scholarly journals B-vitamins and prevention of dementia

2008 ◽  
Vol 67 (1) ◽  
pp. 75-81 ◽  
Author(s):  
Robert Clarke
Keyword(s):  
Folic Acid ◽  
Cognitive Function ◽  
Meta Analysis ◽  
B Vitamins ◽  
Vitamin Supplementation ◽  
Vitamin B ◽  
Cross Sectional ◽  
Principal Investigators ◽  
Individual Participant ◽  
B Vitamin

Elevated plasma homocysteine (Hcy) concentrations have been implicated with risk of cognitive impairment and dementia, but it is unclear whether low vitamin B12 or folate status is responsible for cognitive decline. Most studies reporting associations between cognitive function and Hcy or B-vitamins have used a cross-sectional or case–control design and have been unable to exclude the possibility that such associations are a result of the disease rather than being causal. The Hcy hypothesis of dementia has attracted considerable interest, as Hcy can be easily lowered by folic acid and vitamin B12, raising the prospect that B-vitamin supplementation could lower the risk of dementia. While some trials assessing effects on cognitive function have used folic acid alone, vitamin B12 alone or a combination, few trials have included a sufficient number of participants to provide reliable evidence. An individual-patient-data meta-analysis of all randomised trials of the effects on cognitive function and vascular risk of lowering Hcy with B-vitamins will maximise the power to assess the epidemiologically-predicted differences in risk. Among the twelve large randomised Hcy-lowering trials for prevention of vascular disease, data should be available on about 30 000 participants with cognitive function. The principal investigators of such trials have agreed to combine individual-participant data from their trials after their separate publication.

scholarly journals  Prevalence Of Vitamin B Complex Deficiencies In Women In Reproductive Age, Pregnant Or Lactating Woman In Brazil: A Systematic Review And Meta-Analysis Protocol

2021 ◽  
Author(s):  
Michel Carlos Mocellin ◽  
Cintia Chaves Curioni ◽  
Alessandra da Silva Pereira ◽  
Simone Augusta Ribas ◽  
Michelle Teixeira Teixeira ◽  
...  
Keyword(s):  
Systematic Review ◽  
Data Extraction ◽  
Meta Analysis ◽  
Population Based ◽  
B Vitamins ◽  
Reproductive Age ◽  
Vitamin B ◽  
Prevalence Rates ◽  
Eligibility Criteria ◽  
Cross Sectional

Abstract Background: Complex B vitamin deficiency are involved with several outcomes in fertility and pregnancy. In Brazil, the national prevalence rates of these micronutrients deficiencies in women at reproductive age was not known. Therefore, this study aims to systematically identify, select, evaluate, analyze and report the prevalence rates of complex B vitamins deficiencies in women at reproductive age in Brazil, and identify variables that may modify the outcome rates.Methods: A systematic review will be conducted guided by the following question: “What is the prevalence of vitamin B complex deficiencies in women at reproductive age in Brazil?”. The studies will be identified and selected from a literature search using electronic databases, consultation to researchers/specialists, as well as reference lists of eligible studies and reviews on the topic. Major eligibility criteria include observational cross-sectional and cohort studies performed in women with 10-49 years old from Brazil; pregnant and lactating mothers; and which that investigated the deficiency of complex B vitamins by laboratorial test. Two reviewers independently will perform the screening and selection of studies, to subsequently perform data extraction and risk assessment of bias. For data report, a narrative approach will be used to summarize the characteristics of the included studies and the individual prevalence found for each micronutrient tested, and if the studies are sufficiently homogeneous, a quantitative synthesis (meta-analysis) will be performed.Discussion: Identify the national and regional prevalence rates of complex B vitamins deficiencies allow the policy makers discuss, plan and implement public policy to prevent and/or reduces the rates, if they are larger, or at least highlight discussions about a program of screening the vitamins deficiencies in this specific population for to know the epidemiologic scenario among the years, serving as an indirect indicator of the socioeconomic and dietary patterns of this population. Also, specifically for folates, this study allows to compare the prevalence rates of deficiency of this vitamin before and after the mandatory fortification of wheat and corn flours implemented since 2004. Nevertheless, the evidence gathered may highlight the need for population-based studies to investigate the deficiency of these vitamins.Systematic review registration: PROSPERO registration number: CRD42020188474

scholarly journals High folic acid or folate combined with low vitamin B-12 status: potential but inconsistent association with cognitive function in a nationally representative cross-sectional sample of US older adults participating in the NHANES

