scholarly journals Association of vitamin C, vitamin D, vitamin E and risk of bladder cancer: a dose-response meta-analysis

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Fuqiang Chen ◽  
Qingshu Li ◽  
Yang Yu ◽  
Wenrong Yang ◽  
Fei Shi ◽  
...  
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.


2019 ◽  
Vol 109 (1) ◽  
pp. 43-54 ◽  
Author(s):  
Hong Jiang ◽  
Yue Yin ◽  
Chang-Rui Wu ◽  
Yan Liu ◽  
Fang Guo ◽  
...  

ABSTRACT Background Existing studies suggest that dietary vitamins and carotenoids might be associated with a reduced risk of age-related cataract (ARC), although a quantitative summary of these associations is lacking. Objectives The aim of this study was to conduct a meta-analysis of randomized controlled trials (RCTs) and cohort studies of dietary vitamin and carotenoid intake and ARC risk. Methods The MEDLINE, EMBASE, ISI Web of Science, and Cochrane Library databases were searched from inception to June 2018. The adjusted RRs and corresponding 95% CIs for the associations of interest in each study were extracted to calculate pooled estimates. Dose-response relations were assessed with the use of generalized least-squares trend estimation. Results We included 8 RCTs and 12 cohort studies in the meta-analysis. Most vitamins and carotenoids were significantly associated with reduced risk of ARC in the cohort studies, including vitamin A (RR: 0.81; 95% CI: 0.71, 0.92; P = 0.001), vitamin C (RR: 0.80; 95% CI: 0.72, 0.88; P < 0.001), vitamin E (RR: 0.90; 95% CI: 0.80, 1.00; P = 0.049), β-carotene (RR: 0.90; 95% CI: 0.83, 0.99; P = 0.023), and lutein or zeaxanthin (RR: 0.81; 95% CI: 0.75, 0.89; P < 0.001). In RCTs, vitamin E (RR: 0.97; 95% CI: 0.91, 1.03; P = 0.262) or β-carotene (RR: 0.99; 95% CI: 0.92, 1.07; P = 0.820) intervention did not reduce the risk of ARC significantly compared with the placebo group. Further dose-response analysis indicated that in cohort studies the risk of ARC significantly decreased by 26% for every 10-mg/d increase in lutein or zeaxanthin intake (RR: 0.74; 95% CI: 0.67, 0.80; P < 0.001), by 18% for each 500-mg/d increase in vitamin C intake (RR: 0.82; 95% CI: 0.74, 0.91; P < 0.001), by 8% for each 5-mg/d increase in β-carotene intake (RR: 0.92; 95% CI: 0.88, 0.96; P < 0.001), and by 6% for every 5 mg/d increase in vitamin A intake (RR: 0.94; 95% CI: 0.90, 0.98; P < 0.001). Conclusions Higher consumption of certain vitamins and carotenoids was associated with a significant decreased risk of ARC in cohort studies, but evidence from RCTs is less clear.


2019 ◽  
Author(s):  
Lin Zhang ◽  
Huachun Zou ◽  
Yang Zhao ◽  
Chunlei Hu ◽  
Adejare (Jay) Atanda ◽  
...  

