scholarly journals The Regulation of Dietary Iron Bioavailability by Vitamin C: A Systematic Review and Meta-Analysis

2017 ◽  
Vol 76 (OCE4) ◽  
Author(s):  
A. Heffernan ◽  
C. Evans ◽  
M. Holmes ◽  
J.B. Moore
Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3910
Author(s):  
Aileen Hill ◽  
Kai Clasen ◽  
Sebastian Wendt ◽  
Ádám Majoros ◽  
Christian Stoppe ◽  
...  

The authors thank the readers for pointing out the issues [...]


2019 ◽  
Vol 22 (10) ◽  
pp. 1872-1887 ◽  
Author(s):  
Ahmad Jayedi ◽  
Ali Rashidy-Pour ◽  
Mohammad Parohan ◽  
Mahdieh Sadat Zargar ◽  
Sakineh Shab-Bidar

AbstractObjectiveThe present review aimed to quantify the association of dietary intake and circulating concentration of major dietary antioxidants with risk of total CVD mortality.DesignSystematic review and meta-analysis.SettingSystematic search in PubMed and Scopus, up to October 2017.ParticipantsProspective observational studies reporting risk estimates of CVD mortality across three or more categories of dietary intakes and/or circulating concentrations of vitamin C, vitamin E and β-carotene were included. A random-effects meta-analysis was conducted.ResultsA total of fifteen prospective cohort studies and three prospective evaluations within interventional studies (320 548 participants and 16 974 cases) were analysed. The relative risks of CVD mortality for the highest v. the lowest category of antioxidant intakes were as follows: vitamin C, 0·79 (95 % CI 0·68, 0·89; I2=46 %, n 10); vitamin E, 0·91 (95 % CI 0·79, 1·03; I2=51 %, n 8); β-carotene, 0·89 (95 % CI 0·73, 1·05; I2=34 %, n 4). The relative risks for circulating concentrations were: vitamin C, 0·60 (95 % CI 0·42, 0·78; I2=65 %, n 6); α-tocopherol, 0·82 (95 % CI 0·76, 0·88; I2=0 %, n 5); β-carotene, 0·68 (95 % CI 0·52, 0·83; I2=50 %, n 6). Dose–response meta-analyses demonstrated that the circulating biomarkers of antioxidants were more strongly associated with risk of CVD mortality than dietary intakes.ConclusionsThe present meta-analysis demonstrates that higher vitamin C intake and higher circulating concentrations of vitamin C, vitamin E and β-carotene are associated with a lower risk of CVD mortality.


Angiology ◽  
2016 ◽  
Vol 68 (5) ◽  
pp. 389-413 ◽  
Author(s):  
Sadegh Ali-Hassan-Sayegh ◽  
Seyed Jalil Mirhosseini ◽  
Zahra Ghodratipour ◽  
Zahra Sarrafan-Chaharsoughi ◽  
Elham Rahimizadeh ◽  
...  

This systematic review with meta-analysis sought to determine the strength of evidence for the effects of hydration (sodium bicarbonate [SB] and normal saline [NS]), supplementations ( N-acetylcysteine [NAC] and vitamin C), and some common drugs (adenosine antagonists [AAs], statins, loop diuretics, and angiotensin-converting enzyme inhibitors [ACEIs]) on the incidence of contrast-induced nephropathy (CIN) and requirement for hemodialysis after coronary angiography. After screening, a total of 125 trials that reported outcomes were identified. Pooled analysis indicated beneficial effects of SB versus NS (odds ratio [OR] = 0.73; 95% confidence interval [CI]: 0.56-0.94; P = .01), NAC (OR = 0.79; 95% CI: 0.70-0.88; P = .001), vitamin C (OR = 0.64; 95% CI: 0.45-0.89; P = .01), statins (OR = 0.45; 95% CI: 0.35-0.57; P = .001), AA (OR = 0.28; 95% CI: 0.14-0.47; P = .001), loop diuretics (OR = 0.97; 95% CI: 0.33-2.85; P = .9), and ACEI (OR = 1.06; 95% CI: 0.69-1.61; P = .8). Overall, hydration with SB, use of supplements, such as NAC and vitamin C, and administration of statins and AA should always be considered for the prevention of CIN after coronary angiography.


