-
Journal of the American Heart... Dec 2023Cardiovascular calcification, characterized by deposition of calcium phosphate in the arterial wall and heart valves, is associated with cardiovascular morbidity and...
BACKGROUND
Cardiovascular calcification, characterized by deposition of calcium phosphate in the arterial wall and heart valves, is associated with cardiovascular morbidity and mortality and is commonly seen in aging, diabetes, and chronic kidney disease. Whether evidence-based interventions could significantly attenuate cardiovascular calcification progression remains uncertain.
METHODS AND RESULTS
We conducted a systematic review of randomized controlled trials involving interventions, compared with placebo, another comparator, or standard of care, to attenuate cardiovascular calcification. Included clinical trials involved participants without chronic kidney disease, and the outcome was cardiovascular calcification measured using radiological methods. Quality of evidence was determined by the Cochrane risk of bias and Grading of Recommendations, Assessment, Development, and Evaluations assessment. Forty-nine randomized controlled trials involving 9901 participants (median participants 104, median duration 12 months) were eligible for inclusion. Trials involving aged garlic extract (n=6 studies) consistently showed attenuation of cardiovascular calcification. Trials involving 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (n=14), other lipid-lowering agents (n=2), hormone replacement therapies (n=3), vitamin K (n=5), lifestyle measures (n=4), and omega-3 fatty acids (n=2) consistently showed no attenuation of cardiovascular calcification with these therapies. Trials involving antiresorptive (n=2), antihypertensive (n=2), antithrombotic (n=4), and hypoglycemic agents (n=3) showed mixed results. Singleton studies involving salsalate, folate with vitamin B6 and 12, and dalcetrapib showed no attenuation of cardiovascular calcification. Overall, Cochrane risk of bias was moderate, and the Grading of Recommendations, Assessment, Development, and Evaluations assessment for a majority of analyses was moderate certainty of evidence.
CONCLUSIONS
Currently, there are insufficient or conflicting data for interventions evaluated in clinical trials for mitigation of cardiovascular calcification. Therapy involving aged garlic extract appears most promising, but evaluable studies were small and of short duration.
Topics: Humans; Antioxidants; Diabetes Mellitus; Disease Progression; Hypoglycemic Agents; Randomized Controlled Trials as Topic; Renal Insufficiency, Chronic; Vascular Calcification; Garlic; Phytotherapy; Plant Extracts
PubMed: 38014685
DOI: 10.1161/JAHA.123.031676 -
The Cochrane Database of Systematic... Jun 2015Vitamin B6 plays vital roles in numerous metabolic processes in the human body, such as nervous system development and functioning. It has been associated with some... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Vitamin B6 plays vital roles in numerous metabolic processes in the human body, such as nervous system development and functioning. It has been associated with some benefits in non-randomised studies, such as higher Apgar scores, higher birthweights, and reduced incidence of pre-eclampsia and preterm birth. Recent studies also suggest a protection against certain congenital malformations.
OBJECTIVES
To evaluate the clinical effects of vitamin B6 supplementation during pregnancy and/or labour.
SEARCH METHODS
We searched the Cochrane Pregnancy and Childbirth Group Trials Register (31 March 2015) and reference lists of retrieved studies.
SELECTION CRITERIA
We included randomised controlled trials comparing vitamin B6 administration in pregnancy and/or labour with: placebos, no supplementations, or supplements not containing vitamin B6.
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. For this update, we assessed methodological quality of the included trials using risk of bias and the GRADE approach.
