Serum levels of 25-hydroxyvitamin D predicts infarct volume and mortality in ischemic stroke patients

Vitamin D Activates Nrf2 to Prevent Nerve Injury and Reduce Brain Damage in Acute Cerebral Infarction

OBJECTIVE

This study aimed to investigate the neuroprotective effects of cholecalciferol cholesterol emulsion (CCE), a vitamin D (VD) precursor, in a murine model of acute cerebral infarction (ACI) and to elucidate the role of the Nrf2 signaling pathway in mediating these effects.

METHODS

Forty C57BL/6J mice (male and female) were divided into five groups (n = 10 per group): control, control + CCE, ACI, ACI + CCE, and ACI + CCE + ML385 (an Nrf2 inhibitor). ACI was induced by middle cerebral artery occlusion (MCAO). CCE was administered for three weeks prior to ACI induction, and ML385 was administered intravenously to inhibit Nrf2. Neurological function, brain edema, and infarct size, as well as inflammatory and apoptotic marker levels, were assessed post-ACI. Statistical analyses were conducted via one-way ANOVA and Student's t test, with P < 0.05 considered significant.

RESULTS

Compared to ACI group, CCE significantly reduced neurological deficits, brain edema, and infarct size (P < 0.01). The ACI + CCE group presented improved short-term memory retention, as evidenced by shorter avoidance latency in shuttle avoidance tests (P < 0.01). CCE administration attenuated the expression of inflammatory markers (IL-6, MIF, Lp-PLA2) while increasing IL-10 levels (P < 0.001). Furthermore, CCE increased Nrf2 and HO-1 expression and reduced apoptosis by decreasing the Bax/Bcl-2 ratio in brain tissue (P < 0.001). ML385 abolished these neuroprotective effects, confirming the role of the Nrf2 pathway in mediating the benefits of VD.

CONCLUSION

VD, via VD receptor-mediated activation of the Nrf2/HO-1 pathway, reduces inflammation, apoptosis, and neurological damage following ACI. These findings support the therapeutic potential of VD in the treatment of ischemic stroke and highlight the importance of Nrf2 in mediating these effects.

Role of vitamin D in the association between pre-stroke sleep quality and poststroke depression and anxiety

PURPOSE

Poor sleep quality, mood disorders, and vitamin D deficiency are common in stroke. We investigated the association between serum vitamin D levels and pre-stroke sleep quality and the occurrence of poststroke depression (PSD) and poststroke anxiety (PSA) in acute ischemic stroke (AIS).

METHODS

This prospective cross-sectional study included hospitalized patients with AIS and age- and sex-matched controls. Vitamin D levels were measured within 24 h of admission. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) at admission. The severity of depression and anxiety symptoms was evaluated according to Beck Depression Inventory and Beck Anxiety Inventory scores, respectively, within 72 h after admission.

RESULTS

Comparing 214 AIS patients with 103 controls, patients had significantly higher scores of Beck Depression Inventory, Beck Anxiety Inventory, and PSQI and lower vitamin D levels (p < 0.001). Among AIS patients, Beck Depression Inventory (p = 0.004) and Beck Anxiety Inventory (p = 0.018) scores were significantly higher in bad sleepers (PSQI score ≥ 6) than in good sleepers (PSQI score ≤ 5). Correlation analysis revealed negative correlations between serum vitamin D levels and Beck Depression Inventory (r =  - 0.234; p < 0.001), Beck Anxiety Inventory (r =  - 0.135; p = 0.016), and PSQI (r =  - 0.218; p < 0.001) scores.

CONCLUSION

Decreased serum vitamin D levels at admission are associated with a high risk for PSD and PSA in patients with poor pre-stroke sleep quality during the early stages of AIS.

Vitamin D and ischemic stroke - Association, mechanisms, and therapeutics

Confronting the rising tide of ischemic stroke and its associated mortality and morbidity with ageing, prevention and acute management of ischemic stroke is of paramount importance. Mounting observational studies have established a non-linear association of vitamin D status with cardiovascular diseases, including ischemic stroke. Paradoxically, current clinical trials fail to demonstrate the cardiovascular benefits of vitamin D supplementation. We aim to update recent clinical and experimental findings on the role of vitamin D in the disease course of ischemic stroke, from its onset, progression, recovery, to recurrence, and the established and alternative possible pathophysiological mechanisms. This review justifies the necessities to address stroke etiological subtypes and focus on vitamin D-deficient subjects for investigating the potential of vitamin D supplementation as a preventive and therapeutic approach for ischemic stroke. Well-powered clinical trials are warranted to determine the efficacy, safety, timing, target individuals, optimal dosages, and target 25OHD concentrations of vitamin D supplementation in the prevention and treatment of ischemic stroke.

