Vitamin D and neurocognitive dysfunction: preventing "D"ecline?

Postpartum depression and vitamin D: A systematic review

Postpartum depression (PPD) is a prevalent mood disorder estimated to affect 20%-40% of women worldwide after childbirth. In recent studies, the effect of vitamin D on prevention of mood disorders and depression has been investigated, but it is still unclear how vitamin D may affect PPD. The evidence on the relevance between vitamin D deficiency and PPD is inconsistent, and assessment of the recent literature has not previously been carried out. Moreover, there are few clinical studies on PPD and vitamin D supplementation. Five studies have so far assessed the relationship between the levels of vitamin D and PPD. Findings from cohort studies suggest that vitamin-D deficiency is related to the incidence of PPD and vitamin D may play a significant role in the recovery of women with PPD, but it is uncertain whether these actions are the effect of vitamin D on the function of hypothalamic-pituitary-adrenal (HPA) axis, the levels of estradiol, serotonin, pro-inflammatory cytokines, and/or of other mechanisms involved in PPD.

Low 25-Hydroxyvitamin D Concentrations and Risk of Incident Cognitive Impairment in Black and White Older Adults: The Health ABC Study

Using data from the Health, Aging, and Body Composition study, we examined whether low 25-hydroxyvitamin D (25[OH]D) concentrations were associated with prevalent or incident cognitive impairment. Serum 25(OH)D concentrations were measured in 2,786 older adults and categorized as <20 ng/mL, 20 to <30 ng/mL, or ≥30 ng/mL. Cognitive impairment was defined as a score >1.5 standard deviations below race and education specific means on either digit symbol substitution test or modified mini-mental state test. Logistic regression determined the odds of cognitive impairment at baseline and year 5 by 25(OH)D category. 25(OH)D concentrations were <30 ng/mL in 57.3% of whites and 84.6% of blacks. After excluding participants with baseline cognitive impairment (n = 340), 13% of whites and 13% of blacks developed cognitive impairment by year 5. In whites, 25(OH)D concentrations <30 ng/mL were not associated with prevalent or incident cognitive impairment. Black participants with 25(OH)D concentrations <20 ng/mL had a higher odds of prevalent, but not incident cognitive impairment (OR (95% CI): 2.05 (1.08-3.91), p = 0.03) compared to participants with 25(OH)D concentrations ≥30 ng/mL. Low 25(OH)D concentrations were associated with twofold higher odds of prevalent cognitive impairment in blacks.

Is there a role for vitamin D in supporting cognitive function as we age?

Globally, an estimated 46 million people are currently living with dementia and this figure is projected to increase 3-fold by 2050, highlighting this major public health concern and its substantial associated healthcare costs. With pharmacological treatment yet to reach fruition, the emphasis on evidence-based preventative lifestyle strategies is becoming increasingly important and several modifiable lifestyle factors have been identified that may preserve cognitive health. These include good cardiovascular health, physical activity, low alcohol intake, smoking and a healthy diet, with growing interest in vitamin D. The aim of the present paper is to review the evidence supporting the potential roles of vitamin D in ageing and cognitive health in community-dwelling older adults. Furthermore, to describe the utility and challenges of cognitive assessments and outcomes when investigating vitamin D in this context. Evidence indicates that serum 25-hydroxyvitamin D (25(OH)D) may impact brain health. There is a biological plausibility from animal models that vitamin D may influence neurodegenerative disorders, through several mechanisms. Epidemiological evidence supports associations between low serum 25(OH)D concentrations and poorer cognitive performance in community-dwelling older populations, although an optimal 25(OH)D level for cognitive health could not be determined. The effect of raising 25(OH)D concentrations on cognitive function remains unclear, as there is a paucity of interventional evidence. At a minimum, it seems prudent to aim to prevent vitamin D deficiency in older adults, with other known common protective lifestyle factors, as a viable component of brain health strategies.

Serum 25-hydroxyvitamin D and the risk of stroke in Hong Kong Chinese

Low vitamin D levels have been associated with various cardiovascular diseases; however, whether it is associated with stroke remains inconclusive. We aimed to evaluate the association between serum 25-hydroxyvitamin D and risk of stroke. We conducted a cohort study consisting of 3,458 participants from the Hong Kong Osteoporosis Study aged ≥45 at baseline, examined between 1995 and 2010 and followed up using electronic medical records. Ischaemic and haemorrhagic stroke were defined using the ICD-9 code. In multivariable Cox-proportional hazard regression, quintiles 1 and 4 were significantly associated with increased risk of stroke when compared to the highest quintile (Quintile 1: HR, 1.78; 95 % CI, 1.16–2.74 and quintile 4: HR, 1.61; 95 % CI, 1.07–2.43). A similar association was observed in both men and women. In subgroup analysis, the association was specifically observed for ischaemic stroke, but not haemorrhagic stroke. Using a penalized regression spline, the association between vitamin D and risk of stroke was in a reverse J-shape, with the lowest risk of stroke being observed at 25(OH)D levels between 70 and 80 nmol/l. In conclusion, a low vitamin D level is associated with increased risk of ischaemic stroke; however, whether high vitamin D level is also associated with increased risk of stroke requires further study.

Supplementary Material to this article is available at www.thrombosis-online.com.

Dementia and fragility fractures: Issues and solutions

Dementia and fragility fractures are two conditions that pose significant morbidity and mortality to the elderly population. The occurrence of the 'gerontic' boom as a result of improved healthcare meant a continued increase in the prevalence of fragility fractures and dementia. This represents a major public health problem with significant socioeconomic repercussions. It is therefore important for healthcare professionals to gain a better understanding on the relationship between these two commonly co-existing conditions. In this review, we present the available literature surrounding the relationship between fragility fractures and dementia, and the common challenges faced in the management of these two conditions. Combining evidence from the literature along with our current clinical practice, we propose a management pathway aimed at early diagnosis, prevention and management of these two often co-existing conditions. This alongside with a multidisciplinary approach will not only translate to improved patient outcomes and survivorship, but also reduced healthcare cost and socio-economic burden. To date, there is insufficient evidence from the literature to suggest whether dementia is the cause or effect for fragility fractures, or if indeed there is a bidirectional relationship between the two conditions. Further studies are required to shed light onto this important clinical topic.

IMPACT OF VITAMIN D DEFICIENCY ON COGNITIVE FUNCTIONS IN TYPE 2 DIABETIC PATIENTS

OBJECTIVE

We hypothesized that vitamin D-deficient diabetic patients might demonstrate cognitive deficits and therefore investigated this association in patients with diabetes mellitus (DM).

METHODS

This study comprised 236 patients with type 2 DM (118 with vitamin D deficiency (less than 20 ng/mL) and 118 without vitamin D deficiency as the control group). All patients were outpatients in the endocrinology clinics of Baskent University, Turkey from 1 October 2013 to 31 January 2014 and, chosen in a randomized manner according to their application time. The serum vitamin D levels were measured and cognitive functions were evaluated using the Mini Mental Status Examination (MMSE).

RESULTS

The mean age in the study and control group was 57.02±7.30 and 58.92±7.58 years, respectively (p=0.051). The male:female ratio in the study and control group was 1.00:1.46 and 1.00:2.11, respectively. The study group was further divided into three subgroups: patients with mild, moderate, and severe vitamin D deficiency. The study outcomes revealed no significant relationship between the vitamin D deficiency level and the total score or subscores of the MMSE (p<0.05).

CONCLUSIONS

These study results do not confirm the hypothesis that vitamin D deficiency unfavorably affects cognitive functions in patients with type 2 DM.