MAIN RESULTS
Four trials (1646 women) were included. The method of randomisation was unclear in all four trials and allocation concealment was reported in only one trial. Two trials used blinding of participants and outcomes. Vitamin B6 as oral capsules or lozenges resulted in decreased risk of dental decay in pregnant women (capsules: risk ratio (RR) 0.84; 95% confidence interval (CI) 0.71 to 0.98; one trial, n = 371, low quality of evidence; lozenges: RR 0.68; 95% CI 0.56 to 0.83; one trial, n = 342, low quality of evidence). A small trial showed reduced mean birthweights with vitamin B6 supplementation (mean difference -0.23 kg; 95% CI -0.42 to -0.04; n = 33; one trial). We did not find any statistically significant differences in the risk of eclampsia (capsules: n = 1242; three trials; lozenges: n = 944; one trial), pre-eclampsia (capsules n = 1197; two trials, low quality of evidence; lozenges: n = 944; one trial, low-quality evidence) or low Apgar scores at one minute (oral pyridoxine: n = 45; one trial), between supplemented and non-supplemented groups. No differences were found in Apgar scores at five minutes, or breastmilk production between controls and women receiving oral (n = 24; one trial) or intramuscular (n = 24; one trial) loading doses of pyridoxine at labour. Overall, the risk of bias was judged as unclear. The quality of the evidence using GRADE was low for both pre-eclampsia and dental decay. The other primary outcomes, preterm birth before 37 weeks and low birthweight, were not reported in the included trials.
AUTHORS' CONCLUSIONS
There were few trials, reporting few clinical outcomes and mostly with unclear trial methodology and inadequate follow-up. There is not enough evidence to detect clinical benefits of vitamin B6 supplementation in pregnancy and/or labour other than one trial suggesting protection against dental decay. Future trials assessing this and other outcomes such as orofacial clefts, cardiovascular malformations, neurological development, preterm birth, pre-eclampsia and adverse events are required.
Topics: Birth Weight; Dental Caries; Dietary Supplements; Eclampsia; Female; Humans; Infant, Newborn; Labor, Obstetric; Pre-Eclampsia; Pregnancy; Pregnancy Outcome; Pyridoxine; Randomized Controlled Trials as Topic; Vitamin B Complex
PubMed: 26039815
DOI: 10.1002/14651858.CD000179.pub3 -
Journal of the American Medical... Nov 2022To examine the association between B vitamins status and the risk of dementia in older adults through a systematic review and meta-analysis of cohort studies. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To examine the association between B vitamins status and the risk of dementia in older adults through a systematic review and meta-analysis of cohort studies.
DESIGN
Systematic review and meta-analysis.
SETTING AND PARTICIPANTS
Older adults aged ≥60 years from community, nursing home, institution, or hospital.
METHODS
PubMed, Cochrane Library, EMBASE, Web of Science, CINAHL, ClinicalTrials, WHO-ICTRP, NHS Trusts, and ACTR were searched from the date of their inception up to November 28, 2021. We included cohort studies that assessed the association between serum B vitamins or B vitamins intake and the risk of dementia among older adults aged ≥60 years. The quality of all studies was assessed by the modified Newcastle-Ottawa Scale (NOS). The hazard ratios (HRs) and 95% CIs were calculated by the random effects model. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach was used to rate the certainty of evidence.
RESULTS
Eleven cohort studies with sample sizes ranging from 233 to 3634 were included in the meta-analysis. Levels of serum folate showed statistically significant association with the risk of dementia (≥10 nmol/L: HR 1.57, 95% CI 1.01-2.46, low certainty; <10 nmol/L: HR 0.93, 95% CI 0.88-0.99, very low certainty). However, levels of vitamin B intake showed no statistically significant effects on risk of dementia; levels of serum vitamin B and vitamin B intake also showed no statistically significant effects on risk of dementia in older adults.
CONCLUSIONS AND IMPLICATIONS
The results from our meta-analysis suggest that vitamin B, B, and folate may not be modifiable risk factors for dementia among older adults. Current evidence on the relationship between vitamin B status and dementia is not sufficient for development of vitamin B recommendations. More high-quality cohort studies are needed to confirm the relationship between the two in the future.
