scholarly journals Vitamin D supplementation and energy and metabolic homoeostasis in obese and overweight subjects: a protocol for a systematic review

BMJ Open ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. e051230
Author(s):  
Yu He ◽  
Xiao Yang ◽  
Min Li ◽  
Anren Zhang ◽  
Nianyi Sun
Keyword(s):  
Vitamin D ◽  
Systematic Reviews ◽  
Vitamin D Supplementation ◽  
Bibliographic Databases ◽  
Controlled Trials ◽  
Cochrane Central Register ◽  
Pathophysiological Mechanism ◽  
Manual Search ◽  
Obese Subjects ◽  
Overweight Subjects

IntroductionObesity and vitamin D deficiency are major public health problems. According to the pathophysiological mechanism of obesity as well as the bidirectional relationship between obesity and vitamin D metabolism and storage, vitamin D supplementation in obese and overweight subjects could have beneficial effects on the energy and metabolic homoeostasis. This review will assess the efficacy of vitamin D supplementation on the energy and metabolic homoeostasis in overweight and obese subjects.Methods and analysisIn accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols, we retrieved the relevant literature from the following electronic bibliographic databases: MEDLINE/PubMed, EMBASE and the Cochrane Central Register of Controlled Trials, from inception to June 2021. A manual search of the reference lists of all the relevant research articles will be performed to identify additional studies. We will include randomised controlled trials (RCTs) published in English that examine the effects of vitamin D supplementation on energy and metabolic homoeostasis in overweight and obese subjects. RCTs with multiple vitamin D groups will also be included. Two reviewers will independently complete the article selection, data extraction and rating. The bias tool from the Cochrane Handbook for Systematic Reviews of Interventions was used to assess the methodological quality of the included studies. A narrative or quantitative synthesis will be performed based on the available data. The planned start and end dates for the study were 1 February 2021 and 1 March 2022.Ethics and disseminationEthical approval will not be required for this review. The results of this review will be disseminated in a peer-reviewed journal.PROSPERO registration numberCRD42021228981.

scholarly journals Effectiveness and safety of steady versus intermittent high dose vitamin D supplementation for the prevention of falls and fractures among adults: a protocol for systematic review and network meta-analysis

BMJ Open ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. e027349
Author(s):  
Banaz Al-khalidi ◽  
Joycelyne Efua Ewusie ◽  
Jemila Hamid ◽  
Samantha Kimball
Keyword(s):  
Systematic Review ◽  
Vitamin D ◽  
Comparative Effectiveness ◽  
Meta Analysis ◽  
Institutional Care ◽  
Vitamin D Supplementation ◽  
Controlled Trials ◽  
High Dose ◽  
Cochrane Central Register ◽  
Dosing Schedule

IntroductionClinical trials and systematic reviews of trials involving vitamin D supplementation have mainly focused on defining the optimal amount of vitamin D dosage. However, the comparative effectiveness of different dosing schedules (ie, daily vs bolus dosing schedule) has been largely unexplored; and currently, there is no consensus regarding the optimal vitamin D dosing schedule. Our objective is to conduct a systematic review and network meta-analysis (NMA) to evaluate the comparative effectiveness and safety of steady (eg, daily, weekly) and intermittent high-dose (eg, monthly, yearly) vitamin D dosing schedules; and to determine the effectiveness of the various dosing schedules and combinations of treatments.Methods and analysisWe will conduct a systematic search and review of literature from major medical databases (MEDLINE, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials and ClinicalTrials.gov) involving studies that compare vitamin D supplementation alone or in combination with calcium. Only randomised controlled trials (RCTs) will be considered. We will, however, consider various settings (eg, community, institutional care) and study designs (eg, cluster RCTs, cross-over trials). Our primary outcomes include falls and fractures including hip-fracture and non-vertebral fractures. Secondary outcomes will include muscle strength, physical performance, gait and mobility limitation. A Bayesian NMA will be conducted, and the results will be presented in the form of treatment effect estimates and ranking probabilities, with corresponding CIs. Pairwise meta-analysis will also be conducted for studies reporting head-to-head comparisons. Subgroup analysis will be performed with respect to pre-determined subgroups; including vitamin D status as measured by serum 25-hydroxyvitamin D levels, age and follow-up time. Sensitivity analysis will also be performed with respect to risk of bias.Ethics and disseminationThis study is a systematic review and meta-analysis of published RCTs; therefore, no ethical approval is required. Results will be disseminated through open access peer-reviewed publications.Systematic review registrationPROSPERO CRD42018112662.