Baseline vitamin D levels and functional outcome in thrombolyzed stroke patients

Background

The primary treatment for acute ischemic stroke (AIS) patients is intravenous recombinant tissue plasminogen activator (IV rt-PA). A link between vitamin D insufficiency and worse post-stroke outcomes and more severe strokes was suggested. The present study aimed to assess the prognostic significance of baseline vitamin D levels in AIS patients treated with rt-PA. The present prospective study was conducted 66 patients with acute ischemic stroke within the therapeutic window and treated with rt-PA. Vitamin D levels were assessed using commercial double antibody sandwich enzyme linked immunosorbent assay. The primary study outcome is patient disability of any degree as assessed by the modified Rankin scale (mRS).

Results

The present study included 66 ischemic stroke patients treated with rt-PA. At baseline, there were 37 patients (56.1%) with low vitamin D levels. Comparison between patients with normal and low vitamin D levels regarding baseline data revealed that the former group were significantly younger and had significantly smaller infarct size patients with normal vitamin D had significantly lower NIHSS at day 2 and day 7. Interestingly, patients with low vitamin D levels had significantly higher frequency of rt-PA related hemorrhage, higher frequency of chest infection, longer hospital stay and higher mRS at 90 days. Multivariate logistic regression analysis identified vitamin D level as significant predictor of functional outcome at 90 days.

Conclusions

Baseline vitamin D levels is considered a significant predictor of functional outcome in AIS patients treated with rt-PA. It’s also related to infarct size and treatment complications.

Vitamin D in atherosclerosis and cardiovascular events

Both experimental and clinical findings linking vitamin D to cardiovascular (CV) risk have prompted consideration of its supplementation to improve overall health. Yet several meta-analyses do not provide support for the clinical effectiveness of this strategy. Meanwhile, the understanding of the roles of vitamin D in the pathophysiology of CV diseases has evolved. Specifically, recent work has revealed some non-classical pleiotropic effects of vitamin D, increasing the complexity of vitamin D signalling. Within particular microenvironments (e.g. dysfunctional adipose tissue and atherosclerotic plaque), vitamin D can act locally at cellular level through intracrine/autocrine/paracrine feedforward and feedback circuits. Within atherosclerotic tissues, 'local' vitamin D levels may influence relevant systemic consequences independently of its circulating pool. Moreover, vitamin D links closely to other signalling pathways of CV relevance including those driving cellular senescence, ageing, and age-related diseases-among them CV conditions. This review updates knowledge on vitamin D biology aiming to clarify the widening gap between experimental and clinical evidence. It highlights the potential reverse causation confounding correlation between vitamin D status and CV health, and the need to consider novel pathophysiological concepts in the design of future clinical trials that explore the effects of vitamin D on atherosclerosis and risk of CV events.

Microglia/macrophages require vitamin D signaling to restrain neuroinflammation and brain injury in a murine ischemic stroke model

Vitamin D deficiency is associated with worse clinical outcomes after ischemic stroke; nevertheless, the pathophysiological mechanisms remain largely unexplored. In this study, we characterized the molecular mechanisms of how vitamin D signaling modulated stroke progression in male mouse ischemia-reperfusion stroke models. We found that vitamin D receptor (VDR) exhibited a predominant upregulation in peri-infarct microglia/macrophages following cerebral ischemia. Conditional Vdr inactivation in microglia/macrophages markedly augmented infarct volumes and neurological deficits. VDR-deficient microglia/macrophages exhibited a more primed proinflammatory phenotype with substantial secretion of TNF-α and IFN-γ. These inflammatory cytokines further enhanced CXCL10 release from endothelial cells and blood-brain barrier disruption, and ultimately infiltration of peripheral T lymphocytes. Notably, blocking TNF-α and IFN-γ significantly ameliorated stroke phenotypes in Vdr conditional knockout mice. Collectively, VDR signaling in microglia/macrophages plays a crucial role in restraining ischemia-elicited neuroinflammation and stroke progression. Our findings delineate a novel mechanism underlying the association between vitamin D deficiency and poor stroke outcomes, and underline the significance of maintaining a functional vitamin D signaling in the management of acute ischemic stroke.

