The effects of vitamin D administration on brain inflammatory markers in high fat diet induced obese rats

Neuroprotective effects of vitamin D in an Alzheimer's disease rat model: Improvement of mitochondrial dysfunction via calcium/calmodulin-dependent protein kinase kinase 2 activation of Sirtuin1 phosphorylation

Mitochondrial dysfunction is an early event in Alzheimer's disease (AD) pathogenesis. To assess the impact of vitamin D3 (Vit.D) on neurogenesis, we investigated its role in mitigating cognitive impairment and mitochondrial dysfunction through calcium/calmodulin-dependent protein kinase kinase 2 (CAMKK2)-mediated phosphorylation of Sirtuin1 (SIRT1) in an aluminum-chloride-D-galactose (AlCl3-D-gal)-induced AD rat model. Rats were distributed into four groups: control, AlCl3 + D-gal (10 + 60 mg/kg, ip), Vit.D (500 IU/kg, po), and AlCl3 + D-gal+Vit.D. Novel object recognition (NOR), Morris Water Maze, and passive avoidance (PA) tests were used to measure memory abilities. The hippocampal tissue was used to assess vitamin D3 receptor (VDR) and peroxisome-proliferator-activated-receptor-γ-coactivator-1α (PGC-1α) expression by quantitative real-time polymerase chain reaction (qRT-PCR), CAMKK2, p-SIRT1, phosphorylated-AMP-activated protein kinase (p-AMPK), dynamin-related-protein-1 (Drp1), and mitofusin-1 (Mnf1) proteins by western blot and Ca2+ levels, endothelial nitic oxide synthase (eNOS), superoxide dismutase (SOD), amyloid beta (Aβ), and phospho tau (p-Tau) via enzyme-linked immunosorbent assay(ELISA) in addition to histological and ultrastructural examination of rat's brain tissue. Vit.D-attenuated hippocampal injury reversed the cognitive decline and Aβ aggregation, and elevated p-Tau levels in the AlCl3 + D-gal-induced AD rat model. In AlCl3 + D-gal-exposed rats, Vit.D induced VDR expression, normalized Ca2+ levels, elevated CAMKK2, p-AMPK, p-SIRT1, and PGC-1α expression. Vit.D reduced Drp1, induced Mnf1, increased mitochondrial membrane potential, preserved mitochondrial structure, restored normal mitochondrial function, and retained normal eNOS level and SOD activity in AlCl3 + D-gal rats. In conclusion, our findings proved that Vit.D may ameliorate cognitive deficits in AlCl3 + D-gal-induced AD by restoring normal mitochondrial function and reducing inflammatory and oxidative stress via CAMKK2-AMPK/SIRT1 pathway upregulation.

Vitamin D, Alzheimer's disease and related dementia

Vitamin D has been proposed as a potential strategy to mitigate age-related cognitive decline and dementia, including Alzheimer's dementia, the predominant type of dementia. Rodent studies have provided insight into the potential mechanisms underlying the role of vitamin D in Alzheimer's disease and dementia. However, inconsistencies with respect to age, sex, and genetic background of the rodent models used poses some limitations regarding scientific rigor and translation. Several human observational studies have evaluated the association of vitamin D status with cognitive decline and dementia, and the results are conflicting. Randomized clinical trials of vitamin D supplementation have included cognitive outcomes. However, most of the available trials have not been designed specifically to test the effect of vitamin D on age-related cognitive decline and dementia, so it remains questionable how much additional vitamin D will improve cognitive performance. Here we evaluate the strengths and limitations of the available evidence regarding the role of vitamin D in AD, cognitive decline, dementia.

Molecular Regulation of the CNS by Vitamin D

Vitamin D is a lipid-soluble vitamin that can be found in some foods. It is also produced endogenously (in the presence of ultraviolet light), transported through the blood to the targets organs and this is the reason to consider vitamin D as a hormone. It is known that vitamin D has genomic and non-genomic effects. This review is focused mainly on the vitamin D receptors, the importance of vitamin D as a neuromodulator, the role of vitamin D in the pathophysiology of devastating neurological disorders such as Alzheimer's disease, multiple sclerosis, amyotrophic lateral sclerosis, Parkinson's disease and the benefit of vitamin D and its derivates in alleviating these disorders.

Severe Vitamin D Deficiency-A Possible Cause of Resistance to Treatment in Psychiatric Pathology

In the last few years, vitamin D functions have been studied progressively, and along with their main role in regulating calcium homeostasis, the potential function in the nervous system and the link between different psychiatric disorders and vitamin D deficiency have been revealed. The discovery of vitamin D receptors in multiple brain structures, like the hippocampus, led to the hypothesis that vitamin D deficiency could be responsible for treatment resistance in psychiatric diseases. The aim of this study was to analyze the current knowledge in the literature regarding vitamin D deficiency among individuals afflicted with psychiatric disorders and assess the potential therapeutic benefits of vitamin D supplementation. A systematic search was conducted on the PubMed database for articles published in the last five years (2016-2022) in English, focusing on human subjects. Results show that vitamin D deficiency has implications for numerous psychiatric disorders, affecting mood and behavior through its influence on neurotransmitter release, neurotrophic factors, and neuroprotection. It also plays a role in modulating inflammation, which is often elevated in psychiatric disorders. In conclusion, vitamin D deficiency is prevalent and has far-reaching implications for mental health. This review underscores the importance of exploring the therapeutic potential of vitamin D supplementation in individuals with psychiatric disorders and highlights the need for further research in this complex field.