Topics: Humans; Aged; Vitamin B Complex; Folic Acid; Vitamin B 12; Cohort Studies; Dementia
PubMed: 35779574
DOI: 10.1016/j.jamda.2022.05.022 -
International Journal of Molecular... May 2024The published data on the vitamin status of patients with phenylketonuria (PKU) is contradictory; therefore, this systematic review and meta-analysis evaluated the... (Meta-Analysis)
Meta-Analysis Review
The published data on the vitamin status of patients with phenylketonuria (PKU) is contradictory; therefore, this systematic review and meta-analysis evaluated the vitamin status of PKU patients. A comprehensive search of multiple databases (PubMed, Web of Sciences, Cochrane, and Scopus) was finished in March 2024. The included studies compared vitamin levels between individuals diagnosed with early-treated PKU and healthy controls while excluding pregnant and lactating women, untreated PKU or hyperphenylalaninemia cases, control groups receiving vitamin supplementation, PKU patients receiving tetrahydrobiopterin or pegvaliase, and conference abstracts. The risk of bias in the included studies was assessed by the Newcastle-Ottawa scale. The effect sizes were expressed as standardised mean differences. The calculation of effect sizes with 95% CI using fixed-effects models and random-effects models was performed. A -value < 0.05 was considered statistically significant. The study protocol was registered in the PROSPERO database (CRD42024519589). Out of the initially identified 11,086 articles, 24 met the criteria. The total number of participants comprised 770 individuals with PKU and 2387 healthy controls. The meta-analyses of cross-sectional and case-control studies were conducted for vitamin B12, D, A, E, B6 and folate levels. PKU patients demonstrated significantly higher folate levels (random-effects model, SMD: 1.378, 95% CI: 0.436, 2.320, = 0.004) and 1,25-dihydroxyvitamin D concentrations (random-effects model, SMD: 2.059, 95% CI: 0.250, 3.868, = 0.026) compared to the controls. There were no significant differences in vitamin A, E, B6, B12 or 25-dihydroxyvitamin D levels. The main limitations of the evidence include a limited number of studies and their heterogeneity and variability in patients' compliance. Our findings suggest that individuals with PKU under nutritional guidance can achieve a vitamin status comparable to that of healthy subjects. Our study provides valuable insights into the nutritional status of PKU patients, but further research is required to confirm these findings and explore additional factors influencing vitamin status in PKU.
Topics: Phenylketonurias; Humans; Vitamins; Vitamin D; Folic Acid; Vitamin B 12; Vitamin A
PubMed: 38791104
DOI: 10.3390/ijms25105065 -
Nutrients Jul 2023Nutritional deficiencies during pregnancy can have serious consequences for the health of the (unborn) child. This systematic review provides an updated overview of the... (Review)
Review
Nutritional deficiencies during pregnancy can have serious consequences for the health of the (unborn) child. This systematic review provides an updated overview of the available food and nutrient intake data for pregnant women in The Netherlands and an evaluation based on the current recommendations. Embase, MEDLINE, and national institute databases were used. Articles were selected if they had been published since 2008 and contained data on food consumption, nutrient intake, or the status of healthy pregnant women. A qualitative comparison was made with the 2021 Dutch Health Council recommendations and reference values. A total of 218 reports were included, representing 54 individual studies. Dietary assessments were primarily performed via food frequency questionnaires. Protein, vitamin A, thiamin, riboflavin, vitamin B, folate, vitamin B, vitamin C, iron, calcium, and magnesium intakes seemed to be adequate. For folate and vitamin D, supplements were needed to reach the recommended intake. The reasons for concern are the low intakes of fruits, vegetables, and (fatty) fish, and the intakes of alcohol, sugary drinks, and salt. For several foods and nutrients, no or limited intake data were found. High-quality, representative, and recent data are needed to evaluate the nutrient intake of pregnant women in order to make accurate assessments and evaluations, supporting scientific-based advice and national nutritional policies.
Topics: Animals; Female; Pregnancy; Humans; Pregnant Women; Netherlands; Energy Intake; Eating; Vitamins; Folic Acid; Diet
PubMed: 37447397
DOI: 10.3390/nu15133071 -
Transsulfuration and folate pathways in rheumatoid arthritis: A systematic review and meta-analysis.European Journal of Clinical... Apr 2024Metabolomic assessment of the transsulfuration and folic acid biochemical pathways could lead to the identification of promising biomarkers of nitric oxide dysregulation... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Metabolomic assessment of the transsulfuration and folic acid biochemical pathways could lead to the identification of promising biomarkers of nitric oxide dysregulation and oxidative stress in rheumatoid arthritis (RA).