2020 ◽  
Vol 112 (6) ◽  
pp. 1547-1557 ◽  
Author(s):  
Regan L Bailey ◽  
Shinyoung Jun ◽  
Lisa Murphy ◽  
Ralph Green ◽  
Jaime J Gahche ◽  
...  
Keyword(s):  
Older Adults ◽  
Folic Acid ◽  
Cognitive Function ◽  
Serum Folate ◽  
Vitamin B ◽  
Digit Symbol Substitution Test ◽  
Cross Sectional ◽  
Folate Status ◽  
Normal Vitamin ◽  
Vitamin B 12

ABSTRACT Background Potential safety concerns relative to impaired cognitive function may exist when high folic acid exposures are combined with low vitamin B-12 status. Objectives We aimed to examine the relation of the coexistence of high folate and low vitamin B-12 status with cognitive function, utilizing various definitions of “high” folate status. Methods Cross-sectional data from older adults (≥60 y; n = 2420) from the 2011–2014 NHANES were analyzed. High folate status was defined as unmetabolized serum folic acid (UMFA) > 1 nmol/L or serum total folate > 74.1 nmol/L, and low vitamin B-12 status as methylmalonic acid > 271 nmol/L or serum vitamin B-12 < 150 pmol/L. Logistic regression models estimated ORs of scoring low on 1 of 4 cognitive tests: the Digit Symbol Substitution Test (DSST), the Consortium to Establish a Registry for Alzheimer's Disease Delayed Recall (CERAD-DR) and Word Learning tests, and the Animal Fluency test (AF). Results A significant interaction was observed relative to scoring low on the DSST (<34; UMFA; P-interaction = 0.0071) and AF (serum folate; P-interaction = 0.0078) for low vitamin B-12 and high folate status. Among those with low vitamin B-12, high UMFA or high serum total folate was associated with higher risk of scoring low on the DSST (OR: 2.16; 95% CI: 1.05, 4.47) and the AF (OR: 1.93; 95% CI: 1.08, 3.45). Among those with “normal” vitamin B-12, higher UMFA or serum total folate was protective on the CERAD-DR. In noninteraction models, when high folate and normal vitamin B-12 status was the reference group, low vitamin B-12 combined with high UMFA was associated with greater risk based on the DSST (<34, OR: 2.87; 95% CI: 1.85, 4.45; <40, OR: 2.22; 95% CI: 1.31, 3.75) and AF (OR: 1.97; 95% CI: 1.30, 2.97); but low vitamin B-12 and lower UMFA (OR: 1.69; 95% CI: 1.16, 2.47) was also significantly associated for DSST < 40 risk. Conclusions Low vitamin B-12 was associated with cognitive impairment both independently and in an interactive manner with high folate for certain cognitive performance tests among older adults.

Plasma concentrations of vitamin B12 and folate and global cognitive function in an older population: cross-sectional findings from The Irish Longitudinal Study on Ageing (TILDA)

2020 ◽  
Vol 124 (6) ◽  
pp. 602-610 ◽  
Author(s):  
Deirdre M. A. O’Connor ◽  
Eamon J. Laird ◽  
Daniel Carey ◽  
Aisling M. O’Halloran ◽  
Robert Clarke ◽  
...  
Keyword(s):  
Older Adults ◽  
Folic Acid ◽  
Longitudinal Study ◽  
Cognitive Function ◽  
Cognitive Performance ◽  
Vitamin B ◽  
Plasma Vitamin ◽  
Cross Sectional ◽  
Folate Status ◽  
Global Cognitive Function