scholarly journals Vitamin D in Breastfed Infants: Systematic Review of Alternatives to Daily Supplementation

2019 ◽  
Author(s):  
Karen M O'Callaghan ◽  
Mahgol Taghivand ◽  
Anna Zuchniak ◽  
Akpevwe Onoyovwi ◽  
Jill Korsiak ◽  
...  
Keyword(s):  
Systematic Review ◽  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Weighted Mean Difference ◽  
Meta Analysis ◽  
Pooled Analysis ◽  
Vitamin D Supplementation ◽  
Controlled Trials ◽  
Cochrane Central Register ◽  
Term Infants

ABSTRACT Daily oral vitamin D supplementation (400 IU) is recommended for breastfeeding infants (≤1 y). Recent studies have examined alternative approaches to preventing vitamin D deficiency in this population. This systematic review and meta-analysis aimed to estimate the effects of maternal postpartum (M-PP) or infant intermittent (I-INT) vitamin D supplementation on infant 25-hydroxyvitamin D [25(OH)D] concentrations in comparison to routine direct infant daily (I-D) oral supplementation (400 IU). MEDLINE, MEDLINE In-Process, Embase, the Cochrane Database of Systematic Reviews, and the Cochrane Central Register of Controlled Trials were searched up to December 2018. Inclusion criteria consisted of published, peer-reviewed, vitamin D intervention trials involving lactating women and/or exclusively or partially breastfed term infants. Two reviewers independently extracted study characteristics (e.g., sample size, intervention dose, and duration and mode of administration) and related biochemical and clinical outcomes. Of 28 included trials, 5 randomized controlled trials were incorporated in meta-analyses examining infant 25(OH)D. Overall, M-PP supplementation resulted in modestly lower infant 25(OH)D compared with I-D supplementation (weighted mean difference = −8.1 nmol/L; 95% CI: −15.4, −0.9; I2 = 45%; P = 0.14; 3 trials), but the 2 most recent trials found M-PP to achieve similar infant 25(OH)D as I-D. Comparison of I-INT with I-D was confined to 2 trials with contradictory findings, and it was considered inappropriate for pooled analysis. Meta-analysis was therefore limited by a small number of eligible trials with variable quality of analytically derived 25(OH)D data and inconsistent reporting of safety outcomes, including effects on calcium homeostasis. Considering all 28 included trials, this systematic review highlights M-PP and I-INT regimens as plausible substitutes for routine daily infant vitamin D supplementation, but evidence remains too weak to support a policy update. Dose-ranging, adequately powered trials are required to establish the efficacy, safety, and feasibility of alternative strategies to prevent vitamin D deficiency in breastfeeding infants. This review was registered with PROSPERO as CRD42017069905.

scholarly journals Maternal and Neonatal Metabolic Outcomes of Vitamin D Supplementation in Gestational Diabetes Mellitus: A Systematic Review and Meta-Analysis

2018 ◽  
Vol 73 (2) ◽  
pp. 145-159 ◽  
Author(s):  
Fatemeh Jahanjoo ◽  
Azizeh Farshbaf-Khalili ◽  
Seyed Kazem Shakouri ◽  
Neda Dolatkhah
Keyword(s):  
Diabetes Mellitus ◽  
Vitamin D ◽  
Gestational Diabetes ◽  
Gestational Diabetes Mellitus ◽  
Meta Analysis ◽  
Density Lipoprotein ◽  
Vitamin D Supplementation ◽  
Controlled Trials ◽  
Cochrane Central Register ◽  
Hs Crp

Introduction: Many scientists have revealed the association between vitamin D deficiency and gestational diabetes mellitus (GDM). The purpose of this review was to evaluate the impact of vitamin D supplementation on maternal and neonatal health measures in GDM. Methods: A comprehensive systematic literature search in the electronic databases including Cochrane Central Register of Controlled Trials, MEDLINE (PubMed), Scopus, Web of Sciences, EMBASE, Google Scholar, Clininaltrial.gov, and ProQuest as well as SID, Magiran, Irandoc, and Iranmedex for Persian literature review carried out up to January 2018. All RCTs and quasi-experimental studies that compared vitamin D supplementation with placebo or without supplementation on GDM women were included in this review. Results: Five randomized controlled trials involving 310 women were included in the meta-analysis. There were significant differences in fasting Plasma Glucose (FPG; mean difference [MD] –12.54, 95% CI –15.03 to –10.05; 3 trials, 223 participants); total cholesterol (TC; MD –24.77, 95% CI –32.57 to –16.98; 3 trials, 223 participants); low-density lipoprotein (LDL) cholesterol (MD –18.92, 95% CI –24.97 to –12.88; 3 trials, 223 participants); high-density lipoprotein (HDL) cholesterol (MD, 3.87, 95% CI 1.20–6.55; 3 trials, 223 participants); high sensitivity C-reactive protein ­(hs-CRP; MD –1.35, 95% CI –2.41 to –0.28; 2 trials, 126 participants); and Newborns’ hyperbilirubinemia (OR 0.33, 95% CI 0.13–0.80; 2 trials, 129 participants). Conclusions: Supplementation of GDM women with vitamin D may lead to an improvement in FPG, TC, LDL, HDL, hs-CRP serum levels as well as in newborns’ hyperbilirubinemia.

