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Hemilä H, Chalker E. Vitamin C reduces the severity of common colds: a meta-analysis. BMC Public Health 2023; 23:2468. [PMID: 38082300 PMCID: PMC10712193 DOI: 10.1186/s12889-023-17229-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 11/14/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND Randomized trials have shown that vitamin C shortens the duration of common colds. Some trials reported greater effects on severe cold symptoms compared with mild symptoms. This review systematically compares the effects of vitamin C on severe and mild common cold symptoms. METHODS We included all placebo-controlled trials of orally administered vitamin C in doses of at least 1 g/day for the common cold for people in good health at baseline. The analysis was restricted to trials which reported both the total duration of the common cold, and the severity of the common cold measured using severity scales, the duration of more severe stages of the cold, or proxies for severe colds such as days indoors. Findings were pooled using the inverse variance, fixed effect options of the metacont function of the R package meta to calculate the ratio of means estimate. RESULTS Fifteen comparisons from 10 trials which reported both mild and severe symptoms were identified. All trials were randomized and double-blind. Compared to placebo, vitamin C significantly decreased the severity of the common cold by 15% (95% CI 9-21%). The direct comparison of the effect of vitamin C on mild and severe symptoms was limited to five comparisons which found that vitamin C had a significant benefit on the duration of severe symptoms. In this subset, there was a significant difference in the size of the effect of vitamin C on the overall duration of colds versus the duration of severe colds (P = 0.002), and vitamin C had no significant effect on the duration of mild symptoms. CONCLUSIONS The common cold is the leading cause of acute morbidity and a major cause of absenteeism from work and school. However, absenteeism is dependent on the severity of symptoms. The finding that vitamin C may have a greater effect on more severe measures of the common cold is therefore important. Further research on the therapeutic effects of vitamin C on the common cold should measure outcomes of differing levels of severity.
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Affiliation(s)
- Harri Hemilä
- Department of Public Health, University of Helsinki, POB 20, Helsinki, FI, FI-00014, Finland.
| | - Elizabeth Chalker
- Biological Data Science Institute, Australian National University, Canberra, ACT, 2601, Australia
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Chen HY, Hsu M, Lio CWJ. Micro but mighty-Micronutrients in the epigenetic regulation of adaptive immune responses. Immunol Rev 2022; 305:152-164. [PMID: 34820863 PMCID: PMC8766944 DOI: 10.1111/imr.13045] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 11/11/2021] [Accepted: 11/14/2021] [Indexed: 01/03/2023]
Abstract
Micronutrients are essential small molecules required by organisms in minute quantity for survival. For instance, vitamins and minerals, the two major categories of micronutrients, are central for biological processes such as metabolism, cell replication, differentiation, and immune response. Studies estimated that around two billion humans worldwide suffer from micronutrient deficiencies, also known as "hidden hunger," linked to weakened immune responses. While micronutrients affect the immune system at multiple levels, recent studies showed that micronutrients potentially impact the differentiation and function of immune cells as cofactors for epigenetic enzymes, including the 2-oxoglutarate-dependent dioxygenase (2OGDD) family involved in histone and DNA demethylation. Here, we will first provide an overview of the role of DNA methylation in T cells and B cells, followed by the micronutrients ascorbate (vitamin C) and iron, two critical cofactors for 2OGDD. We will discuss the emerging evidence of these micronutrients could regulate adaptive immune response by influencing epigenetic remodeling.
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Affiliation(s)
| | | | - Chan-Wang Jerry Lio
- Corresponding author: Chan-Wang Jerry Lio (), Address: 460 W 12 Ave, Columbus, Ohio, USA 43064, Tel: (614)-247-5337
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Daei Sorkhabi A, Sarkesh A, Daei Sorkhabi A, Entezari-Maleki T, Rashedi J, Bannazadeh Baghi H. Vitamin supplementation as a potential adjunctive therapeutic approach for COVID-19: biological and clinical plausibility. J Basic Clin Physiol Pharmacol 2021; 33:55-77. [PMID: 34380185 DOI: 10.1515/jbcpp-2021-0111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 07/17/2021] [Indexed: 12/11/2022]
Abstract
The recent pandemic, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of Coronavirus Disease 2019 (COVID-19) has introduced itself into the human population in the 21st century after the coronavirus diseases SARS-CoV and Middle East respiratory syndrome (MERS-CoV). Major investigations are underway worldwide in the search for pharmaceutical interventions for COVID-19 and many agents are administered in off-label routes. Several cases are under study to check or restrict clinical manifestations of COVID-19. According to the fact that the efficacy of some micro-nutrients like vitamins is proven to treat or prevent infectious diseases because of their antimicrobial and immunomodulatory activity, the potential role of vitamins in the COVID-19 treatment or prevention must be considered.