Vitamin D3 attenuates cognitive deficits and neuroinflammatory responses in ICV-STZ induced sporadic Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by intracellular neurofibrillary tangles and extracellular Aβ deposition. Growing experimental evidence indicate diverse biological effects of vitamin D₃ including antioxidant, neuroprotective, anti-inflammatory and cardiovascular benefits. However, the underlying neuroprotective mechanism of vitamin D₃ is still largely elusive. Therefore, the present study was aimed to investigate the neuroprotective effects of vitamin D₃ on ICV-STZ induced sporadic AD. Our study demonstrated that vitamin D3 pretreatment significantly improved spatial learning and memory functions and effectively mitigated ICV-STZ mediated neuronal oxidative stress, mitochondrial aberrations and improved cholinergic functions. Moreover, vitamin D₃ attenuated hippocampal neuroinflammatory response and reduced neuronal death in cortex and hippocampus. Our findings indicated that prophylactic vitamin D₃ supplementation ameliorated ICV-STZ mediated neurobehavioral alterations, oxidative stress and neuroinflammation thereby improving cholinergic functions and reversed degenerative changes in brain. Thus, our study further provides evidence for its therapeutic supplementation for various neurodegenerative disorders including AD.

Vitamin D Receptor and Megalin Gene Polymorphisms Are Associated with Longitudinal Cognitive Change among African-American Urban Adults

Background: The link between longitudinal cognitive change and polymorphisms in the vitamin D receptor (VDR) and MEGALIN [or LDL receptor-related protein 2 (LRP2)] genes remains unclear, particularly among African-American (AA) adults.Objectives: We aimed to evaluate associations of single nucleotide polymorphisms (SNPs) for VDR [rs11568820 (Cdx-2:T/C), rs1544410 (BsmI:G/A), rs7975232 (ApaI:A/C), rs731236 (TaqI:G/A)] and LRP2 [rs3755166:G/A,rs2075252:C/T, rs2228171:C/T] genes with longitudinal cognitive performance change in various domains of cognition.Methods: Data from 1024 AA urban adult participants in the Healthy Aging in Neighborhoods of Diversity Across the Life Span (Baltimore, Maryland) with complete genetic data were used, of whom 660-797 had complete data on 9 cognitive test scores at baseline and/or the first follow-up examination and complete covariate data (∼52% female; mean age: ∼52 y; mean years of education: 12.6 y). Time between examination visits 1 (2004-2009) and 2 (2009-2013) ranged from <1 y to ∼8 y, with a mean ± SD of 4.64 ± 0.93 y. Latent class and haplotype analyses were conducted by creating gene polymorphism groups that were related to longitudinal annual rate of cognitive change predicted from mixed-effects regression models.Results: Among key findings, the rs3755166:G/A MEGALIN SNP was associated with faster decline on the Mini-Mental State Examination overall (β = -0.002, P = 0.018) and among women. VDR₂ (BsmI/ApaI/TaqI: G-/A-/A-) SNP latent class [SNPLC; compared with VDR₁ (ApaI: "AA")] was linked to faster decline on the Verbal Fluency Test, Categorical, in women, among whom the MEGALIN₂ (rs2228171: "TT") SNPLC (compared with MEGALIN₁:rs2228171: "CC") was also associated with a faster decline on the Trailmaking Test, Part B (Trails B), but with a slower decline on the Digit Span Backward (DS-B). Moreover, among men, the VDR₁ SNP haplotype (SNPHAP; GCA:baT) was associated with a slower decline on the Trails B, whereas the MEGALIN₁ SNPHAP (GCC) was associated with a faster decline on the DS-B, reflected as a faster decline on cognitive domain 2 ("visual/working memory").Conclusion:VDR and MEGALIN gene variations can alter age-related cognitive trajectories differentially between men and women among AA urban adults, specifically in global mental status and domains of verbal fluency, visual/working memory, and executive function.

Serum 25-hydroxyvitamin D deficiency and hepatic encephalopathy in chronic liver disease

AIM

To investigate the relationship between 25-hydroxyvitamin D (25-OHD) deficiency and hepatic encephalopathy (HE) in patients with chronic liver disease (CLD).

METHODS

A retrospective analysis of the results of 392 adult patients with chronic liver disease who were assessed for liver transplantation between 2006 and 2010 was undertaken. HE, severity of CLD, nutritional status and 25-OHD were analysed in patients assessed for liver transplantation between 2006 and 2010. Patients who presented with acute, fulminant or subacute disease, with a primary diagnosis of liver cancer, were assessed for re-transplantation or who did not have a 25-OHD measurement were excluded from the analysis.

RESULTS

One hundred and sixty-five patients were included in this analysis. The mean age of all patients was 53 ± 8 years. Moderate to severe 25-OHD deficiency was identified in 49 patients of whom 36 had grade 2-3 HE compared with 13 patients who were not encephalopathic (P ≤ 0.0001). Mild 25-OHD deficiency was not associated with HE. There was a significant correlation between the severity of 25-OHD deficiency and the severity of liver disease (r = 0.39, P ≤ 0.0001) and disease severity and the presence of HE (P ≤ 0.0001). Importantly, individuals with 25-OHD deficiency were more likely to have a diagnosis of overt HE (OHE) at a significantly lower model for end stage liver disease (MELD) score than individuals without OHE (P ≤ 0.0001). This significant difference was observed with MELD scores from 10 to 38.

CONCLUSION

25-OHD deficiency was observed in the majority of patients with CLD and for the first time was found to be significantly worse in patients with OHE.

Vitamin D is not associated with incident dementia or cognitive impairment: an 18-y follow-up study in community-living old men

Background: Vitamin D has been implicated as being important for maintaining cognitive function in old age. Results from longitudinal studies examining the association of vitamin D with incident dementia and cognitive impairment have been inconsistent.Objective: We investigated the relation between vitamin D, assessed in 3 different ways, and the risk of dementia.Design: We measured plasma 25-hydroxyvitamin D [25(OH)D] with the use of high-performance liquid chromatography-mass spectrometry, assessed dietary vitamin D intake with the use of 7-d dietary records, and created a vitamin D-synthesis genetic risk score (GRS) at baseline (1991-1995) in a cohort of 1182 Swedish men (mean age: 71 y). In a maximum of 18 y (median: 12 y) of follow-up, 116 men developed Alzheimer disease, 64 men developed vascular dementia, and 250 men developed all-cause dementia. An additional 80 men declined in cognitive function as assessed with the use of the Mini-Mental State Examination. Adjusted HRs and ORs were calculated with the use of Cox and logistic regressions.Results: The mean ± SD plasma 25(OH)D concentration was 68.7 ± 19.1 nmol/L. Plasma 25(OH)D, dietary vitamin D intake, and vitamin D-synthesis GRS were not associated with any cognitive outcomes (crude and adjusted HRs and ORs were ∼1.0 for all continuous exposures). The adjusted HR for all-cause dementia was 0.88 (95% CI: 0.59, 1.31) in men with plasma 25(OH)D concentrations ≤50 compared with >75 nmol/L. The adjusted HR for all-cause dementia was 0.92 (95% CI: 0.63, 1.32) for the lowest compared with highest tertiles of vitamin D intake. The adjusted HR for the continuous GRS for all-cause dementia was 1.04 (95% CI: 0.91, 1.19).Conclusion: In this cohort study, we show that there is no association between baseline vitamin D status and long-term risk of dementia or cognitive impairment over an 18-y period of time.

Role of Vitamin D in the Outcome of Ischemic Stroke- A Randomized Controlled Trial

INTRODUCTION

Vitamin D deficiency has reached epidemic proportions in India with prevalence rates of 70-100% in the general population. Low vitamin D levels are associated with worse outcomes in ischemic strokes. The outcome of stroke after vitamin D replenishment has not been much studied.

AIM

To compare the stroke outcome between patients receiving vitamin D supplementation and patients without vitamin D supplementation by Scandinavian Stroke Scale (SSS) and thus, to assess the long term outcome of ischemic stroke patients with low vitamin D level by supplementation of vitamin D.

MATERIALS AND METHODS

This is a non blinded randomized controlled trial conducted in ischemic stroke patients. The patients were divided into two groups (A and B) where Group A received a single dose of 6 lac IU of Cholecalciferol Intramascular (IM) injection and Group B were not given vitamin D. Finally 30 patients in each group were analyzed. SSS was applied to evaluate the stroke severity at the onset and at the follow up after three months in both groups. The difference in SSS was analyzed using SPSS software. Independent t-test was applied and p-value < 0.05 was taken as significant.

