Hypovitaminosis D in the elderly: from bone to brain

On-admission serum 25(OH)D level and mortality within one year in older patients

BACKGROUND

Mounting evidence suggests that vitamin D deficiency is associated with a higher risk of many chronic non-skeletal, age-associated diseases as well as mortality.

AIM

To determine, in older patients aged ≥ 80, the prevalence of vitamin D deficiency and its association with comorbidity, laboratory tests, length of stay and mortality within one year from blood withdrawal on admission to acute geriatrics ward.

METHODS

We retrospectively surveyed electronic hospital health records of 830 older patients. The recorded data included patient demographics (e.g., age, sex, stay duration, readmissions number, death within one year from blood withdrawal on admission), medical diagnoses, laboratory results, including 25-hydroxyvitamin D [25(OH)D], and medications. We compared the characteristics of the patients who survived to those who died within one year.

RESULTS

On admission, in 53.6% patients, vitamin D levels were lower than 50 nmol/L, and in 32%, the levels were ≤ 35 nmol/L. Persons who died were likely to be older, of male sex, were likely to be admitted for pneumonia or CHF, were likely to have lower level of albumin or hemoglobin, lower level of vitamin D or higher vitamin B12 and higher level of creatinine, were also likely to have had a lengthier hospitalization stay, a greater number of hospitalizations in the last year, a higher number of comorbidities, to have consumption of ≥5 drugs or likely to being treated with insulin, diuretics, antipsychotics, anticoagulants or benzodiazepines. Higher age, male sex, on-admission CHF, higher number of drugs, lower albumin, higher vitamin B12, vitamin D < 50 nmol/L, and consumption of antipsychotics and anticoagulants - were predictors of mortality.

CONCLUSION

Hypovitaminosis D is predictive of mortality in older patients within one year from hospitalization in the acute geriatric ward, but a causal relationship cannot be deduced. Nevertheless, older patients in acute care settings, because of their health vulnerability, should be considered for vitamin D testing. In the acutely ill patients, early intervention with vitamin D might improve outcomes. Accurate evaluation of mortality predictors in this age group patients may be more challenging and require variables that were not included in our study.

Vitamin D, a Secosteroid Hormone and Its Multifunctional Receptor, Vitamin D Receptor, in Alzheimer's Type Neurodegeneration

Vitamin D is a secosteroid hormone exerting neurosteroid-like properties. Its well-known nuclear hormone receptor, and recently proposed as a mitochondrial transcription factor, vitamin D receptor, acts for its primary functions. The second receptor is an endoplasmic reticulum protein, protein disulfide isomerase A3 (PDIA3), suggested to act as a rapid response. Vitamin D has effects on various systems, particularly through calcium metabolism. Among them, the nervous system has an important place in the context of our subject. Recent studies have shown that vitamin D and its receptors have numerous effects on the nervous system. Neurodegeneration is a long-term process. Throughout a human life span, so is vitamin D deficiency. Our previous studies and others have suggested that the out-come of long-term vitamin D deficiency (hypovitaminosis D or inefficient utilization of vitamin D), may lead neurons to be vulnerable to aging and neurodegeneration. We suggest that keeping vitamin D levels at adequate levels at all stages of life, considering new approaches such as agonists that can activate vitamin D receptors, and utilizing other derivatives produced in the synthesis process with UVB are crucial when considering vitamin D-based intervention studies. Given most aspects of vitamin D, this review outlines how vitamin D and its receptors work and are involved in neurodegeneration, emphasizing Alzheimer's disease.

Characterization of methylation patterns associated with lifestyle factors and vitamin D supplementation in a healthy elderly cohort from Southwest Sweden

Numerous studies have shown that lifestyle factors, such as regular physical activity and vitamin D intake, may remarkably improve overall health and mental wellbeing. This is especially important in older adults whose vitamin D deficiency occurs with a high prevalence. This study aimed to examine the influence of lifestyle and vitamin D on global DNA methylation patterns in an elderly cohort in Southwest of Sweden. We also sought to examine the methylation levels of specific genes involved in vitamin D's molecular and metabolic activated pathways. We performed a genome wide methylation analysis, using Illumina Infinium DNA Methylation EPIC 850kBeadChip array, on 277 healthy individuals from Southwest Sweden at the age of 70–95. The study participants also answered queries on lifestyle, vitamin intake, heart medication, and estimated health. Vitamin D intake did not in general affect methylation patterns, which is in concert with other studies. However, when comparing the group of individuals taking vitamin supplements, including vitamin D, with those not taking supplements, a difference in methylation in the solute carrier family 25 (SCL25A24) gene was found. This confirms a previous finding, where changes in expression of SLC25A24 were associated with vitamin D treatment in human monocytes. The combination of vitamin D intake and high physical activity increased methylation of genes linked to regulation of vitamin D receptor pathway, the Wnt pathway and general cancer processes. To our knowledge, this is the first study detecting epigenetic markers associated with the combined effects of vitamin D supplementation and high physical activity. These results deserve to be further investigated in an extended, interventional study cohort, where also the levels of 25(OH)D₃ can be monitored.

Vitamin D Supplementation and Cognition in Adults: A Systematic Review of Randomized Controlled Trials

BACKGROUND

The role of vitamin D supplementation in improving cognition and slowing the incidence of minor and major neurocognitive disorders is a matter of debate. To our knowledge, no systematic review of randomized controlled trials (RCTs) has examined this question in adults.

