1,25-dihydroxyvitamin D3 suppresses renin gene transcription by blocking the activity of the cyclic AMP response element in the renin gene promoter

Renin angiotensin system-induced muscle wasting: putative mechanisms and implications for clinicians

Renin angiotensin system (RAS) alters various mechanisms related to muscle wasting. The RAS system consists of classical and non-classical pathways, which mostly function differently. Classical RAS pathway, operates through angiotensin II (AngII) and angiotensin type 1 receptors, is associated with muscle wasting and sarcopenia. On the other hand, the non-classical RAS pathway, which operates through angiotensin 1-7 and Mas receptor, is protective against sarcopenia. The classical RAS pathway might induce muscle wasting by variety of mechanisms. AngII reduces body weight, via reduction in food intake, possibly by decreasing hypothalamic expression of orexin and neuropeptide Y, insulin like growth factor-1 (IGF-1) and mammalian target of rapamycin (mTOR), signaling, AngII increases skeletal muscle proteolysis by forkhead box transcription factors (FOXO), caspase activation and muscle RING-finger protein-1 transcription. Furthermore, AngII infusion in skeletal muscle reduces phospho-Bad (Ser136) expression and induces apoptosis through increased cytochrome c release and DNA fragmentation. Additionally, Renin angiotensin system activation through AT1R and AngII stimulates tumor necrosis factor-α, and interleukin-6 which induces muscle wasting, Last but not least classical RAS pathway, induce oxidative stress, disturb mitochondrial energy metabolism, and muscle satellite cells which all lead to muscle wasting and decrease muscle regeneration. On the contrary, the non-classical RAS pathway functions oppositely to mitigate these mechanisms and protects against muscle wasting. In this review, we summarize the mechanisms of RAS-induced muscle wasting and putative implications for clinical practice. We also emphasize the areas of uncertainties and suggest potential research areas.

Calcium, magnesium, and vitamin D supplementations as complementary therapy for hypertensive patients: a systematic review and meta-analysis

BACKGROUND

Hypertension, the first global modifiable risk factor for cardiovascular disease (CVD) morbidity and mortality, is a consequential and remediable threat to the health of individuals and society. Therefore, we conducted this study to explore the role of calcium (Ca++), magnesium (Mg++), and vitamin D (Vit-D) supplementation as complementary therapies for hypertension, focusing on their effects on systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse rate.

METHODS

This systematic review and meta-analysis examined relevant 6509 articles in PubMed, Scopus, Web of Science, and Cochrane CENTRAL up to October 2024. The primary outcome was the difference in blood pressure measurements (systolic and diastolic) and the pulse rate. The extracted data were analyzed using Open Meta Analyst software.

RESULTS

This systematic review and meta-analysis included 40 studies; of them, 24 studies were analyzed. Ca++ was associated with a significant drop in the DBP (MD: -2.04, 95% CI [-3.39, -0.69], P = 0.01), but not in the SBP (P = 0.34) or pulse rate (P = 0.84). Mg++ significantly reduced DBP (MD: -1.64, 95% CI [-3.19, -0.09], P = 0.04), but had no significant effect on the SBP (P = 0.16) or pulse rate (P = 0.81). The estimated effect of Vit-D showed a significant reduction in SBP (MD: -2.83, 95% CI [-5.47, -0.199], P = 0.04) and DBP (MD: -1.64, 95% CI [-2.97, -0.3], P = 0.01).

CONCLUSION

Ca++ and Mg++ significantly reduced DBP but had no significant effect on SBP or the pulse rate. Whereas, vitamin D significantly reduced SBP and DBP.

C-terminal FGF-23 production coupling with aldosterone via FAM20C and predicting cardiovascular events in primary aldosteronism

This study examined the involvement of fibroblast growth factor-23 (FGF-23) in primary aldosteronism (PA), a condition characterized by elevated aldosterone levels and hypertension. We recruited patients with unilateral PA (uPA) and observed increased levels of C-terminal FGF-23 (cFGF-23) and C-terminal to intact FGF-23 (iFGF-23) in patients with uPA compared with essential hypertension control participants. Elevated preoperative cFGF-23 levels were associated with adverse outcomes, including mortality and cardiovascular or kidney events. Plasma cFGF-23 levels demonstrated a nonlinear rise with aldosterone, but iFGF-23 levels were not correlated with plasma aldosterone concentration. Higher cFGF-23 levels independently predicted hypertension remission after adrenalectomy for patients with uPA. Patients with uPA, who exhibited elevated cFGF-23 levels, had decreased levels after adrenalectomy. In cell cultures, aldosterone enhanced cleavage of iFGF-23, leading to increased levels of cFGF-23 fragments, an effect mitigated by silencing of family with sequence similarity 20, member C (FAM20C). However, the enhancement of cFGF-23 levels remained unaffected by the furin inhibitor. The study suggests that aldosterone influences FGF-23 phosphorylation by interacting with FAM20C, with docking experiments indicating aldosterone's binding to FAM20C. This work highlights that patients with uPA with elevated cFGF-23 levels are associated with cardiovascular risks, and adrenalectomy reduces cFGF-23. Aldosterone likely promotes cFGF-23 production through FAM20C-mediated phosphorylation of iFGF-23.

Unveiling the Interplay-Vitamin D and ACE-2 Molecular Interactions in Mitigating Complications and Deaths from SARS-CoV-2

The interaction of the SARS-CoV-2 spike protein with membrane-bound angiotensin-converting enzyme-2 (ACE-2) receptors in epithelial cells facilitates viral entry into human cells. Despite this, ACE-2 exerts significant protective effects against coronaviruses by neutralizing viruses in circulation and mitigating inflammation. While SARS-CoV-2 reduces ACE-2 expression, vitamin D increases it, counteracting the virus's harmful effects. Vitamin D's beneficial actions are mediated through complex molecular mechanisms involving innate and adaptive immune systems. Meanwhile, vitamin D status [25(OH)D concentration] is inversely correlated with severity, complications, and mortality rates from COVID-19. This study explores mechanisms through which vitamin D inhibits SARS-CoV-2 replication, including the suppression of transcription enzymes, reduced inflammation and oxidative stress, and increased expression of neutralizing antibodies and antimicrobial peptides. Both hypovitaminosis D and SARS-CoV-2 elevate renin levels, the rate-limiting step in the renin-angiotensin-aldosterone system (RAS); it increases ACE-1 but reduces ACE-2 expression. This imbalance leads to elevated levels of the pro-inflammatory, pro-coagulatory, and vasoconstricting peptide angiotensin-II (Ang-II), leading to widespread inflammation. It also causes increased membrane permeability, allowing fluid and viruses to infiltrate soft tissues, lungs, and the vascular system. In contrast, sufficient vitamin D levels suppress renin expression, reducing RAS activity, lowering ACE-1, and increasing ACE-2 levels. ACE-2 cleaves Ang-II to generate Ang(1-7), a vasodilatory, anti-inflammatory, and anti-thrombotic peptide that mitigates oxidative stress and counteracts the harmful effects of SARS-CoV-2. Excess ACE-2 molecules spill into the bloodstream as soluble receptors, neutralizing and facilitating the destruction of the virus. These combined mechanisms reduce viral replication, load, and spread. Hence, vitamin D facilitates rapid recovery and minimizes transmission to others. Overall, vitamin D enhances the immune response and counteracts the pathological effects of SARS-CoV-2. Additionally, data suggests that widely used anti-hypertensive agents-angiotensin receptor blockers and ACE inhibitors-may lessen the adverse impacts of SARS-CoV-2, although they are less potent than vitamin D.