RESULTS

Mean±SD of vitamin D levels in Group A and Group B were 17.98±3.81ng/ml and 18.44±4.69 ng/ml respectively. Mean±SD of SSS at time of admission and after three months for Group A was 32.50±11.61 and 38.89±8.34; and for Group B 35.82±8.56 and 38.32±7.10. The difference in SSS from time of admission and after three months, in Group A (6.39±4.56) and Group B (2.50±2.20) were analyzed statistically and found to be highly significant (p<0.001).

CONCLUSION

The results showed that there is a significant improvement in the stroke outcome after three months in those patients who were supplemented with vitamin D. Thus screening for vitamin D deficiency in stroke patients is essential and vitamin D replenishment will improve the stroke outcome.

Low serum 25-hydroxyvitamin D is associated with higher risk of frequent headache in middle-aged and older men

Vitamin D has been suggested to have a role in various neurovascular diseases, but the data regarding headache is inconclusive. Our aim was to investigate the associations between serum 25-hydroxyvitamin D [25(OH)D], a marker for vitamin D status, and risk of frequent headache. The study population consisted of 2601 men from the population-based Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD) from eastern Finland, aged 42–60 years in 1984–1989. The cross-sectional associations with prevalence of self-reported frequent headache (defined as weekly or daily headaches) were estimated with multivariable-adjusted odds ratios. The average serum 25(OH) concentration was 43.4 nmol/L (SD 18.9, min-max 7.8–136.1 nmol/L). A total of 250 men (9.6%) reported frequent headache. The average serum 25(OH)D concentration among those with frequent headache was 38.3 nmol/L (SD 18.8) and 43.9 nmol/L (SD 18.9) among those without frequent headache, after adjustment for age and year and month of blood draw (P for difference <0.001). After multivariable adjustments, those in the lowest vs. the highest serum 25(OH)D quartile had 113% (95% CI 42, 218%; P for trend <0.001) higher odds for frequent headache. In conclusion, low serum 25(OH)D concentration was associated with markedly higher risk of frequent headache in men.

Vitamin D Insufficiency and Cognitive Function Trajectories in Older Adults: The Rancho Bernardo Study

BACKGROUND

Evidence of a role for vitamin D (VitD) in cognitive aging is mixed and based primarily on extreme VitD deficiency. We evaluated the association of VitD insufficiency with cognitive function in older, community-dwelling adults living in a temperate climate with year-round sunshine.

METHODS

A population-based longitudinal study of 1,058 adults (median age 75; 62% women) who had cognitive function assessed and serum levels of 25-hydroxyvitaminD (25OHD) measured in 1997-99 and were followed for up to three additional cognitive function assessments over a 12-year period.

RESULTS

Overall, 14% (n = 145) of participants had VitD insufficiency defined as 25OHD <30 ng/ml. Adjusting for age, sex, education, and season, VitD insufficiency was associated with poorer baseline performance on the Mini-Mental Status Exam (MMSE) (p = 0.013), Trails Making Test B (Trails B) (p = 0.015), Category Fluency (p = 0.006), and Long Term Retrieval (p = 0.019); differences were equivalent to 5 years of age. For those with VitD insufficiency, the odds of mildly impaired performance at baseline were 38% higher for MMSE (p = 0.08), 78% higher for Trails B (p = 0.017), and 2-fold higher for Category Fluency and Long Term Retrieval (both p = 0.001). VitD insufficiency was not related to the rate of cognitive decline on any test or the risk of developing impaired performance during follow-up.

CONCLUSION

In this population with little VitD deficiency, even moderately low VitD was associated with poorer performance on multiple domains of cognitive function. Low VitD did not predict 12-year cognitive decline. Clinical trials are essential to establish a causal link between VitD and cognitive well-being.

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.

Effect of vitamin D supplementation and isokinetic training on muscle strength, explosive strength, lean body mass and gait in severely burned children: A randomized controlled trial

OBJECTIVE

To determine the effects of vitamin D (VD) supplementation and isokinetic training on muscle strength, explosive strength (counter movement jump) (ES), lean body mass (LBM) and gait parameters in severe pediatric burn.

METHODS

Forty-eight burned children with circumferential lower extremity burns covering 40-55% of the total body surface area (TBSA), aged 10-16 years (Mean±SD 13.01±1.75), were randomized into the standard of care (n=16), isokinetic (n=17) and VD (n=15) groups. Unburned children (n=20) served as matched controls. All burned children received 12 weeks of routine physical therapy program (RPTP). In addition, the isokinetic group received isokinetic training for the quadriceps dominant limb 3 times per week at angular velocity 150°/s, and the VD group received the isokinetic training plus an oral daily dose of vitamin D₃ 1000 IU (Cholecalciferol). The primary measures, assessed at baseline and 12 weeks, included quadriceps strength by isokinetic dynamometer, ES, LBM by dual-energy X-ray absorptiometry (DEXA) and gait parameters by GAITRite system.

RESULTS

The VD and isokinetic groups showed significant improvement in quadriceps strength, ES, LBM and gait parameters compared with the standard of care, and VD group show significant improvement in the VD level as compared with the other groups. The outcome measures (and percent of improvement where applicable) for the VD, isokinetic and standard of care are as follows: quadriceps strength, 85.25±0.93Nm (85%), 64.25±0.93 (36%) and 51.88±1.31Nm (12%); stride length, 94.00±2.69 (7%), 110.60±2.87 (25%) and 139.56±2.57 (60%); step length, 67.26±2.45 (72%), 55.25±2.49 (43%) and 43.76±1.34 (18%); velocity, 133.94±1.65 (82%), 99.94±1.65 (35%) and 80.11±1.91 (9%); and cadence, 140.63±1.36 (68%), 132.63±1.36 (58%) and 90.35±1.32 (9%), VD level 43.33±7.48 (75%), 24.77±7.38 (5%) and 25.63±8.39 (4%) respectively.

CONCLUSIONS

VD supplementation combined with exercise training significantly increased muscle strength, ES, LBM, gait and VD level in severely burned children.

Serum 25-hydroxyvitamin D deficiency predicts poor outcome amongst acute ischaemic stroke patients with low high density lipoprotein cholesterol

BACKGROUND AND PURPOSE

Current observational studies indicate that a lower vitamin D level is associated with a higher risk of poor ischaemic stroke prognosis. Whether this association is affected by lipid levels is unclear. Our aim was to examine the effect of serum vitamin D especially its deficiency on the global outcome of ischaemic stroke stratified by individual lipid component level.

METHODS

A total of 3181 ischaemic patients from China Antihypertensive Trial in Acute Ischaemic Stroke were included in this study and their baseline serum 25-hydroxyvitamin D levels were tested. They were prospectively followed up for death, major disability and vascular events for 3 months after acute ischaemic stroke. A multivariable logistic model was used to evaluate the association between serum 25-hydroxyvitamin D levels and clinical outcomes of ischaemic stroke in the 3-month period of follow-up in all patients and in different lipid-level subgroups.

RESULTS

Vitamin D deficiency was associated with poor clinical outcomes only in ischaemic stroke patients with high density lipoprotein cholesterol (HDLC) <1.04 mmol/l rather than all patients. The multivariable adjusted odds ratios (95% confidence intervals) of major disability and composite adverse events were 1.98 (1.08-3.63) and 2.24 (1.22-4.12), respectively. There was a significant interaction effect between vitamin D and HDLC levels on major disability and the composite outcome (P for interaction < 0.05 for both). A significant linear trend existed between 25-hydroxyvitamin D and risk of poor prognosis (P = 0.03).

CONCLUSIONS

Vitamin D deficiency may be merely an independent risk factor of poor prognosis in ischaemic stroke patients with low HDLC level.

