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Journal Francais D'ophtalmologie May 2022There is currently a lack of high-quality research on the best dietary recommendations for patients with early glaucoma or at high risk for glaucoma. This meta-analysis... (Meta-Analysis)
Meta-Analysis
There is currently a lack of high-quality research on the best dietary recommendations for patients with early glaucoma or at high risk for glaucoma. This meta-analysis aims to clarify the relationship between vitamin intake and glaucoma risk. Electronic databases, including PubMed, EMbase, ScienceDirect, Cochrane Database, Clinicaltrials.gov, and Google Scholar, were searched for publications indexed as of September 18, 2021. Data were expressed as odds ratios (ORs) with 95% confidence intervals (CIs). The I index was used to assess heterogeneity. We performed five meta-analyses of existing studies to summarize the evidence on the association between vitamin intake and glaucoma risk. The initial search identified 689 studies, eight of which (262,189 patients) met the eligibility criteria for the meta-analysis. The data showed that high-dose intake of vitamins A (OR=0.63, 95%CI [0.53, 0.76]) and B (OR=0.71, 95%CI [0.64, 0.80]) but not vitamins C (OR=0.69, 95%CI [0.48, 1.01]), D (OR=0.90, 95%CI [0.45, 1.83]), or E (OR=0.91, 95%CI [0.71, 1.16]) was associated with a low prevalence of glaucoma. The results of this study demonstrated that high-dose intake of vitamins A and B, but not vitamins C, D, or E, was associated with a low prevalence of glaucoma.
Topics: Ascorbic Acid; Glaucoma; Humans; Odds Ratio; Vitamin A; Vitamins
PubMed: 35120728
DOI: 10.1016/j.jfo.2021.10.010 -
The Cochrane Database of Systematic... Apr 2016Iron-deficiency anaemia is highly prevalent among non-pregnant women of reproductive age (menstruating women) worldwide, although the prevalence is highest in... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Iron-deficiency anaemia is highly prevalent among non-pregnant women of reproductive age (menstruating women) worldwide, although the prevalence is highest in lower-income settings. Iron-deficiency anaemia has been associated with a range of adverse health outcomes, which restitution of iron stores using iron supplementation has been considered likely to resolve. Although there have been many trials reporting effects of iron in non-pregnant women, these trials have never been synthesised in a systematic review.
OBJECTIVES
To establish the evidence for effects of daily supplementation with iron on anaemia and iron status, as well as on physical, psychological and neurocognitive health, in menstruating women.
SEARCH METHODS
In November 2015 we searched CENTRAL, Ovid MEDLINE, EMBASE, and nine other databases, as well as four digital thesis repositories. In addition, we searched the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) and reference lists of relevant reviews.
SELECTION CRITERIA
We included randomised controlled trials (RCTs) and quasi-RCTs comparing daily oral iron supplementation with or without a cointervention (folic acid or vitamin C), for at least five days per week at any dose, to control or placebo using either individual- or cluster-randomisation. Inclusion criteria were menstruating women (or women aged 12 to 50 years) reporting on predefined primary (anaemia, haemoglobin concentration, iron deficiency, iron-deficiency anaemia, all-cause mortality, adverse effects, and cognitive function) or secondary (iron status measured by iron indices, physical exercise performance, psychological health, adherence, anthropometric measures, serum/plasma zinc levels, vitamin A status, and red cell folate) outcomes.
DATA COLLECTION AND ANALYSIS
We used the standard methodological procedures of Cochrane.