Sodium-glucose cotransporter 2 inhibitors and renin-angiotensin-aldosterone system, possible cellular interactions and benefits

Sodium glucose cotransporter 2 inhibitors (SGLT2is) are a newly developed class of anti-diabetics which exert potent hypoglycemic effects in the diabetic milieu. However, the evidence suggests that they also have extra-glycemic effects. The renin-angiotensin-aldosterone system (RAAS) is a hormonal system widely distributed in the body that is important for water and electrolyte homeostasis as well as renal and cardiovascular function. Therefore, modulating RAAS activity is a main goal in patients, notably diabetic patients, which are at higher risk of complications involving these organ systems. Some studies have suggested that SGLT2is have modulatory effects on RAAS activity in addition to their hypoglycemic effects and, thus, these drugs can be considered as promising therapeutic agents for renal and cardiovascular disorders. However, the exact molecular interactions between SGLT2 inhibition and RAAS activity are not clearly understood. Therefore, in the current study we surveyed the literature for possible molecular mechanisms by which SGLT2is modulate RAAS activity.

Unlocking insights: Navigating COVID-19 challenges and Emulating future pandemic Resilience strategies with strengthening natural immunity

The original COVID-19 vaccines, developed against SARS-CoV-2, initially mitigated hospitalizations. Bivalent vaccine boosters were used widely during 2022-23, but the outbreaks persisted. Despite this, hospitalizations, mortality, and outbreaks involving dominant mutants like Alpha and Delta increased during winters when the population's vitamin D levels were at their lowest. Notably, 75 % of human immune cell/system functions, including post-vaccination adaptive immunity, rely on adequate circulatory vitamin D levels. Consequently, hypovitaminosis compromises innate and adaptive immune responses, heightening susceptibility to infections and complications. COVID-19 vaccines primarily target SARS-CoV-2 Spike proteins, thus offering only a limited protection through antibodies. mRNA vaccines, such as those for COVID-19, fail to generate secretory/mucosal immunity-like IgG responses, rendering them ineffective in halting viral spread. Additionally, mutations in the SARS-CoV-2 binding domain reduce immune recognition by vaccine-derived antibodies, leading to immune evasion by mutant viruses like Omicron variants. Meanwhile, the repeated administration of bivalent boosters intended to enhance efficacy resulted in the immunoparesis of recipients. As a result, relying solely on vaccines for outbreak prevention, it became less effective. Dominant variants exhibit increased affinity to angiotensin-converting enzyme receptor-2, enhancing infectivity but reducing virulence. Meanwhile, spike protein-related viral mutations do not impact the potency of widely available, repurposed early therapies, like vitamin D and ivermectin. With the re-emergence of COVID-19 and impending coronaviral pandemics, regulators and health organizations should proactively consider approval and strategic use of cost-effective adjunct therapies mentioned above to counter the loss of vaccine efficacy against emerging variants and novel coronaviruses and eliminate vaccine- and anti-viral agents-related serious adverse effects. Timely implementation of these strategies could reduce morbidity, mortality, and healthcare costs and provide a rational approach to address future epidemics and pandemics. This perspective critically reviews relevant literature, providing insights, justifications, and viewpoints into how the scientific community and health authorities can leverage this knowledge cost-effectively.

Gprc5a is a novel parathyroid hormone-inducible gene and negatively regulates osteoblast proliferation and differentiation

Teriparatide is a peptide derived from a parathyroid hormone (PTH) and an osteoporosis therapeutic drug with potent bone formation-promoting activity. To identify novel druggable genes that act downstream of PTH signaling and are potentially involved in bone formation, we screened PTH target genes in mouse osteoblast-like MC3T3-E1 cells. Here we show that Gprc5a, encoding an orphan G protein-coupled receptor, is a novel PTH-inducible gene and negatively regulates osteoblast proliferation and differentiation. PTH treatment induced Gprc5a expression in MC3T3-E1 cells, rat osteosarcoma ROS17/2.8 cells, and mouse femurs. Induction of Gprc5a expression by PTH occurred in the absence of protein synthesis and was mediated primarily via the cAMP pathway, suggesting that Gprc5a is a direct target of PTH signaling. Interestingly, Gprc5a expression was induced additively by co-treatment with PTH and 1α, 25-dihydroxyvitamin D3 (calcitriol), or retinoic acid in MC3T3-E1 cells. Reporter analysis of a 1 kb fragment of human GPRC5A promoter revealed that the promoter fragment showed responsiveness to PTH via the cAMP response element, suggesting that GPRC5A is also a PTH-inducible gene in humans. Gprc5a knockdown promoted cell viability and proliferation, as demonstrated by MTT and BrdU assays. Gprc5a knockdown also promoted osteoblast differentiation, as indicated by gene expression analysis and mineralization assay. Mechanistic studies showed that Gprc5a interacted with BMPR1A and suppressed BMP signaling induced by BMP-2 and constitutively active BMP receptors, ALK2 (ACVR1) Q207D and ALK3 (BMPR1A) Q233D. Thus, our results suggest that Gprc5a is a novel gene induced by PTH that acts in an inhibitory manner on both cell proliferation and osteoblast differentiation and is a candidate for drug targets for osteoporosis.

Mini-encyclopedia of mitochondria-relevant nutraceuticals protecting health in primary and secondary care-clinically relevant 3PM innovation

Despite their subordination in humans, to a great extent, mitochondria maintain their independent status but tightly cooperate with the "host" on protecting the joint life quality and minimizing health risks. Under oxidative stress conditions, healthy mitochondria promptly increase mitophagy level to remove damaged "fellows" rejuvenating the mitochondrial population and sending fragments of mtDNA as SOS signals to all systems in the human body. As long as metabolic pathways are under systemic control and well-concerted together, adaptive mechanisms become triggered increasing systemic protection, activating antioxidant defense and repair machinery. Contextually, all attributes of mitochondrial patho-/physiology are instrumental for predictive medical approach and cost-effective treatments tailored to individualized patient profiles in primary (to protect vulnerable individuals again the health-to-disease transition) and secondary (to protect affected individuals again disease progression) care. Nutraceuticals are naturally occurring bioactive compounds demonstrating health-promoting, illness-preventing, and other health-related benefits. Keeping in mind health-promoting properties of nutraceuticals along with their great therapeutic potential and safety profile, there is a permanently growing demand on the application of mitochondria-relevant nutraceuticals. Application of nutraceuticals is beneficial only if meeting needs at individual level. Therefore, health risk assessment and creation of individualized patient profiles are of pivotal importance followed by adapted nutraceutical sets meeting individual needs. Based on the scientific evidence available for mitochondria-relevant nutraceuticals, this article presents examples of frequent medical conditions, which require protective measures targeted on mitochondria as a holistic approach following advanced concepts of predictive, preventive, and personalized medicine (PPPM/3PM) in primary and secondary care.