Genetic modifications associated with ketogenic diet treatment in the BTBRT+Tf/J mouse model of autism spectrum disorder

BACKGROUND

Autism spectrum disorder (ASD) is a prevalent and heterogeneous neurodevelopmental disorder characterized by hallmark behavioral features. The spectrum of disorders that fall within the ASD umbrella encompass a distinct but overlapping symptom complex that likely results from an array of molecular and genetic aberrations rather than a single genetic mutation. The ketogenic diet (KD) is a high-fat low-carbohydrate anti-seizure and neuroprotective diet that has demonstrated efficacy in the treatment of ASD-like behaviors in animal and human studies.

METHODS

We investigated changes in mRNA and gene expression in the BTBR mouse model of ASD that may contribute to the behavioral phenotype. In addition, we sought to examine changes in gene expression following KD treatment in BTBR mice.

RESULTS

Despite significant behavioral abnormalities, expression changes in BTBR mice did not differ substantially from controls; only 33 genes were differentially expressed in the temporal cortex, and 48 in the hippocampus. Examination of these differentially expressed genes suggested deficits in the stress response and in neuronal signaling/communication. After treatment with the KD, both brain regions demonstrated improvements in ASD deficits associated with myelin formation and white matter development.

CONCLUSIONS

Although our study supports many of the previously known impairments associated with ASD, such as excessive myelin formation and impaired GABAergic transmission, the RNAseq data and pathway analysis utilized here identified new therapeutic targets for analysis, such as Vitamin D pathways and cAMP signaling. Autism Res 2017, 10: 456-471. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

Vitamin D Insufficiency is Associated with Reduced Parasympathetic Nerve Fiber Function in Type 2 Diabetes

OBJECTIVE

Vitamin D insufficiency is prevalent in subjects with type 2 diabetes mellitus (T2DM) and is associated with peripheral neuropathy. However, there are little data regarding vitamin D status in patients with cardiovascular autonomic neuropathy. Our objective was to evaluate the association of cardiovascular autonomic function, 25-hydroxyvitamin D (25[OH]D) insufficiency (i.e., levels <30 ng/mL), and multiple metabolic parameters in subjects with T2DM.

METHODS

We examined 50 individuals with T2DM. Cardiovascular autonomic function (i.e., parasympathetic function) was assessed by RR-variation during deep breathing (i.e., mean circular resultant [MCR] and expiration/inspiration [E/I] ratio). Metabolic parameters included measures of adiposity, glycemic control, insulin resistance, calcium metabolism, and 25(OH)D.

RESULTS

Participants with 25(OH)D insufficiency (n = 26) were younger (66 ± 9 vs. 60 ± 10 years, P<.05), more insulin resistant, had a higher body mass index (BMI) and lower adiponectin levels. The MCR (39.5 ± 26.3 vs. 27.6 ± 17.2, P<.01) and E/I ratio (1.21 ± 0.17 vs. 1.15 ± 0.09, P<.01) were lower for those with 25(OH)D insufficiency after controlling for age. A stepwise selection procedure regressing MCR and E/I ratio on a number of metabolic parameters resulted in a model identifying age and 25(OH)D insufficiency as significant determinants for both measures. The interaction of age x 25(OH)D insufficiency was also included (MCR model, R2 = 0.491, P<.001; E/I ratio, R2 = 0.455, P<.001). Neither glycemic control nor other metabolic parameters were selected.

CONCLUSION

Our results suggest that 25(OH)D insufficiency is associated with reduced parasympathetic function, with a stronger association in younger persons with T2DM. Studies are needed to determine if vitamin D supplementation into the sufficient range could prevent or delay the onset of cardiovascular autonomic dysfunction.

Vitamin D Levels and the Risk of Cognitive Decline in Chinese Elderly People: the Chinese Longitudinal Healthy Longevity Survey

BACKGROUND

Vitamin D has a neuroprotective function, potentially important for the prevention of cognitive decline. Prospective studies from Western countries support an association between lower vitamin D level and future cognitive decline in elderly people. No prospective study has examined this association in Asia.

METHODS

This community-based cohort study of elderly people in China follows 1,202 cognitively intact adults aged ≥60 years for a mean duration of 2 years. Plasma vitamin D level was measured at the baseline. Cognitive state of participants was assessed using the Mini-Mental State Examination (MMSE). Cognitive impairment was defined as an MMSE score <18. Cognitive decline was defined as ≥3 points decline from baseline. Multivariable logistic regression models were used to examine the association between quartiles of vitamin D levels with cognitive decline and incidence of cognitive impairment.

RESULTS

Participants with low vitamin D level had an increased risk of cognitive decline. Compared with the highest quartile of vitamin D levels, the multivariable odds ratios (ORs; 95% confidence interval) for cognitive decline were 2.1 (1.3-3.4) for the second highest quartile, 2.2 (1.4-3.6) for the third highest quartile, and 2.0 (1.2-3.3) for the lowest quartile. The multivariable ORs of incident cognitive impairment for the second highest, third highest, and lowest versus highest quartiles of vitamin D levels were 1.9 (0.9-4.1), 2.6 (1.2-5.6), and 3.2 (1.5-6.6), respectively.

CONCLUSIONS

This first follow-up study of elderly people, including the oldest-old, in Asia shows that low vitamin D levels were associated with increased risk of subsequent cognitive decline and impairment.

Dietary Nutrient Intake in School-Aged Children With Heavy Prenatal Alcohol Exposure

BACKGROUND

Nutrition is an important factor that affects brain development. Nutritional deficiencies can exacerbate alcohol's damaging effects. Conversely, nutritional supplementation can serve a protective role against alcohol damage and may prove to be a worthwhile intervention strategy. This study investigated dietary intake in school-aged children with heavy prenatal alcohol exposure to understand their nutritional status, compared to a national sample of typically developing children and Dietary Reference Intakes.

METHODS

Dietary intake data were collected from children with confirmed histories of heavy prenatal alcohol exposure (5 to 10 years, n = 55) using the Automated Self-Administered 24-Hour Dietary Recall (ASA24). Observed nutrient levels were compared to the Dietary Reference Intakes to evaluate adequacy of nutrient intake as well as to national averages for same-aged children (What We Eat in America, NHANES 2007-2008).

RESULTS

Alcohol-exposed children exhibited poorer nutritional status compared to the typically developing NHANES sample, consuming lower levels of protein, omega-3 fatty acids, magnesium, potassium, zinc, vitamins C and K, niacin, and choline. Moreover, their diets did not meet Recommended Dietary Allowance or Adequate Intake for dietary fiber, potassium, vitamins E and K, omega-3 fatty acids, and choline.

CONCLUSIONS

The present findings are consistent with prior studies investigating nutritional intake in preschoolers with FASD, indicating that these children are vulnerable to nutritional inadequacies. Moreover, data suggest a specific profile of dietary intake in this population. As several nutrients are important for cognitive development, targeted interventions in clinical populations might be effective in boosting outcomes. Thus, further clinical investigation into the role of nutrition in improving cognitive outcomes is warranted.

Serum 25-hydroxyvitamin D concentrations in Mid-adulthood and Parkinson's disease risk

BACKGROUND

Low vitamin D levels are common among patients with Parkinson's disease (PD). Experimental evidence further suggests that vitamin D may be protective against PD. The objective of this study was to prospectively assess the association between serum 25-hydroxyvitamin D and PD among 12,762 participants of the Atherosclerosis Risk in Communities Study cohort.

METHODS

Serum samples were collected in 1990-1992, and 25-hydroxyvitamin D was measured by liquid chromatography mass spectrometry. A total of 67 incident PD cases were identified through December 31, 2008. The median length of follow-up was 17 years. We used Cox proportional hazards models to obtain hazard ratios and 95% confidence intervals, adjusting for age, sex, and race. We did not find any association between serum 25-hydroxyvitamin D concentrations and PD risk, regardless of how serum 25-hydroxyvitamin D was modeled. Compared with participants with serum 25-hydroxyvitamin D < 20 ng/mL, the hazards ratio for PD was 1.05 (95% confidence interval, 0.58-1.90) for 20-30 ng/mL and 1.14 (95% confidence interval, 0.59- 2.23) for ≥30 ng/mL. Similar results were obtained in sensitivity analyses that included white participants only and that were stratified by the length of follow-up.