METHODS
We conducted a systematic review and meta-analysis of transsulfuration (methionine, homocysteine, and cysteine) and folic acid (folic acid, vitamin B , and vitamin B ) metabolites in RA patients in remission and healthy controls. Electronic databases were searched from inception to 15 July 2023 for relevant articles. We assessed the risk of bias using the JBI checklist and the certainty of evidence using GRADE.
RESULTS
In 28 eligible studies, compared to controls, RA patients had significantly higher concentrations of homocysteine (standardized mean difference, SMD = 0.74, 95% CI 0.54-0.93, p < 0.001; low certainty of evidence) and methionine (SMD = 1.00, 95% CI 0.57-1.44, p < 0.001; low certainty) and lower concentrations of vitamin B (SMD = -6.62, 95% CI -9.65 to -3.60, p < 0.001; low certainty). By contrast, there were non-significant between-group differences in vitamin B and folic acid. In meta-regression and subgroup analysis, there were no associations between the effect size and several study and patient characteristics except for homocysteine (year of publication, C-reactive protein, triglycerides, and analytical method) and folic acid (biological matrix).
CONCLUSIONS
The results of our study suggest that homocysteine, methionine, and vitamin B are promising biomarkers to assess nitric oxide dysregulation and oxidative stress in RA. (PROSPERO registration number: CRD42023461081).
Topics: Humans; Folic Acid; Nitric Oxide; Vitamin B 12; Vitamin B 6; Methionine; Vitamins; Arthritis, Rheumatoid; Biomarkers; Homocysteine
PubMed: 38214126
DOI: 10.1111/eci.14158 -
Psychological Medicine Jul 2017When used as an adjunctive with antipsychotics, certain vitamins and minerals may be effective for improving symptomatic outcomes of schizophrenia, by restoring... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
When used as an adjunctive with antipsychotics, certain vitamins and minerals may be effective for improving symptomatic outcomes of schizophrenia, by restoring nutritional deficits, reducing oxidative stress, or modulating neurological pathways.
METHOD
We conducted a systematic review of all randomized controlled trials (RCTs) reporting effects of vitamin and/or mineral supplements on psychiatric symptoms in people with schizophrenia. Random-effects meta-analyses were used to calculate the standardized mean difference between nutrient and placebo treatments.
RESULTS
An electronic database search in July 2016 identified 18 eligible RCTs, with outcome data for 832 patients. Pooled effects showed that vitamin B supplementation (including B6, B8 and B12) reduced psychiatric symptoms significantly more than control conditions [g = 0.508, 95% confidence interval (CI) 0.01-1.01, p = 0.047, I 2 = 72.3%]. Similar effects were observed among vitamin B RCTs which used intention-to-treat analyses (g = 0.734, 95% CI 0.00-1.49, p = 0.051). However, no effects of B vitamins were observed in individual domains of positive and negative symptoms (both p > 0.1). Meta-regression analyses showed that shorter illness duration was associated with greater vitamin B effectiveness (p = 0.001). There were no overall effects from antioxidant vitamins, inositol or dietary minerals on psychiatric symptoms.
CONCLUSIONS
There is preliminary evidence that certain vitamin and mineral supplements may reduce psychiatric symptoms in some people with schizophrenia. Further research is needed to examine how the benefits of supplementation relate to nutrient deficits and the impact upon underlying neurobiological pathways, in order to establish optimal nutrient formulations for improving clinical outcomes in this population. Future studies should also explore the effects of combining beneficial nutrients within multi-nutrient formulas.
