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Systematic review with dose-response meta-analyses between vitamin B-12 intake and European Micronutrient Recommendations Aligned's prioritized biomarkers of vitamin B-12 including randomized controlled trials and observational studies in adults and elderly persons.

BACKGROUND: Many randomized controlled trials (RCTs) and observational studies have provided information on the association between vitamin B-12 intake and biomarkers. The use of these data to estimate dose-response relations provides a useful means to summarize the body of evidence.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet] - Centre for Reviews and Dissemination (UK).

Version: 2013

Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency

Vitamin B12 deficiency can cause anaemia and neurological complications. Vitamin B12 is rarely prescribed in the oral form in most countries. Two randomised controlled studies were included in this review. The trials recruited a total of 108 participants and followed up 93 of these from 90 days to four months. The evidence derived from these limited studies suggests that high oral doses of B12 (1000 mcg and 2000 mcg) could be as effective as intramuscular administration in achieving haematological and neurological responses.

Cochrane Database of Systematic Reviews: Plain Language Summaries [Internet] - John Wiley & Sons, Ltd.

Version: 2009

Interventions for lowering plasma homocysteine levels in dialysis patients

People with advanced kidney disease frequently develop heart disease, which is the most common cause of deaths in these people. An increased level of the amino acid (homocysteine) in the blood is a risk factor for heart disease in people with advanced kidney disease. Therapies that reduce homocysteine levels (e.g. folic acid, vitamins B6 and B12) are often used, but the benefits and harms of their use are unclear. We aimed to assess the benefits and harms of homocysteine‐lowering therapies in people with advanced kidney disease who were on dialysis.

Cochrane Database of Systematic Reviews: Plain Language Summaries [Internet] - John Wiley & Sons, Ltd.

Version: 2016

No evidence that folic acid with or without vitamin B12 improves cognitive function of unselected elderly people with or without dementia. Long‐term supplementation may benefit cognitive function of healthy older people with high homocysteine levels

In the economically developed world, folate deficiency is one of the commonest vitamin deficiencies. Several reports suggest a higher prevalence of various psychiatric disorders in elderly people with folate deficiency. There is interest in whether dietary supplements of folic acid (an artificial chemical analogue of naturally occurring folates) can improve cognitive function of people at risk of cognitive decline associated with ageing or dementia, whether by affecting homocysteine metabolism or through other mechanisms. Eight trials met the criteria for inclusion. It was not possible to pool the data because the trials studied different populations, tested folic acid in different doses, and used different outcome measures. There were two trials of folic acid in conjunction with B12. The analysis showed significant benefit of folic acid over placebo in some measures of cognition in a long‐term trial recruiting elderly people with high homocysteine levels from a general population. In one pilot trial, 1 mg/day of folic acid was associated with significant improvement in behavioural response to cholinesterase inhibitors in people with Alzheimer's disease.

Cochrane Database of Systematic Reviews: Plain Language Summaries [Internet] - John Wiley & Sons, Ltd.

Version: 2009

Vitamin B and its derivatives for diabetic kidney disease

Diabetic kidney disease (DKD) is a disorder which results in excessive protein, mainly albumin, loss in urine. DKD is a major cause of kidney failure and cardiovascular disease in patients with diabetes. Although vitamin B is commonly used in DKD, its effects are unclear. This review included nine studies with a total of 1354 participants. One study reported improvement in urinary albumin levels following use of thiamine. None of the other studies reported improvement in kidney function or reduction in urinary albumin excretion after two to 36 months monotherapy with vitamin B therapy. Vitamin B therapy was reported to well‐tolerated with mild side effects in studies with treatment duration of more than six months. Studies of less than six months duration did not explicitly report adverse events; they reported that the drugs were well‐tolerated without any serious drug related adverse events. All these findings require confirmation in larger studies before they can be accepted as definite.

Cochrane Database of Systematic Reviews: Plain Language Summaries [Internet] - John Wiley & Sons, Ltd.