Ablation of Vitamin D Signaling in Cardiomyocytes Leads to Functional Impairment and Stimulation of Pro-Inflammatory and Pro-Fibrotic Gene Regulatory Networks in a Left Ventricular Hypertrophy Model in Mice

The association between vitamin D deficiency and cardiovascular disease remains a controversial issue. This study aimed to further elucidate the role of vitamin D signaling in the development of left ventricular (LV) hypertrophy and dysfunction. To ablate the vitamin D receptor (VDR) specifically in cardiomyocytes, VDRfl/fl mice were crossed with Mlcv2-Cre mice. To induce LV hypertrophy experimentally by increasing cardiac afterload, transverse aortic constriction (TAC) was employed. Sham or TAC surgery was performed in 4-month-old, male, wild-type, VDRfl/fl, Mlcv2-Cre, and cardiomyocyte-specific VDR knockout (VDRCM-KO) mice. As expected, TAC induced profound LV hypertrophy and dysfunction, evidenced by echocardiography, aortic and cardiac catheterization, cardiac histology, and LV expression profiling 4 weeks post-surgery. Sham-operated mice showed no differences between genotypes. However, TAC VDRCM-KO mice, while having comparable cardiomyocyte size and LV fibrosis to TAC VDRfl/fl controls, exhibited reduced fractional shortening and ejection fraction as measured by echocardiography. Spatial transcriptomics of heart cryosections revealed more pronounced pro-inflammatory and pro-fibrotic gene regulatory networks in the stressed cardiac tissue niches of TAC VDRCM-KO compared to VDRfl/fl mice. Hence, our study supports the notion that vitamin D signaling in cardiomyocytes plays a protective role in the stressed heart.

Physiological Evidence and Therapeutic Outcomes of Vitamin D on Cardiovascular Diseases

Vitamin D hormone is an important regulator of various physiological functions, and its deficiency is characterized by an imbalance in parathyroid hormone and calcium homeostasis. The role of vitamin D in cardiovascular physiology is well demonstrated in animal and humanbased studies. In this context, hyperlipidemia, increased atherogenic plaques, cardiac inflammation, hypertension, myocarditis, myocardial infarction, and heart failure are some of the commonest known conditions connected with vitamin D deficiency. Supplementation of vitamin D is recommended to achieve normal serum vitamin D concentrations, nonetheless, in clinical trials often seen discrepancies concerning the supplementation effects and effectiveness. This review summarizes the data on the role of vitamin D in cardiovascular health along with some recent clinical findings regarding the effects of vitamin D supplementation.

The Role of the FGF19 Family in the Pathogenesis of Gestational Diabetes: A Narrative Review

Gestational diabetes mellitus (GDM) is one of the most common pregnancy complications. Understanding the pathogenesis and appropriate diagnosis of GDM enables the implementation of early interventions during pregnancy that reduce the risk of maternal and fetal complications. At the same time, it provides opportunities to prevent diabetes, metabolic syndrome, and cardiovascular diseases in women with GDM and their offspring in the future. Fibroblast growth factors (FGFs) represent a heterogeneous family of signaling proteins which play a vital role in cell proliferation and differentiation, repair of damaged tissues, wound healing, angiogenesis, and mitogenesis and also affect the regulation of carbohydrate, lipid, and hormone metabolism. Abnormalities in the signaling function of FGFs may lead to numerous pathological conditions, including metabolic diseases. The FGF19 subfamily, also known as atypical FGFs, which includes FGF19, FGF21, and FGF23, is essential in regulating metabolic homeostasis and acts as a hormone while entering the systemic circulation. Many studies have pointed to the involvement of the FGF19 subfamily in the pathogenesis of metabolic diseases, including GDM, although the results are inconclusive. FGF19 and FGF21 are thought to be associated with insulin resistance, an essential element in the pathogenesis of GDM. FGF21 may influence placental metabolism and thus contribute to fetal growth and metabolism regulation. The observed relationship between FGF21 and increased birth weight could suggest a potential role for FGF21 in predicting future metabolic abnormalities in children born to women with GDM. In this group of patients, different mechanisms may contribute to an increased risk of cardiovascular diseases in women in later life, and FGF23 appears to be their promising early predictor. This study aims to present a comprehensive review of the FGF19 subfamily, emphasizing its role in GDM and predicting its long-term metabolic consequences for mothers and their offspring.

Vitamin A, D, E, and K as Matrix Metalloproteinase-2/9 Regulators That Affect Expression and Enzymatic Activity

Fat-soluble vitamins (vitamin A, D, E, and K) assume a pivotal role in maintaining human homeostasis by virtue of their enzymatic functions. The daily inclusion of these vitamins is imperative to the upkeep of various physiological processes including vision, bone health, immunity, and protection against oxidative stress. Current research highlights fat-soluble vitamins as potential therapeutics for human diseases, especially cancer. Fat-soluble vitamins exert their therapeutic effects through multiple pathways, including regulation of matrix metalloproteinases' (MMPs) expression and enzymatic activity. As MMPs have been reported to be involved in the pathology of various diseases, such as cancers, cardiovascular diseases, and neurological disorders, regulating the expression and/or activity of MMPs could be considered as a potent therapeutic strategy. Here, we summarize the properties of fat-soluble vitamins and their potential as promising candidates capable of effectively modulating MMPs through multiple pathways to treat human diseases.

Associations of Serum 25(OH)D With Risk of Recurrent Cardiovascular Events in Individuals With Coronary Heart Disease

CONTEXT

Few studies have examined the relationship between vitamin D and the risk of recurrent cardiovascular (CV) events in people with coronary heart disease (CHD).

OBJECTIVE

This study aimed to investigate the associations of serum 25-hydroxyvitamin D (25(OH)D) concentration and the vitamin D receptor (VDR) polymorphisms with the risk of recurrent CV events in individuals with established CHD.

METHODS

A total of 22 571 participants with CHD were included from the UK Biobank. Recurrent CV events, including myocardial infarction (MI), heart failure (HF), stroke, and CV disease mortality, were identified from electronic health records. Cox proportional-hazard models were used to calculate hazard ratios (HRs) and 95% CIs.

RESULTS

The median (interquartile range) of serum 25(OH)D concentration was 44.8 nmol/L (range, 30.3-61.4 nmol/L), and 58.6% of participants had 25(OH)D below 50 nmol/L. During a median follow-up of 11.2 years, a total of 3998 recurrent CV events were documented. After multivariable adjustment, there was a nonlinear inverse relationship between serum 25(OH)D and recurrent CV events (P nonlinearity <.01), and the decreasing risk gradually leveled off at around 50 nmol/L. Compared with participants with serum 25(OH)D less than 25.0 nmol/L, the HRs (95% CIs) for participants with serum 25(OH)D of 50.0 to 74.9 nmol/L were 0.64 (0.58-0.71) for recurrent CV events, 0.78 (0.65-0.94) for MI, 0.66 (0.57-0.76) for HF, and 0.66 (0.52-0.84) for stroke. In addition, these associations were not modified by genetic variants in the VDR.

CONCLUSION

In people with established CHD, higher serum 25(OH)D concentrations were nonlinearly associated with a lower risk of recurrent CV events, with a potential threshold around 50 nmol/L. These findings highlight the importance of maintaining adequate vitamin D status in the prevention of recurrent CV events among individuals with CHD.