The association between screen use and central obesity among children and adolescents: a systematic review and meta-analysis

Currently, there is no summative study evaluating the association between central obesity and screen time. This systematic review and meta-analysis aimed to summarize the results of studies evaluating the association between screen time and central obesity among children and adolescents. To this end, we performed a systematic search in three electronic databases, including Scopus, PubMed, and Embase to retrieve the related studies up to March 2021. Nine studies were eligible to be included in the meta-analysis. There was no association between odds of central obesity and screen time [odds ratio (OR) 1.136; 95% CI 0.965-1.337; P = 0.125]; however, waist circumference (WC) was 1.23 cm higher in those with highest screen time versus those in the lowest screen time category [weighted mean difference (WMD) = 1.23; 95% 95% CI 0.342-2.112; P = 0.007; Fig. 3]. Moreover, the possible sources of heterogeneity in the included studies were continent and sample size. No evidence of publication bias was reported. For the first time, the current systematic review and meta-analysis revealed that those with the highest screen time had higher WC compared with those with the lowest screen time. Although, there was no association between odds of central obesity and screen time. Due to the observational design of the included studies, it is impossible to infer the cause-effect relationship. Therefore, further interventional and longitudinal studies are warranted to better elucidate the causality of these associations.

Sea buckthorn polysaccharide ameliorates high-fat diet induced mice neuroinflammation and synaptic dysfunction via regulating gut dysbiosis

Currently, definitive treatment for neurodegenerative diseases without side effects has not been developed, therefore, exploring natural polysaccharides with neuroprotection to prevent the occurrences and progressions of cognitive dysfunctions has important significance. The purpose of this study was to investigate the effects of sea buckthorn polysaccharide (SBP) on high-fat diet (HFD) induced mice cognitive dysfunctions and attempted to explore its biological mechanisms. Behavior tests (Y-maze and Barnes maze) suggested that SBP effectively alleviated the HFD induced behavioral disorders, which was in accordance with the inhibition of neuroinflammation via suppressing the NF-κB pathway and amelioration of synaptic dysfunction via upregulating CREB/BDNF/TrkB pathway in mice brain. Furthermore, SBP alleviated the gut barrier impairment, inflammatory responses, and lipopolysaccharide invasion into blood circulation via regulating the gut microbiome structure, especially correcting the reduction of Ileibacterium and increase of Lactobacillus, Dubosiella, Olsenella, Helicobacter, and Ruminiclostridium_9 in HFD mice. Therefore, the reversal effects of SBP on gut dysbiosis might be the important reason for its positive effects on cognitive dysfunction induced by HFD in mice.

Supplementation of Vitamin D and Mental Health in Adults with Respiratory System Diseases: A Systematic Review of Randomized Controlled Trials

Vitamin D is indicated to be beneficial for the prevention and treatment of both respiratory health and mental health problems, while mental health issues are a common consequence of diseases of the respiratory system. The aim of the presented systematic review was to gather available evidence regarding the influence of the supplementation of vitamin D on mental health in adults with respiratory system diseases obtained within randomized controlled trials (RCTs). The systematic review was conducted on the basis of the PubMed and Web of Science databases in agreement with the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), while being registered within the database of the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42020155779). A total of 8514 studies published before September 2021 were screened and 5 RCTs were included, which were assessed using the revised Cochrane risk-of-bias tool for randomized trials. Screening, inclusion, reporting, and assessment were conducted by two researchers independently. The studies focused on the assessment of patients with chronic obstructive pulmonary disease, but also increased susceptibility to respiratory tract infections, pulmonary tuberculosis, and bronchial asthma. The studies were conducted for various periods of time-from 2 months to a year-while the dose of vitamin D applied was also diverse-from 4000 IU applied daily, to 100,000 IU applied weekly, or monthly. The psychological measures applied within the studies allowed the assessment, mainly, of quality of life, but also well-being, and depression. For the majority of studies, some concerns regarding risk of bias were defined, resulting from the randomization process and selection of reported results; however, for one study, the risk was even defined as high. Within the included studies, three studies confirmed a beneficial effect of vitamin D (including those with a high risk of bias), but two studies did not confirm it. Taking into account the evidence gathered, in spite of a positive influence of vitamin D on mental health in individuals with increased susceptibility to respiratory tract infections and bronchial asthma, the conducted systematic review is not a strong confirmation of the beneficial effect of the supplementation of vitamin D on mental health in adults with respiratory system diseases.

Vitamin D improves hepatic steatosis in NAFLD via regulation of fatty acid uptake and β-oxidation

INTRODUCTION

The study aimed to explore the association of serum 25(OH)D₃ and hepatic steatosis in non-alcoholic fatty liver disease (NAFLD) patients and to determine whether the effect of vitamin D (VD) is mediated by activation of the peroxisome proliferator-activated receptor α (PPARα) pathway.

METHODS

The study contained a case-control study, in vivo and in vitro experiments. A case-control study was conducted to compare serum parameters between NAFLD patients and controls and to evaluate the association of 25(OH)D₃ and NAFLD. In vivo study, male Wistar rats were randomly divided into control and model groups, fed a standard chow diet and a high-fat diet (HFD), respectively, for 7 weeks to generate an NAFLD model. Then, the rats were treated with VD and a PPARα antagonist (MK886) for 7 weeks. Tissue and serum were collected and assessed by biochemical assays, morphological analysis, histological analysis, and western blot analysis. In vitro, HepG2 cells were incubated with oleic acid (OA) to induce steatosis, which was evaluated by staining. HepG2 cells were pretreated with MK886 followed by calcitriol treatment, and differences in lipid metabolism-related proteins were detected by western blot.