AbstractThe uncertainty surrounding high intakes of folic acid and associations with cognitive decline in older adults with low vitamin B12 status has been an obstacle to mandatory folic acid fortification for many years. We estimated the prevalence of combinations of low/normal/high vitamin B12 and folate status and compared associations with global cognitive function using two approaches, of individuals in a population-based study of those aged ≥50 years in the Republic of Ireland. Cross-sectional data from 3781 men and women from Wave 1 of The Irish Longitudinal Study on Ageing were analysed. Global cognitive function was assessed by the Mini Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). Prevalence estimates for combinations of vitamin B12 (plasma vitamin B12 < or ≥258 pmol/l) and folate (plasma folate ≤ or >45·3 nmol/l) concentrations were generated. Negative binomial regression models were used to investigate the associations of vitamin B12 and folate status with global cognitive function. Of the participants, 1·5 % (n 51) had low vitamin B12 (<258 pmol/l) and high folate (>45·3 nmol/l) status. Global cognitive performance was not significantly reduced in these individuals when compared with those with normal status for both B-vitamins (n 2433). Those with normal vitamin B12/high folate status (7·6 %) had better cognitive performance (MMSE: incidence rate ratio (IRR) 0·82, 95 % CI 0·68, 0·99; P = 0·043, MoCA: IRR 0·89, 95 % CI 0·80, 0·99; P = 0·025). We demonstrated that high folate status was not associated with lower cognitive scores in older adults with low vitamin B12 status. These findings provide important safety information that could guide fortification policy recommendations in Europe.

Efficacy of Vitamin B Supplementation on Cognition in Elderly Patients With Cognitive-Related Diseases

2016 ◽  
Vol 30 (1) ◽  
pp. 50-59 ◽  
Author(s):  
Dong-Mei Zhang ◽  
Jian-Xin Ye ◽  
Jun-Shan Mu ◽  
Xiao-Ping Cui
Keyword(s):  
Folic Acid ◽  
Alzheimer Disease ◽  
Elderly Patients ◽  
Cognitive Decline ◽  
Meta Analysis ◽  
Vitamin B ◽  
Cognitive Improvement ◽  
Serum Homocysteine ◽  
Significant Difference ◽  
B Vitamin

Increase in serum homocysteine is shown to be a potential risk factor for cognitive impairment. Evidence suggests that vitamin B supplementation may reduce cognitive decline by lowering the homocysteine levels. The current meta-analysis evaluated the efficacy of folic acid along with vitamin B12 and/or B6 in lowering homocysteine, thereby attenuating cognitive decline in elderly patients with Alzheimer disease or dementia. Randomized controlled trials (RCTs) comparing the efficacy of folate and B vitamin supplementation in patients with cognitive decline secondary to Alzheimer disease or dementia were identified using the keywords, “homocysteine, hyper-homocysteinemia, B vitamin, vitamin B6, B12, folic acid, cognitive, Alzheimer’s disease, and dementia.” The outcome measures analyzed were the Mini-Mental State Examination (MMSE) score and serum homocysteine. Of the 77 studies identified, 4 RCTs were included in the current meta-analysis. The baseline characteristics, age, and gender distribution of patients among the 2 groups (supplement vs placebo) were comparable. The results reveal that the intervention group achieved significantly greater reduction in homocysteine levels than the control (pooled difference in means = −3.625, 95% confidence interval [CI] = −5.642 to −1.608, P < .001). However, no significant difference in MMSE (pooled difference in means = 0.027, 95% CI = −0.518 to 0.573, P = 0.921) was observed between the groups. Taken together, vitamin B supplementation was effective in reducing serum homocysteine levels. However, it did not translate into cognitive improvement, indicating that the existing data on vitamin B-induced improvement in cognition by lowering homocysteine levels are conflicting.

Impact of B-vitamin supply on major metabolic pathways of lactating dairy cows

2006 ◽  
Vol 86 (2) ◽  
pp. 213-220 ◽  
Author(s):  
C. L. Girard ◽  
J. J. Matte
Keyword(s):  
Folic Acid ◽  
Dairy Cows ◽  
Metabolic Pathways ◽  
Dry Matter ◽  
Milk Protein ◽  
B Vitamins ◽  
Dry Matter Intake ◽  
Vitamin B ◽  
Metabolic Efficiency ◽  
B Vitamin