OBJECTIVES

The purpose of this systematic review is to synthesize the evidence regarding the effects of vitamin D supplementation on cognitive performance and neurocognitive disorders in adults.

METHODS

A systematic search of scientific articles in English or French was conducted. The MEDLINE (PubMed), EMBASE (Ovid, EMBASE), PsychINFO, and Cochrane Central databases were searched for records without any limit on publication date in May 2021. Inclusion criteria were (1) human participants, (2) RCT, (3) participant age ≥ 18, (4) vitamin D supplementation as the intervention, and (5) cognition (i.e., cognitive performance or cognitive status such as cognitively healthy or minor and major neurocognitive disorder) as the primary outcome. Two independent reviewers both assessed all eligible studies' full texts and the risk of bias arising from methodological issues using a standardized procedure.

RESULTS

Of the 2137 abstracts identified, 61 (2.9%) met screening inclusion criteria. After full text examination, 41 records (67.2%) were excluded. As a result, 20 RCTs (32.8%) were included in the systematic review. The review yielded mixed findings and, thus, failed to find evidence supporting cognitive benefits from vitamin D supplementation or suggesting a causal association between vitamin D and cognitive function. Half of the RCTs reported mixed results, one quarter negative results, and the last quarter positive effects for vitamin D supplementation on cognitive performance. The variability in serum 25-dihydroxyvitamin D concentration thresholds, the cognitive tests employed, the supplementation doses, and the samples' characteristics (i.e., ethnicity or number of participants) may explain these mixed findings.

CONCLUSION

This systematic review of RCTs does not support a role for vitamin D supplementation in enhancing cognition in adults.

Molecular basis of vitamin D action in neurodegeneration: the story of a team perspective

Vitamin D, a secosteroid hormone, has, over the years, mainly been known for its classic role in the maintenance of calcium homeostasis of the human body. However, there is increasing understanding that vitamin D contributes to the regulation of Ca²⁺ homeostasis, especially via voltage-gated calcium channels, in another major organ that uses calcium, the brain. Almost 30 years ago, the role of dysregulation in the aging brain and in Alzheimer's disease (AD) gave rise to the Ca²⁺ hypothesis of brain aging and dementia. We thus made calcium homeostasis the starting point of our studies, proposing the notion that the consequences of long-term deficiency and/or inefficient utilization of vitamin D may cause the disruption of calcium homeostasis in neurons, this creating a vulnerability of neurons to aging and neurodegeneration. In this mini-review, we aim to describe the potential of vitamin D (cholecalciferol) as a neurosteroid based on our findings and conclusions.

Vitamin D basis of Alzheimer's disease: from genetics to biomarkers

Alzheimer's disease (AD) is a progressive neurodegenerative disorder seen mostly in the elderly population. While to date AD research has focused on either neurochemical disruptions, genetic studies, or the pathological hallmarks, little has been done to establish a novel approach that would encompass all three aspects, one that would overcome the current barriers in AD research and determine the cause of AD and, eventually, discover a treatment. Meanwhile, there have been strong indications in recent years that vitamin D, a secosteroid hormone, and its receptors are fundamentally involved in neurodegenerative mechanisms. Observational studies have pointed to vitamin D deficiency as a genetic risk factor for AD, Parkinson's disease (PD), vascular dementia, and multiple sclerosis (MS), as well as other neurological disorders, brought about by alterations in genes involved in metabolism, transportation, and actions of vitamin D. Molecular studies have demonstrated that vitamin D treatments prevent amyloid production while also increasing its clearance from the brain in AD. Finally, recent vitamin D intervention studies have reported significant improvement in cognitive performance in subjects with senile dementia, mild cognitive impairment, and AD. This review aims to describe how a vitamin D research strategy, fully integrating all aspects of present-day AD research, would elucidate the genetic, molecular, and biochemical background of the disease.

Amyloid Beta 1-42 Alters the Expression of miRNAs in Cortical Neurons

Recently, Aβ1-42 was demonstrated to have the potential to translocate into the nucleus and to be involved in the transcriptional regulation of certain neurodegeneration-related genes. This data raises the question of whether Aβ-induced neurodegeneration might include the expression of miRNAs. Thus, our aim in this study was to investigate the effects of Aβ1-42 on certain miRNAs which are related with vitamin D metabolism, neuronal differentiation, development, and memory. This question was investigated in primary cortical neurons that were treated with 10 μM Aβ and/or 10^-8 M 1,25-dihydroxyvitamin D3 at different time points by expression analysis of let-7a-5p, miR-26b-5p, miR-27b-3p, miR-31a-5p, miR-125b-5p, and miR-192-5p with qRT-PCR. Our data indicate that amyloid pathology has effects on the expression of miRNAs. Furthermore, some of these miRNAs simultaneously regulate the proteins or the enzymes involved in neuronal metabolism. The experimental setup that we used and the data we acquired supply valuable information about the miRNAs that play a part in the Aβ pathology and suggested Aβ as a counterpart of vitamin D at the crossroads of neuronal differentiation, development, and memory.

Cognitive Functioning of Geriatric Patients: Is Hypovitaminosis D the Next Marker of Cognitive Dysfunction and Dementia?