scholarly journals Effect of vitamin D supplementation on serum 25-hydroxyvitamin D concentration in children and adolescents: a systematic review and meta-analysis protocol

BMJ Open ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. e021636 ◽  
Author(s):  
Golaleh Asghari ◽  
Hossein Farhadnejad ◽  
Farhad Hosseinpanah ◽  
Nazanin Moslehi ◽  
Parvin Mirmiran ◽  
...  
Keyword(s):  
Vitamin D ◽  
Children And Adolescents ◽  
Vitamin D Supplementation ◽  
Control Group ◽  
Placebo Control ◽  
Controlled Trials ◽  
Cochrane Central Register ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D ◽  
The Impact

IntroductionThe importance of vitamin D for bone health as well as its role in non-skeletal functions has long been documented. However, review investigations on the effect of vitamin D supplementation on serum 25-hydroxyvitamin D (25(OH)D) levels in children and adolescents are scarce. The aims of the current study were to assess the impact of various doses of vitamin D supplementation on serum 25(OH)D concentrations in children and adolescents, and to identify relevant determinants of variations in the effect of vitamin D supplementation.MethodsPubMed, Scopus, ISI Web of Science and Cochrane Central Register of Controlled Trials databases up to 27 September 2017 will systematically be searched for randomised controlled trials of vitamin D supplementation. We considered articles with the following control groups as eligible: placebo control, control group without any supplementation or a comparative arm investigation. Two reviewers will assess articles for eligibility according to prespecified selection criteria, after which data extraction and quality appraisal will be conducted by two independent reviewers. The quality assessment will be assessed using the Jadad scale. Meta-analyses will be conducted where appropriate. We will express continuous measures (ie, serum 25(OH)D concentration) as mean differences with 95% CIs. Heterogeneity of the data will be investigated via visual inspection of the forest plots and using χ2test on N-1 df, with a significance level of α=0.1. We will also assess individual study and subgroup characteristics and perform a sensitivity analysis. Publication bias will be assessed using funnel plot and statistical analysis of Egger’s test.Ethics and disseminationEthics approval is not required because the work will be carried out on published documents. The authors will publish findings from this review through peer-reviewed publication or conference presentations.PROSPERO registration numberCRD42017067179.

scholarly journals Considerations for conducting systematic reviews: evaluating the performance of different methods for de-duplicating references

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Sandra McKeown ◽  
Zuhaib M. Mir
Keyword(s):  
Systematic Reviews ◽  
False Positive ◽  
Evidence Synthesis ◽  
False Negative ◽  
Ease Of Use ◽  
Bibliographic Databases ◽  
Controlled Trials ◽  
Cochrane Central Register ◽  
Central Register

Abstract Background Systematic reviews involve searching multiple bibliographic databases to identify eligible studies. As this type of evidence synthesis is increasingly pursued, the use of various electronic platforms can help researchers improve the efficiency and quality of their research. We examined the accuracy and efficiency of commonly used electronic methods for flagging and removing duplicate references during this process. Methods A heterogeneous sample of references was obtained by conducting a similar topical search in MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and PsycINFO databases. References were de-duplicated via manual abstraction to create a benchmark set. The default settings were then used in Ovid multifile search, EndNote desktop, Mendeley, Zotero, Covidence, and Rayyan to de-duplicate the sample of references independently. Using the benchmark set as reference, the number of false-negative and false-positive duplicate references for each method was identified, and accuracy, sensitivity, and specificity were determined. Results We found that the most accurate methods for identifying duplicate references were Ovid, Covidence, and Rayyan. Ovid and Covidence possessed the highest specificity for identifying duplicate references, while Rayyan demonstrated the highest sensitivity. Conclusion This study reveals the strengths and weaknesses of commonly used de-duplication methods and provides strategies for improving their performance to avoid unintentionally removing eligible studies and introducing bias into systematic reviews. Along with availability, ease-of-use, functionality, and capability, these findings are important to consider when researchers are selecting database platforms and supporting software programs for conducting systematic reviews.

