scholarly journals Low Vitamin D and Its Association with Cognitive Impairment and Dementia

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Sadia Sultan ◽  
Uzma Taimuri ◽  
Shatha Abdulrzzaq Basnan ◽  
Waad Khalid Ai-Orabi ◽  
Afaf Awadallah ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Vitamin D ◽  
Cognitive Impairment ◽  
Behavioral Problems ◽  
Small Sample Size ◽  
Vitamin D Supplementation ◽  
Small Sample ◽  
Vitamin D Levels ◽  
Prevention And Treatment

Vitamin D is a neurosteroid hormone that regulates neurotransmitters and neurotrophins. It has anti-inflammatory, antioxidant, and neuroprotective properties. It increases neurotrophic factors such as nerve growth factor which further promotes brain health. Moreover, it is also helpful in the prevention of amyloid accumulation and promotes amyloid clearance. Emerging evidence suggests its role in the reduction of Alzheimer’s disease hallmarks such as amyloid-beta and phosphorylated tau. Many preclinical studies have supported the hypothesis that vitamin D leads to attentional, behavioral problems and cognitive impairment. Cross-sectional studies have consistently found that vitamin D levels are significantly low in individuals with Alzheimer’s disease and cognitive impairment compared to healthy adults. Longitudinal studies and meta-analysis have also exhibited an association of low vitamin D with cognitive impairment and Alzheimer’s disease. Despite such evidence, the causal association cannot be sufficiently answered. In contrast to observational studies, findings from interventional studies have produced mixed results on the role of vitamin D supplementation in the prevention and treatment of cognitive impairment and dementia. The biggest issue of the existing RCTs is their small sample size, lack of consensus over the dose, and age of initiation of vitamin D supplements to prevent cognitive impairment. Therefore, there is a need for large double-blind randomized control trials to assess the benefits of vitamin D supplementation in the prevention and treatment of cognitive impairment.

scholarly journals The non-genomic vitamin D pathway links β-amyloid to autophagic apoptosis in Alzheimer's disease

2021 ◽  
Author(s):  
Rai-Hua Lai ◽  
Yueh-Ying Hsu ◽  
Feng-Shiun Shie ◽  
Mei-Hsin Chen ◽  
Jyh-Lyh Juang
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Vitamin D ◽  
Cognitive Impairment ◽  
Vitamin D Deficiency ◽  
Epidemiological Studies ◽  
Vitamin D Supplementation ◽  
Adult Brain ◽  
Plasma Vitamin ◽  
Vitamin D Levels

Vitamin D is an important hormonal molecule, which exerts genomic and non-genomic actions in maintaining brain development and adult brain health. Many epidemiological studies have associated vitamin D deficiency with Alzheimer's disease (AD). Nevertheless, the underlying signaling pathway through which this occurs remains to be characterized. We were intrigued to find that although vitamin D levels are significantly low in AD patients, their hippocampal vitamin D receptor (VDR) levels are inversely increased in the cytosol of the brain cells, and colocalized with Aβ plaques, gliosis and autophagosomes, suggesting that a non-genomic form of VDR is implicated in AD. Mechanistically, Aβ induces the conversion of nuclear heterodimer of VDR/RXR heterodimer into a cytoplasmic VDR/p53 heterodimer. The cytosolic VDR/p53 complex mediates the Aβ induced autophagic apoptosis. Reduction of p53 activity in AD mice reverses the VDR/RXR formation and rescues AD brain pathologies and cognitive impairment. In line with the impaired genomic VDR pathway, the transgenic AD mice fed a vitamin D sufficient diet exhibit lower plasma vitamin D levels since early disease phases, raising the possibility that vitamin D deficiency may actually be an early manifestation of AD. Despite the deficiency of vitamin D in AD mice, vitamin D supplementation not only has no benefit but lead to exacerbated Aβ depositions and cognitive impairment. Together, these data indicate that the impaired genomic vitamin D pathway links Aβ to induce autophagic apoptosis, and suggest that VDR/p53 pathway could be targeted for the treatment of AD.

