness great potential in reducing respiratory illness related morbidity and mortality in the developing world. In this review we have summarized the findings from published systematic reviews/meta-analysis, experimental and observational studies that looked into different nutritional interventions for preventing respiratory diseases in developing countries.

Topics: Ascorbic Acid; Breast Feeding; Developing Countries; Dietary Supplements; Humans; Malnutrition; Respiratory Tract Diseases; Risk Factors; Trace Elements; Vitamin A; Vitamin D; Vitamins; Zinc

Topics: Air Pollutants; alpha-Tocopherol; Animals; Ascorbic Acid; Dietary Supplements; Humans; Oxidative Stress; Ozone; Respiratory Mucosa; Respiratory System; Respiratory Tract Diseases; Vitamins

The deleterious effects of cigarette smoking on antioxidant protection and chronic disease risk are well known. Recent studies show that exposure of nonsmokers to environmental tobacco smoke results in increased oxidant damage linked to heart and respiratory diseases. The new findings provide support for efforts to minimize exposure of nonsmokers to environmental tobacco smoke and oxidizing air pollutants and demonstrate the importance of vitamin C for antioxidant protection.

Topics: Ascorbic Acid; Heart Diseases; Humans; Oxidants; Respiratory Tract Diseases; Tobacco Smoke Pollution

Unlike most animals, which form ascorbic acid by metabolizing glucose, humans require an exogenous source. Vitamin C occurs primarily in fruits and vegetables, and scurvy develops from inadequate consumption of these sources, usually because of ignorance about proper nutrition, psychiatric disorders, alcoholism, or social isolation. The earliest symptom of scurvy, occurring only after many weeks of deficient intake, is fatigue. The most common cutaneous findings are follicular hyperkeratosis, perifollicular hemorrhages, ecchymoses, xerosis, leg edema, poor wound healing, and bent or coiled body hairs. Gum abnormalities, which occur only in patients with teeth, include gingival swelling, purplish discoloration, and hemorrhages. Pain in the back and joints is common, sometimes accompanied by obvious hemorrhage into the soft tissue and joints. Syncope and sudden death may occur. Anemia is frequent, leukopenia occasional. Treatment with vitamin C results in rapid, often dramatic, improvement. (J Am Acad Dermatol 1999;41:895-906.). At the conclusion of this learning activity, participants should be familiar with the history, pathogenesis, clinical features, and treatment of scurvy in adults.

Topics: Adult; Animals; Ascorbic Acid; Cardiovascular Diseases; History, 15th Century; History, 17th Century; History, 18th Century; History, 19th Century; History, 20th Century; Humans; Nutrition Policy; Respiratory Tract Diseases; Scurvy; Skin Diseases

A review of the literature relating to possible clinical implications of ascorbic acid (AA) supplementation was conducted. Factors requiring a higher AA intake include smoking, alcohol ingestion, stress, diabetes mellitus, pregnancy, and certain drugs, including oral contraceptives, some antibiotics, acetylsalicylate and anti-inflammatory medications. AA has been found to significantly increase wound healing, reduce the inflammatory response, lessen respiratory distress, enhance immune function and serve to benefit many common conditions including osteoarthritis. It is concluded that vitamin C supplementation could be utilized for many conditions seen by chiropractors.

Topics: Age Factors; Alcoholism; Animals; Anti-Bacterial Agents; Anti-Inflammatory Agents; Ascorbic Acid; Aspirin; Chiropractic; Contraceptives, Oral; Diet; Drug Interactions; Female; Fruit; Humans; Immunity; Inflammation; Nutritional Requirements; Pregnancy; Respiratory Tract Diseases; Smoking; Stress, Physiological; Wound Healing

Topics: Animals; Arginine; Ascorbic Acid; Bronchi; Carbonates; Copper; Detergents; Dithiothreitol; Expectorants; Glucocorticoids; Humans; Hydrolases; Iodides; Ipecac; Mucus; Quaternary Ammonium Compounds; Respiratory Tract Diseases; Trachea; Urea; Water