Version: 2015

Vitamin-mineral supplementation and the progression of atherosclerosis: a meta-analysis of randomized controlled trials

BACKGROUND: Laboratory and observational studies suggest that antioxidant and B vitamin supplementation may prevent atherosclerosis. Although trials have not shown a benefit of these supplements on clinical cardiovascular events, it is unknown whether they affect the progression of atherosclerosis as measured by imaging techniques.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet] - Centre for Reviews and Dissemination (UK).

Version: 2006

Anemia, iron and vitamin B deficiencies after sleeve gastrectomy compared to Roux-en-Y gastric bypass: a meta-analysis

BACKGROUND: The effective treatment of postoperative anemia and nutritional deficiencies is critical for the successful management of bariatric patients. However, the evidence for nutritional risk or support of bariatric patients remains scarce. The aims of this study were to assess current evidence of the association between 2 methods of bariatric surgery, sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB), and postoperative anemia and nutritional deficiencies.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet] - Centre for Reviews and Dissemination (UK).

Version: 2013

Effects of methylcobalamin on diabetic peripheral neuropathy: a systematic review

Bibliographic details: Jia H Y, Tian H M, Wei D.  Effects of methylcobalamin on diabetic peripheral neuropathy: a systematic review. Chinese Journal of Evidence-Based Medicine 2005; 5(8): 609-617

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet] - Centre for Reviews and Dissemination (UK).

Version: 2005

Heterogeneity and lack of good quality studies limit association between folate, vitamins B-6 and B-12, and cognitive function

We conducted a systematic review to evaluate the association between folate, vitamin B-6, vitamin B-12, and cognitive function in the elderly. Our search was conducted in Medline for English-language publications of human subjects from 1966 through November 2006; we supplemented these results with information from article reviews and domain experts. We included longitudinal cohort and case-control studies of B vitamins and analyses of cognitive tests or Alzheimer's disease. We evaluated the quality and heterogeneity of study outcomes and assessed 30 different cognitive function tests. Of 24 studies that met eligibility criteria, 16 were determined to be of fair quality. A majority of the studies reviewed 2 or more B vitamins. Considerable heterogeneity was found among B-vitamin-level thresholds, comparisons, and data analyses. Six of 10 folate studies reported a significant association between low baseline blood folate concentrations and subsequent poor test performance in the global cognitive domain, and 4 of 9 folate studies found associations between low blood folate concentrations and increased prevalence of Alzheimer's disease. Studies did not reveal an association of vitamin B-6 and vitamin B-12 blood concentrations with cognitive-test performance or Alzheimer's disease, nor was B-vitamin dietary intake associated with cognitive function. Higher plasma homocysteine concentrations were associated with poorer cognitive function. Although the majority of studies indicated that low blood folate concentrations predicted poorer cognitive function, data supporting this association were limited because of the heterogeneity in cognition-assessment methodology, and scarcity of good quality studies and standardized threshold levels for categorizing low B-vitamin status.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet] - Centre for Reviews and Dissemination (UK).

Version: 2007

Diagnostic performance of serum cobalamin tests: a systematic review and meta-analysis

AIMS: Serum cobalamin (cbl, vitamin B(12)) tests are routinely ordered for investigating conditions potentially amenable to cbl supplementation. This study aimed to systematically assess the evidence of diagnostic accuracy for serum cbl tests across patient subgroups.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet] - Centre for Reviews and Dissemination (UK).

Version: 2011

Anemia, iron and vitamin B12 deficiencies after sleeve gastrectomy compared to Roux-en-Y gastric bypass: a meta-analysis

BACKGROUND: The effective treatment of postoperative anemia and nutritional deficiencies is critical for the successful management of bariatric patients. However, the evidence for nutritional risk or support of bariatric patients remains scarce. The aims of this study were to assess current evidence of the association between 2 methods of bariatric surgery, sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB), and postoperative anemia and nutritional deficiencies.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet] - Centre for Reviews and Dissemination (UK).