Knowledge of the major nutrient requirements of dairy cows has increased substantially during the past decades. Little is known, however, about the importance of the roles played by B vitamins. Since most of those vitamins act as essential cofactors in energy, protein and lipid metabolism, it is likely that as milk yield increases, the demand for these cofactors also increases. The supply of B vitamins from dietary sources and synthesis by the ruminal microflora is generally sufficient to avoid deficiency symptoms, but could be insufficient for optimizing metabolic efficiency, production, composition and the nutritional quality of milk in high-producing dairy cows. Results from recent experiments show how the supply of three B vitamins — folic acid, biotin and vitamin B12 — affects major metabolic pathways. Supplementary biotin has frequently been reported to increase milk yield but has a limited effect on milk composition. Folic acid supplements have been found to increase milk and milk protein yields in multiparous cows without affecting dry matter intake when vitamin B12 supply was adequate. An insufficient vitamin B12 supply blocked those effects but they can be restored through vitamin B12 supplementation. Supplemental vitamin B12 and biotin increased milk and milk protein yields without changing dry matter intake. Vitamin B12 utilization by tissues increased in cows fed supplementary folic acid simultaneously; plasma glucose also increased in these cows but plasma biotin decreased. From these findings, it appears that, in high-producing dairy cows, especially in early lactation, the strong competition for nutrients that occurs between gluconeogenesis, methylneogenesis and protein synthesis increases the amount of folic acid, vitamin B12 and biotin required to maintain metabolic efficiency, especially when the nutrient supply is limited. These observations emphasize the need to review the paradigm according to which B-vitamin supply by ruminal microflora cannot be limiting in dairy cow. Key words: Dairy cow, B vitamins, folic acid, vitamin B12, biotin, lactation, metabolism

scholarly journals Homocysteine-lowering vitamins do not lower plasmaS-adenosylhomocysteine in older people with elevated homocysteine concentrations

2010 ◽  
Vol 103 (11) ◽  
pp. 1629-1634 ◽  
Author(s):  
Timothy J. Green ◽  
C. Murray Skeaff ◽  
Jennifer A. McMahon ◽  
Bernard J. Venn ◽  
Sheila M. Williams ◽  
...  
Keyword(s):  
Older People ◽  
Vascular Disease ◽  
B Vitamins ◽  
Vitamin Supplementation ◽  
Vitamin B ◽  
Elevated Plasma ◽  
Vascular Events ◽  
Folate Supplementation ◽  
Plasma Thcy ◽  
B Vitamin

Elevated plasma total homocysteine (tHcy) is a risk factor for vascular disease but lowering tHcy with B-vitamins, including folate, has generally not reduced vascular events in secondary prevention trials. Elevated plasmaS-adenosylhomocysteine (AdoHcy) concentration may be a more sensitive indicator of vascular disease than plasma tHcy. However, unlike tHcy, plasma AdoHcy did not correlate with folate concentration in one study indicating that folate supplementation may not lower AdoHcy. Our aim was to determine whether providing B-vitamin supplements to healthy older people with elevated tHcy (>13 μmol/l) affects plasma AdoHcy andS-adenosylmethionine (AdoMet) concentrations. Healthy older participants (n276; ≥ 65 years) were randomised to receive a daily supplement containing folate (1 mg), vitamin B12(500 μg) and vitamin B6(10 mg), or placebo, for 2 years. Of these participants, we selected the first fifty participants in each treatment group and measured plasma AdoHcy and AdoMet. Plasma tHcy was 4·4 (95 % CI 3·2, 5·6;P < 0·001) μmol/l lower at 2 years in the vitamins group compared with the placebo group. At 2 years, there were no significant differences in plasma AdoMet (+4 % (95 % CI − 2, 11);P = 0·19), AdoHcy ( − 1 % (95 % CI − 10, 8);P = 0·61) or the AdoMet:AdoHcy ratio (0·22 (95 % CI − 0·04, 0·49);P = 0·10) between the two groups. In conclusion, B-vitamin supplementation of older people lowered plasma tHcy but had no effect on plasma AdoMet or AdoHcy concentration. If elevated plasma AdoHcy is detrimental, this may explain why B-vitamins have generally failed to reduce vascular events in clinical trials.

scholarly journals Addressing optimal folate and related B-vitamin status through the lifecycle: health impacts and challenges