The study objective is to investigate whether vitamin D is associated with the cognitive function of geriatric patients. This cross-sectional study involved 357 patients hospitalized in the geriatric ward who complained of memory problems (mean age: 82.3 years). The level of cognitive function was measured with the Mini-Mental State Examination (MMSE) and the clinical diagnosis of dementia was established according to the International Classification of Diseases (ICD-10) criteria. The serum 25-hydroxy vitamin D was measured with liquid chromatography-tandem mass spectrometry. The iterative Bayesian model averaging (BMA) procedure was applied to linear and logistic regression models in order to identify the best set of factors describing cognitive dysfunction and dementia, respectively. According to BMA, there is strong evidence that higher vitamin D levels, higher body mass index (BMI), and higher mobility function measured with the Timed Up and Go (TUG) test are independently associated with better cognitive performance and lower risk of dementia. Additionally, there is strong evidence that fewer years of education and lower vitamin B12 plasma levels independently describe worse cognitive performance. However, vitamin B12 levels higher than 800 pg/mL is negatively associated with the MMSE performance. Hypovitaminosis D in geriatric patients is an underrated marker of cognitive dysfunction and dementia.

Vitamin D Receptor Regulates Amyloid Beta 1-42 Production with Protein Disulfide Isomerase A3

The challenge of understanding the biology of neuronal amyloid processing could provide a basis for understanding the amyloid pathology in Alzheimer's disease (AD). Based on our previous studies, we have suggested that AD might be the consequence of a hormonal imbalance in which the critical hormone is vitamin D. The present study primarily focused on the creation of a condition that prevents the genomic or nongenomic action of vitamin D by disrupting vitamin D receptors (VDR or PDIA3/1,25MARRS); the effects of these disruptions on the series of proteins involved in secretases that play a crucial role in amyloid pathology and on amyloid beta (Aβ) production in primary cortical neurons were observed. VDR and PDIA3/1,25MARRS genes were silenced separately or simultaneously in E16 primary rat cortical neurons. The expression of target genes involved in APP processing, including Presenilin1, Presenilin2, Nicastrin, BACE1, ADAM10, and APP, was investigated with qRT-PCR and Western blot in this model. 1,25-Dihydroxyvitamin D₃ treatments were used to verify any transcriptional regulation data gathered from siRNA treatments by determining the mRNA expression of the target genes. Immunofluorescence labeling was used for the verification of silencing experiments and intracellular Aβ1-42 production. Extracellular Aβ1-42 level was assessed with ELISA. mRNA and protein expression results showed that 1,25-dihydroxyvitamin D₃ might affect the transcriptional regulation of the genes involved in APP processing. The intracellular and extracellular Aβ1-42 measurements in our study support this suggestion. Consequently, we suggest that 1,25-dihydroxyvitamin D₃ and its receptors are important parts of the amyloid processing pathway in neurons.

Effect of vitamin D levels on radiographic knee osteoarthritis and functional status

Objectives

This study aims to investigate the effect of serum levels of 25 hydroxyvitamin D (25(OH)D) in patients with primary knee osteoarthritis (OA) and to assess its relationship with the radiographic grading and functional status.

Patients and methods

Serum 25(OH)D levels were measured in 107 patients (90 females, 17 males; mean age 63.0±9.6 years; range, 40 to 86 years) with primary knee OA. Radiographic grading was based on the Kellgren-Lawrence Grading Scale and the Osteoarthritis Research Society International (OARSI) Atlas Grading Scale, while the functional status was assessed using the Lequesne indices and Turkish version of the Knee Injury and Osteoarthritis Outcome Score-Physical Function Short-Form (KOOS-PS). Pain was evaluated using the Visual Analog Scale for Pain (VAS-Pain). Data including age, sex, disease duration, body mass index (BMI), and pain severity were recorded.

Results

The mean 25(OH)D level was 13.4±10.6 ng/mL, and 90 patients (84.1%) had vitamin D deficiency. The presence of severe osteophytes was observed in 67 patients (62.6%) and 85 patients (79.4%) had Grade 2-3 joint space narrowing (JSN). The mean KOOS-PS and Lequesne scores were 40.1±12.3 and 12.9±3.6, respectively. There was no correlation between serum 25(OH)D levels and functional status.

Conclusion

Our study results show that serum 25(OH)D level is not related to the severity of the radiographic knee OA grading or to the functional assessment. Age and BMI are the factors affecting the radiological knee OA severity, while age, sex, BMI, and pain severity are the main determinants of the functional status.

Association of Serum Vitamin D with the Risk of Incident Dementia and Subclinical Indices of Brain Aging: The Framingham Heart Study

BACKGROUND

Identifying nutrition- and lifestyle-based risk factors for cognitive impairment and dementia may aid future primary prevention efforts.

OBJECTIVE

We aimed to examine the association of serum vitamin D levels with incident all-cause dementia, clinically characterized Alzheimer's disease (AD), MRI markers of brain aging, and neuropsychological function.

METHODS

Framingham Heart Study participants had baseline serum 25-hydroxyvitamin D (25(OH)D) concentrations measured between 1986 and 2001. Vitamin D status was considered both as a continuous variable and dichotomized as deficient (<10 ng/mL), or at the cohort-specific 20th and 80th percentiles. Vitamin D was related to the 9-year risk of incident dementia (n = 1663), multiple neuropsychological tests (n = 1291) and MRI markers of brain volume, white matter hyperintensities and silent cerebral infarcts (n = 1139).