scholarly journals Effect of Vitamin D Supplementation on the Progression of Alzheimer’s Disease in Rats: A Mechanistic Approach

2021 ◽  
Author(s):  
Parmi Patel ◽  
Jigna Samir Shah
Keyword(s):  
Oxidative Stress ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Vitamin D ◽  
Vitamin D Supplementation ◽  
Cognitive Status ◽  
Tau Proteins ◽  
Biochemical Alterations ◽  
Vitamin D Levels ◽  
The Brain

Abstract Purpose: A multifaceted treatment approach can be effective for Alzheimer's disease (AD). However, currently, it involves only symptomatic treatment with cholinergic drugs. Beneficial effects of high vitamin D levels or its intake in the prevention and treatment of cognitive disorders have been reported. Thus, the present study examined the preventive effect of vitamin D supplementation on AD progression and evaluated its impact on the accumulation or degradation of Aβ plaques. Methods: A single intraperitoneal injection of scopolamine was used to induce AD in rats. Treatment of vitamin D was provided for 21 days after the injection. Various behavioral parameters like learning, spatial memory and exploratory behavior, biochemical alterations in the brain homogenate and histology of the hippocampus were investigated. Results: Our results indicated that scopolamine-induced rats depicted cognitive deficits with high Aβ levels and hyperphosphorylated tau proteins in the brain tissue, while vitamin D supplementation could significantly improve the cognitive status and lower these protein levels. These results were supported by the histopathological and immunohistochemical staining of the hippocampal brain region. Furthermore, mechanistic analysis depicted that vitamin D supplementation improved the Aβ protein clearance by increasing the neprilysin levels. It also reduced the accumulation of Aβ plaques by lowering neuroinflammation as well as oxidative stress. Conclusion: The present findings indicate that vitamin D supplementation can delay AD progression by an increase in Aβ plaques degradation or reducing inflammation and oxidative stress.

scholarly journals VITAMIN D AND DEMENTIA

2015 ◽  
pp. 1-10
Author(s):  
T.J. Littlejohns ◽  
K. Kos ◽  
W.E. Henley ◽  
E. Kuma ◽  
D.J. Llewellyn
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Vitamin D ◽  
Longitudinal Studies ◽  
Ventricular Volume ◽  
Vitamin D Supplementation ◽  
Small Sample ◽  
Double Blind ◽  
Cross Sectional ◽  
Increased Risk

Emerging evidence suggests that low vitamin D concentrations are potentially involved in the pathogenesis of dementia. This is of particular interest when considering the high prevalence of vitamin D deficiency in elderly adults and the urgent need to identify modifiable risk factors for dementia. Studies have found that vitamin D is implicated in procognitive and neuroprotective functions, including the reduction of Alzheimer’s disease hallmarks such as amyloid beta and phosphorylated tau. Cross-sectional studies have consistently found that vitamin D concentrations are significantly lower in individuals with Alzheimer’s disease and cognitive impairment compared to healthy controls. Longitudinal studies support an association between low vitamin D concentrations and an increased risk of dementia and cognitive decline. Neuroimaging studies are beginning to uncover the potential neurodegenerative and cerebrovascular mechanisms that underlie these associations such as white matter hyperintensities and enlarged ventricular volume, although there is currently a lack of longitudinal studies. In contrast to observational studies, findings from interventional studies have produced mixed results on the benefits of vitamin D supplementation on dementia and cognitive outcomes. Interpretation of the findings from these studies is hampered by several major methodological limitations, such as small sample sizes, inadequate doses and inclusion of participants unlikely to benefit from vitamin D supplementation. There is a need for large double-blind randomised-control trials investigating whether vitamin D supplementation can halt or delay the risk of dementia-related outcomes in individuals with low vitamin D concentrations.

scholarly journals Revisiting vitamin D status and supplementation for inpatients with intellectual and developmental disability in the north of England, UK