CONCLUSION

This prospective study lends no support to the hypothesis that vitamin D may reduce the risk of PD. © 2016 International Parkinson and Movement Disorder Society.

Vitamin D and Sunlight Exposure in Newly-Diagnosed Parkinson's Disease

Circulating vitamin D has previously been found to be lower in patients with Parkinson’s disease (PD), while the effects of sunlight exposure have not yet been fully investigated. Therefore, we evaluated the associations between serum vitamin D, vitamin D intake, sunlight exposure, and newly-diagnosed PD patients in a Chinese population. This case-control study measured serum 25-hydroxyvitamin D (25(OH)D) levels and sunlight exposure in 201 patients with newly-diagnosed PD and 199 controls without neurodegenerative diseases. Data on vitamin D intake and sunlight exposure were obtained using a self-report questionnaire. Multivariable logistic regressions were employed to evaluate the associations between serum 25(OH)D levels, sunlight exposure, and PD. Adjustments were made for sex, age, smoking, alcohol use, education, BMI, and vitamin D intake. There were significantly lower levels of serum 25(OH)D (20.6 ± 6.5 ng/mL), daily vitamin D intake (8.3 ± 3.7 g/day), and sunlight exposure (9.7 ± 4.1 h/week) in patients with PD compared to healthy controls (p < 0.05). Crude odds ratios (ORs) for PD in the quartiles of serum 25(OH)D were 1 (reference), 0.710 (0.401, 1.257), 0.631 (0.348, 1.209), and 0.483 (0.267, 0.874), respectively. Crude ORs for PD in quartiles of sunlight exposure were 1 (reference), 0.809 (0.454, 1.443), 0.623 (0.345, 1.124) and 0.533 (0.294, 0.966), respectively. A significant positive correlation between serum 25(OH)D and sunlight exposure was found, but serum 25(OH)D was not correlated with daily vitamin D intake. This study indicates that lower levels of serum 25(OH)D and sunlight exposure are significantly associated with an increased risk for PD.

Vitamin D Supplementation Affects the Beck Depression Inventory, Insulin Resistance, and Biomarkers of Oxidative Stress in Patients with Major Depressive Disorder: A Randomized, Controlled Clinical Trial

BACKGROUND

Vitamin D may decrease depression symptoms through its beneficial effects on neurotransmitters, metabolic profiles, biomarkers of inflammation, and oxidative stress.

OBJECTIVE

This study was designed to assess whether vitamin D supplementation can reduce symptoms of depression, metabolic profiles, serum high-sensitivity C-reactive protein (hs-CRP), and biomarkers of oxidative stress in patients with major depressive disorder (MDD).

METHODS

This randomized, double-blind, placebo-controlled clinical trial was performed in 40 patients between 18 and 65 y of age with a diagnosis of MDD based on criteria from the Diagnostic and Statistical Manual of Mental Disorders. Patients were randomly assigned to receive either a single capsule of 50 kIU vitamin D/wk (n = 20) or placebo (n = 20) for 8 wk. Fasting blood samples were taken at baseline and postintervention to quantify relevant variables. The primary [Beck Depression Inventory (BDI), which examines depressive symptoms] and secondary (glucose homeostasis variables, lipid profiles, hs-CRP, and biomarkers of oxidative stress) outcomes were assessed.

RESULTS

Baseline concentrations of mean serum 25-hydroxyvitamin D were significantly different between the 2 groups (9.2 ± 6.0 and 13.6 ± 7.9 μg/L in the placebo and control groups, respectively, P = 0.02). After 8 wk of intervention, changes in serum 25-hydroxyvitamin D concentrations were significantly greater in the vitamin D group (+20.4 μg/L) than in the placebo group (-0.9 μg/L, P < 0.001). A trend toward a greater decrease in the BDI was observed in the vitamin D group than in the placebo group (-8.0 and -3.3, respectively, P = 0.06). Changes in serum insulin (-3.6 compared with +2.9 μIU/mL, P = 0.02), estimated homeostasis model assessment of insulin resistance (-1.0 compared with +0.6, P = 0.01), estimated homeostasis model assessment of β cell function (-13.9 compared with +10.3, P = 0.03), plasma total antioxidant capacity (+63.1 compared with -23.4 mmol/L, P = 0.04), and glutathione (+170 compared with -213 μmol/L, P = 0.04) in the vitamin D group were significantly different from those in the placebo group.

CONCLUSION

Overall, vitamin D supplementation of patients with MDD for 8 wk had beneficial effects on the BDI, indicators of glucose homeostasis, and oxidative stress. This trial was registered at www.irct.ir as IRCT201412065623N29.

The effect of cigarette smoking on vitamin D level and depression in male patients with acute ischemic stroke

OBJECTIVE

The association between low vitamin D levels and depression has been well documented in nonstroke subjects. Accumulating evidence shows that low vitamin D levels may be also associated with depression post stroke. Cigarette smoking was associated with lower vitamin D levels. The purposes of this study were to compare vitamin D levels in smokers to nonsmokers and examine the association between vitamin D levels and depression symptoms in patients with acute ischemic stroke.

MATERIALS AND METHODS

Serum levels of 25-hydroxyvitamin D [25(OH)D] were measured in 194 males within 24h after admission: 116 smokers and 78 nonsmokers. Depression symptoms were assessed with the 17-item Hamilton Depression Scale (HAMD-17). Patients with the HAMD-17 score >7 were identified to have depression symptoms.

RESULTS

The chi-square test showed that the frequency of depression in the smoker group was 23.3% (27/116), which was significantly higher than that in the nonsmoker group (11.5%=9/78), with an odds ratios (OR) of 2.33 (95% CI: 1.03-5.27; χ(2)=4.25, df=1, p=0.039, φ=0.15). Vitamin D levels were significantly lower in smokers than in nonsmokers (52.4±20.8 vs 61.7±19.2; F=9.88, p=0.002), with an effect size of 0.05 (ηp(2)). Patients with depression symptoms showed lower vitamin D levels than those with no depression symptoms (49.2±19.6 vs 57.7±20.6; F=5.03, p=0.03), with an effect size of 0.03 (ηp(2)).

CONCLUSION

Higher rates of depression in smokers with acute ischemic stroke may be associated with lower vitamin D levels induced by smoking.

Vitamin D3 attenuates oxidative stress and cognitive deficits in a model of toxic demyelination

OBJECTIVES

Multiple sclerosis (MS) is a demyelinating disease. The prevalence of MS is highest where environmental supplies of vitamin D are low. Cognitive deficits have been observed in patients with MS. Oxidative damage may contribute to the formation of MS lesions. Considering the involvement of hippocampus in MS, an attempt is made in this study to investigate the effects of vitamin D3 on behavioral process and the oxidative status in the dorsal hippocampus (CA1 area) following the induction of experimental demyelination in rats.

MATERIALS AND METHODS

Animals were divided into six groups.

CONTROL GROUP

animals received no surgery and treatment; saline group: animals received normal saline; sham group: animals received 150 μl sesame oil IP; vitamin D3 group: animals received 5 μg/kg vitamin D3 IP; lysophosphatidyl choline (LPC) group (toxic demyelination's model): animals received LPC by stereotaxic intra-hippocampal injection of 2 μl LPC in CA1 area; Vitamin D3- treated group: animals were treated with vitamin D3 at doses of 5 μg/kg IP for 7 and 21 days post lesion. The spatial memory, biochemical parameters including catalase (CAT) activities and lipid peroxidation levels were investigated.

RESULTS

Animals in LPC group had more deficits in spatial memory than the control group in radial arm maze. Vitamin D3 significantly improved spatial memory compared to LPC group. Also, results indicated that vitamin D3 caused a decrease in lipid peroxidation levels and an increase in CAT activities.

CONCLUSION

Current findings suggest that vitamin D3 may have a protective effect on cognitive deficits and oxidative stress in toxic demyelination's model.