Topics: Dietary Supplements; Humans; Schizophrenia; Vitamin B Complex
PubMed: 28202095
DOI: 10.1017/S0033291717000022 -
Cells Aug 2023There is an increasing interest in biomarkers of nitric oxide dysregulation and oxidative stress to guide management and identify new therapeutic targets in patients... (Meta-Analysis)
Meta-Analysis Review
There is an increasing interest in biomarkers of nitric oxide dysregulation and oxidative stress to guide management and identify new therapeutic targets in patients with chronic obstructive pulmonary disease (COPD). We conducted a systematic review and meta-analysis of the association between circulating metabolites within the arginine (arginine, citrulline, ornithine, asymmetric, ADMA, and symmetric, SDMA dimethylarginine), transsulfuration (methionine, homocysteine, and cysteine) and folic acid (folic acid, vitamin B, and vitamin B) metabolic pathways and COPD. We searched electronic databases from inception to 30 June 2023 and assessed the risk of bias and the certainty of evidence. In 21 eligible studies, compared to healthy controls, patients with stable COPD had significantly lower methionine (standardized mean difference, SMD = -0.50, 95% CI -0.95 to -0.05, = 0.029) and folic acid (SMD = -0.37, 95% CI -0.65 to -0.09, = 0.009), and higher homocysteine (SMD = 0.78, 95% CI 0.48 to 1.07, < 0.001) and cysteine concentrations (SMD = 0.34, 95% CI 0.02 to 0.66, = 0.038). Additionally, COPD was associated with significantly higher ADMA (SMD = 1.27, 95% CI 0.08 to 2.46, = 0.037), SDMA (SMD = 3.94, 95% CI 0.79 to 7.08, = 0.014), and ornithine concentrations (SMD = 0.67, 95% CI 0.13 to 1.22, = 0.015). In subgroup analysis, the SMD of homocysteine was significantly associated with the biological matrix assessed and the forced expiratory volume in the first second to forced vital capacity ratio, but not with age, study location, or analytical method used. Our study suggests that the presence of significant alterations in metabolites within the arginine, transsulfuration, and folic acid pathways can be useful for assessing nitric oxide dysregulation and oxidative stress and identifying novel treatment targets in COPD. (PROSPERO registration number: CRD42023448036.).
Topics: Humans; Cysteine; Nitric Oxide; Metabolomics; Arginine; Methionine; Racemethionine; Folic Acid; Homocysteine; Vitamins
PubMed: 37681911
DOI: 10.3390/cells12172180 -
The Cochrane Database of Systematic... Jan 2015Cardiovascular disease, which includes coronary artery disease, stroke and congestive heart failure, is a leading cause of death worldwide. Homocysteine is an amino acid... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Cardiovascular disease, which includes coronary artery disease, stroke and congestive heart failure, is a leading cause of death worldwide. Homocysteine is an amino acid with biological functions in methionine metabolism. A postulated risk factor is an elevated circulating total homocysteine level, which is associated with cardiovascular events. The impact of homocysteine-lowering interventions, given to patients in the form of vitamins B6, B9 or B12 supplements, on cardiovascular events. This is an update of a review previously published in 2009 and 2013.
OBJECTIVES
To determine whether homocysteine-lowering interventions, provided in patients with and without pre-existing cardiovascular disease are effective in preventing cardiovascular events, as well as all-cause mortality and evaluate their safety.
SEARCH METHODS
We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2014, Issue 1), MEDLINE (1950 to January week 5 2014), EMBASE (1980 to 2014 week 6) and LILACS (1986 to February 2014). We also searched Web of Science (1970 to 7 February 2014). We handsearched the reference lists of included papers. We also contacted researchers in the field. There was no language restriction in the search.
SELECTION CRITERIA
We included randomised controlled trials assessing the effects of homocysteine-lowering interventions for preventing cardiovascular events with a follow-up period of one year or longer. We considered myocardial infarction and stroke as the primary outcomes. We excluded studies in patients with end-stage renal disease.
DATA COLLECTION AND ANALYSIS
We performed study selection, 'Risk of bias' assessment and data extraction in duplicate. We estimated risk ratios (RR) for dichotomous outcomes. We measured statistical heterogeneity using the I(2) statistic. We used a random-effects model.