RESULTS

NAFLD patients were characterized by impaired liver function, dyslipidemia, and insulin resistance. Serum 25(OH)D₃ was negatively associated with alanine aminotransferase (ALT) in NAFLD. VD deficiency was a risk factor for patients with no advanced fibrosis. Adequate VD status (25(OH)D₃ >20 ng/mL) had a protective effect in patients after adjustment for confounding variables. NAFLD rats showed hyperlipidemia with severe hepatic steatosis, systematic inflammation, and lower serum 25(OH)D₃. VD treatment ameliorated hepatic steatosis both in NAFLD rats and OA-induced HepG2 cells. Further, MK886 inhibited the anti-steatosis effect of VD.

CONCLUSION

The study revealed that an adequate VD level may act as a protective factor in NAFLD and that VD may alleviate hepatic steatosis via the PPARα signaling pathway.

Vitamin D3 supplementation ameliorates cognitive impairment and alters neurodegenerative and inflammatory markers in scopolamine induced rat model

A multifaceted approach can be effective for the treatment of dementia including the most common form, Alzheimer's disease (AD). However, currently, it involves only symptomatic treatment with cholinergic drugs. Beneficial effects of high Vitamin D₃ levels or its intake in the prevention and treatment of cognitive disorders have been reported. Thus, the present study examined the preventive effect of Vitamin D₃ (Calcitriol) supplementation on cognitive impairment and evaluated its impact on the accumulation or degradation of Aβ plaques. A single intraperitoneal injection of scopolamine was used to induce cognitive impairment in rats. Treatment of Vitamin D₃ was provided for 21 days after the injection. Various behavioral parameters like learning, spatial memory and exploratory behavior, biochemical alterations in the brain homogenate and histology of the hippocampus were investigated. Our results indicated that scopolamine-induced rats depicted cognitive deficits with high Aβ levels and hyperphosphorylated tau proteins in the brain tissue, while Vitamin D supplementation could significantly improve the cognitive status and lower these protein levels. These results were supported by the histopathological and immunohistochemical staining of the hippocampal brain region. Furthermore, mechanistic analysis depicted that Vitamin D supplementation improved the Aβ protein clearance by increasing the neprilysin levels. It also reduced the accumulation of Aβ plaques by lowering neuroinflammation as well as oxidative stress. The present findings indicate that Vitamin D₃ supplementation can ameliorate cognitive deficits and thereby delay AD progression by increasing Aβ plaque degradation, reducing inflammation and oxidative stress.

Vitamin D supplementation combined with aerobic physical exercise restores the cell density in hypothalamic nuclei of rats exposed to monosodium glutamate

BACKGROUND & AIMS

In view of the increase in the prevalence of obesity and metabolic syndrome in childhood and adolescence, this study proposed the early and combined use of treatments to restore brain areas related to satiety. The vitamin D supplementation, aerobic exercise and the combination of these interventions on the structure of arcuate (ARC) and ventromedial (VMH) nuclei of hypothalamus were investigated in monosodium glutamate (MSG)-treated rats.

METHODS

Wistar rats were separated into five groups: Control group (CT); Obese group injected with MSG (OB); Obese group supplemented with vitamin D (OBvd); Obese group submitted to forced swimming training (OBexe) and Obese group treated with vitamin D supplementation and forced swimming training (OBvd + exe).

RESULTS

In the OB group, the visceral fat weight was significantly higher, there was a reduction in the number of glial cells in the ARC nucleus and also in the number of neurons in the ARC and VMH nuclei. Aerobic exercise was able to reduce the visceral fat weight in the OBexe group. The combination of treatments used in the OBvd + exe group reversed the loss of neurons and glial cells produced by MSG in the ARC nucleus. All treated groups exhibited a higher number of neurons in VMH nucleus, but an increase in the glial cells were observed only in the OBexe and OBvd + exe groups.

CONCLUSIONS

The effectiveness of obesity treatment can be favored through the early and combined use of vitamin D supplementation and aerobic exercise, since these therapies are able to restore brain nuclei involved in the control of food intake.

Vitamin D3 exerts immunomodulatory and memory improving properties in rats with lipopolysaccharide-induced inflammation

INTRODUCTION

Vitamin D is a fat-soluble secosteroid, its primary function being regulation of calcium-phosphate homeostasis and maintenance of bone integrity and mineralization. Recently, pleotropic effects of this vitamin have been recognized, including an immunomodulatory role and involvement in normal brain development and functioning.

Vitamin D Mitigates Hyperglycemia-Induced Cognition Decline in Danio rerio (Zebrafish) through the Activation of Antioxidant Mechanisms

Hyperglycemia contributes to the development of cognition impairment and related disorders, induces oxidative stress in neuronal cells; thereby, impairs normal signaling mechanisms involved in cognition processes. Studies have shown a significant decrease in the vitamin D in individuals with hyperglycemia and cognition impairment. But whether supplementing vitamin D has any beneficiary impact on mitigating hyperglycemia-induced cognition impairment is unknown. We have first tested the impact of hyperglycemia on the induction of cognition deficiency in a zebrafish model. Next, the molecular mechanisms related to oxidative stress, which are deregulated in hyperglycemic zebrafish brains, have been explored. Subsequently, the impact of supplementing the water with vitamin D and a known activator of nuclear factor erythroid-2 related factor 2 (Nrf2) i.e., sulforaphane (SFN) on learning and memory functions were assessed. We showed a significant increase in the oxidative stress in the brain tissue of zebrafish residing in hyperglycemic water (111 mM glucose). Addition of vitamin D and SFN increased Nrf2, but differentially modulated its target genes (NQO1, SOD, GPx etc) activity in zebrafish and neuronal cell lines thereby improved the hyperglycemia-induced decline of cognition impairment. Mechanistically, vitamin D binds to the Keap1 protein; thereby, interfering with its binding to Nrf2, which leads to the activation of antioxidant mechanisms in the cells. In summary, reducing the oxidative stress through vitamin D treatment is a possible option for controlling the cognition impairment in diabetic population, but studies testing this possibility in clinical trials are currently needed.