Version: 2014

Serum level of homocysteine, folate and vitamin-B12 in epileptic patients under carbamazepine and sodium valproate treatment: a systematic review and meta-analysis

BACKGROUND: Numerous studies have shown that long term treatment with anticonvulsants may be an important risk factor for the onset of atherosclerosis, or worsening of its symptoms. There are many contradictory reports regarding these effects.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet] - Centre for Reviews and Dissemination (UK).

Version: 2013

Effectiveness of vitamin B12 on recurrent aphthous stomatitis in long term care: a systematic review

Bibliographic details: Liu HL, Chiu S, Chen KH.  Effectiveness of vitamin B12 on recurrent aphthous stomatitis in long term care: a systematic review. JBI Database of Systematic Reviews and Implementation Reports 2013; 11(2): 281-307

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet] - Centre for Reviews and Dissemination (UK).

Version: 2013

Meta-analysis of methylcobalamin alone and in combination with lipoic acid in patients with diabetic peripheral neuropathy

AIMS: To compare the efficacy and safety of daily lipoic acid (300-600 mg i.v.) plus methylcobalamin (500-1000 mg i.v. or im.) (LA-MC) with that of methylcobalamin alone (MC) on diabetic peripheral neuropathy (DPN).

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet] - Centre for Reviews and Dissemination (UK).

Version: 2013

Vitamin B12 intake and status and cognitive function in elderly people.

Current recommendations on vitamin B12 intake vary from 1.4 to 3.0 μg per day and are based on the amount needed for maintenance of hematologic status or on the amount needed to compensate obligatory losses. This systematic review evaluates whether the relation between vitamin B12 intake and cognitive function should be considered for underpinning vitamin B12 recommendations in the future. The authors summarized dose-response evidence from randomized controlled trials and prospective cohort studies on the relation of vitamin B12 intake and status with cognitive function in adults and elderly people. Two randomized controlled trials and 6 cohort studies showed no association or inconsistent associations between vitamin B12 intake and cognitive function. Random-effects meta-analysis showed that serum/plasma vitamin B12 (50 pmol/L) was not associated with risk of dementia (4 cohort studies), global cognition z scores (4 cohort studies), or memory z scores (4 cohort studies). Although dose-response evidence on sensitive markers of vitamin B12 status (methylmalonic acid and holotranscobalamin) was scarce, 4 of 5 cohort studies reported significant associations with risk of dementia, Alzheimer's disease, or global cognition. Current evidence on the relation between vitamin B12 intake or status and cognitive function is not sufficient for consideration in the development of vitamin B12 recommendations. Further studies should consider the selection of sensitive markers of vitamin B12 status.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet] - Centre for Reviews and Dissemination (UK).

Version: 2013

Interventions with vitamins B6, B12 and C in pregnancy

The water-soluble vitamins B6, B12 and C play important roles in maternal health as well as fetal development and physiology during gestation. This systematic review evaluates the risks and benefits of interventions with vitamins B6, B12 and C during pregnancy on maternal, neonatal and child health and nutrition outcomes. Relevant publications were identified by searching PubMed, Popline and Web of Science databases. Meta-analyses were conducted for outcomes where results from at least three controlled trials were available. Potential benefits of vitamin B6 supplementation were reduction in nausea and vomiting, improvement in dental health, and treatment of some cases of anaemia. In meta-analysis based on three small studies, vitamin B6 supplementation had a significant positive effect on birthweight (d = 217 g [95% confidence interval (CI) 130, 304]). Interventions with vitamin C alone or combined with vitamin E did not systematically reduce the incidence of pre-eclampsia, premature rupture of membranes, or other adverse pregnancy outcomes. In meta-analyses, vitamins C and E increased the risk of pregnancy-related hypertension (relative risk 1.10 [95% CI 1.02, 1.19]). Effects of vitamin B6 or C intervention on other neonatal outcomes, including preterm birth, low birthweight, and perinatal morbidity and mortality, were not significant. Data on child health outcomes were lacking. Despite the prevalence of vitamin B12 deficiency amongst populations with limited intake of animal source foods, no intervention trials have evaluated vitamin B12 supplementation before or during pregnancy. In conclusion, existing evidence does not justify vitamin C supplementation during pregnancy. Additional studies are needed to confirm positive effects of vitamin B6 supplementation on infant birthweight and other outcomes. While vitamin B12 supplementation may reduce the incidence of neural tube defects in the offspring based on theoretical considerations, research is needed to support this hypothesis.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet] - Centre for Reviews and Dissemination (UK).