Vitamin D deficiency enhances vascular oxidative stress, inflammation, and angiotensin II levels in the microcirculation of diabetic patients

Low vitamin D (vitD) levels have been reported to be a risk factor for diabetes-related cardiovascular complications. This study examined the effects of vitD deficiency on oxidative stress (OS), inflammation, and levels of the vasoconstrictor angiotensin II (Ang II) in the microvascular tissue of type 2 diabetic patients. Patients were categorized into (i) vitD non-deficient diabetics (DNP, n = 10) and (ii) vitD-deficient diabetics (DDP, n = 10), based on their serum 25(OH)D levels. Subcutaneous fat tissues with intact blood vessels were collected during lower limb surgical procedures. The blood vessel were isolated; measurements of the antioxidant enzyme superoxide dismutase (SOD) activity, OS marker malondialdehyde (MDA), Ang II, and the inflammatory marker, TNF-α of the microvascular tissues were determined. Elevated MDA levels and reduced SOD activity, with higher levels of TNF-α and Ang II were observed in the microvascular tissues of DDP compared to DNP. VitD deficiency did not associate with glycemic parameters (fasting blood glucose and glycated hemoglobin) levels. In conclusion, vitD deficiency was correlated with higher microvascular tissue OS, inflammation, and Ang II levels in type 2 diabetic patients. This may contribute to early vasculopathy that occurs in diabetic patients, thus, may contribute to the planning of therapeutic strategies to delay or prevent cardiovascular complications.

METTL14-upregulated miR-6858 triggers cell apoptosis in keratinocytes of oral lichen planus through decreasing GSDMC

Oral lichen planus (OLP), a chronic inflammatory disorder, is characterized by the massive cell apoptosis in the keratinocytes of oral mucosa. However, the mechanism responsible for triggering oral keratinocyte apoptosis is not fully explained. Here, we identify that Gasdermin C (GSDMC) downregulation contributes to apoptosis in human oral keratinocytes. Mechanistically, we describe that activated nuclear factor kappa B (NF-κB) pathway induces overexpression of methyltransferase-like 14 (METTL14), which increases N6-adenosine methylation (m6A) levels in the epithelial layer of OLP. m6A modification is capable of regulating primary miR-6858 processing and alternative splicing, leading to miR-6858 increases. miR-6858 can bind and promote GSDMC mRNA degradation. Forced expression of GSDMC is able to rescue cell apoptosis in human oral keratinocyte models resembling OLP. Collectively, our data unveil that m6A modification regulates miR-6858 production to decrease GSDMC expression and to trigger keratinocyte apoptosis in the context of OLP.

Vitamin D: An Overview of Gene Regulation, Ranging from Metabolism to Genomic Effects

Vitamin D is a pro-hormone characterized by an intricate metabolism and regulation. It is well known for its role in calcium and phosphate metabolism, and in bone health. However, several studies have assessed a huge number of extra-skeletal functions, ranging from cell proliferation in some oncogenic pathways to antioxidant and immunomodulatory functions. Vitamin D exerts its role by binding to VDRs (vitamin D receptors), which are located in many different tissues. Moreover, VDRs are able to bind hundreds of genomic loci, modulating the expression of various primary target genes. Interestingly, plenty of gene polymorphisms regarding VDRs are described, each one carrying a potential influence against gene expression, with relapses in several chronic diseases and metabolic complications. In this review, we provide an overview of the genetic aspects of vitamin D and VDR, emphasizing the gene regulation of vitamin D, and the genetic modulation of VDR target genes. In addition, we briefly summarize the rare genetic disease linked to vitamin D metabolism.

Microglia and Brain Disorders: The Role of Vitamin D and Its Receptor

Accounting for 5-20% of the total glial cells present in the adult brain, microglia are involved in several functions: maintenance of the neural environment, response to injury and repair, immunesurveillance, cytokine secretion, regulation of phagocytosis, synaptic pruning, and sculpting postnatal neural circuits. Microglia contribute to some neurodevelopmental disorders, such as Nasu-Hakola disease (NHD), Tourette syndrome (TS), autism spectrum disorder (ASD), and schizophrenia. Moreover, microglial involvement in neurodegenerative diseases, such as Alzheimer's (AD) and Parkinson's (PD) diseases, has also been well established. During the last two decades, epidemiological and research studies have demonstrated the involvement of vitamin D3 (VD3) in the brain's pathophysiology. VD3 is a fat-soluble metabolite that is required for the proper regulation of many of the body's systems, as well as for normal human growth and development, and shows neurotrophic and neuroprotective actions and influences on neurotransmission and synaptic plasticity, playing a role in various neurological diseases. In order to better understand the exact mechanisms behind the diverse actions of VD3 in the brain, a large number of studies have been performed on isolated cells or tissues of the central nervous system (CNS). Here, we discuss the involvement of VD3 and microglia on neurodegeneration- and aging-related diseases.

Implications of vitamin D deficiency in systemic inflammation and cardiovascular health

Clinical, epidemiological, and molecular studies have sufficiently highlighted the vitality of vitamin D [25(OH)D and 1,25(OH)2D] in human health and wellbeing. Globally, vitamin D deficiency (VDD) has become a public health concern among all age groups. There is a very high prevalence of VDD per the estimates from several epidemiological studies on different ethnic populations. But, population-specific scales do not support these estimates to define VDD clinically and consistent genetic associations. However, clinical studies have shown the relevance of serum vitamin D screening and oral supplementation in improving health conditions, pointing toward a more prominent role of vitamin D in health and wellness. Routinely, the serum concentration of vitamin D is measured to determine the deficiency and is correlated with physiological conditions and clinical symptoms. Recent research points toward a more inclusive role of vitamin D in different disease pathologies and is not just limited to otherwise bone health and overall growth. VDD contributes to the natural history of systemic ailments, including cardiovascular and systemic immune diseases. Considering its significant impact on premature morbidity and mortality, there is a compelling need to comprehensively review and document the direct and indirect implications of VDD in immune system deregulation, systemic inflammatory conditions, and cardio-metabolism. The recommendations from this review call for furthering our research concerning vitamin D and its direct and indirect implications.

The effects of vitamin D on all-cause mortality in different diseases: an evidence-map and umbrella review of 116 randomized controlled trials

Purpose

To conduct a solid evidence by synthesizing meta-analyses and updated RCTs about the effects of vitamin D on all-cause mortality in different health conditions.

Methods

Data sources: Pubmed, Embase, Web of Science, the Cochrane Library, Google Scholar from inception until 25th April, 2022. Study selection: English-language, meta-analyses and updated RCTs assessing the relationships between vitamin D and all-cause mortality. Data synthesis: Information of study characteristics, mortality, supplementation were extracted, estimating with fixed-effects model. A Measurement Tool to Assess Systematic Reviews, Grading of Recommendations Assessment, Development and Evaluation, and funnel plot was used to assess risk of bias. Main outcomes: All-cause mortality, cancer mortality, cardiovascular disease mortality.

Results

In total of 27 meta-analyses and 19 updated RCTs were selected, with a total of 116 RCTs and 149, 865 participants. Evidence confirms that vitamin D reduces respiratory cancer mortality (RR, 0.56 [95%CI, 0.33 to 0.96]). All-cause mortality is decreased in patients with COVID-19 (RR, 0.54[95%CI, 0.33 to 0.88]) and liver diseases (RR, 0.64 [95%CI, 0.50 to 0.81]), especially in liver cirrhosis (RR, 0.63 [95%CI, 0.50 to 0.81]). As for other health conditions, such as the general health, chronic kidney disease, critical illness, cardiovascular diseases, musculoskeletal diseases, sepsis, type 2 diabetes, no significant association was found between vitamin D and all-cause mortality.