Vitamin D serum level predicts stroke clinical severity, functional independence, and disability—A retrospective cohort study

Background

Stroke is a leading cause of mortality and disability and one of the most common neurological conditions globally. Many studies focused on vitamin D as a stroke risk factor, but only a few focused on its serum level as a predictor of stroke initial clinical severity and recovery with inconsistent results. The purpose of this study was to assess the relationship between serum vitamin D levels and stroke clinical severity at admission and functional independence and disability at discharge in Saudi Arabia.

Methodology

A retrospective cohort study of adult ischemic stroke patients who had their vitamin D tested and admitted within 7 days of exhibiting stroke symptoms at King Abdulaziz Medical City (KAMC) Jeddah, Saudi Arabia. Based on vitamin D level, the patients were categorized into normal [25(OH)D serum level ≥ 75 nmol/L], insufficient [25(OH)D serum level is 50–75 nmol/L], and deficient [25(OH)D serum level ≤ 50 nmol/L]. The primary outcome was to assess the vitamin D serum level of ischemic stroke patients’ clinical severity at admission and functional independence at discharge. The National Institute of Health Stroke Scale (NIHSS) was used to assess the clinical severity, whereas the modified Rankin scale (mRS) was used to assess functional independence and disability.

Results

The study included 294 stroke patients, out of 774, who were selected based on the inclusion and exclusion criteria. The mean age of the participants was 68.2 ± 13.4 years, and 49.3% were male. The patients’ distribution among the three groups based on their vitamin D levels is: normal (n = 35, 11.9%), insufficient (n = 66, 22.5%), and deficient (n = 196, 65.6%). After adjusting for potential covariates, regression analysis found a significant inverse relationship of NIHSS based on 25(OH)D serum level (beta coefficient: −0.04, SE: 0.01, p = 0.003). Patients with deficient serum vitamin D level also had significantly higher odds of worse functional independence in mRS score [OR: 2.41, 95%CI: (1.13–5.16), p = 0.023] when compared to participants with normal vitamin D level.

Conclusion

Low vitamin D levels were associated with higher severity of stroke at admission and poor functional independence and disability at discharge in patients with acute ischemic stroke. Further randomized clinical and interventional studies are required to confirm our findings.

The Role of Vitamin D in Stroke Prevention and the Effects of Its Supplementation for Post-Stroke Rehabilitation: A Narrative Review

Hypovitaminosis D is a serious public health problem, representing an independent factor in mortality among the general population. Vitamin D deficiency may affect up to one billion people worldwide. Recently, the potential association between vitamin D levels and stroke has gained increasing attention. Many studies suggest that maintaining normal serum vitamin D levels is associated with improvement of the cardiovascular system and a reduction in stroke risk. As a neurosteroid, vitamin D influences brain development and function and immunomodulation and affects brain neuroplasticity. It supports many processes that maintain homeostasis in the body. As stroke is the second most common cause of death worldwide, more studies are needed to confirm the positive effects of vitamin D supplementation, its dosage at different stages of the disease, method of determination, and effect on stroke onset and recovery. Many studies on stroke survivors indicate that serum vitamin D levels only offer insignificant benefits and are not beneficial to recovery. This review article aims to highlight recent publications that have examined the potential of vitamin D supplementation to improve rehabilitation outcomes in stroke survivors. Particular attention has been paid to stroke prevention.

Pooled incidence and case-fatality of acute stroke in Mainland China, Hong Kong, and Macao: A systematic review and meta-analysis

Background

Stroke incidence and case-fatality in Mainland China, Hong Kong, and Macao vary by geographic region and rates often differ across and within regions. This systematic review and meta-analysis (SR) estimated the pooled incidence and short-term case-fatality of acute first ever stroke in mainland China, Hong Kong, and Macao.

Methods

Longitudinal studies published in English or Chinese after 1990 were searched in PubMed/Medline, EMBASE, CINAHL, Web of Science, SinoMed and CQVIP. The incidence was expressed as Poisson means estimated as the number of events divided by time at risk. Random effect models calculated the pooled incidence and pooled case-fatality. Chi-squared trend tests evaluated change in the estimates over time. When possible, age standardised rates were calculated. Percent of variation across studies that was due to heterogeneity rather than chance was tested using the I2 statistic.The effect of covariates on heterogeneity was investigated using meta-regressions. Publication bias was tested using funnel plots and Egger’s tests.