scholarly journals Vitamin D supplementation for the prevention of childhood acute respiratory infections: a systematic review of randomised controlled trials

2015 ◽  
Vol 114 (7) ◽  
pp. 1026-1034 ◽  
Author(s):  
Limin Xiao ◽  
Chao Xing ◽  
Zhongrong Yang ◽  
Shaojun Xu ◽  
Min Wang ◽  
...  
Keyword(s):  
Vitamin D ◽  
Respiratory Infections ◽  
Vitamin D Supplementation ◽  
Controlled Trials ◽  
Cochrane Central Register ◽  
Acute Respiratory Infections ◽  
Healthy Children ◽  
Central Register ◽  
Repeated Infections ◽  
Randomised Controlled

Results from recent trials assessing the effect of vitamin D supplementation on the prevention of childhood acute respiratory infections (ARI) have been inconsistent. In the present study, we determined whether vitamin D supplementation prevents ARI in healthy children and repeated infections in children with previous ARI. We conducted a systematic literature search using MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials. The search included only randomised controlled clinical trials (RCT) comparing vitamin D supplementation with either placebo or no intervention in children younger than 18 years of age. We identified seven RCT and found that the summary estimates were not statistically significantly associated with a reduction in the risk of ARI (relative risk (RR) 0·79, 95 % CI 0·55, 1·13), all-cause mortality (RR 1·18, 95 % CI 0·71, 1·94), or the rate of hospital admission due to respiratory infection in healthy children (RR 0·95, 95 % CI 0·72, 1·26). However, in children previously diagnosed with asthma, vitamin D supplementation resulted in a 74 % reduction in the risk of asthma exacerbation (RR 0·26, 95 % CI 0·11, 0·59; test of heterogeneity, I2= 0·0 %). Our findings indicate a lack of evidence supporting the routine use of vitamin D supplementation for the prevention of ARI in healthy children; however, they suggest that such supplementation may benefit children previously diagnosed with asthma. Due to the heterogeneity of the included studies and possible publication biases related to this field, these results should be interpreted with caution.

scholarly journals Vitamin D supplementation, COVID-19 and disease severity: a meta-analysis

QJM ◽  
2021 ◽  
Author(s):  
K Shah ◽  
D Saxena ◽  
D Mavalankar
Keyword(s):  
Vitamin D ◽  
Randomized Controlled Trials ◽  
Usual Care ◽  
Odds Ratio ◽  
Meta Analysis ◽  
Vitamin D Supplementation ◽  
Hospitalized Patients ◽  
Controlled Trials ◽  
Randomized Controlled

Abstract Objective: Current meta-analysis aims to understand the effect of oral supplementation of vitamin D on intensive care unit (ICU) requirement and mortality in hospitalized COVID-19 patients. Methods: Databases PubMed, preprint servers, and google scholar were searched from December 2019 to December 2020. Authors searched for the articles assessing role of vitamin D supplementation on COVID-19. Cochrane RevMan tool was used for quantitative assessment of the data, where heterogeneity was assessed using I2 and Q statistics and data was expressed using odds ratio with 95% confidence interval. Results: Final meta-analysis involved pooled data of 532 hospitalized patients (189 on vitamin D supplementation and 343 on usual care/placebo) of COVID-19 from three studies (Two randomized controlled trials, one retrospective case-control study). Statistically (p<0.0001) lower ICU requirement was observed in patients with vitamin D supplementation as compared to patients without supplementations (odds ratio: 0.36; 95% CI: 0.210-0.626). However, it suffered from significant heterogeneity, which reduced after sensitivity analysis. In case of mortality, vitamin D supplements has comparable findings with placebo treatment/usual care (odds ratio: 0.93; 95% CI: 0.413-2.113; p=0.87). The studies did not show any publication bias and had fair quality score. Subgroup analysis could not be performed due to limited number of studies and hence dose and duration dependent effect of vitamin D could not be evaluated. Conclusions: Although the current meta-analysis findings indicate potential role of vitamin D in improving COVID-19 severity in hospitalized patients, more robust data from randomized controlled trials are needed to substantiate its effects on mortality.

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