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Affiliation(s)
- Amin Daei Sorkhabi
- Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
- Immunology Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Aila Sarkesh
- Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
- Immunology Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Alireza Daei Sorkhabi
- Immunology Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Taher Entezari-Maleki
- Department of Clinical Pharmacy, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
- Cardiovascular Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Jalil Rashedi
- Department of Laboratory Sciences, Faculty of Paramedicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Hossein Bannazadeh Baghi
- Immunology Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
- Department of Virology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
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Vitamin C zum Schutz vor SARS-CoV-2 und zur Behandlung von COVID-19. JOURNAL FÜR GYNÄKOLOGISCHE ENDOKRINOLOGIE/SCHWEIZ 2020. [PMCID: PMC7481539 DOI: 10.1007/s41975-020-00155-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Die neue Erkrankung COVID-19 wird durch das Virus SARS-CoV-2 ausgelöst. Aufgrund der globalen pandemischen Ausbreitung und der hohen Anzahl an Todesfällen stellen diese Erkrankung und deren Folgen einen hochaktuellen Schwerpunkt für die Erforschung und Entwicklung neuer Therapieansätze dar. Einer dieser Ansätze ist eine Therapie mit Vitamin C, ein vielversprechendes Vorgehen, das von diversen Arbeitsgruppen weltweit verfolgt wird. Hierbei wird die Wirkung der verschiedenen Vitamin-C-Anwendungen sowohl als Prophylaxe wie auch als Therapie der COVID-19-Erkrankung untersucht. Aktuelle Daten der Literatur zeigen, dass Vitamin C ohne signifikante Nebenwirkungen auf verschiedene pathophysiologische Prozesse der SARS-CoV-2-Infektion wirkt. Die Interleukin-6- zu Interleukin-10-Ratio oder das Verhältnis der Neutrophilen- zu der Lymphozytenzahl kann als Verlaufsparameter verwendet werden, um die Dynamik des Entzündungsgeschehens und so das Ansprechen auf die Therapie zu beurteilen. In diesem Rahmen kann der Vitamin-C-Spiegel des Blutserums kostengünstig und schnell im Kapillarblut anhand des Glukosespiegels überwacht werden. (Stand: Mai 2020)
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Abstract
In the early literature, vitamin C deficiency was associated with pneumonia. After its identification, a number of studies investigated the effects of vitamin C on diverse infections. A total of 148 animal studies indicated that vitamin C may alleviate or prevent infections caused by bacteria, viruses, and protozoa. The most extensively studied human infection is the common cold. Vitamin C administration does not decrease the average incidence of colds in the general population, yet it halved the number of colds in physically active people. Regularly administered vitamin C has shortened the duration of colds, indicating a biological effect. However, the role of vitamin C in common cold treatment is unclear. Two controlled trials found a statistically significant dose-response, for the duration of common cold symptoms, with up to 6-8 g/day of vitamin C. Thus, the negative findings of some therapeutic common cold studies might be explained by the low doses of 3-4 g/day of vitamin C. Three controlled trials found that vitamin C prevented pneumonia. Two controlled trials found a treatment benefit of vitamin C for pneumonia patients. One controlled trial reported treatment benefits for tetanus patients. The effects of vitamin C against infections should be investigated further.
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Affiliation(s)
- Harri Hemilä
- Department of Public Health, University of Helsinki, Helsinki FI-00014, Finland.
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Robitaille L, Hoffer LJ. A simple method for plasma total vitamin C analysis suitable for routine clinical laboratory use. Nutr J 2016; 15:40. [PMID: 27102999 PMCID: PMC4839128 DOI: 10.1186/s12937-016-0158-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 04/13/2016] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND In-hospital hypovitaminosis C is highly prevalent but almost completely unrecognized. Medical awareness of this potentially important disorder is hindered by the inability of most hospital laboratories to determine plasma vitamin C concentrations. The availability of a simple, reliable method for analyzing plasma vitamin C could increase opportunities for routine plasma vitamin C analysis in clinical medicine. METHODS Plasma vitamin C can be analyzed by high performance liquid chromatography (HPLC) with electrochemical (EC) or ultraviolet (UV) light detection. We modified existing UV-HPLC methods for plasma total vitamin C analysis (the sum of ascorbic and dehydroascorbic acid) to develop a simple, constant-low-pH sample reduction procedure followed by isocratic reverse-phase HPLC separation using a purely aqueous low-pH non-buffered mobile phase. Although EC-HPLC is widely recommended over UV-HPLC for plasma total vitamin C analysis, the two methods have never been directly compared. We formally compared the simplified UV-HPLC method with EC-HPLC in 80 consecutive clinical samples. RESULTS The simplified UV-HPLC method was less expensive, easier to set up, required fewer reagents and no pH adjustments, and demonstrated greater sample stability than many existing methods for plasma vitamin C analysis. When compared with the gold-standard EC-HPLC method in 80 consecutive clinical samples exhibiting a wide range of plasma vitamin C concentrations, it performed equivalently. CONCLUSION The easy set up, simplicity and sensitivity of the plasma vitamin C analysis method described here could make it practical in a normally equipped hospital laboratory. Unlike any prior UV-HPLC method for plasma total vitamin C analysis, it was rigorously compared with the gold-standard EC-HPLC method and performed equivalently. Adoption of this method could increase the availability of plasma vitamin C analysis in clinical medicine.