2019 ◽  
Vol 78 (3) ◽  
pp. 449-462 ◽  
Author(s):  
Helene McNulty ◽  
Mary Ward ◽  
Leane Hoey ◽  
Catherine F. Hughes ◽  
Kristina Pentieva
Keyword(s):  
Folic Acid ◽  
Methylenetetrahydrofolate Reductase ◽  
Folic Acid Supplementation ◽  
B Vitamins ◽  
Food Sources ◽  
Natural Food ◽  
Vitamin B ◽  
Genetic Characteristics ◽  
Increased Risk ◽  
B Vitamin

The functional effects of folate within C1 metabolism involve interrelationships with vitamin B12, vitamin B6 and riboflavin, and related gene–nutrient interactions. These B vitamins have important roles throughout life, from pregnancy, through childhood, to middle and older age. Achieving optimal nutritional status for preventing folate-related disease is challenging, however, primarily as a result of the poor stability and incomplete bioavailability of folate from natural food sources when compared with the synthetic vitamin form, folic acid. Thus, in European countries, measures to prevent neural tube defects (NTD) have been largely ineffective because of the generally poor compliance of women with folic acid supplementation as recommended before and in early pregnancy. In contrast, countries worldwide with mandatory folic acid fortification policies have experienced marked reductions in NTD. Low vitamin B12 status is associated with increased risk of cognitive dysfunction, CVD and osteoporosis. Achieving optimal B12 status can be problematic for older people, however, primarily owing to food-bound B12 malabsorption which leads to sub-clinical deficiency even with high dietary B12 intakes. Optimising B-vitamin intake may be particularly important for sub-populations with impaired folate metabolism owing to genetic characteristics, most notably the 677C→T variant in the gene encoding the enzyme methylenetetrahydrofolate reductase (MTHFR). This common folate polymorphism is linked with several adverse health outcomes, including stroke, however, recent evidence has identified its novel interaction with riboflavin (the MTHFR cofactor) in relation to blood pressure and risk of developing hypertension. This review addresses why and how the optimal status of folate-related B vitamins should be achieved through the lifecycle.

scholarly journals Arm Based on LEg blood pressures (ABLE-BP): can systolic leg blood pressure measurements predict systolic brachial blood pressure? Protocol for an individual participant data meta-analysis from the INTERPRESS-IPD Collaboration

BMJ Open ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. e040481
Author(s):  
Sinead T J McDonagh ◽  
James P Sheppard ◽  
Fiona C Warren ◽  
Kate Boddy ◽  
Leon Farmer ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Public Involvement ◽  
Meta Analysis ◽  
Patient And Public Involvement ◽  
Prognostic Models ◽  
Individual Participant Data ◽  
Dissemination Strategy ◽  
Cross Sectional ◽  
Individual Participant ◽  
Meta Analyses

IntroductionBlood pressure (BP) is normally measured on the upper arm, and guidelines for the diagnosis and treatment of high BP are based on such measurements. Leg BP measurement can be an alternative when brachial BP measurement is impractical, due to injury or disability. Limited data exist to guide interpretation of leg BP values for hypertension management; study-level systematic review findings suggest that systolic BP (SBP) is 17 mm Hg higher in the leg than the arm. However, uncertainty remains about the applicability of this figure in clinical practice due to substantial heterogeneity.AimsTo examine the relationship between arm and leg SBP, develop and validate a multivariable model predicting arm SBP from leg SBP and investigate the prognostic association between leg SBP and cardiovascular disease and mortality.Methods and analysisIndividual participant data (IPD) meta-analyses using arm and leg SBP measurements for 33 710 individuals from 14 studies within the Inter-arm blood pressure difference IPD (INTERPRESS-IPD) Collaboration. We will explore cross-sectional relationships between arm and leg SBP using hierarchical linear regression with participants nested by study, in multivariable models. Prognostic models will be derived for all-cause and cardiovascular mortality and cardiovascular events.Ethics and disseminationData originate from studies with prior ethical approval and consent, and data sharing agreements are in place—no further approvals are required to undertake the secondary analyses proposed in this protocol. Findings will be published in peer-reviewed journal articles and presented at conferences. A comprehensive dissemination strategy is in place, integrated with patient and public involvement.PROSPERO registration numberCRD42015031227.