Interrelationship between Vitamin D and Calcium in Obesity and Its Comorbid Conditions

Obesity has been linked to vitamin D (VD) deficiency and low calcium (CAL) status. In the last decade, dietary supplementation of vitamin D and calcium (VD–CAL) have been extensively studied in animal experiments and human studies. However, the physiological mechanisms remain unknown as to whether the VD–CAL axis improves homeostasis and reduces biomarkers in regulating obesity and other metabolic diseases directly or indirectly. This review sought to investigate their connections. This topic was examined in scientific databases such as Web of Science, Scopus, and PubMed from 2011 to 2021, and 87 articles were generated for interpretation. Mechanistically, VD–CAL regulates from the organs to the blood, influencing insulin, lipids, hormone, cell, and inflammatory functions in obesity and its comorbidities, such as non-alcoholic fatty liver disease, cardiovascular disease, and type-2 diabetes mellitus. Nevertheless, previous research has not consistently shown that simultaneous VD–CAL supplementation affects weight loss or reduces fat content. This discrepancy may be influenced by population age and diversity, ethnicity, and geographical location, and also by degree of obesity and applied doses. Therefore, a larger prospective cohort and randomised trials are needed to determine the exact role of VD–CAL and their interrelationship.

Effect of vitamin D supplementation on the incidence and prognosis of depression: An updated meta-analysis based on randomized controlled trials

Background

There have been several controversies about the correlation between vitamin D and depression. This study aimed to investigate the relationship between vitamin D supplementation and the incidence and prognosis of depression and to analyze the latent effects of subgroups including population and supplement strategy.

Methods

A systematic search for articles before July 2021 in databases (PubMed, EMBASE, Web of Science, and the Cochrane Library) was conducted to investigate the effect of vitamin D supplementation on the incidence and prognosis of depression.

Results

This meta-analysis included 29 studies with 4,504 participants, indicating that the use of vitamin D was beneficial to a decline in the incidence of depression (SMD: −0.23) and improvement of depression treatment (SMD: −0.92). Subgroup analysis revealed that people with low vitamin D levels (<50 nmol/L) and females could notably benefit from vitamin D in both prevention and treatment of depression. The effects of vitamin D with a daily supplementary dose of >2,800 IU and intervention duration of ≥8 weeks were considered significant in both prevention and treatment analyses. Intervention duration ≤8 weeks was recognized as effective in the treatment group.

Conclusion

Our results demonstrate that vitamin D has a beneficial impact on both the incidence and the prognosis of depression. Whether suffering from depression or not, individuals with low vitamin D levels, dose >2,800 IU, intervention duration ≥8 weeks, and all females are most likely to benefit from vitamin D supplementation.

Effect of Different Vitamin D Levels on Cognitive Function in Aged Mice After Sevoflurane Anesthesia

Although the biological relationship between vitamin D (VD) deficiency and cognitive function has been recognized by many scholars, the theoretical mechanisms involved are still not well-understood. In this study, we demonstrated the role of VD in alleviating the cognitive dysfunction in aged mice caused by sevoflurane anesthesia. Forty female C57BL/6 mice aged 12 months were selected for the experiment. VD (-) and VD (+) mouse models and sevoflurane anesthesia models were established. Mice were randomly divided into normal elderly group (NC group), normal aged mice + sevoflurane anesthesia treatment group (NS group), aged VD (-) mice + sevoflurane anesthesia treatment group [VD (-) group], and aged VD (+) + sevoflurane anesthesia treatment group [VD (+) group]. To compare the emergence time after sevoflurane anesthesia in aged mice with different levels of VD and to test the cognitive function of four groups through the water maze. Inflammatory factor expression and cholinergic activity in hippocampus tissue of all mice were measured at the end of behavioral tests. These data show that, low levels of VD aggravated the delayed emergence and cognitive dysfunction in aged mice caused by sevoflurane anesthesia, while higher levels of VD mitigated this impairment by enhancing cholinergic activity and reducing inflammatory factor expression in the hippocampus.

Vitamin D level in relation to depression symptoms during adolescence

BACKGROUND

This study aimed to investigate the association between 25-hydroxyvitamin D (25(OH)D) and depression symptoms among adolescents in Kuwait, a country with a high prevalence of vitamin D deficiency.

METHODS

A school based cross-sectional study was conducted on randomly selected 704 adolescents in middle schools. Data on depression symptoms were collected using the Children's Depression Inventory (CDI). Data on covariates were collected from the parents by self-administered questionnaire and from adolescents by face-to-face interview. Blood samples were analyzed in an accredited laboratory; and 25(OH)D was measured using liquid chromatography-tandem mass spectrometry.