RESULTS

In adjusted models, participants with vitamin D deficiency (n = 104, 8% of the cognitive sample) displayed poorer performance on Trail Making B-A (β= -0.03 to -0.05±0.02) and the Hooper Visual Organization Test (β= -0.09 to -0.12±0.05), indicating poorer executive function, processing speed, and visuo-perceptual skills. These associations remained when vitamin D was examined as a continuous variable or dichotomized at the cohort specific 20th percentile. Vitamin D deficiency was also associated with lower hippocampal volumes (β= -0.01±0.01) but not total brain volume, white matter hyperintensities, or silent brain infarcts. No association was found between vitamin D deficiency and incident all-cause dementia or clinically characterized AD.

CONCLUSIONS

In this large community-based sample, low 25(OH)D concentrations were associated with smaller hippocampal volume and poorer neuropsychological function.

The role of vitamin D in the prevention of late-life depression

BACKGROUND

In this article, we review current evidence regarding potential benefits of vitamin D for improving mood and reducing depression risk in older adults. We summarize gaps in knowledge and describe future efforts that may clarify the role of vitamin D in late-life depression prevention.

METHODS

MEDLINE and PsychINFO databases were searched for all articles on vitamin D and mood that had been published up to and including May 2015. Observational studies and randomized trials with 50 or more participants were included. We excluded studies that involved only younger adults and/or exclusively involved persons with current depression.

RESULTS

Twenty observational (cross-sectional and prospective) studies and 10 randomized trials (nine were randomized placebo-controlled trials [RCTs]; one was a randomized blinded comparison trial) were reviewed. Inverse associations of vitamin D blood level or vitamin D intake with depression were found in 13 observational studies; three identified prospective relations. Results from all but one of the RCTs showed no statistically significant differences in depression outcomes between vitamin D and placebo groups.

LIMITATIONS

Observational studies were mostly cross-sectional and frequently lacked adequate control of confounding. RCTs often featured low treatment doses, suboptimal post-intervention changes in biochemical levels of vitamin D, and/or short trial durations.

CONCLUSION

Vitamin D level-mood associations were observed in most, but not all, observational studies; results indicated that vitamin D deficiency may be a risk factor for late-life depression. However, additional data from well-designed RCTs are required to determine the impact of vitamin D in late-life depression prevention.

Serum 25-hydroxyvitamin D level and the risk of mild cognitive impairment and dementia: the Korean Longitudinal Study on Health and Aging (KLoSHA)

OBJECTIVE

The association of low vitamin D status with mild cognitive impairment (MCI), a preclinical condition that can lead to dementia, has not yet been fully explored. Our aim was to investigate the association between vitamin D status and the future risk of MCI and dementia in older adults.

DESIGN, SETTING AND PARTICIPANTS

We conducted a population-based prospective study as a part of the Korean Longitudinal Study on Health and Aging. Four hundred and twelve elderly participants who completed evaluations of cognitive function and metabolic parameters in 2005-2006 and 2010-2011 were analysed.

MAJOR OUTCOME MEASURE

The rate of development of MCI or dementia during the study period was compared according to baseline vitamin D status. Binary logistic regression analysis was performed to investigate any independent association between vitamin D status and the risks of MCI or dementia.

RESULTS

Among 405 subjects that remained after excluding seven demented subjects at baseline, 338 subjects remained unchanged or improved in their diagnosis for cognitive function during the study period, whereas 67 subjects showed progression to MCI or dementia. When analyzing 236 subjects whose baseline mini-mental state examination (MMSE) scores were <27, severe vitamin D deficiency at baseline, defined as <25 nmol/l, was independently associated with the progression of cognitive impairment. Among 297 subjects who were normal at baseline, 50 acquired MCI and 247 remained normal. Severe vitamin D deficiency was also independently associated with the development of MCI when analyzing 145 subjects whose baseline MMSE scores were <27.

CONCLUSION

Severe vitamin D deficiency was independently associated with the future risk of MCI as well as dementia, especially in older adults whose baseline MMSE scores had decreased only modestly.

Prognostic significance of 25-hydroxivitamin D entirely explained by a higher comorbidity burden: experience from a South-Eastern European Dialysis Cohort

Vitamin D deficiency is still a common problem particularly in the elderly and in individuals with various degrees of renal impairment. The present study aimed to evaluate the association between plasma concentrations of 25(OH)D and death in a large cohort of prevalent patients on hemodialysis (HD) from south-east Romania, a typical Balkan region. This is an observational prospective study that included a total of 570 patients on maintenance HD. Study patients were classified into three groups by baseline 25(OH)D levels: (1) sufficient 25(OH)D--i.e., >30 ng/mL; (2) insufficient 25(OH)D--i.e., between 10 and 29 ng/mL; and (3) deficient 25(OH)D--i.e., <10 ng/mL. During the follow-up period of 14 months, 68 patients (11.9%) died, the Kaplan-Meier analysis showing significant differences in all-cause mortality for chronic kidney disease patients in different 25(OH)D groups (P = 0.002). Unadjusted Cox regression analysis also showed significant differences in survival. The multivariate Cox regression model showed no significant differences in survival according to vitamin D levels. Hazard ratio for death in the "<10 ng/mL" group was 1.619 (P = 0.190) and in the "10-30 ng/mL" group was 0.837 (P = 0.609). In our dialysis population with a high comorbidity burden, low 25(OH)D concentration was not associated with mortality in the adjusted Cox model, suggesting that vitamin D deficiency could represent only a non-specific marker for a poor health status, with less impact on mortality.