BJPsych Open ◽  
2021 ◽  
Vol 7 (S1) ◽  
pp. S14-S14
Author(s):  
Vlad Ciausu ◽  
Marcin Ostrowski ◽  
Bethany Dudley ◽  
Iain McKinnon ◽  
Chris Ince
Keyword(s):  
Vitamin D ◽  
Physical Health ◽  
Developmental Disability ◽  
Small Sample Size ◽  
Vitamin D Supplementation ◽  
Small Sample ◽  
Inpatient Service ◽  
Intellectual And Developmental Disability ◽  
Vitamin D Levels ◽  
Secure Unit

AimsVitamin D deficiency is common among people with Intellectual and Developmental Disability (IDD) and is linked to worse health outcomes.Our aims were to re-evaluate vitamin D testing and supplementation among inpatients with IDD, examine any correlates with physical health conditions including COVID-19 and make recommendations for the current regime of supplementation and testing within inpatient IDD services.MethodThe study population comprised inpatients who were in any of the Northgate Hospital IDD inpatient services in Northumberland, UK. The wards sampled were the Medium Secure Unit, Low Secure Unit, Hospital Based Rehabilitation Wards and Specialist Autism Inpatient Service. Records of all inpatients between January 2019 and July 2020 were examined for 25-hydroxyvitamin D [25(OH)D] level, ward area, supplementation status, test seasonality, medication, and health status.We performed a correlation to see whether there was an association between vitamin D level and length of time on treatment. In addition, comparison of the replete and inadequate group for age, ethnicity, seasonality, ward location and psychotropic medication was undertaken.Data on physical health risk factors, obesity and COVID-19 infection were also collected. The physical comorbidities were described in order to evaluate whether any emerging patterns relating to COVID-19 infection were emerging.ResultThere were 67 inpatients in Northgate IDD services on 1 January 2019, with 11 further patients admitted up to the end of the sampling period on 31 July 2020. Nineteen patients were discharged during that period, so the sample comprised 78 patients.Ages were comparable across three of the ward areas, except for an older group of patients in the hospital-based rehabilitation setting. Mean 25(OH)D level for supplemented (800IU/day) patients was 75nmol/l (SD 20) compared to 40nmol/l (SD 19) in the non-supplemented group (p < 0.001).Thirty-eight percent of those who were inpatients during the first wave of the COVID-19 pandemic developed symptoms, but the small sample size could not establish vitamin D levels as a predictor of outcome.ConclusionOur findings show that clinicians continue to offer vitamin D supplementation for inpatients, at a dose of 800IU (20μg) per day.The mean vitamin D levels we observed were higher for those on supplements compared to our 2013 baseline data, whereas patients not on supplementation now had levels akin to those found previously. Vitamin D (800IU/day) supplementation is effective but adequacy of the nationally recommended dose of 400IU/day is unclear. Links to COVID-19 merit further research.

scholarly journals Serum vitamin D in patients with mild cognitive impairment and Alzheimer's disease

2018 ◽  
Vol 8 (3) ◽  
pp. e00936 ◽  
Author(s):  
Shinji Ouma ◽  
Midori Suenaga ◽  
Funda F. Bölükbaşı Hatip ◽  
Izzettin Hatip-Al-Khatib ◽  
Yoshio Tsuboi ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Vitamin D ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Serum Vitamin ◽  
Serum Vitamin D

Detection of prospective memory deficits in mild cognitive impairment of suspected Alzheimer’s disease etiology using a novel event-based prospective memory task

2009 ◽  
Vol 15 (1) ◽  
pp. 154-159 ◽  
Author(s):  
ALBERTO BLANCO-CAMPAL ◽  
ROBERT F. COEN ◽  
BRIAN A. LAWLOR ◽  
JOSEPH B. WALSH ◽  
TERESA E. BURKE
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Prospective Memory ◽  
Small Sample ◽  
Cutoff Score ◽  
Convenience Sample ◽  
Disease Etiology ◽  
Event Based