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Affiliation(s)
- Line Robitaille
- Lady Davis Institute for Medical Research and Department of Medicine, McGill University and Jewish General Hospital, 3755 Cote Sainte Catherine, Montreal, QC H3T 1E2 Canada
| | - L. John Hoffer
- Lady Davis Institute for Medical Research and Department of Medicine, McGill University and Jewish General Hospital, 3755 Cote Sainte Catherine, Montreal, QC H3T 1E2 Canada
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Hemilä H. Vitamin C and common cold-induced asthma: a systematic review and statistical analysis. ALLERGY, ASTHMA, AND CLINICAL IMMUNOLOGY : OFFICIAL JOURNAL OF THE CANADIAN SOCIETY OF ALLERGY AND CLINICAL IMMUNOLOGY 2013; 9:46. [PMID: 24279478 PMCID: PMC4018579 DOI: 10.1186/1710-1492-9-46] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Accepted: 11/07/2013] [Indexed: 12/17/2022]
Abstract
BACKGROUND Asthma exacerbations are often induced by the common cold, which, in turn, can be alleviated by vitamin C. OBJECTIVE To investigate whether vitamin C administration influences common cold-induced asthma. METHODS Systematic review and statistical analysis of the identified trials. Medline, Scopus and Cochrane Central were searched for studies that give information on the effects of vitamin C on common cold-induced asthma. All clinically relevant outcomes related to asthma were included in this review. The estimates of vitamin C effect and their confidence intervals [CI] were calculated for the included studies. RESULTS Three studies that were relevant for examining the role of vitamin C on common cold-induced asthma were identified. The three studies had a total of 79 participants. Two studies were randomized double-blind placebo-controlled trials. A study in Nigeria on asthmatics whose asthma attacks were precipitated by respiratory infections found that 1 g/day vitamin C decreased the occurrence of asthma attacks by 78% (95% CI: 19% to 94%). A cross-over study in former East-Germany on patients who had infection-related asthma found that 5 g/day vitamin C decreased the proportion of participants who had bronchial hypersensitivity to histamine by 52 percentage points (95% CI: 25 to 71). The third study did not use a placebo. Administration of a single dose of 1 gram of vitamin C to Italian non-asthmatic common cold patients increased the provocative concentration of histamine (PC20) 3.2-fold (95% CI: 2.0 to 5.1), but the vitamin C effect was significantly less when the same participants did not suffer from the common cold. CONCLUSIONS The three reviewed studies differed substantially in their methods, settings and outcomes. Each of them found benefits from the administration of vitamin C; either against asthma attacks or against bronchial hypersensitivity, the latter of which is a characteristic of asthma. Given the evidence suggesting that vitamin C alleviates common cold symptoms and the findings of this systematic review, it may be reasonable for asthmatic patients to test vitamin C on an individual basis, if they have exacerbations of asthma caused by respiratory infections. More research on the role of vitamin C on common cold-induced asthma is needed.
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Affiliation(s)
- Harri Hemilä
- Department of Public Health, POB 41, University of Helsinki, Mannerheimintie 172, FIN-00014 Helsinki, Finland.
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Abstract
BACKGROUND Pneumonia is one of the most common serious infections, causing two million deaths annually among young children in low-income countries. In high-income countries pneumonia is most significantly a problem of the elderly. OBJECTIVES To assess the prophylactic and therapeutic effects of vitamin C on pneumonia. SEARCH METHODS We searched CENTRAL 2013, Issue 3, MEDLINE (1950 to March week 4, 2013), EMBASE (1974 to April 2013) and Web of Science (1955 to April 2013). SELECTION CRITERIA To assess the therapeutic effects of vitamin C, we selected placebo-controlled trials. To assess prophylactic effects, we selected controlled trials with or without a placebo. DATA COLLECTION AND ANALYSIS Two review authors independently read the trial reports and extracted data. MAIN RESULTS We identified three prophylactic trials which recorded 37 cases of community-acquired pneumonia in 2335 people. Only one was satisfactorily randomised, double-blind and placebo-controlled. Two trials examined military recruits and the third studied boys from "lower wage-earning classes" attending a boarding school in the UK during World War II. Each of these three trials found a statistically significant (80% or greater) reduction in pneumonia incidence in the vitamin C group. We identified two therapeutic trials involving 197 community-acquired pneumonia patients. Only one was satisfactorily randomised, double-blind and placebo-controlled. That trial studied elderly patients in the UK and found lower mortality and reduced severity in the vitamin C group; however, the benefit was restricted to the most ill patients. The other therapeutic trial studied adults with a wide age range in the former Soviet Union and found a dose-dependent reduction in the duration of pneumonia with two vitamin C doses. We identified one prophylactic trial recording 13 cases of hospital-acquired pneumonia in 37 severely burned patients; one-day administration of vitamin C had no effect on pneumonia incidence. The identified studies are clinically heterogeneous which limits their comparability. The included studies did not find adverse effects of vitamin C. AUTHORS' CONCLUSIONS The prophylactic use of vitamin C to prevent pneumonia should be further investigated in populations who have a high incidence of pneumonia, especially if dietary vitamin C intake is low. Similarly, the therapeutic effects of vitamin C should be studied, especially in patients with low plasma vitamin C levels. The current evidence is too weak to advocate prophylactic use of vitamin C to prevent pneumonia in the general population. Nevertheless, therapeutic vitamin C supplementation may be reasonable for pneumonia patients who have low vitamin C plasma levels because its cost and risks are low.