RESULTS

Of 704 adolescents, 94 (13.35%; 95%CI:10.35-17.06%) had depression symptom (a score of 19 or more on the CDI). There was no significant difference in the median CDI score between different vitamin D status (p = 0.366). There was also no significant correlation between serum 25(OH)D concentration and CDI score (Spearman's rank correlation = 0.01; p = 0.825).There was no significant association between 25(OH)D and depression symptoms whether 25(OH)D was fitted as a continuous variable (crude odds ratio (OR) 0 .99 [95%CI: 0.98, 1.01], p = 0.458 and adjusted OR 1.01 [95%CI: 0.99, 1.02], p = 0.233), categorical variable as per acceptable cut-of points (crude analysis p = 0.376 and adjusted analysis p = 0.736), or categorical variable as quartiles (crude analysis p = 0.760 and adjusted analysis p = 0.549).

CONCLUSION

Vitamin D status does not seem to be associated with depression symptoms among adolescents in our setting. Nevertheless, it is important to have sufficient vitamin D levels during adolescence for several other health benefits.

Vitamin D3 intake as modulator for the early biomarkers of myocardial tissue injury in diabetic hyperlipidaemic rats

CONTEXT

Myocardial cell death occurs within hours following the onset of myocardial ischaemia and its chief cause is atherosclerosis. There is a link between vitamin D3 deficiency and many cardiovascular risk factors.

OBJECTIVE

This study compared the effect of vitamin D3 on early biomarkers of myocardial injury, to that of atorvastatin.

METHODS

Diabetic hyperlipidaemia was induced in Wistar rats, which were divided into 3 groups: diabetic hyperlipidaemic control, diabetic hyperlipidaemic rats treated with atorvastatin and diabetic hyperlipidaemic rats treated with vitamin D3. Blood glucose, glycated haemoglobin and lipid profile were evaluated. Markers of myocardial injury were examined including cardiac troponin, heart fatty acid binding protein (HFABP) and C-terminal pro-endothelin-1 (CT-pro-ET-1).

RESULTS

Vitamin D3 and atorvastatin intake improved lipid profile and glucose homeostasis, and reduced levels of predictive biomarkers of myocardial injury.

CONCLUSION

Vitamin D3 can be used in a suitable dose as a safe and protective candidate against myocardial injury.

Maternal vitamin D supplementation and treadmill exercise attenuated vitamin D deficiency-induced anxiety-and depressive-like behaviors in adult male offspring rats

BACKGROUND

Vitamin D is a vital neuroactive steroid for brain development and function. Vitamin D deficiency is a worldwide health problem, particularly in children and women. Gestational or developmental vitamin D deficiency is associated with an increased risk of neurodevelopmental and neuropsychiatric disorders. This study examined the effect of maternal vitamin D dietary manipulations and treadmill exercise on anxiety-and depressive-related behaviors, pro-inflammatory cytokines, and prefrontal cortex (PFC) protein levels of brain-derived neurotrophic factor (BDNF) and vitamin D receptor (VDR) in adult male offspring born to vitamin D-deficient diet (VDD)-fed dams.

METHODS AND RESULTS

Female rats were provided standard diet (SD) or VDD for six weeks and then were treated with SD (started a week before mating throughout gestation and lactation) and treadmill exercise (a week before mating until gestational day 20). Male offspring were separated on postnatal day (PND) 21 and fed SD chow until PND90. Our results demonstrated that maternal vitamin D deficiency increased anxiety and depression-related behaviors, increased levels of TNF-α and IL-1β in serum, and decreased prefrontal protein expressions of BDNF and VDR in adult male offspring. However, maternal vitamin D supplementation and treadmill exercise reversed these changes alone or in combination.

CONCLUSION

It seems that developmental vitamin D deficiency disrupts brain development and has a long-lasting effect on VDR and BDNF signaling in the rat brain resulting in neuropsychiatric disorders in offspring. Therefore, vitamin D supplementation and physical exercise are reasonable strategies to prevent these neurobehavioral impairments.

Adherence to the Mediterranean diet and subjective well-being among Chilean children

Scientific literature has demonstrated positive associations between psychological health (e.g., self-esteem, self-concept) and quality of diet in young population. However, the relationship between subjective well-being (SWB) (referred to the way in which individuals experience and evaluate their lives in positive versus negative ways) and adherence to the MD, as well as the specific eating MD patterns in this population is unexplored. The aim of this study was two-fold: first, to explore the association between subjective well-being (SWB) and adherence to the MD, and second, to determine the possible MD specific eating patterns that could be associated with SWB among Chilean schoolchildren. This cross-sectional study includes a sample of 1490 children aged 8-12 (33.6% girls). SWB was evaluated according to Diener's tripartite model, evaluating the life satisfaction (CUBE questionnaire), positive affect and negative affect (PANAS-C8 questionnaire). Adherence to the MD was assessed by the Mediterranean Diet Quality Index for Children and Adolescents (KIDMED) questionnaire. Both life satisfaction (p = 0.009) and positive affect (p = 0.041) are significant higher in children with high adherence to the MD in comparison to non-adherence peers. Similarly, daily intake of fruit or fruit juice was associated with life satisfaction (β = 0.117, p = 0.008) and positive affect (β = 0.087, p = 0.050). This association was also found for the intake of a dairy product for breakfast (life satisfaction: β = 0.117, p = 0.005; positive affect: β = 0.104, p = 0.013). Our study demonstrated that higher life satisfaction and SWB are related with higher adherence to the MD, as well as, with the intake of fruit/fruit juice and dairy intake (for breakfast); not being so for negative affect.