Version: 2012

A systematic review of acupuncture or acupoint injection for management of burning mouth syndrome

OBJECTIVE: Burning mouth syndrome (BMS) is a common chronic pain condition that lacks a satisfactory treatment approach. This systematic review was designed to examine the effects of acupuncture or acupoint injection on the management of BMS and to evaluate the evidence supporting the use of acupuncture therapy for BMS in clinical practice.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet] - Centre for Reviews and Dissemination (UK).

Version: 2012

Efficacy of vitamins B supplementation on mild cognitive impairment and Alzheimer's disease: a systematic review and meta-analysis

Despite B vitamin supplementation playing an important role in cognitive function, the exact effect remains unknown. The aim of this study was to systematically review and quantitatively synthesize the efficacy of treatment with vitamins B supplementation in slowing the rate of cognitive, behavioral, functional and global decline in individuals with MCI or AD. A systematic literature search in PubMed, EMBASE, International Pharmaceutical Abstracts, clinicaltrials. gov, the Cochrane Controlled Trials Register, the Cochrane Database of Systematic Reviews, and the Cochrane Cognitive Improvement Group specialized registry was conducted on April 2014, with no limit of date. Five trials met the eligibility criteria and were selected for this meta-analysis. Meta-analysis showed moderate beneficial effects of vitamins B supplementation on memory (SMD 0.60, 95% CI 0.20, 1.00), whereas no significant difference on general cognitive function (WMD -0.10, 95% CI -0.80, 0.59), executive function (SMD 0.05, 95% CI -0.11, 0.21) and attention (WMD -0.03, 95% CI -1.20, 1.14) were found in MCI patients. In addition, no significantly cognitive benefits on the Alzheimer's Disease Assessment Scale (ADAS-cog) (WMD 1.01, 95% CI -0.68, 2.70) and Mini Mental State Examination (MMSE) (WMD -0.22, 95% CI -1.00, 0.57), functional (SMD 0.13, 95% CI -0.05, 0.31), behavioral (SMD 0.04, 95% CI -0.16, 0.25) or global (WMD 0.07, 95% CI -0.48, 0.62) change were observed in AD patients. Collectively, weak evidence of benefits was observed for the domains of memory in patients with MCI. Nevertheless, future standard RCTs are still needed to determine whether it was still significant in larger populations. However, the data does not yet provide adequate evidence of an effect of vitamins B on general cognitive function, executive function and attention in people with MCI. Similarly, folic acid alone or vitamins B in combination are unable to stabilize or slow decline in cognition, function, behavior, and global change of AD patients.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet] - Centre for Reviews and Dissemination (UK).

Version: 2014

Effectiveness of vitamin B12 on diabetic neuropathy: systematic review of clinical controlled trials

This review assessed the effectiveness of vitamin B12 for the treatment of diabetic neuropathy. The authors concluded that vitamin B12 treatment appears to improve symptomatic relief more than electrophysiologic results. This conclusion should be viewed as tentative given the poor quality of the evidence reviewed.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet] - Centre for Reviews and Dissemination (UK).

Version: 2005

Vitamin B12 status, cognitive decline and dementia: a systematic review of prospective cohort studies

This review concluded that there was insufficient evidence to show a clear link between serum vitamin B12 concentrations and cognitive decline or dementia in older adults. Given the differences between studies and limitations of the evidence, the authors' cautious conclusions and recommendations for future research seem appropriate.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet] - Centre for Reviews and Dissemination (UK).

Version: 2012

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