The Role of Vitamin D₃ in the Development and Neuroprotection of Midbrain Dopamine Neurons

Vitamin D has long been synonymous with bone health. More recently, new health benefits are continually being associated with vitamin D, including a burgeoning field on neuroprotective properties. This has generated a huge explosion of interest in recent years in the potential for vitamin D to be used not only as a therapeutic in neurodegenerative disease, including Parkinson's disease, but also as biomarkers and for risk association. With an emphasis on Parkinson's disease, this chapter will discuss recent evidence supporting the assertion that vitamin D can be a useful therapeutic agent used as an intervention therapy to be combined with existing treatments; and the case for further development of novel treatments utilizing the potential of vitamin D. In addition, we present novel, previously unpublished evidence showing that in a unilateral model of Parkinson's disease, vitamin D can not only reduce the extent of denervation, but that this is also reflected in functional benefit to the animals. The potential of vitamin D is slowly being realized; in the future, it will be widely associated with far more than just bone health and may even contribute to an elusive treatment of neurodegenerative illness.

25-Hydroxyvitamin D3 Deficiency Independently Predicts Cognitive Impairment in Patients with Systemic Lupus Erythematosus

OBJECTIVES

Cognitive dysfunction has been reported in 20-80% of SLE patients. Converging evidence has indicated the importance of vitamin D as a neuroimmunomodulator for cognitive function. In this study, we evaluated the relationship between vitamin D and cognitive dysfunction.

METHODS

Consecutive age- and gender-matched SLE patients and healthy controls (HCs) were administered Automated Neuropsychological Assessment Metrics in this cross-sectional study. The primary outcome was the total throughput score (TTS). Anxiety and depression were measured using the Hospital Anxiety and Depression Scale (HADS). Levels of 25-hydroxyvitamin D [25(OH)D3 and total 25(OH)D] were measured using Liquid Chromatography-Tandem Mass Spectrometry.

RESULTS

In total, 61 SLE patients and 61 HCs were studied. SLE patients scored significantly lower than HCs in the TTS (p = 0.004). There were no statistically significant differences in 25(OH)D3 levels, total 25(OH)D levels and total 25(OH)D deficiency between SLE patients and HCs. However, more SLE patients had 25(OH)D3 deficiency compared to HCs [12 (19.7%) versus 2 (3.3%), p = 0.003]. Deficiency of 25(OH)D3 (β = -63.667, SE = 27.456, p = 0.025), but not other vitamin D variables, independently predicted worse TTS after adjusting for age, education, gender, ethnicity, HADS-Total, duration of SLE, SELENA-SLEDAI, SLICC/ACR Damage Index and cumulative steroid dose in SLE patients. Age (β = -4.261, SE = 0.866, p < 0.001) was the only predictor of TTS after adjusting for education, gender, ethnicity, HADS-Total, vitamin D levels or status in HCs.

CONCLUSIONS

Deficiency of 25(OH)D3, a potentially modifiable risk factor, independently predicted cognitive impairment in SLE patients.

Inverse associations of outdoor activity and vitamin D intake with the risk of Parkinson's disease

Early studies had suggested that vitamin D intake was inversely associated with neurodegenerative diseases, such as Alzheimer's disease and multiple sclerosis. However, the associations of vitamin D intake and outdoor activities with Parkinson's disease (PD) are still unclear, so this study is to evaluate these relationships from a case-control study in elderly Chinese. The study population involved 209 cases with new onsets of PD and 210 controls without neurodegenerative diseases. The data on dietary vitamin D and outdoor activities were collected using a food-frequency questionnaire and self-report questionnaire. Multivariable logistic regressions were used to examine the associations between dietary outdoor activities, vitamin D intake and PD. Adjustment was made for sex, age, smoking, alcohol use, education, and body mass index (BMI). Adjusted odds ratios (ORs) for PD in quartiles for outdoor physical activity were 1 (reference), 0.739 (0.413, 1.321), 0.501 (0.282, 0.891), and 0.437 (0.241, 0.795), respectively (P=0.002 for trend). Adjusted ORs for PD in quartiles for total vitamin D intake were 1 (reference), 0.647 (0.357, 1.170), 0.571 (0.318, 1.022), and 0.538 (0.301, 0.960), respectively (P=0.011 for trend). Our study suggested that outdoor activity and total vitamin D intake were inversely associated with PD, and outdoor activity seems to be more significantly associated with decreased risk for PD.

The new insight on the regulatory role of the vitamin D3 in metabolic pathways characteristic for cancerogenesis and neurodegenerative diseases

Apart from the classical function of regulating intestinal, bone and kidney calcium and phosphorus absorption as well as bone mineralization, there is growing evidence for the neuroprotective function of vitamin D3 through neuronal calcium regulation, the antioxidative pathway, immunomodulation and detoxification. Vitamin D3 and its derivates influence directly or indirectly almost all metabolic processes such as proliferation, differentiation, apoptosis, inflammatory processes and mutagenesis. Such multifactorial effects of vitamin D3 can be a profitable source of new therapeutic solutions for two radically divergent diseases, cancer and neurodegeneration. Interestingly, an unusual association seems to exist between the occurrence of these two pathological states, called "inverse comorbidity". Patients with cognitive dysfunctions or dementia have considerably lower risk of cancer, whereas survivors of cancer have lower prevalence of central nervous system (CNS) disorders. To our knowledge, there are few publications analyzing the role of vitamin D3 in biological pathways existing in carcinogenic and neuropathological disorders.

Vitamin D as a marker of cognitive decline in elderly Indian population

Objectives:

Very few studies in India have addressed the role of vitamin D in cognitive function. The present study was conducted to assess the serum levels of 25-hydroxyvitamin D (25(OH)D) and its association with markers of cognitive impairment and homocysteine levels in the elderly Indian population.

Materials and Methods:

The study population consisted of patients with dementia (Group A, n = 32), mild cognitive impairment (MCI; Group B, n = 24), and elderly age-matched controls (Group C, n = 30). Measurement of serum levels of 25(OH)D and total homocysteine were done.

Results:

Significant decreased concentration of 25(OH)D and increased concentration of homocysteine was observed. Association of serum levels of vitamin D with markers of cognitive decline as well as serum homocysteine levels was observed in patients with dementia and MCI when compared to controls.

Conclusion:

Correlation of vitamin D with markers of cognitive decline and homocysteine opens a new door for early diagnosis of cognitive impairment.

Association between pre-hospital vitamin D status and hospital-acquired new-onset delirium

The goal of the present study was to determine whether pre-hospital 25-hydroxyvitamin D (25(OH)D) levels are associated with the risk of hospital-acquired new-onset delirium (HANOD). We performed a retrospective cohort study of 4508 adult inpatients at two teaching hospitals in Boston from 1993 to 2006. All patients had 25(OH)D levels measured before hospital admission. The main outcome measure was HANOD, defined as the onset of delirium during an acute care hospitalisation. Patients with a history of delirium or dementia, or those with a diagnosis of delirium or dementia upon acute care hospitalisation were excluded from the analysis. To test the association of pre-hospital 25(OH)D levels with HANOD, we constructed a multivariable logistic regression model to adjust for clinically relevant covariates. Among our patient cohort, the mean 25(OH)D level was 22 (sd 13) ng/ml and approximately 4% of patients met the criteria for HANOD. Following adjustment for age, sex, race (non-white v. white), patient type (medical v. surgical) and Deyo-Charlson Index, patients with 25(OH)D levels < 10, 10-19·9 and 20-29·9 ng/ml had higher odds of HANOD than patients with 25(OH)D levels ≥ 30 ng/ml: OR 2·15 (95% CI 1·32, 3·50), OR 1·54 (95% CI 0·98, 2·43) and OR 1·23 (95% CI, 0·76, 1·99), respectively. These data support the rationale for randomised, controlled trials to test the role of vitamin D supplementation in the prevention of HANOD.