Vitamin D Combined with Pioglitazone Mitigates Type-2 Diabetes-induced Hepatic Injury Through Targeting Inflammation, Apoptosis, and Oxidative Stress

Inflammation is a major pathophysiological factor in development of type-2 diabetes mellitus (T2DM). Vitamin D (VITD) plays an imperative role in modulation of several inflammatory responses. The current study aimed to investigate the possible beneficial effects of coadministration of VITD with pioglitazone (PIO), a PPAR-γ agonist, in fructose/streptozotocin (F/STZ) T2DM model in male Wistar rats. T2DM was induced by maintaining rats on 10% (w/v) fructose in drinking water for 9 weeks with an intraperitoneal injection of sub-diabetogenic dose of STZ (35 mg/kg) by the end of the fourth week. One week after STZ injection, PIO (10 mg/kg/day) alone or with VITD (500 IU/kg/day) was administered orally to diabetic rats till the end of the experiment. Blood samples were collected, livers were homogenized to determine biochemical parameters, and samples of livers were fixed in 10% formalin in saline for histological examination. Administration of PIO alone improved diabetes-induced inflammatory and oxidative states besides controlling hyperglycemia and decreasing apoptosis. Coadministration of VIT D with PIO promoted additional improvement in glycemic and lipid profiles, provided further control on diabetic-induced hepatic inflammation evident by downregulating TLR2, TLR4, and IKK-β while upregulating IκB-α expression and reducing inflammatory cytokines namely; NF-κB, TNF-α, IL-6, and IL-1β, decreasing apoptosis and oxidative stress by hampering caspase-3 and MDA contents, respectively, and improved liver histology than PIO alone. These beneficial effects of VIT D may expand its use by diabetics combined with antidiabetic drugs due to its anti-inflammatory, antioxidant, and antiapoptotic properties.

Maternal vitamin D administration attenuates metabolic disturbances induced by prenatal exposure to dexamethasone in a sex-dependent manner

PURPOSE

The overexposure to synthetic glucocorticoids (GC) during pregnancy can predispose to metabolic diseases during adulthood. Vitamin D is not only crucial for fetal development, but also exerts direct effects on the GC sensitivity and down-regulates GC receptors. Given the vitamin D effects on glucocorticoid-related parameters, we aimed to investigate a possible protective role of maternal vitamin D administration on the glucose homeostasis of rats exposed to dexamethasone in utero.

METHODS

Pregnant rats received dexamethasone (0.1 mg/kg, Dex) daily between the 14th and 19th days of pregnancy. A subgroup of dexamethasone-treated dams received oral administration of vitamin D (500UI, DexVD) during the whole gestation. The corresponding control groups of dams were included (CTL and VD groups, respectively). Male and female offspring were evaluated at 3, 6 and 12 months of age.

RESULTS

Prenatal exposure to dexamethasone caused metabolic disruption in an age and sex-dependent manner being the older male offspring more susceptible to insulin resistance, fatty liver and beta-cell mass expansion than females. Furthermore, we demonstrated that prenatal GC led to glucose intolerance in male and female offspring in an age-dependent manner. Maternal vitamin D administration did not influence glucose intolerance but attenuated the insulin resistance, liver lipid accumulation and prevented the beta-cell mass expansion caused by prenatal dexamethasone in the male offspring.

CONCLUSION

Maternal vitamin D administration mitigates metabolic disturbances that occur later in life in male rats exposed to GC in utero. Moreover, our data suggest vitamin D as an important nutritional supplement for pregnant overexposed to GC during gestation.

Cellular Senescence and Vitamin D Deficiency Play a Role in the Pathogenesis of Obesity-Associated Subclinical Atherosclerosis: Study of the Potential Protective Role of Vitamin D Supplementation

The exact link between obesity, vitamin D deficiency, and their relation to cellular senescence in the pathogenesis of subclinical atherosclerosis is still under debate. Therefore, the current study aims to verify the possible role of vitamin D deficiency and cellular senescence in the pathogenesis of obesity-related subclinical atherosclerosis. Moreover, it aims to investigate the possible protective role of vitamin D supplementation. Fifty-seven male albino rats were enrolled in the study and classified into four groups: negative (10) and positive control groups (10), an obese model group (24), and a vitamin-D-supplemented obese group (13). Aortic tissue samples and fasting blood samples were collected. The following biochemical investigations were performed: serum cholesterol, triglycerides, HDL-C, LDL-C, ALT, AST, CPK, CK-MB, and hs-cTnt. HOMA-IR was calculated. Moreover, serum SMP-30, 25 (OH)Vitamin D3, and eNOS were determined by the ELISA technique. Aortic gene expression of eNOS, SMP-30, and P53 was estimated by real-time qRT-PCR. Serum 25(OH) D3 and SMP-30 were lower in the obese group. In addition, the obese group showed higher serum lipid profile, HOMA-IR, eNOS, ALT, AST, CPK, CK-MB, and hs-cTnt than the control groups, while decreased levels were found in the vitamin-D-treated obese group. Gene expression of eNOS and SMP-30 were in accordance with their serum levels. A positive correlation was found between vitamin D level and SMP-30. In conclusion, obesity is associated with vitamin D deficiency and enhanced cellular senescence. They could play a role in the pathogenesis of obesity-associated subclinical atherosclerosis and endothelial dysfunction. Vitamin D supplements could play a protective role against such obesity-related comorbidity.

Association of vitamin D metabolites with cognitive function and brain atrophy in elderly individuals - the Austrian stroke prevention study

BACKGROUND

Vitamin D is a well-established regulator of calcium and phosphate metabolism that has neurotrophic and neuroprotective properties. Deficiency of vitamin D has been proposed to promote cognitive dysfunction and brain atrophy. However, existing studies provide inconsistent results. Here we aimed to investigate the association between vitamin D metabolites, cognitive function and brain atrophy in a cohort of well-characterized community-dwelling elderly individuals with normal neurological status and without history of stroke and dementia.