Cognitive function and risk for depression in old age: a meta-analysis of published literature

2010 ◽  
Vol 23 (4) ◽  
pp. 516-525 ◽  
Author(s):  
Chang-Quan Huang ◽  
Zheng-Rong Wang ◽  
Yong-Hong Li ◽  
Yi-Zhou Xie ◽  
Qing-Xiu Liu
Keyword(s):  
Cognitive Impairment ◽  
Relative Risk ◽  
Cognitive Function ◽  
Longitudinal Studies ◽  
Old Age ◽  
Meta Analysis ◽  
Incidence Rates ◽  
Cochrane Library ◽  
Cross Sectional ◽  
Risk For Depression

ABSTRACTBackground: We assessed the relationship between cognitive impairment (including mild cognitive impairment with no signs of dementia, and dementia) and risk for depression in old age (60 years and older).Methods: MEDLINE, EMBASE and the Cochrane Library database were used to identify potential studies. All of the clinical studies that produced data on the association between cognitive function and risk of depression among individuals aged 55 years or older were identified and included in this review. The studies were classified into cross-sectional and longitudinal subsets. The quantitative meta-analysis of cross-sectional and longitudinal studies were performed. For prevalence and incidence rates of depression, odds risk (OR) and relative risk (RR) were calculated, respectively.Results: Since all but two studies found in the search were for individuals aged 60 years or over, we assessed and reported on results for this larger group only. In this review we included 13 cross-sectional and four prospective longitudinal studies. The quantitative meta-analysis showed that, in old age, individuals with non-dementia cognitive impairment had neither significant higher prevalence nor incidence rates of depression than those without (odds risk (OR): 1.48, 95% confidence intervals (95% CI): 0.87–2.52; relative risk (RR): 1.12, 95% CI: 0.62–2.01). In old age, individuals with dementia had both significant higher prevalence and incidence rates of depression than those without (OR: 1.82, 95% CI: 1.15–2.89; RR: 3.92, 95% CI: 1.93–7.99).Conclusions: Despite the methodological limitations of this meta-analysis, we found that in old age, there was no association between depression and cognitive impairment with no dementia; however, there was a definite association between depression and dementia and thus dementia might be a risk for depression.

Long-Term Cognitive Decline After Stroke: An Individual Participant Data Meta-Analysis

Stroke ◽  
2021 ◽  
Author(s):  
Jessica W. Lo ◽  
John D. Crawford ◽  
David W. Desmond ◽  
Hee-Joon Bae ◽  
Jae-Sung Lim ◽  
...  
Keyword(s):  
Risk Factors ◽  
Cognitive Function ◽  
Cognitive Decline ◽  
Recurrent Stroke ◽  
Meta Analysis ◽  
Older Age ◽  
Individual Participant Data ◽  
Individual Participant ◽  
Global Cognition

Background and Purpose: Poststroke cognitive impairment is common, but the trajectory and magnitude of cognitive decline after stroke is unclear. We examined the course and determinants of cognitive change after stroke using individual participant data from the Stroke and Cognition Consortium. Methods: Nine longitudinal hospital-based cohorts from 7 countries were included. Neuropsychological test scores and normative data were used to calculate standardized scores for global cognition and 5 cognitive domains. One-step individual participant data meta-analysis was used to examine the rate of change in cognitive function and risk factors for cognitive decline after stroke. Stroke-free controls were included to examine rate differences. Based on the literature and our own data that showed short-term improvement in cognitive function after stroke, key analyses were restricted to the period beginning 1-year poststroke to focus on its long-term effects. Results: A total of 1488 patients (mean age, 66.3 years; SD, 11.1; 98% ischemic stroke) were followed for a median of 2.68 years (25th–75th percentile: 1.21–4.14 years). After an initial period of improvement through up to 1-year poststroke, decline was seen in global cognition and all domains except executive function after adjusting for age, sex, education, vascular risk factors, and stroke characteristics (−0.053 SD/year [95% CI, −0.073 to −0.033]; P <0.001 for global cognition). Recurrent stroke and older age were associated with faster decline. Decline was significantly faster in patients with stroke compared with controls (difference=−0.078 SD/year [95% CI, −0.11 to −0.045]; P <0.001 for global cognition in a subgroup analysis). Conclusions: Patients with stroke experience cognitive decline that is faster than that of stroke-free controls from 1 to 3 years after onset. An increased rate of decline is associated with older age and recurrent stroke.

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