Conclusions

Vitamin D may reduce respiratory cancer mortality in respiratory cancer patients and all-cause mortality in COVID-19 and liver disorders' patients. No benefits showed in all-cause mortality after vitamin D intervention among other health conditions. The hypothesis of reduced mortality with vitamin D still requires exploration.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=252921, identifier: CRD42021252921.

The Role of Vitamin D in Health and Disease: A Narrative Review on the Mechanisms Linking Vitamin D with Disease and the Effects of Supplementation

Vitamin D insufficiency or deficiency (VDD) is a very prevalent condition in the general population. Vitamin D is necessary for optimal bone mineralization, but apart from the bone effects, preclinical and observational studies have suggested that vitamin D may have pleiotropic actions, whereas VDD has been linked to several diseases and higher all-cause mortality. Thus, supplementing vitamin D has been considered a safe and inexpensive approach to generate better health outcomes-and especially so in frail populations. Whereas it is generally accepted that prescribing of vitamin D in VDD subjects has demonstrable health benefits, most randomized clinical trials, although with design constraints, assessing the effects of vitamin D supplementation on a variety of diseases have failed to demonstrate any positive effects of vitamin D supplementation. In this narrative review, we first describe mechanisms through which vitamin D may exert an important role in the pathophysiology of the discussed disorder, and then provide studies that have addressed the impact of VDD and of vitamin D supplementation on each disorder, focusing especially on randomized clinical trials and meta-analyses. Despite there already being vast literature on the pleiotropic actions of vitamin D, future research approaches that consider and circumvent the inherent difficulties in studying the effects of vitamin D supplementation on health outcomes are needed to assess the potential beneficial effects of vitamin D. The evaluation of the whole vitamin D endocrine system, rather than only of 25-hydroxyvitamin D levels before and after treatment, use of adequate and physiologic vitamin D dosing, grouping based on the achieved vitamin D levels rather than the amount of vitamin D supplementation subjects may receive, and sufficiently long follow-up are some of the aspects that need to be carefully considered in future studies.

Vitamin D Determinants, Status, and Antioxidant/Anti-inflammatory-Related Effects in Cardiovascular Risk and Disease: Not the Last Word in the Controversy

Beyond its key role in calcium homeostasis, vitamin D has been found to significantly affect the cardiovascular (CV) system. In fact, low vitamin D levels have been associated with increased CV risk, as well as increased CV morbidity and mortality. The majority of effects of this molecule are related directly or indirectly to its antioxidative and anti-inflammatory properties. Generally, vitamin D insufficiency is considered for 25-hydroxyvitamin D (25(OH)D) levels between 21-29 ng/mL (corresponding to 52.5-72.5 nmol/L), deficiency as 25(OH)D levels less than 20 ng/mL (<50 nmol/L), and extreme deficiency as 25(OH)D less than 10 ng/mL (<25 nmol/L). However, the definition of an optimal vitamin D status, as defined by 25(OH)D, remains controversial for many extra-bone conditions, including CV disease. In this review, confounding factors affecting the 25(OH)D measurement and status will be discussed. In particular, available evidence on the mechanism and role of vitamin D in relation to CV risk and disease through its antioxidant effect will be reported, also facing the aspect regarding the debate on the minimum blood 25(OH)D level required to ensure optimal CV health.

Vitamin D deficiency and vitamin D receptor FokI polymorphism as risk factors for COVID-19

BACKGROUND

Given the sparse data on vitamin D status in pediatric COVID-19, we investigated whether vitamin D deficiency could be a risk factor for susceptibility to COVID-19 in Egyptian children and adolescents. We also investigated whether vitamin D receptor (VDR) FokI polymorphism could be a genetic marker for COVID-19 susceptibility.

METHODS

One hundred and eighty patients diagnosed to have COVID-19 and 200 matched control children and adolescents were recruited. Patients were laboratory confirmed as SARS-CoV-2 positive by real-time RT-PCR. All participants were genotyped for VDR Fok1 polymorphism by RT-PCR. Vitamin D status was defined as sufficient for serum 25(OH) D at least 30 ng/mL, insufficient at 21-29 ng/mL, deficient at <20 ng/mL.

RESULTS

Ninety-four patients (52%) had low vitamin D levels with 74 (41%) being deficient and 20 (11%) had vitamin D insufficiency. Vitamin D deficiency was associated with 2.6-fold increased risk for COVID-19 (OR = 2.6; [95% CI 1.96-4.9]; P = 0.002. The FokI FF genotype was significantly more represented in patients compared to control group (OR = 4.05; [95% CI: 1.95-8.55]; P < 0.001).

CONCLUSIONS

Vitamin D deficiency and VDR Fok I polymorphism may constitute independent risk factors for susceptibility to COVID-19 in Egyptian children and adolescents.

IMPACT

Vitamin D deficiency could be a modifiable risk factor for COVID-19 in children and adolescents because of its immune-modulatory action. To our knowledge, ours is the first such study to investigate the VDR Fok I polymorphism in Caucasian children and adolescents with COVID-19. Vitamin D deficiency and the VDR Fok I polymorphism may constitute independent risk factors for susceptibility to COVID-19 in Egyptian children and adolescents. Clinical trials should be urgently conducted to test for causality and to evaluate the efficacy of vitamin D supplementation for prophylaxis and treatment of COVID-19 taking into account the VDR polymorphisms.

Association of ApaI rs7975232 and BsmI rs1544410 in clinical outcomes of COVID-19 patients according to different SARS-CoV-2 variants

A growing body of research has shown how important vitamin D is in the prognosis of coronavirus disease 19 (COVID-19). The vitamin D receptor is necessary for vitamin D to perform its effects, and its polymorphisms can help in this regard. Therefore, we aimed to evaluate whether the association of ApaI rs7975232 and BsmI rs1544410 polymorphisms in different severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants were influential in the outcomes of COVID-19. The polymerase chain reaction-restriction fragment length polymorphism method was utilized to determine the different genotypes of ApaI rs7975232 and BsmI rs1544410 in 1734 and 1450 patients who had recovered and deceased, respectively. Our finding revealed that the ApaI rs7975232 AA genotype in the Delta and Omicron BA.5 and the CA genotype in the Delta and Alpha variants were associated with higher mortality rate. Also, the BsmI rs1544410 GG genotype in the Delta and Omicron BA.5 and the GA genotype in the Delta and Alpha variants were related to a higher mortality rate. The A-G haplotype was linked with COVID-19 mortality in both the Alpha and Delta variants. The A-A haplotype for the Omicron BA.5 variants was statistically significant. In conclusion, our research revealed a connection between SARS-CoV-2 variants and the impacts of ApaI rs7975232 and BsmI rs1544410 polymorphisms. However, more research is still needed to substantiate our findings.