The Influence of Vitamin D Treatment on the Inducible Nitric Oxide Synthase (INOS) Expression in Primary Hippocampal Neurons

INTRODUCTION

Neurodegeneration is a process that is characterized by the loss of neuronal structure and function and eventually ends with neuronal death. An elevated level of inducible nitric oxide synthase (iNOS) is suggested to accompany this process by inducing oxidative and nitrosative damage. Vitamin D is reported to protect glial cells against neurotoxicity via suppressing iNOS synthesis. Though there was no data about whether iNOS is regulated by vitamin D in hippocampal neurons. In this study our aim was to determine any alteration in iNOS expression of hippocampal neurons in response to vitamin D treatment.

METHOD

Twenty four and 48 hours of vitamin D treatments were performed on primary hippocampal neuron cultures that were prepared from Sprague dawley rat embryos (E18). The alterations in the iNOS mRNA expression were determined with quantative real time polymerase chain reaction (qRT-PCR). The cytotoxicity levels of each group were investigated by the measurement of lactate dehydrogenase (LDH) that is released to culture medium.

RESULTS

No difference was observed between groups in 24 hours of treatment regarding the iNOS expression. Though the iNOS mRNA level of vitamin D treated group was significantly lower than that of control group on the 48th hours of treatment (p<.001). Vitamin D treatment also attenuated the LDH release which is an indicator of cytotoxicity (p<.001).

CONCLUSION

Our results indicated that vitamin D has the potential to prevent oxidative damage by suppressing iNOS expression.

Beta amyloid suppresses the expression of the vitamin d receptor gene and induces the expression of the vitamin d catabolic enzyme gene in hippocampal neurons

BACKGROUND/AIMS

The beta amyloid aggregations present in Alzheimer's disease affect neurons through various toxic alterations. The aim of this study was to determine the expression of the vitamin D receptor (VDR), 25-hydroxyvitamin D3 24-hydroxylase (an accelerator of vitamin D catabolism), and the L-type voltage-sensitive calcium channel A1C (LVSCC-A1C) in hippocampal neurons in response to beta amyloid and vitamin D treatments to test the protective effects of vitamin D and the probable effects of beta amyloid on vitamin D catabolism.

METHODS

The expression of the VDR, 24-hydroxylase (24OHase) and LVSCC-A1C mRNAs were studied using quantitative real-time polymerase chain reaction, and the cytotoxicity levels were determined by an ELISA in primary hippocampal neuron cultures prepared from Sprague-Dawley rat embryos.

RESULTS

Our results demonstrated that beta amyloid suppressed the expression of VDR mRNA and induced the expression of 24OHase and LVSCC-A1C mRNAs.

CONCLUSION

Beta amyloid may disrupt the vitamin D-VDR pathway and cause defective utilization of vitamin D by suppressing the level of the VDR and elevating the level of 24OHase.

Low serum vitamin D is not associated with an increase in mortality in oldest old subjects: the Octabaix three-year follow-up study

BACKGROUND

Poor vitamin D status, i.e. low serum levels of 25-hydroxyvitamin D [25(OH)D], is common in the general population. Prospective epidemiologic data on the association between vitamin D and mortality in oldest old subjects are limited.

OBJECTIVE

This study aimed to determine whether 25(OH)D concentrations were prospectively and independently associated with cardiovascular disease (CVD) mortality and all-cause mortality in oldest old subjects.

METHODS

A total of 312 subjects aged 85 years old at baseline (Octabaix study) were followed for 3 years. Sociodemographic and overall geriatric assessment data were collected. Serum 25(OH)D concentrations were used to assess vitamin D status. Data on overall and cardiovascular mortality were collected.

RESULTS

The mean serum 25(OH)D levels were 28 ± 30 ng/ml. During the follow-up period, 58 subjects (18.5%) died. Twenty-five of the deaths (8%) were related to CVD. There were no differences in mortality rates according to the different quartiles of vitamin D (p = 0.41 for total mortality and p = 0.86 for CVD mortality).

CONCLUSION

In community-dwelling oldest old subjects, serum 25(OH)D levels were not associated with overall or CVD mortality after a 3-year follow-up.

Association between serum levels of 25-hydroxyvitamin D and osteoarthritis: a systematic review

OBJECTIVE

To systematically review the evidence for association between serum 25-hydroxyvitamin D (25-(OH)D) and OA and the effect of vitamin D therapy on OA.

METHODS

An English Medline, EMBASE and Cochrane Library search for vitamin D and OA from January 1980 to June 2012 was performed. Randomized controlled trials (RCTs), cohort, case-control and cross-sectional studies in adults were included. The methodological quality of the selected studies was assessed and a best-evidence synthesis was used to summarize the results due to the heterogeneity of the studies.

RESULTS

Of the 86 evaluated articles, 2 RCTs and 13 observational studies were included in the final analyses. The number of participants ranged from 64 to 1644 (0-100% women). The RCTs were only reported in abstract form and showed inconsistent results, most likely due to variations in their study design. There was insufficient or limited evidence for associations between 25-(OH)D and hand or hip OA. For knee radiographic OA as assessed by the Kellgren and Lawrence (KL) score, there was moderate evidence showing that low levels of 25-(OH)D were associated with increased progression of radiographic OA. Strong evidence for an association between 25-(OH)D and cartilage loss was apparent when joint space narrowing and changes in cartilage volume were considered collectively as cartilage loss.

CONCLUSION

25-(OH)D appears to be implicated in structural changes of knee OA rather than symptoms, and further well-designed RCTs are required to determine whether vitamin D supplementation can slow disease progression. There is insufficient evidence for other sites.