ABSTRACTObjectivesTo assess the association between blood circulating Vitamin D levels and colorectal cancer risk in the Asian population.DesignThis is a systematic review and dose-response meta-analysis of observational studies that investigated the relationship between blood circulating Vitamin D levels and colorectal cancer risk in the Asian population.Data SourcesRelevant studies were identified through a literature search in MEDLINE, EMBASE, and Web of Science from January 1980 to 31 January 2019. Eligibility criteria: original studies published in peer-reviewed journals investigating the association between blood circulating Vitamin D levels and the risk of colorectal cancer and/or adenoma in Asian countries.Data extraction and synthesisTwo authors independently extracted data and assessed the quality of included studies. Study-specific ORs were pooled using a random-effects model. A dose-response meta-analysis was performed with generalized least squares regression. We applied the Newcastle-Ottawa Scale quality assessment to evaluate the quality of the selected studies.ResultsThe eight included studies encompassed a total of 2,916 cases and 6,678 controls. The pooled ORs of colorectal cancer for the highest versus lowest categories of blood circulating Vitamin D levels was 0.75 [95% CI, 0.58-0.97] up to 36.5 ng/mL in the Asian population. There was heterogeneity among the studies (I2=53.9%, Pheterogeneity=0.034). The dose-response meta-analysis indicated a significant linear relationship (Pnon-linearity=0.11). An increment of 16 ng/mL in blood circulating Vitamin D level corresponded to an OR of 0.79 [95% CI, 0.64-0.97].ConclusionsThe results of this meta□analysis indicate that blood circulating Vitamin D level is associated with decreased risk of colorectal cancer in Asian countries. The dose-response meta-analysis shows that the strength of this association among the Asian population is similar to that among the Western population. Our study suggests that the Asian population should improve nutritional status and maintain a higher level of blood circulating Vitamin D.Strengths and limitations of this studyOur study seeks to extend previous work by including a number of new studies and by distinguishing the Asian population explicitly.The number of included studies is not sufficient to provide a robust estimate, so the results should be interpreted in the context of the limitations of the available data.Heterogeneous definitions of blood circulating Vitamin D categories were used across studies. The variability in definitions could limit comparability between studies.Our study included seven case-control studies; the study design implies that the measurement of blood circulating Vitamin D is measured in individuals already diagnosed with colorectal cancer. Results from case-control studies need to be interpreted cautiously because of the potential for reverse causation.Time of blood sampling in relation to outcome ascertainment also varied among studies. Such cross-sectional measurements may not accurately reflect an individual’s Vitamin D status across time.


2017 ◽  
Vol 17 (2) ◽  
pp. 217-225 ◽  
Author(s):  
Kejia Hu ◽  
David Frederick Callen ◽  
Jiayuan Li ◽  
Hong Zheng

Studies have shown that vitamin D could have a role in breast cancer survival; however, the evidence of the relationship between patients’ vitamin D levels and their survival has been inconsistent. This meta-analysis explores possible dose-response relationships between vitamin D levels and overall survival by allowing for differences in vitamin D levels among populations of the various studies. Studies relating vitamin D (25-OH-D [25-hydroxyvitamin D]) levels in breast cancer patients with their survival were identified by searching PubMed and Embase. A pooled HR (hazard ratio) comparing the highest with the lowest category of circulating 25-OH-D levels were synthesized using the Mantel-Haenszel method under a fixed-effects model. A two-stage fixed-effects dose-response model including both linear (a log-linear dose-response regression) and nonlinear (a restricted cubic spline regression) models were used to further explore possible dose-response relationships. Six studies with a total number of 5984 patients were identified. A pooled HR comparing the highest with the lowest category of circulating 25-OH-D levels under a fixed-effects model was 0.67 (95% confidence interval = 0.56-0.79, P < .001). Utilizing a dose-response meta-analysis, the pooled HR for overall survival in breast cancer patients was 0.994 (per 1 nmol/L), Pfor linear trend < .001. At or above a 23.3 nmol/L threshold, for a 10 nmol/L, 20 nmol/L, or 25 nmol/L increment in circulating 25-OH-D levels, the risk of breast cancer overall mortality decreased by 6%, 12%, and 14%, respectively. There was no significant nonlinearity in the relationship between overall survival and circulating 25-OH-D levels. Our findings suggest that there is a highly significant linear dose-response relationship between circulating 25-OH-D levels and overall survival in patients with breast cancer. However, better designed prospective cohort studies and clinical trials are needed to further confirm these findings.


Author(s):  
Rosmi Jose ◽  
Venketeswaramurthy N ◽  
Sambath Kumar R

This review describes about the literatures addressing the role of vitamin supplementation in schizophrenia. Evidence is suggesting that vitamin supplementation includes Vitamin A, Vitamin D, Vitamin E, Vitamin B complex, and Vitamin C may be important in treatment. In schizophrenia, patients may have increased level of homocysteine (Hcy), due to the polymorphism in methylenetetrahydrofolate reductase and hypofunction of N-methyl-D-aspartate receptors. The vitamins main effects are reduced the Hcy level and maintain dopamine and serotonin levels. Add-on treatment with high-dose B vitamins including B6, B9, and B12 and also Vitamin D can significantly reduce symptoms of schizophrenia more than standard treatments alone.


Tumor Biology ◽  
2014 ◽  
Vol 36 (3) ◽  
pp. 1567-1572 ◽  
Author(s):  
Yong Liao ◽  
Jian-Lin Huang ◽  
Ming-Xing Qiu ◽  
Zhi-Wei Ma

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