MAIN RESULTS
In this second updated Cochrane Review, we identified no new randomised controlled trials. Therefore, this new version includes 12 randomised controlled trials involving 47,429 participants. In general terms, 75% (9/12) trials had a low risk of bias. Homocysteine-lowering interventions compared with placebo did not significantly affect non-fatal or fatal myocardial infarction (1743/23,590 (7.38%) versus 1247/20,190 (6.17%); RR 1.02, 95% confidence interval (CI) 0.95 to 1.10, I(2) = 0%, high quality evidence), stroke (968/22,348 (4.33%) versus 974/18,957 (5.13%); RR 0.91, 95% CI 0.82 to 1.0, I(2) = 11%, high quality evidence) or death from any cause (2784/22,648 (12.29%) versus 2502/19,250 (10.64%); RR 1.01, 95% CI 0.96 to 1.07, I(2) = 6%, high quality evidence). Homocysteine-lowering interventions compared with placebo did not significantly affect serious adverse events (cancer) (1558/18,130 (8.59%) versus 1334/14,739 (9.05%); RR 1.06, 95% CI 0.98 to 1.13; I(2) = 0%, high quality evidence).
AUTHORS' CONCLUSIONS
This second update of this Cochrane Review found no evidence to suggest that homocysteine-lowering interventions in the form of supplements of vitamins B6, B9 or B12 given alone or in combination should be used for preventing cardiovascular events. Furthermore, there is no evidence to suggest that homocysteine-lowering interventions are associated with an increased risk of cancer.
Topics: Angina Pectoris; Cardiovascular Diseases; Humans; Hyperhomocysteinemia; Myocardial Infarction; Randomized Controlled Trials as Topic; Risk Factors; Stroke; Vitamin B Complex
PubMed: 25590290
DOI: 10.1002/14651858.CD006612.pub4 -
Systematic Reviews May 2020Development of cognitive decline represents substantial issues in today's society, steadily gaining importance with increasing life expectancy. One potential approach to... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Development of cognitive decline represents substantial issues in today's society, steadily gaining importance with increasing life expectancy. One potential approach to preventing cognitive decline is to lower homocysteine by administering vitamin B. In this systematic review and meta-analysis, we address this topic and investigate whether oral supplementation of vitamin B can successfully prevent cognitive decline in cognitively unimpaired individuals.
METHODS
A computerized systematic literature search was conducted using the electronic databases PubMed, Embase, and the Cochrane Library. Eligibility criteria included oral supplementation with vitamin B (B, B, folic acid, and B) and the absence of cognitive impairment. A meta-analysis was conducted with "global cognition" as the primary outcome of this review. Secondary outcomes were changes in cognitive function in other cognitive domains reported in the included studies. Risk of bias was assessed according to the Cochrane Risk of Bias tool and the GRADE approach to establish the overall certainty of the evidence.
RESULTS
The meta-analysis did not yield a significant overall effect of supplementation with vitamin B on cognitive function (Z = 0.87; p = 0.39; SMD, 0.02; 95% CI, - 0.034, 0.08). A sensitivity analysis focusing on specific risk factors did not alter this result. Some studies reported isolated significant effects of the intervention on secondary outcomes. However, these findings were outnumbered by the number of cognitive tests that did not yield significant effects.
DISCUSSION
We found no overall evidence that oral vitamin B supplementation prevented cognitive decline. The isolated significant effects that were reported could be attributed to methodological issues. The results of this review do not provide evidence that population groups with certain risk factors would profit more from the intervention than others. Our findings do not apply to forms of administration other than oral supplementation nor do they offer information regarding the treatment of cognitively impaired individuals via the administration of vitamin B.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO CRD42017071692.
Topics: Cognitive Dysfunction; Dietary Supplements; Folic Acid; Humans; Vitamin B 12; Vitamin B Complex
PubMed: 32414424
DOI: 10.1186/s13643-020-01378-7