Vitamin D inquiry in hippocampal neurons: consequences of vitamin D-VDR pathway disruption on calcium channel and the vitamin D requirement

Vitamin D receptor (VDR) and the enzymes involved in bioactivation of vitamin D, shown to be expressed in the central nervous system, particularly in areas affected by neurodegenerative disorders, especially in hippocampus. We showed that amyloid beta (Aβ) pathology includes VDR protein depletion and vitamin D-VDR pathway disruption either induced by Aβ or by VDR siRNA have very similar effects on cortical neurons. The goal of this study is to show the presence of 25 hydroxy vitamin D3-24 hydroxylase (24OHase) which is essential for vitamin D catabolism in hippocampal and cortical neurons. Additional goal is to compare the expression pattern of VDR and 24OHase both in hippocampal and in cortical neurons and to investigate the effects of VDR suppression in hippocampal neurons in order to see whether similar mechanisms work in hippocampus and cerebral cortex. Primary neuronal cultures were prepared from Sprague-dawley rat embryos. qRT-PCR was performed to determine VDR, 24OHase, and LVSCC-A1C mRNA expression levels. Cytotoxicity levels were determined by ELISA. Our findings illustrate that 24OHase mRNA was present both in hippocampal and in cortical neurons. VDR and 24OHase mRNA were higher in hippocampal neurons than the cortical ones. LVSCC-A1C mRNA levels increased in hippocampal neurons when VDR is down-regulated. Our results indicate that hippocampal neurons response to VDR suppression similar as cortical neurons, regarding calcium channel regulation. Higher gene expression of 24OHase and VDR might indicate "higher requirement of vitamin D" in hippocampus and potential consequences of vitamin D deficiency in cognitive decline, neurodegeneration, and Alzheimer's disease.

Walk on the sunny side of life--epidemiology of hypovitaminosis D and mental health in elderly nursing home residents

OBJECTIVES

Old age is a well-known risk factor for both depression and hypovitaminosis D, and an association between both conditions has been postulated. We document the prevalence of vitamin D deficiency in nursing home residents, and we examine the link with self-reported depressive symptoms and pharmacotherapy for depression.

DESIGN

Cross- sectional.

SETTING

nursing homes in Antwerp, Belgium.

PARTICIPANTS

Healthy elderly (n=589), with a mean age of 84 years.

MEASUREMENTS

We detected depressive symptoms by means of SF-36, a validated quality of life assessment; we registered the use of antidepressants and anxiolytics, and we measured serum 25(OH)D concentrations in all participants.

RESULTS

Almost our entire study population appeared to be vit D deficient. Comparison of the most severely and least deficient subgroups showed a consistent tendency towards more depressive symptoms and more use of antidepressants in the group with the lowest vit D level.

CONCLUSION

Nursing home residents are particularly vulnerable to preventable vit D deficiency. The relevance of the association with depressive symptoms and the possibilities for treatment are critically reviewed in the discussion.

Vitamin D status in relation to postural stability in the elderly

OBJECTIVES

Postural instability (PI) is an important risk factor for falls, especially in the frail older population. In this study, we investigated the impact of vitamin D deficiency on PI in a sample of community dwelling older subjects. Our objective was to determine the potential association between vitamin D deficiency and PI in older fallers.

DESIGN

Cross-sectional study.

SETTING

Falls and Fractures Clinic, Department of Geriatric Medicine, Nepean Hospital, Penrith, Australia.

PARTICIPANTS

One hundred and forty-five adults aged 65 years and older who have had at least one episode of a fall within the six months prior to assessment at the Falls and Fractures Clinic.

MEASUREMENTS

Serum 25(OH) vitamin D3 [25(OH)D3] and parathyroid hormone concentrations were determined at baseline. Subjects were separated into 3 groups based on serum 25(OH)D3 levels with the following cut-off values: < 30 nmol/L (deficient), 30-50 nmol/L (insufficient) and > 50 nmol/L (normal). Other baseline measurements included body mass index, mini-nutritional assessment, grip strength, serum calcium concentration and creatinine clearance, which were used as covariables. PI was assessed using a computerized virtual reality system (Medicaa, Uruguay). Measured parameters included limits of stability (LOS) and centre of pressure (COP) under eyes closed on foam (ECF) and visio-vestibular stimulation. The estimated swaying area, computed from the ellipse of confidence under eyes closed standing on foam (ECF), was also used as a PI parameter. Gait velocity (GV) was measured using a GaitRITE walkway system.

RESULTS

Posture was impaired in vitamin D deficiency (<30 nmol/L) as indicated by lower LOS (90 +/- 18), higher ECF (25 +/- 10) and slower GV (55 +/- 7) as compared with the insufficient and normal groups. After adjustment for demographic, biochemical and anthropometric variables, vitamin D deficiency significantly correlated with low LOS and high COP under ECF.

CONCLUSION

Low levels of vitamin D were associated with PI. This association could also have an effect on slow GV and increased risk of falls. In conclusion, using an objective method to measure balance in older fallers we have identified a novel role of vitamin D in balance control. Prospective studies are required to confirm the effect of vitamin D on PI and elucidate the mechanisms of this association.

Vitamin D intake and mental health-related quality of life in older women: the Iowa Women's Health Study

OBJECTIVE

Vitamin D deficiency and mood disorders are both prevalent among the elderly. We evaluated the association between vitamin D intake and mental health-related quality of life (QOL) among elderly women participating in a large population-based study.