MAIN RESULTS
The search strategy identified 31,767 records; after screening, 90 full-text reports were assessed for eligibility. We included 67 trials (from 76 reports), recruiting 8506 women; the number of women included in analyses varied greatly between outcomes, with endpoint haemoglobin concentration being the outcome with the largest number of participants analysed (6861 women). Only 10 studies were considered at low overall risk of bias, with most studies presenting insufficient details about trial quality.Women receiving iron were significantly less likely to be anaemic at the end of intervention compared to women receiving control (risk ratio (RR) 0.39 (95% confidence interval (CI) 0.25 to 0.60, 10 studies, 3273 women, moderate quality evidence). Women receiving iron had a higher haemoglobin concentration at the end of intervention compared to women receiving control (mean difference (MD) 5.30, 95% CI 4.14 to 6.45, 51 studies, 6861 women, high quality evidence). Women receiving iron had a reduced risk of iron deficiency compared to women receiving control (RR 0.62, 95% CI 0.50 to 0.76, 7 studies, 1088 women, moderate quality evidence). Only one study (55 women) specifically reported iron-deficiency anaemia and no studies reported mortality. Seven trials recruiting 901 women reported on 'any side effect' and did not identify an overall increased prevalence of side effects from iron supplements (RR 2.14, 95% CI 0.94 to 4.86, low quality evidence). Five studies recruiting 521 women identified an increased prevalence of gastrointestinal side effects in women taking iron (RR 1.99, 95% CI 1.26 to 3.12, low quality evidence). Six studies recruiting 604 women identified an increased prevalence of loose stools/diarrhoea (RR 2.13, 95% CI 1.10, 4.11, high quality evidence); eight studies recruiting 1036 women identified an increased prevalence of hard stools/constipation (RR 2.07, 95% CI 1.35 to 3.17, high quality evidence). Seven studies recruiting 1190 women identified evidence of an increased prevalence of abdominal pain among women randomised to iron (RR 1.55, 95% CI 0.99 to 2.41, low quality evidence). Eight studies recruiting 1214 women did not find any evidence of an increased prevalence of nausea among women randomised to iron (RR 1.19, 95% CI 0.78 to 1.82). Evidence that iron supplementation improves cognitive performance in women is uncertain, as studies could not be meta-analysed and individual studies reported conflicting results. Iron supplementation improved maximal and submaximal exercise performance, and appears to reduce symptomatic fatigue. Although adherence could not be formally meta-analysed due to differences in reporting, there was no evident difference in adherence between women randomised to iron and control.
AUTHORS' CONCLUSIONS
Daily iron supplementation effectively reduces the prevalence of anaemia and iron deficiency, raises haemoglobin and iron stores, improves exercise performance and reduces symptomatic fatigue. These benefits come at the expense of increased gastrointestinal symptomatic side effects.
Topics: Adolescent; Adult; Anemia, Iron-Deficiency; Dietary Supplements; Female; Hemoglobin A; Humans; Iron; Iron Deficiencies; Menstruation; Middle Aged; Randomized Controlled Trials as Topic
PubMed: 27087396
DOI: 10.1002/14651858.CD009747.pub2 -
Neuroepidemiology 2014Vitamin A and carotenoids are involved in signalling pathways regulating gene expression in many organs, including the brain. The dopaminergic system is a target of... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Vitamin A and carotenoids are involved in signalling pathways regulating gene expression in many organs, including the brain. The dopaminergic system is a target of retinoic acid action in the central nervous system. The aim of this review is to assess the epidemiological evidence on the association between blood levels or dietary intakes of vitamin A and carotenoids and risk of Parkinson's disease (PD).
METHODS
PubMed and ISI Web of Science were searched for relevant papers from 1990 to April 2013. Data reported in epidemiological studies assessing the association between vitamin A and/or carotenoids (α-carotene, β-carotene, β-cryptoxanthin, lutein, lycopene, zeaxanthin and canthaxanthin) and PD were extracted for a narrative synthesis and meta-analysis.
RESULTS
Thirteen papers were included out of a total of 362 potentially relevant; of these, eight contributed to the meta-analysis. No statistically significant pooled estimate between micronutrient and PD was detected. Forest plots suggest possible non-significant inverse pooled estimates of α-carotene and β-carotene and risk of PD. A significant association between lutein intake and PD risk was detected in case-control studies only.
CONCLUSIONS
Data published to date are insufficient for drawing definite conclusions about the epidemiological evidence on the association between blood levels or dietary intakes of vitamin A and carotenoids and the risk of PD. Results should be interpreted particularly cautiously given the limitation of the present meta-analysis and the potential publication bias. Authors are urged to follow more closely the recommendations for reporting epidemiological studies in order to enhance the capacity for synthesising the evidence.