Results

Overall, 72 studies were included. The pooled incidences of total stroke (TS), ischaemic stroke (IS) and haemorrhagic stroke (HS) were 468.9 (95% confidence interval (CI): 163.33–1346.11), 366.79 (95% CI: 129.66–1037.64) and 106.67 (95% CI: 55.96–203.33) per 100,000 person-years, respectively, varied according to the four economic regions (East Coast, Central China, Northeast and Western China) with the lowest rates detected in the East Coast. Increased trends over time in the incidence of TS and IS were observed (p<0.001 in both). One-month and three-to-twelve-month case-fatalities were 0.11 (95% CI: 0.04–0.18) and 0.15 (95% CI: 0.12–0.17), respectively for IS; and 0.36 (95% CI: 0.26–0.45) and 0.25 (95% CI: 0.18–0.32), respectively for HS. One-month case-fatality of IS and HS decreased over time for both (p<0.001). Three-to-twelve-month fatalities following IS increased over time (p<0.001). Publication bias was not found.

Conclusions

Regional differences in stroke incidence were observed with the highest rates detected in less developed regions. Although 1-month fatality following IS is decreasing, the increased trends in 3-12-month fatality may suggest an inappropriate long-term management following index hospital discharge.

Registration

Registration-URL: https://www.crd.york.ac.uk/prospero/; Reference code: CRD42020170724

Vitamin D as a Risk Factor for Multiple Sclerosis: Immunoregulatory or Neuroprotective?

Vitamin D insufficiency during childhood has been linked to the development of multiple sclerosis (MS), typically an adult-onset inflammatory demyelinating disease of the central nervous system (CNS). Since vitamin D was known to have immunoregulatory properties on both innate and adaptive immunity, it was hypothesized that low vitamin D resulted in aberrant immune responses and the development of MS. However, vitamin D receptors are present on many cell types, including neurons, oligodendrocytes, astrocytes and microglia, and vitamin D has profound effects on development and function of the CNS. This leads to the possibility that low vitamin D may alter the CNS in a manner that makes it vulnerable to inflammation and the development of MS. This review analysis the role of vitamin D in the immune and nervous system, and how vitamin D insufficiency in children may contribute to the development of MS.

Circulating 25-hydroxy-vitamin D and the risk of cardiovascular diseases. Systematic review and meta-analysis of prospective cohort studies

AIMS

Circulating vitamin D is linked with the risk of cardiovascular disease (CVD). A meta-analysis has yet to explicitly explore correlation between vitamin D and the risk of CVD incidence and recurrent CVD. This meta-analysis examines the association between 25-hydroxy-vitamin D (25(OH)D) and the risk of CVD incidence (fatal, non-fatal, fatal and non-fatal combined events) and the risk of recurrent CVD (fatal, recurrent, and fatal and recurrent combined events). PROSPERO registration-CRD42021251483.

DATA SYNTHESIS

A total of 79 studies (46 713 CVD cases in 1 397 831 participants) were included in the meta-analysis, of which 61 studies examined the risk of CVD incidence events, and 18 studies examined risk of recurrent CVD events. The risk of CVD incidence events (RR = 1.34, 95% CI: 1.26-1.43, p < 0.001) and recurrent CVD events (RR = 1.86, 95% CI: 1.46-2.36, p < 0.001) was higher in the lowest than the highest category of circulating 25(OH)D. Dose-response analysis reported a linear association for every 10 ng/ml increment of 25(OH)D and non-fatal CVD incidence events (RR = 0.94; 95% CI = 0.89-0.98, p = 0.005), lower fatal recurrent CVD events (RR = 0.45; 95% CI = 0.32-0.62, p < 0.001) and lower combined recurrent CVD events (RR = 0.80; 95% CI = 0.65-0.97, p = 0.023). A non-linear association was observed between higher 25(OH)D and lower fatal CVD incidence events (P-nonlinear<0.001), lower combined CVD incidence events (P-nonlinear = 0.001), and lower non-fatal recurrent CVD events (P-nonlinear = 0.044).