Increased Intake of Foods with High Nutrient Density Can Help to Break the Intergenerational Cycle of Malnutrition and Obesity

A workshop held at the University Medical Center in Groningen, The Netherlands, aimed at discussing the nutritional situation of the population in general and the role diet plays during critical windows in the life course, during which the body is programmed for the development of non-communicable diseases (NCDs). NCDs are increasingly prevalent as our society ages, and nutrition is well known to play an important role in determining the risk and the time of onset of many common NCDs. Even in affluent countries, people have difficulties to achieve adequate intakes for a range of nutrients: Economic constraints as well as modern lifestyles lead people to consume diets with a positive energy balance, but low in micronutrients, resulting in increasing prevalence of obesity and suboptimal nutritional status. Information about nutrient density, which refers to the content of micronutrients relative to energy in food or diets, can help identify foods that have a low calorie to nutrient ratio. It thus allows the consumption of diets that cover nutritional needs without increasing the risk of becoming obese. Given the impact a nutrient dense, low energy diet can have on health, researchers, food industry and governments jointly should develop options for affordable, appealing nutrient-rich food products, which, in combination with physical activity, allow for optimal health throughout the life-course.

Vitamin D and Age-Related Health Outcomes: Movement, Mood, and Memory

It has long been recognized that vitamin D plays an important role in calcium homeostasis and musculoskeletal health. More recent evidence supports a role of vitamin D in physical and cognitive function and depressive symptoms through direct effects on skeletal muscle and the brain as well as indirectly through its reported roles in chronic conditions such as cardiovascular disease and diabetes, conditions that frequently lead to declines in physical and cognitive function and depressed mood. The purpose of this review is to summarize the prospective cohort and randomized controlled trial evidence for vitamin D on physical and cognitive function and depressed mood in older adults. Results from both prospective cohort studies and randomized controlled trials of vitamin D supplementation are mixed. Thus, controversy remains over the optimal vitamin D concentration for physical and cognitive function and depressed mood and whether vitamin D supplementation is beneficial for these outcomes.

Parathyroid hormone, cognitive function and dementia: a systematic review

Background

Metabolic factors are increasingly recognized to play an important role in the pathogenesis of Alzheimer’s disease and dementia. Abnormal parathyroid hormone (PTH) levels play a role in neuronal calcium dysregulation, hypoperfusion and disrupted neuronal signaling. Some studies support a significant link between PTH levels and dementia whereas others do not.

Methods

We conducted a systematic review through January 2014 to evaluate the association between PTH and parathyroid conditions, cognitive function and dementia. Eleven electronic databases and citation indexes were searched including Medline, Embase and the Cochrane Library. Hand searches of selected journals, reference lists of primary studies and reviews were also conducted along with websites of key organizations. Two reviewers independently screened titles and abstracts of identified studies. Data extraction and study quality were performed by one and checked by a second reviewer using predefined criteria. A narrative synthesis was performed due to the heterogeneity of included studies.

Results

The twenty-seven studies identified were of low and moderate quality, and challenging to synthesize due to inadequate reporting. Findings from six observational studies were mixed but suggest a link between higher serum PTH levels and increased odds of poor cognition or dementia. Two case-control studies of hypoparathyroidism provide limited evidence for a link with poorer cognitive function. Thirteen pre-post surgery studies for primary hyperparathyroidism show mixed evidence for improvements in memory though limited agreement in other cognitive domains. There was some degree of cognitive impairment and improvement postoperatively in observational studies of secondary hyperparathyroidism but no evident pattern of associations with specific cognitive domains.

Conclusions

Mixed evidence offers weak support for a link between PTH, cognition and dementia due to the paucity of high quality research in this area.

Serum 25-hydroxyvitamin D and cognitive decline: a longitudinal study among non-demented older adults

BACKGROUND/AIMS

Very few studies have investigated the longitudinal association between serum levels of 25-hydroxyvitamin D [25(OH)D] and cognitive impairment not due to dementia. This longitudinal study analysed 25(OH)D and the risk of cognitive decline among non-demented older adults.

METHODS

A subsample of the ESTHER cohort study, aged ≥70 years, was assessed with the Cognitive Telephone Screening Instrument (COGTEL) and underwent 25(OH)D measurements standardized with a reference method (n = 1,302). After an average follow-up of 4.6 years, 527 participants had repeated COGTEL testing and were eligible for analysis. Linear regression models were used to assess longitudinal associations between 25(OH)D levels and cognitive function. Possible practice effects of repeated cognitive testing were addressed with the reliable change index.

RESULTS

A trend of a more pronounced cognitive decline with lower vitamin D levels was observed among both women and men, with a statistically significant difference in COGTEL scores in the lowest vitamin D quintile of the total sample.

CONCLUSIONS

This study indicates that low levels of vitamin D might be associated with cognitive decline among non-demented elderly individuals and highlights the need for further large-scale prospective studies to clarify the potential role of vitamin D in cognitive function at an old age.

Diet, nutrients and metabolism: cogs in the wheel driving Alzheimer's disease pathology?

Alzheimer's disease (AD), the most common form of dementia, is a chronic, progressive neurodegenerative disease that manifests clinically as a slow global decline in cognitive function, including deterioration of memory, reasoning, abstraction, language and emotional stability, culminating in a patient with end-stage disease, totally dependent on custodial care. With a global ageing population, it is predicted that there will be a marked increase in the number of people diagnosed with AD in the coming decades, making this a significant challenge to socio-economic policy and aged care. Global estimates put a direct cost for treating and caring for people with dementia at $US604 billion, an estimate that is expected to increase markedly. According to recent global statistics, there are 35.6 million dementia sufferers, the number of which is predicted to double every 20 years, unless strategies are implemented to reduce this burden. Currently, there is no cure for AD; while current therapies may temporarily ameliorate symptoms, death usually occurs approximately 8 years after diagnosis. A greater understanding of AD pathophysiology is paramount, and attention is now being directed to the discovery of biomarkers that may not only facilitate pre-symptomatic diagnosis, but also provide an insight into aberrant biochemical pathways that may reveal potential therapeutic targets, including nutritional ones. AD pathogenesis develops over many years before clinical symptoms appear, providing the opportunity to develop therapy that could slow or stop disease progression well before any clinical manifestation develops.

Vitamin D status, hypertension and ischemic stroke: a clinical perspective

The relationship between vitamin D deficiency and stroke was cross-sectionally evaluated in the high-risk Asian Indian population. Age- and gender-matched, 239 ischemic stroke patients and 241 control subjects were recruited. Vitamin D status was estimated by measuring serum 25-hydroxyvitamin D (25(OH)D) levels. After multivariate adjustment for a range of potential covariates in a logistic regression model, an inverse association was found between serum 25(OH)D concentration and risk of ischemic stroke: subjects with severely low 25(OH)D levels (⩽9.33 ng ml(-1)) were found to be at 3.13-fold (95% confidence interval (CI), (1.22-8.07)) increased risk of ischemic stroke as compared with those with high levels. Adjustment for systolic blood pressure levels was found to abrogate this association (odds ratio (OR)=2.00, 95% CI=0.61-6.50). On stratification, a pronounced association was found between low 25(OH)D and risk of ischemic stroke in hypertensives, OR=13.54, 95% CI=1.94-94.43 as compared with no association in non-hypertensives, (Pinteraction=0.04). We conclude that high blood pressure partly explains the association between 25(OH)D levels and ischemic stroke. Presence of hypertension amply aggravates the risk of ischemic stroke associated with low vitamin D levels. Meticulous management of hypertension, regular monitoring of serum 25(OH)D levels and treatment of severe vitamin D deficiency, particularly in hypertensive subjects, could help in effective prevention of stroke.

A meta-analysis of high dose, intermittent vitamin D supplementation among older adults

BACKGROUND

The effects of intermittent, high dose vitamin D treatment in older adults have not been documented. We conducted a meta-analysis to provide a quantitative assessment of the efficiency of intermittent, high dose vitamin D treatment on falls, fractures, and mortality among older adults.