Association of serum vitamin D levels and TaqIrs731236 among patients with hypertensive coronary heart disease

The development of cardiovascular diseases (CVD) is influenced through multiple risk factor and hypertension. It may increase the risk of cardiac events, and has a significant impact when combined with other risk factors including low levels of vitamin D and genetic variations like single nucleotide variations (SNV) (TaqIrs731236) in vitamin D receptor (VDR) gene. Blood samples from 500 study participants gathered including 250 hypertensive coronary heart disease patients, 250 age and gender matched healthy controls. To isolate genomic DNA, conventional salting out procedure used followed by amplification of targeted variations through Amplification Refractory Mutation System- Polymerase Chain Reaction (ARMS-PCR) Assay. The amplicon consists of 148 base pairs which was visualized on 2 % agarose gel electrophoresis and confirmed by DNA sequencing. The compared clinical parameters including systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI), high density lipoproteins (HDL), low density lipoproteins (LDL), cholesterol, triglycerides found significantly different among patients when compared with controls (P < 0.001). The Vitamin D exhibited insufficient levels at different stages of hypertension which were statistically, found significantly associated among patients with hypertensive coronary heart disease showing compared to controls (P < 0.001). The genotype association SNV (TaqIrs731236) T > C showed significant association with hypertensive coronary heart disease compared to healthy controls (Chi-Square χ2 = 60.75 and P < 0.00001). Further, the odds ratio of allelic association for risk allele (C) showed the strength of association with risk of disease, which increases by 2.02 times(P = 0.01). The results suggest that (TaqIrs731236) T > C as genetic predisposition factor, may contribute to develop the risk of hypertensive coronary heart disease. Hypertension as a risk factor along with insufficient levels of vitamin D and SNV (TaqIrs731236) as genetic variations may have been an important contributor to disease risk of hypertensive coronary heart disease.

Fok I and Bsm I gene polymorphism of vitamin D receptor and essential hypertension: a mechanistic link

The vitamin D receptor (VDR) gene serves as a good candidate gene for susceptibility to essential hypertension. The gene regulates the renin angiotensin system by influencing blood pressure regulation. Around 3% of the human genome is regulated by the vitamin D endocrine system. Several studies have reported mixed results with respect to relationship of VDR gene and hypertension. Observational evidence supports the concept that vitamin D plays a role in the pathogenesis of cardiovascular disease and arterial hypertension which is further supported by meta-analysis and case control studies reporting how VDR polymorphism leads to the onset and development of hypertension. In this review, we summarize the existing literature on the link between VDR and hypertension, including mechanistic studies, observational data, and clinical trials showing relationship of vitamin D level and hypertension with a focus on recent findings related to genetic studies that showed the relationship of VDR gene polymorphism with vitamin D level in hypertensive and normotensive groups. As a result, determining the association of VDR polymorphisms with essential hypertension is expected to aid in the risk assessment for the condition.

Vitamin D Deficiency: An Underestimated Factor in Sepsis?

Vitamin D is an important immune modulator that is linked to infection susceptibility. It has been suggested that vitamin D deficiency plays a role in sepsis and septic shock because vitamin-D-related pathways are associated with various immunological, endocrine, and endothelial functions. Previous research has yielded inconclusive results regarding the link between mortality and vitamin D deficiency in sepsis patients. In patients with sepsis and severe vitamin D deficiency, an adequate vitamin D concentration may reduce mortality. Randomized controlled trials to assess the influence of vitamin D supplementation on clinical outcomes in sepsis patients with vitamin D deficiency are uncommon. We will provide an overview of the current knowledge about the relationship between vitamin D and sepsis in this review, as well as consider the potential value of vitamin D supplementation in this situation.

Role of vitamin D in pathogenesis and severity of COVID-19 infection

Coronavirus disease (COVID-19) is an infectious disease caused by a new virus that causes respiratory illness. Older adults and individuals who have pre-existing chronic medical conditions are at higher risk for more serious complications from COVID-19. Hypovitaminosis D is attributed to the increased risk of lung injury and acute respiratory distress syndrome (ARDS) as well as diabetes, cardiovascular events and associated comorbidities, which are the main causes of severe clinical complications in COVID-19 patients. Considering the defensive role of vitamin D, mediated through modulation of the innate and adaptive immune system as well as inhibition of the Renin Angiotensin System (RAS), vitamin D supplementation might boost the immune system of COVID-19 patients and reduce severity of the disease in vitamin D deficient individuals.

Role of Vitamin D Deficiency in the Pathogenesis of Cardiovascular and Cerebrovascular Diseases

Deficiency in vitamin D (VitD), a lipid-soluble vitamin and steroid hormone, affects approximately 24% to 40% of the population of the Western world. In addition to its well-documented effects on the musculoskeletal system, VitD also contributes importantly to the promotion and preservation of cardiovascular health via modulating the immune and inflammatory functions and regulating cell proliferation and migration, endothelial function, renin expression, and extracellular matrix homeostasis. This brief overview focuses on the cardiovascular and cerebrovascular effects of VitD and the cellular, molecular, and functional changes that occur in the circulatory system in VitD deficiency (VDD). It explores the links among VDD and adverse vascular remodeling, endothelial dysfunction, vascular inflammation, and increased risk for cardiovascular and cerebrovascular diseases. Improved understanding of the complex role of VDD in the pathogenesis of atherosclerotic cardiovascular diseases, stroke, and vascular cognitive impairment is crucial for all cardiologists, dietitians, and geriatricians, as VDD presents an easy target for intervention.

Association between vitamin D and cardiovascular health: Myth or Fact? A narrative review of the evidence

Vitamin D deficiency is prevalent worldwide. Since the discovery of the expression of vitamin D receptor in ventricular cardiomyocytes, fibroblasts, and blood vessels, there has been a growing body of literature assessing the link between vitamin D status and cardiovascular health from one side, and the effect of vitamin D supplementation on prevention of cardiovascular diseases from the other side. In this review, we summarized studies highlighting the role of vitamin D on cardiovascular health, namely atherosclerosis, hypertension, heart failure, and metabolic syndrome, a recognized significant risk factor for cardiovascular diseases. Studies showed discrepancies between findings from cross-sectional and longitudinal cohorts and those from interventional trials, but also between one outcome and another. Cross-sectional studies found a strong association between low 25 hydroxyvitamin D (25(OH)D3) and acute coronary syndrome, and heart failure. These findings encouraged the promotion for vitamin D supplementation as a preventive measure for cardiovascular diseases in the elderly, namely in women. This fact, however, turned out into a myth with the results of large interventional trials that did not show any benefit from vitamin D supplementation in reducing ischemic events, heart failure or its outcomes, or hypertension. Although some clinical studies showed beneficial effect of vitamin D supplementation on insulin sensitivity and metabolic syndrome, this effect was not consistent across all studies.