CONCLUSIONS

The lowest category of circulating 25(OH)D was associated with a higher risk of CVD incidence events and recurrent CVD events.

Effect of Vitamin D Supplementation on the Prognosis of Post-stroke Fatigue: A Retrospective Cohort Study

Objective: We aimed to evaluate the effect of vitamin D supplementation in post-stroke fatigue (PSF) patients with vitamin D deficiency on fatigue symptoms and outcomes. Methods: Patients with primary acute ischemic stroke (AIS) were recruited consecutively from July 2016 to June 2018. Post-stroke fatigue patients were screened out with the Fatigue Severity Scale (FSS) questionnaire, serum concentrations of 25-hydroxyvitamin D [25-(OH)-D] were assessed with enzyme-linked immunosorbent assay (ELISA), and neurological function was evaluated with FSS and modified Rankin Scale (mRS) scoring criteria. Post-stroke fatigue patients with vitamin D deficiency were divided into two groups: a study group in which patients received vitamin D supplementation (cholecalciferol, 600 IU/day) along with usual care, and a control group in which patients received usual care alone. At the end of 1 and 3 months after treatment, all PSE patients accepted re-measurement of serum vitamin D and re-evaluation of fatigue and neurological function. Results: A total of 532 AIS patients were consecutively recruited to participate in this study. Patients without PSF, non-vitamin D deficiency, pre-stroke fatigue, or vitamin D supplementation were excluded from the study. In addition, patients who were lost to follow-up were also excluded. Finally, 139 out of 532 (26.1%) patients with PSF and vitamin D deficiency received vitamin D supplementation treatment. Fatigue Severity Scale score was significantly lower in the study group than in the control group at 1 month (t = -4.731, p < 0.01) and 3 months (t = -7.937, p < 0.01) after treatment. One month after treatment, mRS score in the study group was lower than that in the control group without statistical difference (t = -0.660, p > 0.05), whereas mRS was significantly higher in the study group than in the control group at 3 months after treatment (t = -4.715, p < 0.01). Conclusions: Our results indicated that vitamin D supplementation could improve fatigue symptoms and neurological outcomes in PSF patients with vitamin D deficiency. Subject to replication in other settings, a randomized controlled trial (RCT) might be undertaken to validate the potential beneficial impact of vitamin D supplementation in post-stroke patients found to be vitamin D deficient.

Stroke-Induced Peripheral Immune Dysfunction in Vitamin D-Deficient Conditions: Modulation by Progesterone and Vitamin D

Vitamin D deficiency (Ddef) alters morphology and outcomes after a stroke. We investigated the interaction of Ddef following post-stroke systemic inflammation and evaluated whether administration of progesterone (P) or vitamin D (D) will improve outcomes. Ddef rats underwent stroke with lipopolysaccharide (LPS)-induced systemic inflammation. Rats were randomly divided into 9 groups and treated with P, D, or vehicle for 4 days. At day 4, rats were tested on different behavioral parameters. Markers of neuronal inflammation, endoplasmic reticulum stress, oxidative stress, white matter integrity, and apoptosis were measured along with immune cell populations from the spleen, thymus, and blood. Severely altered outcomes were observed in the Ddef group compared to the D-sufficient (Dsuf) group. Stroke caused peripheral immune dysfunction in the Dsuf group which was worse in the Ddef group. Systemic inflammation exacerbated injury outcomes in the Dsuf group and these were worse in the Ddef group. Monotherapy with P/D showed beneficial functional effects but the combined treatment showed better outcomes than either alone. Ddef as a comorbid condition with stroke worsens stroke outcomes and can delay functional recovery. Combination treatment with P and D might be promising for future stroke therapeutics in Ddef.

Risk Factors of Vitamin D Deficiency in Chinese Ischemic Stroke Patients: A Cross-Sectional Study

Purpose

Lower serum vitamin D has been reported to be associated with stroke. This study aimed to analyze the risk factors of vitamin deficiency in Chinese stroke patients, and further analyze its impact in different gender and their clinical variables.