STUDY DESIGN

This study was a cross-sectional analysis of the Iowa Women's Health Study, a prospective study of cancer risk factors among post-menopausal women in Iowa that began in 1986. Additional survey data was collected from the cohort members in 1987, 1989, 1992, 1997, and 2004. Data for this analysis came from the 2004 questionnaire.

MAIN OUTCOME MEASURE

Mental health-related QOL was assessed using five scales from the Medical Outcomes Study 36-item Short-form Health Survey. QOL scores were analyzed as continuous variables using linear regression, controlling for age, energy intake, BMI, education, smoking, living arrangement, antidepressant usage, comorbidity history, and physical activity.

RESULTS

Low vitamin D intake (<400 IU/day) was associated with poorer QOL scores compared to women with higher intake (≥400 IU/day). Differences in QOL scores by vitamin D intake group were attenuated with multivariable adjustment, but a significant overall association between vitamin D and QOL scores persisted. Further adjustment for physical activity attenuated all differences as well as the overall association between vitamin D and QOL scores.

CONCLUSIONS

Women who consumed <400 IU/day of vitamin D had significantly lower mental health-related QOL compared to those who consumed ≥400 IU/day. Meeting dietary vitamin D recommendations is a potential method for improving QOL among the elderly.

Vitamin D3-enriched diet correlates with a decrease of amyloid plaques in the brain of AβPP transgenic mice

In addition to its function in calcium and bone metabolism, vitamin D is neuroprotective and important for mitigating inflammation. Alzheimer's disease (AD) is a progressive neurodegenerative disorder of the central nervous system, characterized by neuronal loss in many areas of the brain, and the formation of senile (neuritic) plaques, which increase in number and size over time. The goal of this project was to investigate whether vitamin D3 supplementation would affect amyloid plaque formation in amyloid-β protein precursor (AβPP) transgenic mice that spontaneously develop amyloid plaques within 3-4 months of birth. AβPP mice were fed control, vitamin D3-deficient or vitamin D3-enriched diets for five months, starting immediately after weaning. At the end of the study, the animals were subjected to behavioral studies, sacrificed, and examined for bone changes and brain amyloid load, amyloid-β (Aβ) peptide levels, inflammatory changes, and nerve growth factor (NGF) content. The results obtained indicate that a vitamin D3-enriched diet correlates with a decrease in the number of amyloid plaques, a decrease in Aβ peptides, a decrease in inflammation, and an increase in NGF in the brains of AβPP mice. These observations suggest that a vitamin D3-enriched diet may benefit AD patients.

Nutritional strategies for successful aging

With increasing life expectancy in developed and developing countries, maintaining health and function in old age has become an important goal, including avoidance or optimal control of chronic diseases; maintenance or retarding the decline of physical and cognitive function; optimizing psychological health; and maintaining independent functioning in tasks related to self-care and societal interaction. This article discusses all of those, as well as other components of successful aging such as social network and socioeconomic status.

Utility of geriatric assessment tools to identify 85-years old subjects with vitamin D deficiency

OBJECTIVES

To calculate the prevalence of hypovitaminosis D in subjects aged 85 years old and to study the relationship between some common geriatric evaluation scales and vitamin D status.

DESIGN

Prospective cohort study.

SETTING

A community-based study.

PARTICIPANTS

312 subjects aged 85 years old.

MEASUREMENTS

Geriatric assessment was based on comorbidity, functional status according to the Barthel Index (BI) and Lawton Index (LI), cognitive status measured by the Spanish version of the Mini-Mental State Examination (MEC), nutritional risk according to the Mini Nutritional Assessment (MNA), and gait using the Tinetti Gait Scale. Serum 25(OH)D concentrations were used to assess vitamin D status. Hypovitaminosis D was considered as < 25 ng/ml and deficiency < 11 ng/ml.

RESULTS

Mean serum 25(OH)D level was 28 ± 30 ng/ml. The prevalence of hypovitaminosis D was 52.5% (38.1% insufficiency and 14.4% deficiency). Men had higher levels than women (32.2 ± 44 vs. 25.2 ± 25 ng/ml; p=0.04). The bivariate analyses identified an association between MNA scores and hypovitaminosis D, and showed that females ande participants with poor BI, Tinetti and MNA scores were associated with deficiency. Logistic regression analysis confirmed a significant association between poor MNA scores and both hypovitaminosis D (p < 0.04, OR 1.066, 95% CI 1.002-1.135) and vitamin D deficiency (p < 0.0001, OR 1.192, 95% CI 1.099-1.293).

CONCLUSIONS

More than half the population aged 85 years has a vitamin D deficit and 14.4% show a deficiency. A lower score on the MNA scale is associated with a greater likelihood of having lower vitamin D serum values.

Nutrition and the aging male

Numerous studies have now found that good nutrition coupled with exercise are key factors to aging successfully. In addition, it is now clear that men who drink 2 shots of alcohol (red wine or other) do better. Women are limited to only 1 drink a day. This article examines some key nutritional factors involved in successful aging and highlights different needs between men and women.

Clinical practice in nursing homes as a key for progress

With the aging of the world's population there has become a major need for the development of nursing homes throughout the world. While some countries provide high quality care for the disabled elderly, in others this is not the case. Education of a medical director has been shown to improve the quality of the nursing home. Physicians need to have knowledge of how to implement continuous quality improvement and culture change. Key medical issues include moving to a restraint free environment, subsyndromal delirium, behavioral disturbances, weight loss, pain management, pressure ulcers, falls, hip fractures, polypharmacy, depression and frailty.