Maternal smoking during pregnancy adversely affects offspring lung development, with lifelong decreases in pulmonary function and increased asthma risk. In a primate model, vitamin C blocked some of the in-utero effects of nicotine on lung development and offspring pulmonary function.. To determine if newborns of pregnant smokers randomized to receive daily vitamin C would have improved results of pulmonary function tests (PFTs) and decreased wheezing compared with those randomized to placebo.. Randomized, double-blind trial conducted in 3 sites in the Pacific Northwest between March 2007 and January 2011. One hundred fifty-nine newborns of randomized pregnant smokers (76 vitamin C treated and 83 placebo treated) and 76 newborns of pregnant nonsmokers were studied with newborn PFTs. Follow-up assessment including wheezing was assessed through age 1 year, and PFTs were performed at age 1 year.. Pregnant women were randomized to receive vitamin C (500 mg/d) (n = 89) or placebo (n = 90).. The primary outcome was measurement of newborn pulmonary function (ratio of the time to peak tidal expiratory flow to expiratory time [TPTEF:TE] and passive respiratory compliance per kilogram [Crs/kg]) within 72 hours of age. Secondary outcomes included incidence of wheezing through age 1 year and PFT results at age 1 year. A subgroup of pregnant smokers and nonsmokers had genotyping performed.. Newborns of women randomized to vitamin C (n = 76), compared with those randomized to placebo (n = 83), had improved pulmonary function as measured by TPTEF:TE (0.383 vs 0.345 [adjusted 95% CI for difference, 0.011-0.062]; P = .006) and Crs/kg (1.32 vs 1.20 mL/cm H2O/kg [95% CI, 0.02-0.20]; P = .01). Offspring of women randomized to vitamin C had significantly decreased wheezing through age 1 year (15/70 [21%] vs 31/77 [40%]; relative risk, 0.56 [95% CI, 0.33-0.95]; P = .03). There were no significant differences in the 1-year PFT results between the vitamin C and placebo groups. The effect of maternal smoking on newborn lung function was associated with maternal genotype for the α5 nicotinic receptor (rs16969968) (P < .001 for interaction).. Supplemental vitamin C taken by pregnant smokers improved newborn PFT results and decreased wheezing through 1 year in the offspring. Vitamin C in pregnant smokers may be an inexpensive and simple approach to decrease the effects of smoking in pregnancy on newborn pulmonary function and respiratory morbidities.. clinicaltrials.gov Identifier: NCT00632476.

Topics: Adult; Ascorbic Acid; Dietary Supplements; Double-Blind Method; Female; Humans; Infant; Infant, Newborn; Infant, Newborn, Diseases; Lung; Pregnancy; Prenatal Care; Prenatal Exposure Delayed Effects; Respiratory Function Tests; Respiratory Sounds; Respiratory Tract Diseases; Smoking; Vitamins; Young Adult

Excess production of reactive oxygen species is involved in the pathogenesis of airway disorders in horses. Trace element antioxidants have a beneficial role in oxidant/antioxidant balance. The aim of the present study was to evaluate the effect of a combination of sodium selenite and ascorbic acid on clinical outcome, antioxidant enzymes, and trace elements status in horses with lower airway disease. For this purpose, 40 draft horses with lower airway disease were randomly selected (acute, n = 20; chronic, n = 20). Both acute and chronic cases were randomly allocated into two subgroups (ten each). Groups 1 and 2 were the horses with acute disease, while groups 3 and 4 were chronically ill. For all groups, each horse was administered antibiotic, non-steroidal anti-inflammatory, and mucolytic drug. In addition, groups 2 and 4 were injected with 15 mg/kg sodium selenite and 30 mg/kg ascorbic acid every 24 h for successive 4 weeks. Venous blood samples were obtained from diseased horses on three occasions; at first examination, and at 2 and 4 weeks post-treatment. Clinically, antioxidant supplementation improved the clinical signs with significant decrease (p < 0.05) of the clinical index score in both acute and chronic cases. In supplemented groups compared with non-supplemented, there was a significant increase (p < 0.05) in the levels of copper, zinc, selenium, and iron as well as in the activity of glutathione-S-transferase and catalase. Meanwhile, there was a significant decrease (p < 0.05) in the levels of manganese, malondialdehyde, hydrogen peroxide, and low-density lipoprotein and in the activity of glutathione reductase. The results of the present study indicate that administration of sodium selenite and ascorbic acid may have beneficial effect on clinical outcome and antioxidant balance in horses with acute and chronic lower airway disease.