Interaction of Vitamin D with Peptide Hormones with Emphasis on Parathyroid Hormone, FGF23, and the Renin-Angiotensin-Aldosterone System

The seminal discoveries that parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23) are major endocrine regulators of vitamin D metabolism led to a significant improvement in our understanding of the pivotal roles of peptide hormones and small proteohormones in the crosstalk between different organs, regulating vitamin D metabolism. The interaction of vitamin D, FGF23 and PTH in the kidney is essential for maintaining mineral homeostasis. The proteohormone FGF23 is mainly secreted from osteoblasts and osteoclasts in the bone. FGF23 acts on proximal renal tubules to decrease production of the active form of vitamin D (1,25(OH)₂D) by downregulating transcription of 1α-hydroxylase (CYP27B1), and by activating transcription of the key enzyme responsible for vitamin D degradation, 24-hydroxylase (CYP24A1). Conversely, the peptide hormone PTH stimulates 1,25(OH)₂D renal production by upregulating the expression of 1α-hydroxylase and downregulating that of 24-hydroxylase. The circulating concentration of 1,25(OH)₂D is a positive regulator of FGF23 secretion in the bone, and a negative regulator of PTH secretion from the parathyroid gland, forming feedback loops between kidney and bone, and between kidney and parathyroid gland, respectively. In recent years, it has become clear that vitamin D signaling has important functions beyond mineral metabolism. Observation of seasonal variations in blood pressure and the subsequent identification of vitamin D receptor (VDR) and 1α-hydroxylase in non-renal tissues such as cardiomyocytes, endothelial and smooth muscle cells, suggested that vitamin D may play a role in maintaining cardiovascular health. Indeed, observational studies in humans have found an association between vitamin D deficiency and hypertension, left ventricular hypertrophy and heart failure, and experimental studies provided strong evidence for a role of vitamin D signaling in the regulation of cardiovascular function. One of the proposed mechanisms of action of vitamin D is that it functions as a negative regulator of the renin-angiotensin-aldosterone system (RAAS). This finding established a novel link between vitamin D and RAAS that was unexplored until then. During recent years, major progress has been made towards a more complete understanding of the mechanisms by which FGF23, PTH, and RAAS regulate vitamin D metabolism, especially at the genomic level. However, there are still major gaps in our knowledge that need to be filled by future research. The purpose of this review is to highlight our current understanding of the molecular mechanisms underlying the interaction between vitamin D, FGF23, PTH, and RAAS, and to discuss the role of these mechanisms in physiology and pathophysiology.

Effects of Vitamin D on the Renin-Angiotensin System and Acute Childhood Pneumonia

Vitamin D promotes kidney calcium reabsorption and regulates calcium and phosphate metabolism, as well as the intestinal absorption of calcium and phosphorus and bone mineralization events. Vitamin D is also known for its immunomodulatory properties. It has been shown in the literature that the active form of vitamin D, 1,25-dihydroxyvitamin D, performs multiple functions in the adaptive and innate immune system, as well as acting on the endothelial membrane. Recent evidence shows that vitamin D is a negative endocrine modulator of the renin-angiotensin system (RAS), with protection from diseases leading to lung damage, such as pneumonia caused by various pathogens. Vitamin D support associated with the use of antibiotics could be crucial to counteract these infectious diseases.

Effect of the administration of different forms of vitamin D on central blood pressure and aortic stiffness, and its implication in the reduction of albuminuria in chronic kidney disease

BACKGROUND AND OBJECTIVES

Vitamin D(vitD) participates in phospho-calcium metabolism and exerts multiple pleiotropic effects. There is tissue 1-α (OH)ase that converts 25-OH cholecalciferol (25 (OH) D) in calcitriol that exerts autocrine and paracrine effects. 25 (OH)D deficiency could limit these tissue effects of vitD. The administration of nutritional vitD and the activator of the vitD receptor, paricalcitol, may promote beneficial effects on vascular and renal function. The objective of this work was to study in subjects with chronic kidney disease (CKD) the effect that the administration of different forms of vitD has on arterial function and albuminuria, and the possible relationship between the modifications of these variables.

PATIENTS AND METHODS

We studied in 97 patients with CKD stages 3-4 the effect of the administration of cholecalciferol (group 2; n: 35) and paricalcitol (n: 31; group 3) on parameters derived from brachial blood pressure, aortic blood pressure and on aortic stiffness studied using carotid-femoral pulse velocity (Vp_c-f), and on albuminuria. A group of patients with stages 3-4 CKD who did not receive vitD therapy served as a control group (n: 31; group 1). All parameters were studied at baseline and after the follow-up period which was 7 ± 2 months.

RESULTS

In the baseline phase, no differences were observed between the groups in brachial systolic blood pressure (bSBP), central systolic blood pressure (SBP), brachial pulse pressure (bPP), and central pulse pressure (pCP) or in aortic stiffness that was increased in all groups with a baseline Vp_c-f value of 10.5 (9.2-12.1) m/sec. The baseline albuminuria value in the grouped patients was 229 (43-876) mg / g (median (interquartile range)), with no differences between the groups. Serum calcium and phosphorus increased significantly in those treated with cholecal-ciferol (native vitD) and paricalcitol (active vitD). Parathormone (PTH) values decreased in those treated with paricalcitol.bPP and cPP decreased in all groups treated with native and active vitD. No significant changes in bPP and cPP were observed in the control group. Vp_c-f did not change significantly in any of the groups, although the variation was quantitatively greater in group 3 (11.2±2 vs. 10.7±1.6 (P=.06)). No differences were observed in the changes in Vp_c-f between the groups when adjusted to the baseline values of estimated glomerular filtration rate (eGFR), albuminuria, PTH, vitD, brachial and central blood pressure parameters, and their changes with treatment.Those who received treatment with native and active vitD presented a significant decrease in albuminuria of 17% (group 2) and 21% (group 3) compared to a 16% increase in the untreated group (group 1) (P=.01). A decrease in albuminuria ≥30% was observed more frequently in the groups treated with some form of vitD (group 2: 23%; group 3: 45%) than in the control group (13%) (P=.03). The decrease in albuminuria observed in the groups treated with any of the forms of vitD did not vary when the baseline values of the biochemical parameters of phosphorus-calcium metabolism, those of arterial function (PPb, PPc, Vp_c-f) or its modifications were introduced as covariates. There was no significant correlation between changes in Vp_c-f and albuminuria. In logistic regression, changes in arterial function parameters were also not explanatory for the ≥30% decrease in albuminuria.

CONCLUSIONS

In patients with CKD stages 3-4, treated with RAS blockers and with residual albuminuria, the administration of or paricalcitol reduces brachial and aortic pulse pressures, and albuminuria. The decrease in albuminuria does not seem to be mediated, at least not decisively, by changes in central hemodynamics or aortic stiffness.

Relationships of Serum 25-Hydroxyvitamin D Concentrations, Diabetes, Genetic Susceptibility, and New-Onset Chronic Kidney Disease

OBJECTIVE

The prospective relation of vitamin D status with the risk of chronic kidney diseases (CKD) remains uncertain. We aimed to examine the association of serum 25-hydroxyvitamin D (25OHD) with new-onset CKD in participants with and without diabetes at baseline and examine the potential modifications by genetic susceptibility on the association.

RESEARCH DESIGN AND METHODS

Included were 348,243 adults from the UK Biobank without prior CKD at baseline. Serum 25OHD concentrations were measured by chemiluminescent immunoassay method. Genetic risk score of CKD was calculated by 263 single nucleotide polymorphisms, which showed significant associations with estimated glomerular filtration rate. The primary outcome was new-onset CKD.