Topics: Animals; Carotenoids; Case-Control Studies; Humans; Parkinson Disease; Risk Factors; Vitamin A; beta Carotene
PubMed: 24356061
DOI: 10.1159/000355849 -
International Health Nov 2023Vitamin A deficiency (VAD) during pregnancy is a public health challenge in low-income countries. There are inconsistent findings that can affect policy in planning... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Vitamin A deficiency (VAD) during pregnancy is a public health challenge in low-income countries. There are inconsistent findings that can affect policy in planning appropriate intervention. This systematic review and meta-analysis were conducted to summarize the evidence in order to identify existing gaps and propose strategies to reduce VAD during pregnancy in Ethiopia.
METHODS
This study included published and unpublished observational studies searched from different databases (PubMed, CINHAL [EBSCO], Embase, Google Scholar, Directory of Open Access Journals, Web of Sciences, MEDLINE, Cochrane Library, Scopus, Google Search and MedNar). Statistical analysis was conducted using Stata version 14 software. Heterogeneity and publication bias were assessed. Forest plots were used to present the pooled prevalence using the random effects model.
RESULTS
A total of 37 618 pregnant women from 15 studies were included. The overall pooled prevalence of VAD was 29% (95% confidence interval 21 to 36) with I2=99.67% and p<0.001. Socio-economic and sociodemographic factors were identified as affecting vitamin A deficiencies among pregnant women.
CONCLUSIONS
Nearly one-third of pregnant women in Ethiopia had VAD. Strengthening intervention modalities that aimed to increase the uptake of vitamin A-rich foods can avert VAD among pregnant women in Ethiopia.
Topics: Female; Pregnancy; Humans; Pregnant Women; Vitamin A Deficiency; Ethiopia; Vitamin A; Prevalence; Observational Studies as Topic
PubMed: 37264928
DOI: 10.1093/inthealth/ihad038 -
BMJ Clinical Evidence Jan 2010Evidence for the efficacy of treatments for autism has improved in recent years. In this systematic review the evidence for both drug and non-drug treatments is... (Review)
Review
INTRODUCTION
Evidence for the efficacy of treatments for autism has improved in recent years. In this systematic review the evidence for both drug and non-drug treatments is appraised and clinical guidance is provided for their use.
METHODS AND OUTCOMES
We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of early intensive multidisciplinary intervention programmes in children with autism? What are the effects of dietary interventions in children with autism? What are the effects of drug treatments in children with autism? What are the effects of non-drug treatments in children with autism? We searched: Medline, Embase, The Cochrane Library, and other important databases up to May 2009 (Clinical evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
RESULTS
We found 30 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
CONCLUSIONS
In this systematic review we present information relating to the effectiveness and safety of the following interventions: applied behavioural analysis; auditory integration training; Autism Preschool Programme; casein-free diet; chelation; Child's Talk programme; cognitive behavioural therapy; digestive enzymes; EarlyBird programme; facilitated communication; Floortime therapy; gluten-free diet; immunoglobulins; melatonin; memantine; methylphenidate; More Than Words programme; music therapy; olanzapine; omega-3 fish oil; picture exchange communication system; Portage scheme; probiotics; relationship development interventions; risperidone; secretin; selective serotonin reuptake inhibitors (SSRIs); sensory integration training; social stories; social skills training; Son-Rise programme; TEACCH; vitamin A; vitamin B6 (pyridoxine) plus magnesium; and vitamin C.
Topics: Antipsychotic Agents; Autistic Disorder; Caseins; Double-Blind Method; Humans; Infant; Language Disorders; Magnesium; Memantine; Secretin
PubMed: 21729335
DOI: No ID Found -
Journal of Family Medicine and Primary... Nov 2021Even though vitamin A (Vit A) is one of the essential vitamins required for bone growth and development, it is still uncertain whether its effect on bone mineral density...
BACKGROUND
Even though vitamin A (Vit A) is one of the essential vitamins required for bone growth and development, it is still uncertain whether its effect on bone mineral density (BMD) is beneficial or harmful.
AIM
To assess Vit A's effect and its derivatives on BMD and the risk of developing osteoporosis.
DATA SOURCES
PubMed, Cochrane Library, Science Direct, Embase, and Google Scholar were searched in February 2019 and updated in November 2020.
METHODS
Conducted following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines.