METHODS

Electronic databases were searched for randomized controlled trials (RCTs) on high dose, intermittent vitamin D supplementation among older adults. Two researchers independently screened the literature according to specified inclusive and exclusive criteria to extract the data. Meta-analysis was performed by using Review Manager 5.1.0 software.

RESULTS

Nine trials were included in this meta-analysis. High dose, intermittent vitamin D therapy did not decrease all-cause mortality among older adults. The risk ratio (95% CI) was 1.04 (0.91-1.17). No benefit was seen in fracture or fall prevention. The risk ratio for hip fractures (95% CI) was 1.17 (0.97-1.41) while for non-vertebral fractures (95% CI) it was 1.06 (0.91-1.22), and the risk ratio for falls (95% CI) was 1.02 (0.96-1.08). Results remained robust after sensitivity analysis.

CONCLUSION

Supplementation of intermittent, high dose vitamin D may not be effective in preventing overall mortality, fractures, or falls among older adults. The route of administration of vitamin D supplements may well change the physiological effects.

The Relationship between Serum Vitamin D Level and Attention Deficit Hyperactivity Disorder

OBJECTIVE

Attention deficit hyperactivity disorder (ADHD) is one of the most prevalent mental health disorders. In recent years, the impacts of various micronutrients on ADHD have been studied. However, vitamin D has received much less attention. This study was aimed at evaluating the association and level of serum vitamin D in children with ADHD.

MATERIALS & METHODS

This case-control study was carried out, in 2012, on 6 to 12 yr-old children. Thirty-seven were children with ADHD in the cases group and another 37 healthy children were in the control group. Venous blood sample was drawn from each child to measure the serum level of vitamin D. Other variables were compared as well.

RESULTS

The mean serum vitamin D level of children with ADHD (19.11±10.10 ng/ml) was significantly lower than that of the control group (28.67±13.76 ng/ml) (P<0.001).

CONCLUSION

Deficiency of vitamin D has been proved in various psychiatric diseases. This study evidenced a significantly low level of serum vitamin D in children with ADHD. This suggests the need for regularly monitoring of serum vitamin D levels and treatment of patients with vitamin D deficiencies.

The role of telomeres and vitamin D in cellular aging and age-related diseases

Aging is a complex biological process characterized by a progressive decline of organ functions leading to an increased risk of age-associated diseases and death. Decades of intensive research have identified a range of molecular and biochemical pathways contributing to aging. However, many aspects regarding the regulation and interplay of these pathways are insufficiently understood. Telomere dysfunction and genomic instability appear to be of critical importance for aging at a cellular level. For example, age-related diseases and premature aging syndromes are frequently associated with telomere shortening. Telomeres are repetitive nucleotide sequences that together with the associated sheltrin complex protect the ends of chromosomes and maintain genomic stability. Recent studies suggest that micronutrients, such as vitamin D, folate and vitamin B12, are involved in telomere biology and cellular aging. In particular, vitamin D is important for a range of vital cellular processes including cellular differentiation, proliferation and apoptosis. As a result of the multiple functions of vitamin D it has been speculated that vitamin D might play a role in telomere biology and genomic stability. Here we review existing knowledge about the link between telomere biology and cellular aging with a focus on the role of vitamin D. We searched the literature up to November 2014 for human studies, animal models and in vitro experiments that addressed this topic.

'Vitamin D and cognition in older adults': updated international recommendations

BACKGROUND

Hypovitaminosis D, a condition that is highly prevalent in older adults aged 65 years and above, is associated with brain changes and dementia. Given the rapidly accumulating and complex contribution of the literature in the field of vitamin D and cognition, clear guidance is needed for researchers and clinicians.

METHODS

International experts met at an invitational summit on 'Vitamin D and Cognition in Older Adults'. Based on previous reports and expert opinion, the task force focused on key questions relating to the role of vitamin D in Alzheimer's disease and related disorders. Each question was discussed and voted using a Delphi-like approach.

RESULTS

The experts reached an agreement that hypovitaminosis D increases the risk of cognitive decline and dementia in older adults and may alter the clinical presentation as a consequence of related comorbidities; however, at present, vitamin D level should not be used as a diagnostic or prognostic biomarker of Alzheimer's disease due to lack of specificity and insufficient evidence. This population should be screened for hypovitaminosis D because of its high prevalence and should receive supplementation, if necessary; but this advice was not specific to cognition. During the debate, the possibility of 'critical periods' during which vitamin D may have its greatest impact on the brain was addressed; whether hypovitaminosis D influences cognition actively through deleterious effects and/or passively by loss of neuroprotection was also considered.

CONCLUSIONS

The international task force agreed on five overarching principles related to vitamin D and cognition in older adults. Several areas of uncertainty remain, and it will be necessary to revise the proposed recommendations as new findings become available.

Beneficial effects of vitamin D on falls and fractures: is cognition rather than bone or muscle behind these benefits?

The beneficial effect of vitamin D on bone tissue has long been attributed mainly to its positive effect on the intestinal absorption of calcium and on bone mineralization, which increases the bone mineral density (BMD) and thus decreases the risk of fracture. Recently, numerous extra osseous effects of vitamin D have been described, amongst them a positive effect on neuromuscular and cognitive functions. Several lines of evidence suggest that the beneficial effects of vitamin D on fall and fracture risk can be explained more by its action on the neuromuscular and cognitive functions than by its direct effect on bone metabolism. In this review, we first report on the relationships between vitamin D and osteoporotic fracture risk. Then, we present the data from the literature regarding the effects of vitamin D on risk factors such as fall risk and reduction in BMD, physical performance, and cognitive performance. Specific emphasis is put on the latter because there is evidence of a relationship between low concentration of serum 25-hydroxyvitamin D (the primary indicator of vitamin D status) and low cognitive abilities which have been shown to be a risk factor for falling. It can be further suggested that high risk of fracture in cognitively impaired adults could be explained by lower protective reaction when falling, which would result, for instance, from a lack of planning and foresight of the fall. Future studies are nonetheless needed to elucidate the associations between vitamin D and different risk factors, in particular the link between vitamin D and various cognitive functions.

Effects of vitamin D supplementation on neuroplasticity in older adults: a double-blinded, placebo-controlled randomised trial

Vitamin D can improve muscle function and reduce falls, but whether it can strengthen neural connections within the brain and nervous system is not known. This 10-week randomised controlled trial indicates that treatment with 2,000 IU/day vitamin D3 does not significantly alter neuroplasticity relative to placebo in older adults.

INTRODUCTION

The purpose of this study was to examine the effects of vitamin D supplementation on neuroplasticity, serum brain-derived neurotrophic factor (BDNF) and muscle strength and function in older adults.

METHODS

This was a 10-week double-blinded, placebo-controlled randomised trial in which 26 older adults with 25-hydroxyvitamin D [25OHD] concentrations 25-60 nmol/L were randomised to 2,000 IU/day vitamin D3 or matched placebo. Single- and paired-pulse transcranial magnetic stimulation applied over the motor cortex was used to assess changes in motor-evoked potentials (MEPs) and short-interval intracortical inhibition (SICI), as measures of corticospinal excitability and inhibition respectively, by recording electromyography (EMG) responses to stimulation from the wrist extensors. Changes in muscle strength, stair climbing power, gait (timed-up-and-go), dynamic balance (four square step test), serum 25(OH)D and BDNF concentrations were also measured.

RESULTS

After 10 weeks, mean 25(OH)D levels increased from 46 to 81 nmol/L in the vitamin D group with no change in the placebo group. The vitamin D group experienced a significant 8-11% increase in muscle strength and a reduction in cortical excitability (MEP amplitude) and SICI relative to baseline (all P < 0.05), but these changes were not significantly different from placebo. There was no effect of vitamin D on muscle power, function or BDNF.

CONCLUSIONS

Daily supplementation with 2,000 IU vitamin D3 for 10 weeks had no significant effect on neuroplasticity compared to placebo, but the finding that vitamin D treatment alone was associated with a decrease in corticospinal excitability and intracortical inhibition warrants further investigation as this suggests that it may improve the efficacy of neural transmission within the corticospinal pathway.