2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Dominic J. Hare ◽  
Sabine Braat ◽  
Bárbara R. Cardoso ◽  
Christopher Morgan ◽  
Ewa A. Szymlek-Gay ◽  
...  

Abstract Background Direct supplementation or food fortification with iron are two public health initiatives intended to reduce the prevalence of iron deficiency (ID) and iron deficiency anaemia (IDA) in 4–24-month-old infants. In most high-income countries where IDA prevalence is < 15%, the recommended daily intake levels of iron from supplements and/or consumption of fortified food products are at odds with World Health Organisation (WHO) guidelines that recommend shorter-term (3 months/year) supplementation only in populations with IDA prevalence > 40%. Emerging concerns about delayed neurological effects of early-life iron overexposure have raised questions as to whether recommended guidelines in high-income countries are unnecessarily excessive. This systematic review will gather evidence from supplementation/fortification trials, comparing health outcomes in studies where iron-replete children did or did not receive additional dietary iron; and determine if replete children at study outset were not receiving additional iron show changes in haematological indices of ID/IDA over the trial duration. Methods We will perform a systematic review of the literature, including all studies of iron supplementation and/or fortification, including study arms with confirmed iron-replete infants at the commencement of the trial. This includes both dietary iron intervention or placebo/average dietary intakes. One reviewer will conduct searches in electronic databases of published and ongoing trials (Medline, Web of Science, Scopus, CENTRAL, EBSCO [e.g. CINAHL Complete, Food Science and Technology Abstracts], Embase, ClinicalTrials.gov, ClinicalTrialsRegister.eu and who.it/trialsearch), digital theses and dissertations (WorldCat, Networked Digital Library of Theses and Dissertations, DART-Europe E-theses Portal, Australasian Digital Theses Program, Theses Canada Portal and ProQuest). For eligible studies, one reviewer will use a data extraction form, and a second reviewing entered data for accuracy. Both reviewers will independently perform quality assessments before qualitative and, if appropriate, quantitative synthesis as a meta-analysis. We will resolve any discrepancies through discussion or consult a third author to resolve discrepancies. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement will be used as the basis for reporting. Discussion Recommended iron supplementation and food fortification practices in high-income countries have been criticised for being both excessive and based on outdated or underpowered studies. This systematic review will build a case for revisiting iron intake guidelines for infants through the design of new trials where health effects of additional iron intake in iron-replete infants are the primary outcome. Systematic review registration PROSPERO CRD42018093744.


2018 ◽  
Vol 151 (2) ◽  
pp. 45-52
Author(s):  
Edgar Yaset Caicedo Ochoa ◽  
César Orlando Quintero Moreno ◽  
Yardany Rafael Méndez Fandiño ◽  
Sofía Catalina Sánchez Fonseca ◽  
Héctor Fabio Cortes Motta ◽  
...  

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Shuangdi Chen ◽  
Wenli Zhao ◽  
Binjie Zhang ◽  
Yijun Jia ◽  
Shihua Wu ◽  
...  