METHODS

25(OH)D3, 25(OH)D2 and 24,25(OH)2D3 were measured by liquid-chromatography tandem mass-spectrometry in serum samples from 390 community-dwelling elderly individuals. All participants underwent thorough neuropsychiatric tests capturing memory, executive function and visuopractical skills. In 139 of these individuals, MRI of the brain was performed in order to capture neurodegenerative and vascular changes.

RESULTS

Total 25(OH)D (ß=0.003, 0.037), 24,25(OH)2D3 (ß=0.0456, p=0.010) and vitamin D metabolite ratio (VMR) (ß=0.0467, p=0.012) were significantly related to memory function. Adjustment for multiple testing weakened these relationships, but trends (p≤0.10) remained. 24,25(OH)2D3 and VMR showed similar trends also for visuopractical skills and global cognitive function. No significant relationships existed between vitamin D metabolites and MRI derived indices of neurodegeneration and vascular changes. Sub-group analyses of individuals with low concentrations of 25(OH)D and 24,25(OH)2D3 showed significantly worse memory function compared to individuals with normal or high concentrations.

CONCLUSIONS

Vitamin D deficient individuals appear to have a modest reduction of memory function without structural brain atrophy. Future studies should explore if vitamin D supplementation can improve cognitive function.

The Influence of Vitamin D Intake and Status on Mental Health in Children: A Systematic Review

A potential role of vitamin D in some components of mental health is currently suggested, but the analyses are conducted mainly for adults, while for young individuals mental health is especially important, due to its lifelong effects. The aim of the study was to analyze the association between vitamin D intake or status and mental health in children within a systematic review of literature, including both intervention and observational studies. The literature search was conducted according to the PRISMA guidelines and it covered peer-reviewed studies included in databases of PubMed and Web of Science until October 2019. The studies presenting either vitamin D intake, or vitamin D status in human subjects were allowed (excluding subjects with intellectual disabilities, eating disorders and neurological disorders), while for mental health the various methods of assessment and wide scope of factors were included. The bias was assessed using the Newcastle-Ottawa Scale (NOS). The review was registered in the PROSPERO database (CRD42020155779). A number of 7613 studies after duplicate removing were extracted by two independent researchers, followed by screening and assessment for eligibility, conducted by two independent researchers in two steps (based on title and abstract). Afterwards, the full texts were obtained and after reviewing, a number of 24 studies were included. The synthetic description of the results was prepared, structured around exposure (vitamin D supplementation/status) and outcome (components of mental health). The included studies were conducted either in groups of healthy individuals, or individuals with mental health problems, and they assessed following issues: behavior problems, violence behaviors, anxiety, depressive symptoms/depression, aggressive disorder, psychotic features, bipolar disorder, obsessive compulsive disorder, suicidal incident, as well as general patterns, as follows: mental health, level of distress, quality of life, well-being, mood, sleep patterns. The vast majority of assessed studies, including the most prominent ones (based on the NOS score) supported potential positive influence of vitamin D on mental health in children. As a limitation of the analysis, it should be indicated that studies conducted so far presented various studied groups, outcomes and psychological measures, so more studies are necessary to facilitate comparisons and deepen the observations. Nevertheless, vitamin D intake within a properly balanced diet or as a supplementation, except for a safe sun exposure, should be indicated as an element supporting mental health in children, so it should be recommended to meet the required 25(OH)cholecalciferol blood level in order to prevent or alleviate mental health problems.

Early myocardial injury biomarkers in diabetic hyperlipidemic rats: Impact of 10-dehydrogingerdione and vitamin D3

IMPACT STATEMENT

Hyperlipidemia represents a major risk factor for cardiovascular diseases leading to myocardial injury (MI). The present study aimed to illustrate the pattern of myocardial injury induced in diabetic hyperlipidemic rat model and the effect of vitamin D3, 10-dehydrogingerdione (10-DHGD) intake either individually or in combination form.

High mobility group box-1 mediates hippocampal inflammation and contributes to cognitive deficits in high-fat high-fructose diet-induced obese rats

High-fat high-sugar diet-induced obesity can lead to hippocampal inflammation and cognitive deficits, but the detailed underlying mechanism is still not clear. We aim to investigate the role of HMGB1 in hippocampal inflammatory responses and cognitive impairment in high-fat high-fructose diet (HFHFD)-induced obesity. Rats were fed with a normal control diet or an HFHFD diet for 14 weeks. In the last 6 weeks on the diets, the rats were treated with control, or an HMGB1 inhibitor glycyrrhizin, or an anti-HMGB1 neutralizing monoclonal antibody (mAb). Obesity was induced in the HFHFD-fed rats, which had higher body weight, epididymal white adipose tissue (EWAT) weight and caloric efficiency, and lower brain/body weight ratio, glucose tolerance and insulin sensitivity than the ones on normal diets. In the HFHFD-induced obese rats, the HMGB1 levels in plasma and hippocampus were increased, and the nucleus-to-cytoplasm translocation of HMGB1 was promoted. The hippocampal inflammatory responses were enhanced in the HFHFD-induced obesity, including the activation of TLR4 and NF-κB, the production of IL-1β, TNF-α and IL-6, as well as the activation of microglia and astrocytes. In addition, the hippocampal cell apoptosis and cognitive impairment were observed in the HFHFD-fed rats. The treatment with glycyrrhizin or HMGB1 mAb successfully decreased the HMGB1 levels in plasma and hippocampus, and prevented the HMGB1 translocation from the nucleus to cytoplasm. Inhibiting HMGB1 by glycyrrhizin or HMGB1 mAb suppressed the hippocampal inflammatory, alleviated the apoptosis and ameliorated the cognitive impairment in HFHFD-fed rats. These findings indicate that HMGB1 mediates the hippocampal inflammation and contributes to the cognitive deficits in HFHFD-induced obesity. Therefore, inhibition of HMGB1 may have beneficial effect in protecting against hippocampal inflammation and cognitive deficits in dietary obesity.