Topics: Acute Disease; Animals; Antioxidants; Ascorbic Acid; Chronic Disease; Drug Therapy, Combination; Horse Diseases; Horses; Respiratory Tract Diseases; Sodium Selenite; Trace Elements; Treatment Outcome

Topics: Acetaminophen; Acute Disease; Adolescent; Adult; Analgesics; Antioxidants; Antiviral Agents; Ascorbic Acid; Calcium Gluconate; Combined Modality Therapy; Dibenzoxepins; Drug Combinations; Histamine H1 Antagonists; Humans; Male; Olopatadine Hydrochloride; Respiratory Tract Diseases; Rimantadine; Rutin; Treatment Outcome

Between December 1972 and February 1973, 2349 volunteers participated in a double-blind trial to assess the effect of large doses of vitamin C on the incidence and severity of winter illness. In addition, records were kept but no tablets taken during March. Subjects were randomly allocated to eight treatment regimens: three prophylactic-only (daily dose 0.25, 1 or 2 g), two therapeutic-only (4 or 8 g on the first day of illness), one combination (1 g daily and 4 g on the first day of illness), and two all-placebo. None of the groups receiving vitamin C showed a difference in sickness experience that was statistically significant from that of the placebo groups, but the results obtained were compatible with an effect of small magnitude from both the prophylactic and therapeutic regimens, and an effect of somewhat greater magnitude from the combination regimen. The combination regimen was associated more with a reduction in severity than frequency of illness, although the extra dosage was limited to the first day of illness. In spite of the eightfold range in daily dose, the three prophylactic-only regimens showed no evidence of a dose-related effect, but the 8 g therapeutic dose was associated with less illness than the 4 g therapeutic dose. There was no evidence of side effects from the 1 and 2 g prophylactic doses of vitamin C, and no evidence of a rebound increase in illness during the month following withdrawal of the daily vitamin supplements. On the basis of this and other studies it is suggested that the optimum daily dose of vitamin C is less than 250 mg, except possibly at the time of acute illness, when a larger daily intake may be beneficial.

Topics: Administration, Oral; Adult; Ascorbic Acid; Clinical Trials as Topic; Common Cold; Dose-Response Relationship, Drug; Female; Humans; Male; Patient Dropouts; Placebos; Respiratory Tract Diseases; Seasons; Tablets; Time Factors

Topics: Ascorbic Acid; Child; Female; Humans; Pregnancy; Prenatal Exposure Delayed Effects; Respiratory Tract Diseases; Smoking; Vitamins

Cancerous and non-cancerous respiratory diseases are common and contribute significantly to global disease burden. We aim to quantify the association between plasma vitamin C concentrations as an indicator of high fruit and vegetable consumption and the risk of incident respiratory diseases and associated mortality in a general population.. Nineteen thousand three hundred and fifty-seven men and women aged 40-79 years without prevalent respiratory diseases at the baseline (1993-1997) and participating in the European Prospective Investigation into Cancer (EPIC)-Norfolk study in the United Kingdom were followed through March 2015 for both incidence and mortality from respiratory diseases.. There were a total of 3914 incident events and 407 deaths due to any respiratory diseases (excluding lung cancers), 367 incident lung cancers and 280 lung cancer deaths during the follow-up (total person-years >300,000 years). Cox's proportional hazards models showed that persons in the top quartiles of baseline plasma vitamin C concentrations had a 43% lower risk of lung cancer (hazard ratio (HR) 0.57; 95% confidence interval (CI): 0.41-0.81) than did those in the bottom quartile, independently of potential confounders. The results are similar for any non-cancerous respiratory diseases (HR 0.85; 0.77-0.95), including chronic respiratory diseases (HR 0.81; 0.69-0.96) and pneumonia (HR 0.70; 0.59-0.83). The corresponding values for mortality were 0.54 (0.35-0.81), 0.81 (0.59-1.12), 0.85 (0.44-1.66) and 0.61 (0.37-1.01), respectively. Confining analyses to non-smokers showed 42% and 53% risk reduction of non-smoking-related lung cancer incidence and death.. Higher levels of vitamin C concentrations as a marker of high fruit and vegetable consumption reduces the risk of cancerous and non-cancerous respiratory illnesses including non-smoking-related cancer incidence and deaths.