Objective. To comprehensively compare the effects of conventional therapy combined with intravenous vitamin C and conventional therapy on viral myocarditis in children through a meta-analysis. Methods. Relevant articles including clinical trials of normal treatment combined with intravenous vitamin C and conventional therapy for viral myocarditis in children that were published between January 2000 and February 2018 were selected from PubMed, Cochrane Library, China National Knowledge Infrastructure, China Science and Technology Journal Database, and WANFANG database. The quality of the included studies was assessed using the Cochrane systematic review method (version 5.1.0); data quality was evaluated by two independent researchers. The total effective rate; LDH, CK, and CK-MB levels; and other indicators were analyzed using Rev Man 5.3 software. Results. Eight studies were eligible for this meta-analysis, which included a total of 426 patients in the treatment group and 363 patients in the control group. The meta-analysis results of six studies showed that the total effective rate of intravenous vitamin C combined with conventional therapy was higher than that of conventional therapy alone [Z = 5.46, 95% confidence interval (CI): 1.21 (1.13 to 1.30), P < 0.00001]; that of five studies showed that LDH levels were lower in children receiving intravenous vitamin C combined with conventional therapy than in those receiving conventional therapy alone [Z = 3.70, 95% CI: −1.88 (−2.88 to −0.88), P = 0.0002]; that of three studies showed that CK levels were lower in children receiving intravenous vitamin C combined with conventional therapy than in those receiving conventional therapy alone [Z = 4.21, 95% CI: −0.55 (−0.81 to −0.30), P < 0.0001]; that of four studies showed that CK-MB levels were lower in children receiving intravenous vitamin C combined with conventional therapy than in those receiving conventional therapy alone [Z = 13.64, 95% CI: −1.44 (−1.65 to −1.24), P < 0.00001]; that of two studies showed that CD3 levels were higher in children receiving intravenous vitamin C combined with conventional therapy than in those receiving conventional therapy alone [Z = 2.45, 95% CI: 0.41 (0.08–0.73), P = 0.01]; that of two studies showed no significant difference in changes in CD4 levels between children receiving intravenous vitamin C combined with conventional therapy and those receiving conventional therapy alone [Z = 0.28, 95% CI: −0.21 (−1.69 to 1.28), P = 0.78]; and that of two studies showed no significant difference in changes in CD4/CD8 between children receiving intravenous vitamin C combined with conventional therapy and those receiving conventional therapy alone [Z = 0.07, 95% CI: −0.03 (−0.73 to 0.67), P = 0.94]. Conclusion. The meta-analysis results showed that intravenous vitamin C combined with conventional therapy is better than the simple, conventional therapy for the treatment of viral myocarditis in children in terms of the total effective rate and LDH, CK, and CK-MB levels.


2020 ◽  
Author(s):  
Cong-Cong Zhao ◽  
Li-Nan Han ◽  
Gui-Jun Zhu ◽  
Zhi-Qiang Li ◽  
Zhen-Jie Hu

Abstract Background: The effect of vitamin C on outcomes in sepsis is unclear. This systematic review and meta-analysis included animal and human studies to evaluate the value of intravenous vitamin C as a monotherapy in sepsis. Methods: We searched MEDLINE via PubMed, EMBASE, CENTRAL and CBM for animal studies, randomized controlled trials (RCTs), and quasi-RCTs dated up to August 10, 2020. The included studies compared the effect of intravenous vitamin C and control on outcomes in sepsis. No language restrictions were applied. Two authors independently assessed the eligibility and quality of the trials and extracted data. Results: A total of 7 animal studies and 5 RCTs were included. Four animal studies (n=176) and all 5 RCTs (n=472) reported mortality, the primary outcome of this meta-analysis. The mortality of the vitamin C group was lower than that of the control group (odds ratio (OR) 0.22, 95% CI 0.06 to 0.81, P = 0.02; I2 =60% in animal studies, and OR 0.48, 95% CI 0.33 to 0.71, P < 0.001; I2 =0% in human studies). The GRADE assessment showed that the outcome was downgraded from high- to moderate-quality evidence due to imprecision. With regard to the secondary outcomes, the pooled data from animal studies showed that vitamin C had a beneficial effect on mean arterial pressure (std. mean difference (SMD) 1.36, 95% CI 0.32 to 2.41, P = 0.01; I2 =78%) and capillary density (SMD 1.97, 95% CI 0.89 to 3.04, P=0.69; I2 =0%) but had no effect on the level of lactate. The pooled data from human studies showed that vitamin C was associated with a reduction in vasopressor duration (MD -18.85, 95% CI -24.61 to -11.55, P < 0.001; I2 =0%) but could not shorten the length of ICU stay or duration of mechanical ventilation. No adverse effects were reported.Conclusions: Evidence from animal and human studies suggests that intravenous vitamin C monotherapy can reduce mortality in sepsis, with a moderate quality of evidence. We also found that vitamin C had a beneficial effect on mean arterial pressure, capillary density, and reduction of vasopressor duration in sepsis.


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