RESULTS
A total of 13 studies were included in this report out of 9,124 citations. Five of them were cross-sectional studies, and nine were cohort studies. Three out of five cross-sectional studies showed an increase in BMD, while two showed a decrease in BMD. Four out of eight cohort studies found an increase in BMD; two studies found no association between vitamin A level and BMD; one showed an inverse U-shape association of vitamin A with BMD, suggesting that both the increase or decrease levels of vitamin A affect BMD, while only one study showed a decrease in BMD.
CONCLUSION
Although most of the included studies showed a favorable effect of Vit A on BMD, Vit A's role or its derivatives on BMD change remains unclear.
PubMed: 35136772
DOI: 10.4103/jfmpc.jfmpc_663_21 -
PloS One 2011Despite reported antiproliferative activity of vitamin A and its common use for cancer, there is no comprehensive synthesis of its safety and efficacy in lung cancers.... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Despite reported antiproliferative activity of vitamin A and its common use for cancer, there is no comprehensive synthesis of its safety and efficacy in lung cancers. To address this issue we conducted a systematic review of the safety and efficacy of vitamin A for the treatment and prevention of lung cancers.
METHODS AND FINDINGS
Two independent reviewers searched six electronic databases from inception to July 2009 for clinical, observational, and preclinical evidence pertaining to the safety and efficacy of vitamin A and related retinoids for lung cancers. 248 studies were included for full review and analysis. Five RCTs assessed treatment of lung cancers, three assessed primary prevention, and three looked at secondary prevention of lung cancers. Five surrogate studies, 26 phase I/II, 32 observational, and 67 preclinical studies were also included. 107 studies were included for interactions between vitamin A and chemo- or radiation-therapy. Although some studies demonstrated benefits, there was insufficient evidence overall to support the use of vitamin A or related retinoids for the treatment or prevention of lung cancers. Retinyl palmitate combined with beta carotene increased risk of lung cancer in smokers in the large CARET trial. Pooling of three studies pertaining to treatment and three studies on secondary prevention revealed no significant effects on response rate, second primary tumor, recurrence, 5-year survival, and mortality. There was a small improvement in event free survival associated with vitamin A compared to controls, RR 1.24 (95% CI 1.13-1.35). The synthetic rexinoid bexarotene increased survival significantly among a subset of patients in two RCTs (p<0.014, <0.087).
CONCLUSIONS
There is a lack of evidence to support the use of naturally occurring retinoids for the treatment and prevention of lung cancers. The rexinoid bexarotene may hold promise for use among a subset of patients, and deserves further study.
Topics: Animals; Diterpenes; Humans; Lung Neoplasms; Retinoids; Retinyl Esters; Vitamin A; beta Carotene
PubMed: 21738614
DOI: 10.1371/journal.pone.0021107 -
Annals of Internal Medicine Aug 2019The role of nutritional supplements and dietary interventions in preventing mortality and cardiovascular disease (CVD) outcomes is unclear. (Meta-Analysis)
Meta-Analysis
BACKGROUND
The role of nutritional supplements and dietary interventions in preventing mortality and cardiovascular disease (CVD) outcomes is unclear.
PURPOSE
To examine evidence about the effects of nutritional supplements and dietary interventions on mortality and cardiovascular outcomes in adults.
DATA SOURCES
PubMed, CINAHL, and the Cochrane Library from inception until March 2019; ClinicalTrials.gov (10 March 2019); journal Web sites; and reference lists.
STUDY SELECTION
English-language, randomized controlled trials (RCTs) and meta-analyses of RCTs that assessed the effects of nutritional supplements or dietary interventions on all-cause mortality or cardiovascular outcomes, such as death, myocardial infarction, stroke, and coronary heart disease.
DATA EXTRACTION
Two independent investigators abstracted data, assessed the quality of evidence, and rated the certainty of evidence.