Topics: Adult; Aged; Ascorbic Acid; Female; Humans; Male; Middle Aged; Prospective Studies; Respiratory Tract Diseases; Risk Factors

Particulate matter (PM) from traffic and other sources has been associated with adverse health effects. One unifying theory is that PM, whatever its source, acts on the human body via its capacity to cause damaging oxidation reactions related to its content of pro-oxidants components. Few epidemiological studies have investigated particle oxidative potential (OP) and health. We conducted a time series analysis to assess associations between daily particle OP measures and numbers of deaths and hospital admissions for cardiovascular and respiratory diseases.. During 2011 and 2012 particles with an aerodynamic diameter less than 2.5 and 10μm (PM2.5 and PM10 respectively) were collected daily on Partisol filters located at an urban background monitoring station in Central London. Particulate OP was assessed based on the capacity of the particles to oxidize ascorbate (OP(AA)) and glutathione (OP(GSH)) from a simple chemical model reflecting the antioxidant composition of human respiratory tract lining fluid. Particulate OP, expressed as % loss of antioxidant per μg of PM, was then multiplied by the daily concentrations of PM to derive the daily OP of PM mass concentrations (% loss per m(3)). Daily numbers of deaths and age- and cause-specific hospital admissions in London were obtained from national registries. Poisson regression accounting for seasonality and meteorology was used to estimate the percentage change in risk of death or admission associated with an interquartile increment in particle OP.. We found little evidence for adverse associations between OP(AA) and OP(GSH) and mortality. Associations with cardiovascular admissions were generally positive in younger adults and negative in older adults with confidence intervals including 0%. For respiratory admissions there was a trend, from positive to negative associations, with increasing age although confidence intervals generally included 0%.. Our study, the first to analyse daily particle OP measures and mortality and admissions in a large population over two years, found little evidence to support the hypothesis that short-term exposure to particle OP is associated with adverse health effects. Further studies with improved exposure assessment and longer time series are required to confirm or reject the role of particle OP in triggering exacerbations of disease.

Topics: Adolescent; Adult; Aged; Air Pollutants; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Child; Child, Preschool; Environmental Monitoring; Glutathione; Hospitalization; Humans; Infant; Infant, Newborn; London; Middle Aged; Nitrogen Dioxide; Oxidation-Reduction; Ozone; Particulate Matter; Respiratory Tract Diseases; Sulfur Dioxide; Young Adult

Vitamin D is associated with many health conditions, but optimal blood concentrations are still uncertain.. We examined the prospective relation between serum 25-hydroxyvitamin D [25(OH)D] concentrations [which comprised 25(OH)D3 and 25(OH)D2] and subsequent mortality by the cause and incident diseases in a prospective population study.. Serum vitamin D concentrations were measured in 14,641 men and women aged 42-82 y in 1997-2000 who were living in Norfolk, United Kingdom, and were followed up to 2012. Participants were categorized into 5 groups according to baseline serum concentrations of total 25(OH)D <30, 30 to <50, 50 to <70, 70 to <90, and ≥ 90 nmol/L.. The mean serum total 25(OH)D was 56.6 nmol/L, which consisted predominantly of 25(OH)D3 (mean: 56.2 nmol/L; 99% of total). The age-, sex-, and month-adjusted HRs (95% CIs) for all-cause mortality (2776 deaths) for men and women by increasing vitamin D category were 1, 0.84 (0.74, 0.94), 0.72 (0.63, 0.81), 0.71 (0.62, 0.82), and 0.66 (0.55, 0.79) (P-trend < 0.0001). When analyzed as a continuous variable and with additional adjustment for body mass index, smoking, social class, education, physical activity, alcohol intake, plasma vitamin C, history of cardiovascular disease, diabetes, or cancer, HRs for a 20-nmol/L increase in 25(OH)D were 0.92 (0.88, 0.96) (P < 0.001) for total mortality, 0.96 (0.93, 0.99) (P = 0.014) (4469 events) for cardiovascular disease, 0.89 (0.85, 0.93) (P < 0.0001) (2132 events) for respiratory disease, 0.89 (0.81, 0.98) (P = 0.012) (563 events) for fractures, and 1.02 (0.99, 1.06) (P = 0.21) (3121 events) for incident total cancers.. Plasma 25(OH)D concentrations predict subsequent lower 13-y total mortality and incident cardiovascular disease, respiratory disease, and fractures but not total incident cancers. For mortality, lowest risks were in subjects with concentrations >90 nmol/L, and there was no evidence of increased mortality at high concentrations, suggesting that a moderate increase in population mean concentrations may have potential health benefit, but <1% of the population had concentrations >120 nmol/L.