Methods

982 stroke patients were enrolled. Laboratory parameters such as serum vitamin D, apolipoprotein A-I (ApoA-I), apolipoprotein B (ApoB), ApoA-I/ApoB, cholesterol (CH), fibrinogen (FIB), blood glucose (Glu), high-density lipoprotein (HDL), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) were collected and recorded. The severity of stroke was assessed by National Institute of Health Stroke Scale (NIHSS) score. Based on their serum vitamin D level, patients were divided into three groups: Vitamin D deficiency (<50 nmol/L), vitamin D insufficiency (≥50–75 nmol/L) and vitamin D sufficiency (≥75 nmol/L) and differences were compared among the three groups. Statistical analyses were done to assess the risk factors for serum vitamin D deficiency in our ischemic stroke patients.

Results

Gender, NIHSS, and FIB showed significant differences among the vitamin D groups (P < 0.001 ∼ P = 0.002). The female gender (OR = 2.422, P < 0.001), severity of stroke using NIHSS (OR = 1.055, P = 0.008) and FIB (OR = 1.256, P = 0.005) were risk factors of vitamin D deficiency in ischemic stroke patients. In subgroup analysis, NIHSS was significantly associated with vitamin D deficiency in the male group (OR = 1.087, P = 0.002) and higher FIB group (OR = 1.078, P = 0.001).

Conclusions

The female gender, severity of stroke using NIHSS and FIB were risk factors for vitamin D deficiency in our incident stroke patients. NIHSS was more sensitive to vitamin D deficiency in male ischemic stroke patients. Besides, under higher FIB circumstance, the increasing NIHSS score was more related to the vitamin D deficiency. Levels of vitamin D in patients with ischemic stroke should be well monitored during the disease cascade.

Vitamin D and Stroke: Effects on Incidence, Severity, and Outcome and the Potential Benefits of Supplementation

Vitamin D serum level has been positively associated with improved cardiovascular health, especially with reduction of stroke risk. This systemic review summarizes and synthesizes findings from studies relevant to the relationship between vitamin D and stroke risk, severity, and outcome; potential mechanisms explaining such a relationship; and outcomes from vitamin D supplementation. The literature shows that vitamin D deficiency is a significant risk factor for ischemic stroke, with sun exposure, sex, age, race, diabetes, and genetics playing a role as well. Stroke severity and short- and long-term outcomes also worsen with vitamin D deficiency. The neuroprotective mechanisms by which vitamin D operates to mitigate stroke onset and outcomes have yet to be fully studied, but researchers have proposed several pathways, including promotion of certain neuroprotective growth factors, reduction of arterial pressure through vasodilation, and inhibition of reactive oxygen species. There is some evidence that vitamin D supplementation could lower stroke risk and improve recovery, though outcomes can also be negligible or negative. Although results are mixed and the limitations of vitamin D supplementation merit some caution, vitamin D overall plays a significant role in stroke health. Future research should further develop understanding of the neuroprotective mechanisms of vitamin D and study how supplementation could be administered effectively in stroke treatment.

Prognostic utility of serum 25-hydroxyvitamin D in patients with stroke: a meta-analysis

BACKGROUND

Conflicting findings have been reported on the prognostic significance of serum 25-hydroxyvitamin D level in patients with stroke. The objective of this meta-analysis was to evaluate the prognostic utility of serum 25-hydroxyvitamin D in stroke patients.

METHODS

PubMed and Embase databases were systematically searched for potentially eligible studies until October 16, 2019. Observational studies investigating the association between serum 25-hydroxyvitamin D level and prognosis of patients with stroke were eligible. Multivariable adjusted risk ratios (RR) with 95% confidence intervals (CI) of poor functional outcome, all-cause mortality, and recurrence of stroke were pooled with the lowest versus the highest category of 25-hydroxyvitamin D level.

RESULTS

Eleven articles (ten studies) involving 6845 stroke patients satisfied our predefined inclusion criteria. Lower serum 25-hydroxyvitamin D level was associated with an increased risk of poor functional outcome (RR 1.86; 95% CI 1.16-2.98), all-cause mortality (RR 3.56; 95% CI 1.54-8.25), and recurrence of stroke (RR 5.49; 95% CI 2.69-11.23). Sensitivity analysis further confirmed the above findings.

CONCLUSIONS

Lower serum 25-hydroxyvitamin D level is significantly associated with poorer prognosis in stroke patients. Future prospective studies are warranted to verify the prognostic role and to examine the association in different subtypes of stroke.