Vitamin D deficiency in school-age Iranian children with attention-deficit/hyperactivity disorder (ADHD) symptoms: A critical comparison with healthy controls

The associations between serum vitamin D levels and the severity of attention-deficit/hyperactivity disorder (ADHD) symptoms were assessed among Iranian hospitalized children (50 ADHD cases and 50 healthy (non-ADHD) controls) during 2014-2015. Levels of ADHD severity and serum 25-hydroxyvitamin D (25OHD) were determined by the Conners' Parent Rating Scale (CPRS) test and an ELISA kit, respectively. The serum 25OHD concentrations of <10, 10-29, and >30 ng/mL were respectively considered as deficient (severe deficiency), insufficient (mild deficiency), and sufficient levels of vitamin D. The association of nutrient bioavailability with ADHD was evaluated by statistical and regression analyses.There was no significant difference in the mean of socio-demographic variables (e.g., gender, age, weight, BMI, daily intake of dairy products, and daily sunlight exposure) between ADHD and non-ADHD subjects. The mean serum 25OHD concentration (16.57 ± 9.09 ng/mL) was found to be significantly lower in ADHD children with more parathyroid hormone (PTH) levels as compared to controls (22.01 ± 12.67ng/mL). The sufficient 25OHD concentration was more predominant in the controls than the cases (p = 0.002). A severe deficiency of vitamin D was more found in children with ADHD (3.36 times). There was a negative and significant association between the participants' age and their serum 25OHD levels. Although 25OHD levels in boys were significantly more than those in girls, the reduction of serum 25OHD concentration among boys with ADHD was more severe compared to the patient girls(p = 0.014). The results support the importance of vitamins D role in ADHD patients through the regular monitoring of serum 25OHD levels.

Low vitamin D levels are associated with cognitive impairment in patients with Hashimoto thyroiditis

BACKGROUND

Cognitive impairment is commonly observed in patients with Hashimoto thyroiditis (HT). Low levels of vitamin D have been correlated with cognitive impairment in non-HT population. We examined the association of vitamin D levels with cognitive impairment in patients with HT.

METHODS

We recruited 194 patients with HT and 200 healthy volunteers. Levels of serum 25-hydroxyvitamin D (25(OH)D) were measured using a competitive protein-binding assay. Cognitive funtion was assessed using Montreal Cognitive Assessment score (MoCA). Subjects with a MoCA scores < 26 are considered as having mild cognitive impairment (MCI). Multivariate analysis was performed using logistic regression models.

RESULTS

Fifty-five HT patients (28.4%) were diagnosed as having MCI. Patients with MCI had significantly lower 25(OH)D levels when compared with patients without MCI (33.9 ± 6.2 vs. 44.3 ± 9.6 nmol/L, P < 0.001). Significant differences in 25(OH)D quartiles of HT patients were observed between the patients with MCI and the patients without MCI (P < 0.001). In multivariate analyses, serum 25(OH)D levels (≤ 34.0 and ≥ 47.1 nmol/L) were significantly associated with cognitive impairment in patients with HT (OR 6.279, 95% CI 2.673-14.834, P < 0.001; OR 0.061, 95% CI 0.008-0.491, P = 0.009, respectively).

CONCLUSION

Our results demonstrate an important association between serum vitamin D levels and cognitive impairment in patients with HT.

Vitamin D nanoemulsion enhances hepatoprotective effect of conventional vitamin D in rats fed with a high-fat diet

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is associated with hyperlipidemia, obesity and type II diabetes. Due to increasing prevalence of these diseases globally, NAFLD is considered as a common form of chronic liver diseases. Vitamin D is a fat soluble vitamin with reported anti-inflammatory, anti-oxidant and immune modulating activity. Hypovitaminosis D often coexists with NAFLD and various studies reported beneficial role of vitamin D in modulating NAFLD. However, variable oral bioavailability, poor water solubility, and chemical degradation hinder the clinical application of vitamin D.

PURPOSE

We evaluated the potential protective effect of Vitamin D nanoemulsion (developed by sonication and pH-Shifting of pea protein isolate and canola oil) compared to conventional vitamin D against liver injury in rats fed with high fat diet (HFD).

METHODS

We analyzed liver function enzymes, lipid profile, lipid metabolism, levels and histopathology of inflammation and fibrosis in rat liver tissues.

RESULTS

HFD fed rats exhibited deterioration of liver function, poor lipid profile, decreased fatty acid oxidation and up-regulation of inflammatory cytokines and extracellular matrix deposition. Vitamin D administration reduced elevated liver enzymes, improved lipid profile, enhanced fatty acid oxidation and attenuated liver inflammation and fibrosis. Interestingly, vitamin D nanoemulsion was superior to conventional vitamin D with remarkable hepatoprotective effect against HFD-induced liver injury.

CONCLUSION

This study demonstrated vitamin D nanoemulsion as a more efficient formulation with more prominent hepatoprotective effect against HFD-induced liver injury compared to conventional oral vitamin D.