Topics: Adult; Aged; Aged, 80 and over; Ascorbic Acid; Body Mass Index; Cardiovascular Diseases; Female; Fractures, Bone; Humans; Incidence; Male; Middle Aged; Motor Activity; Multivariate Analysis; Proportional Hazards Models; Prospective Studies; Respiratory Tract Diseases; Socioeconomic Factors; United Kingdom; Vitamin D; Vitamin D Deficiency

This study investigated whether a high dietary intake or serum concentration of antioxidant (pro-) vitamins could attenuate the acute respiratory effects of air pollution in panels of adults (n = 227) aged 50-70 yrs with chronic respiratory symptoms in two winters starting in 1993/1994. Subjects performed daily peak expiratory flow (PEF) measurements in the morning and evening and reported the occurrence of respiratory symptoms in two regions (urban and nonurban) each winter. Logistic regression analysis was used with the prevalences of large PEF decrements as dependent variables and air pollution levels as independent variables. Analyses were performed separately for subjects below and above the median levels of serum beta-carotene and the intake of dietary vitamin C and beta-carotene. Subjects with low levels of serum beta-carotene more often had large PEF decrements when particles <10 microm in diameter or black smoke levels which were higher compared to subjects with high levels of serum beta-carotene. The same results tended to be observed for dietary vitamin C or beta-carotene, but there were less significant air pollution effects in the low dietary antioxidant group. The results suggest that serum beta-carotene and to a lesser extent dietary vitamin C and beta-carotene may attenuate peak expiratory flow decrements due to air pollution in subjects with chronic respiratory symptoms.

Topics: Aged; Air Pollution; Antioxidants; Ascorbic Acid; beta Carotene; Chronic Disease; Diet; Female; Humans; Male; Middle Aged; Netherlands; Peak Expiratory Flow Rate; Respiratory Tract Diseases; Seasons; Smoke; Urban Health

To study the effects of passive smoking on health in adolescent schoolchildren by questionnaire, spirometry and laboratory investigations.. Two schools in the Vanderbijlpark area.. Seven hundred and twenty-six high-school children of average age 16 years.. Lung function, serological abnormality or historical (i.e. questionnaire) evidence of ill health.. The prevalence of respiratory illness before and after 2 years, respiratory symptoms, earache over the past year, low birth weight and learning difficulties were found to be significantly increased in the children exposed to parenteral smoke in the home, especially those exposed to maternal smoking. Spirometric and laboratory parameters, however, were not affected by passive smoking.

Topics: Adolescent; Ascorbic Acid; Cotinine; Female; Hematologic Tests; Humans; Immunologic Tests; Male; Respiratory Tract Diseases; South Africa; Spirometry; Surveys and Questionnaires; Tobacco Smoke Pollution; Vitamin E

It is speculated that hypochlorous acid (HOCl), produced by neutrophils, can disrupt the tracheal epithelial barrier without damage to epithelial cells. This was investigated with solute permeability (P) and electrical conductance (G) measurements on tracheae from 4-wk-old rabbits. A new system for epithelial bioelectric measurements on intact tracheae was developed and validated. Control values of G, short-circuit current, and spontaneous potential difference were 4.9 +/- 0.5 (SE) mS/cm2, 42.6 +/- 4.7 microA/cm2, and 8.9 +/- 1.0 mV (lumen negative), respectively (n = 5). Control P values for sucrose, inulin, and Dextran-20 were 5.14 +/- 0.48, 0.63 +/- 0.10, and 0.057 +/- 0.007 x 10(-7) cm/s, respectively (n = 6). Tracheae treated with HOCl had no effect; 6 mM HOCl, a concentration that could exist in infected airways, significantly increased both P and G (about two- to fourfold) without damage to epithelial cells; and 12 and 30 mM HOCl caused more than 10-fold increases for both P and G with cell disruption. Vitamin C blocked epithelial damage caused by 30 mM HOCl. Tracheae from 1-wk-old rabbits were significantly more sensitive to HOCl than those from 4-wk-old or adult rabbits. This study validated a new bioelectric measurement system and showed that HOCl has both dose- and age-dependent effects on the tracheal epithelium.