Therapeutic potential of vitamin D in AGE/RAGE-related cardiovascular diseases

Cardiovascular diseases (CVDs) are among the leading threats to human health. The advanced glycation end product (AGE) and receptor for AGE (RAGE) signaling pathway regulates the pathogenesis of CVDs, through its effects on arterial stiffness, atherosclerosis, mitochondrial dysfunction, oxidative stress, calcium homeostasis, and cytoskeletal function. Targeting the AGE/RAGE pathway is a potential therapeutic strategy for ameliorating CVDs. Vitamin D has several beneficial effects on the cardiovascular system. Experimental findings have shown that vitamin D regulates AGE/RAGE signaling and its downstream effects. This article provides a comprehensive review of the mechanistic insights into AGE/RAGE involvement in CVDs and the modulation of the AGE/RAGE signaling pathways by vitamin D.

Serum vitamin D deficiency in subjects with severe acquired brain injury and relationship with functional severity

BACKGROUND

Vitamin D may be important for the development and function of the nervous system. Low serum vitamin D levels have been detected in several neurological diseases.

OBJECTIVE

To ascertain the relationship between 25(OH)D serum level and disability in subjects with severe acquired brain injury (sABI).

DESIGN

Prospective cross-sectional study Methods: Consecutive subjects with sABI admitted to neuro-rehabilitation were enrolled. A sample of subjects from the neurological ward was considered the control group. Vitamin D serum levels and blood parameters were measured at admission. Disability Rating Scale (DRS), Glasgow Outcome Scale (GOS), and Level of Cognitive Functioning (LCF) were used in assessing disability.

RESULTS

A total of 104 subjects (34 F, 70 M; mean age 53.9 ± 15.2 years) were enrolled: 54 (19 F, 35 M) with sABI and 50 (15 F, 35 M) subjects as control group. Deficient mean serum levels of vitamin D (19.2 ± 9.4 ng/mL) were detected in the subjects with sABI and a significant inverse correlation between vitamin D serum levels and DRS score was detected (p = 0.04).

CONCLUSION

Subjects with sABI showed vitamin D deficiency that might correlate to disability severity. The reason is unclear and might represent a secondary phenomenon resulting from the inflammatory process.

Vitamin D and cardiovascular disease

Vitamin D, a soluble steroid hormone synthesized in the skin after sun exposure, plays a crucial role in calcium metabolism and is also involved in cardiovascular pathophysiology. The aim of this review is to summarize the available evidence (a) on the association between endogenous vitamin D status and cardiovascular disease, and (b) on the effect of vitamin D supplementation on cardiovascular outcomes. Most studies have shown an inverse association between vitamin D levels and cardiovascular outcomes. Randomized controlled trials, however, do not consistently support a beneficial effect of vitamin D administration on cardiovascular health. Population characteristics, comorbid conditions such as diabetes, the overall population prevalence of cardiovascular disease, vitamin D status and the regimen of vitamin D supplementation may account for the conflicting results.

Vitamin D deficiency in relation to the poor functional outcomes in nondiabetic patients with ischemic stroke

To assess the hypothesis that vitamin D, reflected by 25-hydroxyvitamin D (25(OH) D) would be associated with higher risk of poor functional outcomes amongst nondiabetic stroke patients. The present study was conducted in Nanchang, China. Serum concentration of 25(OH) D and National Institutes of Health Stroke Scale (NIHSS) were measured at the time of admission. Functional outcome was measured by modified Rankin scale (mRS) at 1 year after admission. Multivariate analyses were performed using logistic regression models. The cut point of 25(OH) D level for vitamin D deficiency was 20 ng/ml. In the present study, 266 nondiabetic subjects with stroke were included; 149 out of the 266 patients were defined as vitamin D deficiency (56%). The poor outcome distribution across the 25(OH) D quartiles ranged between 64% (first quartile) and 13% (fourth quartile). In those 149 patients with vitamin D deficiency, 75 patients were defined as poor functional outcomes, giving a prevalence rate of 50% (95% confidence interval (CI): 42–58%). In multivariate analysis models, for vitamin D deficiency, the adjusted risk of poor functional outcomes and mortality increased by 220% (odds ratio (OR): 3.2; 95% CI: 1.7–4.2, P<0.001) and 290% (OR: 3.9; 95% CI: 2.1–5.8, P<0.001), respectively. Vitamin D deficiency is associated with an increased risk of poor functional outcome events in Chinese nondiabetic stroke individuals.