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Affiliation(s)
- Harri Hemilä
- Department of Public Health, POB 41, University of Helsinki, Mannerheimintie 172, Helsinki, Finland, FIN-00014
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Evans-Olders R, Eintracht S, Hoffer LJ. Metabolic origin of hypovitaminosis C in acutely hospitalized patients. Nutrition 2009; 26:1070-4. [PMID: 20018480 DOI: 10.1016/j.nut.2009.08.015] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2009] [Revised: 06/22/2009] [Accepted: 08/12/2009] [Indexed: 12/22/2022]
Abstract
OBJECTIVE Recent studies have indicated a high prevalence of hypovitaminosis C in acutely hospitalized patients. It is unclear whether hypovitaminosis C in this setting represents deficiency or tissue redistribution of the vitamin as part of the acute-phase response. METHODS We administered vitamin C for 1 wk to acutely hospitalized, but not critically ill patients with hypovitaminosis C, on the assumption that a large increase in plasma and mononuclear leukocyte vitamin C concentrations, a decrease in metabolic markers of oxidative stress, or an improvement in psychologic mood state would implicate the initial condition as nutritional deficiency rather than tissue redistribution. RESULTS Vitamin C administration increased plasma and mononuclear leukocyte vitamin C concentrations from subnormal (16.3 ± 12.4 μmol/L and 6.5 ± 5.5 mmol/L, respectively) to normal (71.0 ± 30.9 μmol/L, P < 0.0001, and 8.2 ± 6.8 mmol/L, P < 0.015); the mood disturbance score improved by 33% (P < 0.008). There was no increase in plasma glutathione concentrations or a reduction in plasma or mononuclear leukocyte malondialdehyde concentrations. An inverse relation was observed between plasma C-reactive protein and plasma vitamin C concentrations (P = 0.006). CONCLUSION Although associated with systemic inflammation, the metabolic features of hypovitaminosis C in acutely hospitalized, non-critically ill patients are more consistent with deficiency than with tissue redistribution.
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Affiliation(s)
- Rebecca Evans-Olders
- Lady Davis Institute for Medical Research, McGill University and Jewish General Hospital, Montreal, Quebec, Canada
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Hemilä H, Kaprio J. Modification of the effect of vitamin E supplementation on the mortality of male smokers by age and dietary vitamin C. Am J Epidemiol 2009; 169:946-53. [PMID: 19218294 PMCID: PMC2661323 DOI: 10.1093/aje/kwn413] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study (1985–1993) recruited 29,133 Finnish male cigarette smokers, finding that vitamin E supplementation had no overall effect on mortality. The authors of this paper found that the effect of vitamin E on respiratory infections in ATBC Study participants was modified by age, smoking, and dietary vitamin C intake; therefore, they examined whether the effect of vitamin E supplementation on mortality is modified by the same variables. During a median follow-up time of 6.1 years, 3,571 deaths occurred. Age and dietary vitamin C intake had a second-order interaction with vitamin E supplementation of 50 mg/day. Among participants with a dietary vitamin C intake above the median of 90 mg/day, vitamin E increased mortality among those aged 50–62 years by 19% (95% confidence interval: 5, 35), whereas vitamin E decreased mortality among those aged 66–69 years by 41% (95% CI: −56, −21). Vitamin E had no effect on participants who had a dietary vitamin C intake below the median. Smoking quantity did not modify the effect of vitamin E. This study provides strong evidence that the effect of vitamin E supplementation on mortality varies between different population groups. Further study is needed to confirm this heterogeneity.
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Affiliation(s)
- Harri Hemilä
- Department of Public Health, University of Helsinki, Finland.
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