Topics: Aging; Animals; Ascorbic Acid; Cell Membrane Permeability; Disease Models, Animal; Epithelium; Hypochlorous Acid; Ion Transport; Male; Membrane Potentials; Patch-Clamp Techniques; Rabbits; Respiratory Tract Diseases; Trachea

Topics: Antioxidants; Ascorbic Acid; Brain Diseases; Cardiovascular Diseases; Cells; Free Radical Scavengers; Free Radicals; Humans; Ischemia; Phagocytes; Reactive Oxygen Species; Reperfusion Injury; Respiratory Tract Diseases; Superoxide Dismutase

Ten patients with neutrophil dysfunctions and recurrent pyogenic infections, mainly of the skin middle-ear, and respiratory tract, are described. The most frequently affected functions were chemotaxis and bacterial killing. Pharmacologic restoration of functional defects was tried in all cases. Levamisole was given in two cases and ascorbic acid in the other eight cases. During a follow up of at least 18 months, seven patients showed a complete restoration of neutrophil function and a long-lasting clinical remission. One of the two patients with Chronic Granulomatous Disease has been free from infections for 1 year, despite persistent neutrophil dysfunction, while the other did not display consistent clinical improvement. Another patient, who was given ascorbic acid for a short period only due to non compliance, showed neither laboratory nor clinical improvement.

Topics: Ascorbic Acid; Bacterial Infections; Chemotaxis, Leukocyte; Child; Child, Preschool; Cytotoxicity, Immunologic; Female; Humans; In Vitro Techniques; Infant; Levamisole; Male; Neutrophils; Otitis Media; Phagocytosis; Respiratory Tract Diseases; Skin Diseases, Infectious

Topics: Acute Disease; Adjuvants, Immunologic; Aerosols; Ascorbic Acid; Freeze Drying; Humans; Methylthiouracil; Pentoxyl; Respiratory Tract Diseases; Tonsillitis; Uracil

Topics: Ascorbic Acid; Child; Humans; Respiratory Tract Diseases; Statistics as Topic

Topics: Accidents, Occupational; Ascorbic Acid; Coma; Cyanosis; Environmental Exposure; Euphoria; Gastrointestinal Diseases; Humans; Hydrogen Sulfide; Nausea; Occupational Diseases; Oxygen Inhalation Therapy; Petroleum; Respiratory Tract Diseases; Tachycardia

Topics: Adolescent; Adult; Age Factors; Aged; Ascorbic Acid; Child; Diet Therapy; Dose-Response Relationship, Drug; Female; Health Education; Health Surveys; Humans; Male; Middle Aged; Nutrition Surveys; Nutritional Physiological Phenomena; Respiratory System; Respiratory Tract Diseases; Surveys and Questionnaires; Time Factors

Topics: Absenteeism; Acute Disease; Ascorbic Acid; Coal Mining; Diet; Humans; Influenza, Human; Occupational Diseases; Respiratory Tract Diseases; Seasons; Time Factors

Topics: Animals; Ascorbic Acid; Cat Diseases; Cats; Picornaviridae; Respiratory Tract Diseases; Tracheitis; Uridine; Virus Diseases

Topics: Ascorbic Acid; Blood Chemical Analysis; Child; Gastroenteritis; Jaundice; Liver Diseases; Liver Function Tests; Nutrition Disorders; Respiratory Tract Diseases; Rickets

Topics: Adenoviridae Infections; Aminophylline; Ascorbic Acid; Chlamydophila psittaci; Chloramphenicol; Drug Therapy; Epidemiologic Studies; Epidemiology; France; Humans; Influenza, Human; Military Medicine; Orthomyxoviridae; Orthomyxoviridae Infections; Pneumonia; Pneumonia, Viral; Psittacosis; Radiography, Thoracic; Respiratory Tract Diseases; Sendai virus; Serologic Tests; Vaccination; Virus Diseases

Topics: Ascorbic Acid; Breathing Exercises; Bronchitis; Geriatrics; Humans; Respiratory Function Tests; Respiratory System; Respiratory Tract Diseases; Tetracycline; Vitamin A

Topics: Ascorbic Acid; Humans; Respiratory System; Respiratory Tract Diseases; Rhinitis; Sympathomimetics

Topics: Ascorbic Acid; Citrus; Flavones; Flavonoids; Respiratory System; Respiratory Tract Diseases; Respiratory Tract Infections; Vitamins

Topics: Ascorbic Acid; Diphenhydramine; Humans; Hypersensitivity; Immune System Diseases; Respiratory System; Respiratory Tract Diseases; Vitamins

Topics: Ascorbic Acid; Biomedical Research; Humans; Respiratory System; Respiratory Tract Diseases; Vitamins