Serum 25-hydroxyvitamin D and depressive symptoms in older women and men

CONTEXT

Hypovitaminosis D and depressive symptoms are common conditions in older adults.

OBJECTIVE

We examined the relationship between 25-hydroxyvitamin D [25(OH)D] and depressive symptoms over a 6-yr follow-up in a sample of older adults.

DESIGN AND SETTING

This research is part of a population-based cohort study (InCHIANTI Study) in Tuscany, Italy.

PARTICIPANTS

A total of 531 women and 423 men aged 65 yr and older participated.

MAIN OUTCOME MEASURE

Serum 25(OH)D was measured at baseline. Depressive symptoms were assessed at baseline and at 3- and 6-yr follow-ups using the Center for Epidemiological Studies-Depression Scale (CES-D). Depressed mood was defined as CES-D of 16 or higher. Analyses were stratified by sex and adjusted for relevant biomarkers and variables related to sociodemographics, somatic health, and functional status.

RESULTS

Women with 25(OH)D less than 50 nmol/liter compared with those with higher levels experienced increases in CES-D scores of 2.1 (P = 0.02) and 2.2 (P = 0.04) points higher at, respectively, 3- and 6-yr follow-up. Women with low vitamin D (Vit-D) had also significantly higher risk of developing depressive mood over the follow-up (hazard ratio = 2.0; 95% confidence interval = 1.2-3.2; P = 0.005). In parallel models, men with 25(OH)D less than 50 nmol/liter compared with those with higher levels experienced increases in CES-D scores of 1.9 (P = 0.01) and 1.1 (P = 0.20) points higher at 3- and 6-yr follow-up. Men with low Vit- D tended to have higher risk of developing depressed mood (hazard ratio = 1.6; 95% confidence interval = 0.9-2.8; P = 0.1).

CONCLUSION

Our findings suggest that hypovitaminosis D is a risk factor for the development of depressive symptoms in older persons. The strength of the prospective association is higher in women than in men. Understanding the potential causal pathway between Vit- D deficiency and depression requires further research.

Epidemiology of vitamin D in health and disease

Results from ecological, case-control and cohort studies have shown that vitamin D reduces the risk of bone fracture, falls, autoimmune diseases, type 2 diabetes, CVD and cancer. However, there is still epidemic vitamin D insufficiency especially among individuals living at high latitudes or with dark skin. Serum levels of 25-hydroxyvitamin D (25(OH)D) are considered the best biomarker of vitamin D nutritional status. Appropriate sunshine exposure or oral supplementation is necessary to maintain sufficient vitamin D status, which is generally accepted as serum 25(OH)D>75 nmol/l. Immunoassays, especially RIA, have been primarily used to measure serum 25(OH)D while liquid chromatography-MS (LC-MS) is considered the 'gold standard'. There is significant disparity among the immunoassays, and all immunoassays have considerable bias compared with LC-MS methods. Because of the variations among the results from these different assays, it is necessary that assay-specific reference ranges be established or standardisation of the assays take place. The present review focuses on ecological, case-control, and cohort studies that investigated the role of vitamin D in health and disease. In addition, analytical techniques used in laboratory evaluation of vitamin D nutritional status are also critically reviewed. The majority of the literature included in the present review is selected from that searchable in PubMed up to the end of September 2008.

Vitamin D and cognitive performance in adults: a systematic review

Chronic low serum 25-hydroxyvitamin D (25OHD) concentrations are common in adults and are associated with numerous non-skeletal diseases. Vitamin D receptors (VDR) are located in the human cortex and hippocampus, which are key areas for cognition. The objective of this study was to systematically review all published data from the past 30 years which examined the association between serum 25OHD concentrations and cognitive performance in adults. An English and French Medline, PsycINFO and Cochrane Library search ranging from 1979 to 2008 indexed under the Medical Subject Heading (MeSH) terms 'Vitamin D' or 'Hydroxycholecalciferols' combined with the terms 'Dementia' or 'Cognition' or 'Cognition Disorders' or 'Delirium' or 'Memory' or 'Memory Disorders' or 'Orientation' or 'Executive Functions' or 'Attention' or 'Brain' or 'Neuropsychological Tests' was performed. Of the 99 selected studies, five observational studies met the selection criteria and were included in the final analysis. No prospective cohort study was found. The number of participants ranged from 32 to 9556 community-dwelling older adults (45-65% women). Three studies showed four significant positive associations between serum 25OHD concentrations and global cognitive functions, whereas three other studies exploring specific aspects of cognition showed 11 non-significant associations. This systematic review shows that the association between serum 25OHD concentrations and cognitive performance is not yet clearly established. The inconclusive results of the reviewed studies could be due to methodology, types of the cognitive tasks used and/or the cellular mechanisms of vitamin D.

Some new food for thought: the role of vitamin D in the mental health of older adults

Vitamin D, a multipurpose steroid hormone vital to health, has been increasingly implicated in the pathology of cognition and mental illness. Hypovitaminosis D is prevalent among older adults, and several studies suggest an association between hypovitaminosis D and basic and executive cognitive functions, depression, bipolar disorder, and schizophrenia. Vitamin D activates receptors on neurons in regions implicated in the regulation of behavior, stimulates neurotrophin release, and protects the brain by buffering antioxidant and anti-inflammatory defenses against vascular injury and improving metabolic and cardiovascular function. Although additional studies are needed to examine the impact of supplementation on cognition and mood disorders, given the known health benefits of vitamin D, we recommend greater supplementation in older adults.