DATA SYNTHESIS
Nine systematic reviews and 4 new RCTs were selected that encompassed a total of 277 trials, 24 interventions, and 992 129 participants. A total of 105 meta-analyses were generated. There was moderate-certainty evidence that reduced salt intake decreased the risk for all-cause mortality in normotensive participants (risk ratio [RR], 0.90 [95% CI, 0.85 to 0.95]) and cardiovascular mortality in hypertensive participants (RR, 0.67 [CI, 0.46 to 0.99]). Low-certainty evidence showed that omega-3 long-chain polyunsaturated fatty acid (LC-PUFA) was associated with reduced risk for myocardial infarction (RR, 0.92 [CI, 0.85 to 0.99]) and coronary heart disease (RR, 0.93 [CI, 0.89 to 0.98]). Folic acid was associated with lower risk for stroke (RR, 0.80 [CI, 0.67 to 0.96]; low certainty), whereas calcium plus vitamin D increased the risk for stroke (RR, 1.17 [CI, 1.05 to 1.30]; moderate certainty). Other nutritional supplements, such as vitamin B6, vitamin A, multivitamins, antioxidants, and iron and dietary interventions, such as reduced fat intake, had no significant effect on mortality or cardiovascular disease outcomes (very low- to moderate-certainty evidence).
LIMITATIONS
Suboptimal quality and certainty of evidence.
CONCLUSION
Reduced salt intake, omega-3 LC-PUFA use, and folate supplementation could reduce risk for some cardiovascular outcomes in adults. Combined calcium plus vitamin D might increase risk for stroke.
PRIMARY FUNDING SOURCE
None.
Topics: Cardiovascular Diseases; Cause of Death; Coronary Disease; Diet, Healthy; Dietary Supplements; Humans; Myocardial Infarction; Randomized Controlled Trials as Topic; Stroke; United States
PubMed: 31284304
DOI: 10.7326/M19-0341 -
The American Journal of Tropical... Jul 2020The common cold had resulted in significant economic and social burden worldwide. The effect of vitamin C on preventing common cold in healthy adults has been...
The common cold had resulted in significant economic and social burden worldwide. The effect of vitamin C on preventing common cold in healthy adults has been investigated extensively, but not that of other micronutrients. Thus, we aim to assess the effects of providing micronutrients singly through oral means, on cold incidence, and/or management (in terms of cold duration and symptom severity) in healthy adults from systematically searched randomized controlled trials. From four electronic databases, 660 identified studies were screened and data were extracted from 20 studies (zinc, 10; vitamin D, 8; and vitamins A and E, 2). The quality of selected studies was assessed using the Cochrane risk of bias tool and certainty in the outcomes was assessed with the Grading of Recommendations Assessment, Development and Evaluation approach. The review found that micronutrients supplementation, except vitamin C, may not prevent cold incidence or reduce symptom severity among healthy adults. However, zinc supplementation was observed to potentially reduce cold duration by 2.25 days (when zinc is provided singly, 95% CI: -3.39, -1.12). This suggests that zinc supplementation may reduce the overall burden due to common cold among healthy adults.
Topics: Adolescent; Adult; Aged; Ascorbic Acid; Common Cold; Dietary Supplements; Humans; Incidence; Micronutrients; Middle Aged; Odds Ratio; Randomized Controlled Trials as Topic; Severity of Illness Index; Vitamin A; Vitamin D; Vitamin E; Zinc
PubMed: 32342851
DOI: 10.4269/ajtmh.19-0718 -
BMJ Clinical Evidence Dec 2008Skin disorders associated with photodamage from ultraviolet light include wrinkles, hyperpigmentation, tactile roughness, and telangiectasia, and are more common in... (Review)
Review
INTRODUCTION
Skin disorders associated with photodamage from ultraviolet light include wrinkles, hyperpigmentation, tactile roughness, and telangiectasia, and are more common in people with white compared with other skin types. Wrinkles are also associated with aging, hormonal status, smoking, and intercurrent disease.
METHODS AND OUTCOMES
We conducted a systematic review and aimed to answer the following clinical question: What are the effects of interventions to prevent and treat skin wrinkles? We searched: Medline, Embase, The Cochrane Library, and other important databases up to April 2008 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
RESULTS
We found 20 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
CONCLUSIONS
In this systematic review we present information relating to the effectiveness and safety of the following interventions: carbon dioxide laser, chemical peel, dermabrasion, facelifts, glycolic acid, isotretinoin, lactic acid, natural cartilage polysaccharides (oral or topical), retinyl esters, sunscreens, tazarotene, tretinoin, variable pulse erbium:YAG laser, and vitamin C or E (topical).
Topics: Administration, Oral; Humans; Hyperpigmentation; Isotretinoin; Rhytidoplasty; Skin Aging; Tretinoin
PubMed: 19445782
DOI: No ID Found