AbstractWe investigated the relative discriminatory efficacy of an event-based prospective memory (PM) task, in which specificity of the instructions and perceptual salience of the PM cue were manipulated, compared with two widely used retrospective memory (RM) tests (Rivermead Paragraph Recall Test and CERAD-Word List Test), when detecting mild cognitive impairment of suspected Alzheimer’s disease etiology (MCI-AD) (N = 19) from normal controls (NC) (N = 21). Statistical analyses showed high discriminatory capacity of the PM task for detecting MCI-AD. The Non-Specific-Non-Salient condition proved particularly useful in detecting MCI-AD, possibly reflecting the difficulty of the task, requiring more strategic attentional resources to monitor for the PM cue. With a cutoff score of <4/10, the Non-Specific-Non-Salient condition achieved a sensitivity = 84%, and a specificity = 95%, superior to the most discriminative RM test used (CERAD-Total Learning: sensitivity = 83%; specificity = 76%). Results suggest that PM is an early sign of memory failure in MCI-AD and may be a more pronounced deficit than retrospective failure, probably reflecting the greater self-initiated retrieval demands involved in the PM task used. Limitations include the relatively small sample size, and the use of a convenience sample (i.e. memory clinic attenders and healthy active volunteers), reducing the generalizability of the results, which should be regarded as preliminary. (JINS, 2009, 15, 154–159.)

Vitamin D supplementation restores suppressed synaptic plasticity in Alzheimer's disease

2013 ◽  
Vol 17 (4) ◽  
pp. 172-177 ◽  
Author(s):  
Mohsen Taghizadeh ◽  
Sayyed Alireza Talaei ◽  
Abolghasem Djazayeri ◽  
Mahmoud Salami
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Vitamin D ◽  
Synaptic Plasticity ◽  
Vitamin D Supplementation

scholarly journals Frequency and subgroups of neuropsychiatric symptoms in mild cognitive impairment and different stages of dementia in Alzheimer's disease

2017 ◽  
Vol 30 (1) ◽  
pp. 103-113 ◽  
Author(s):  
N. Siafarikas ◽  
G. Selbaek ◽  
T. Fladby ◽  
J. Šaltytė Benth ◽  
E. Auning ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Factor Analysis ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Cognitive Decline ◽  
Neuropsychiatric Symptoms ◽  
Small Sample ◽  
Psychotic Symptoms ◽  
Cross Sectional

ABSTRACTBackground:Neuropsychiatric symptoms (NPS), such as depression, apathy, agitation, and psychotic symptoms are common in mild cognitive impairment (MCI) and dementia in Alzheimer's disease (AD). Subgroups of NPS have been reported. Yet the relationship of NPS and their subgroups to different stages of cognitive impairment is unclear. Most previous studies are based on small sample sizes and show conflicting results. We sought to examine the frequency of NPS and their subgroups in MCI and different stages of dementia in AD.Methods:This was a cross-sectional study using data from a Norwegian national registry of memory clinics. From a total sample of 4,571 patients, we included those with MCI or AD (MCI 817, mild AD 883, moderate–severe AD 441). To compare variables across groups ANOVA or χ2-test was applied. We used factor analysis of Neuropsychiatric Inventory Questionnaire (NPI-Q) items to identify subgroups of NPS.Results:The frequency of any NPS was 87.2% (AD 91.2%, MCI 79.5%; p < 0.001) and increased with increasing severity of cognitive decline. The most frequent NPS in MCI was depression. Apathy was the most frequent NPS in AD across different stages of severity. The factor analysis identified three subgroups in MCI and mild AD, and a fourth one in moderate–severe AD. We labelled the subgroups “depression,” “agitation,” “psychosis,” and “elation.”Conclusions:The frequency of NPS is high in MCI and AD and increases with the severity of cognitive decline. The subgroups of NPS were relatively consistent from MCI to moderate-severe AD. The subgroup elation appeared only in moderate-severe AD.

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