RESULTS

During a median follow-up duration of 12.1 years, 9,344 new-onset CKD were documented. Overall, there was a significant inverse association between baseline serum 25OHD and new-onset CKD in participants with diabetes (per SD increment, adjusted hazard ratio [HR] 0.91; 95% CI 0.86-0.96), but not in those without diabetes (per SD increment, adjusted HR 0.98; 95% CI 0.96-1.01; P-interaction between serum 25OHD and diabetes = 0.004). Accordingly, among participants with diabetes, compared with those baseline serum 25OHD <25 nmol/L, a significantly lower risk of new-onset CKD was found in those with 25OHD ≥50 nmol/L (adjusted HR 0.77; 95% CI 0.67-0.89). Moreover, the genetic risk of CKD did not significantly modify the association between baseline serum 25OHD and new-onset CKD among participants with diabetes (P-interaction = 0.127).

CONCLUSIONS

There was an inverse association between baseline serum 25OHD and new-onset CKD in participants with diabetes. The inverse association was not found in participants without diabetes.

Impact of Vitamin D3 Versus Placebo on Cardiac Structure and Function: A Randomized Clinical Trial

Background

Vitamin D supplementation leads to regression of left ventricular (LV) hypertrophy and improves LV function in animal models. However, limited data exist from prospective human studies. We examined whether vitamin D supplementation improved cardiac structure and function in midlife/older individuals in a large randomized trial.

Methods and Results

The VITAL (Vitamin D and OmegA‐3 Trial) was a nationwide double‐blind, placebo‐controlled randomized trial that tested the effects of vitamin D3 (2000 IU/d) and n−3 fatty acids (1 g/d) on cardiovascular and cancer risk in 25 871 individuals aged ≥50 years. We conducted a substudy of VITAL in which participants underwent echocardiography at baseline and 2 years. Images were interpreted by a blinded investigator at a central core laboratory. The primary end point was change in LV mass. Among 1054 Greater Boston–area participants attending in‐clinic visits, we enrolled 1025 into this study. Seventy‐nine percent returned for follow‐up and had analyzable echocardiograms at both visits. At baseline, the median age was 64 years (interquartile range, 60–69 years), 52% were men, and 43% had hypertension. After 2 years, the change in LV mass did not significantly differ between the vitamin D and placebo arms (median +1.4 g versus +2.6 g, respectively; P =0.32). Changes in systolic and diastolic LV function also did not differ significantly between arms. There were no significant changes in cardiac structure and function between the n−3 fatty acids and placebo arms.

Conclusions

Among adults aged ≥50 years, neither vitamin D3 nor n−3 fatty acids supplementation had significant effects on cardiac structure and function after 2 years.

Registration

URL: https://clinicaltrials.gov/ ; Unique identifiers: NCT01169259 (VITAL) and NCT01630213 (VITAL‐Echo)

Evidence for the Efficacy of a High Dose of Vitamin D on the Hyperinflammation State in Moderate-to-Severe COVID-19 Patients: A Randomized Clinical Trial

Background and Objectives: Vitamin D supplementation plays a key effect in lowering cytokine storms among COVID-19 patients by influencing the activity of the renin-angiotensin system and the production of the angiotensin-2 converting enzyme. The study was conducted to explore the effect of high-dose intramuscular vitamin D in hospitalized adults infected with moderate-to-severe SARS-CoV-2 in comparison with the standard of care in the COVID-19 protocol. Materials and Methods: Two groups of patients were compared in this prospective randomized controlled trial as the vitamin D was administered orally to group 1 (alfacalcidol 1 mcg/day) and intramuscularly to group 2 (cholecalciferol 200,000 IU). One hundred and sixteen participants were recruited in total, with fifty-eight patients in each group. Following the Egyptian Ministry of Health's policy for COVID-19 management, all patients received the same treatment for a minimum of five days. Results: A significant difference was recorded in the length of hospital stay (8.6 versus 6.8 days), need for high oxygen or non-invasive mechanical ventilator (67% versus 33%), need for a mechanical ventilator (25% versus 75%), clinical improvement (45% versus 55%), the occurrence of sepsis (35% versus 65%), and in the monitored laboratory parameters in favor of high-dose vitamin D. Moreover, clinical improvement was significantly associated with the need for low/high oxygen, an invasive/non-invasive mechanical ventilator (MV/NIMV), and diabetes, while mortality was associated with the need for MV, ICU admission, atrial fibrillation, chronic obstructive pulmonary disease, asthma, and the occurrence of secondary infection. Conclusions: Our study showed that high-dose vitamin D was considered a promising treatment in the suppression of cytokine storms among COVID-19 patients and was associated with better clinical improvement and fewer adverse outcomes compared to low-dose vitamin D.

The Association between Vitamin D Hypovitaminosis and Cardiovascular Disease Risk in Saudi Diabetic Patients Type II

We evaluated the prevalence and association of Vitamin D deficiency with glycemic control and CVD risk in T2DM patients. Serum 25 (OH)D3, lipid profile, glucose panel, HbA1c, serum insulin, and HOMA-IR were assessed in 93 T2DM patients and 69 controls. 10 years and lifetime ASCVD risk scores were calculated. The levels of 25(OH)D3 were significantly low in T2DM patients compared to the control. T2DM patients with hypovitaminosis D displayed significantly increased FBG, insulin, and HOMA-IR compared to normovitaminosis. Their lifetime and 10-year ASCVD risk scores were significantly higher regardless of vitamin D deficiency levels (P=0.006; P=0.023) in comparison to patients with sufficient levels of vitamin D. Among patients, the lifetime and 10 years of ASCVD risk showed a significant negative correlation with serum 25(OH)D3 and HDLc (P=0.037; 0.018) (P=0.0001), respectively, and significant positive correlation with T2DM duration, serum insulin, and HOMA-IR (P=0.018; 0.0001) (P=0.002; 0.001) (P=0.005; 0.001), respectively. The 10-year ASCVD risk exhibited a significant positive correlation with FBG (P=0.003) and HbA1c (P=0.009). T2DM duration was a predictor of vitamin D deficiency among T2DM patients (β = 0.22; CI = 0.002-0.04). There is a considerable association between lifetime and 10 years of ASCVD risk with hypovitaminosis D in T2DM, regardless of the deficiency levels which could be predicted by the diabetes duration.

Vitamin D: a potentially important secosteroid for coping with COVID-19

COVID-19 is a disease that has caused a high number of deaths in the world, and despite being controlled, it requires attention and the search for new quick and economical therapeutic strategies. In this sense, vitamin D stands out, an immunomodulator that has shown beneficial effects in decreasing the risk and severity of acute respiratory tract infections, including COVID-19. Therefore, this review presents a number of experimental, observational and clinical studies on the importance of vitamin D against viral infections with an emphasis on COVID-19, highlighting the relationship between vitamin D, Renin-Angiotensin System and cytokine storms with decreased inflammatory lesions in patients with COVID-19. In addition, aspects of pathophysiology, metabolism, risk factors, sources and recommendations of vitamin D are described. We conclude that vitamin D plays a protective role against inflammatory lesions and can decrease the risk of infections and the severity of COVID-19. Therefore, it is essential to maintain adequate levels of vitamin D to avoid complications related to its deficiency.

Effect of calcifediol supplementation on renin-angiotensin-aldosterone system mediators in dogs with chronic kidney disease

Background

Chronic kidney disease (CKD) leads to low serum concentrations of vitamin D metabolites. Thus, hypovitaminosis D associated with CKD might contribute to disease progression via increased concentration of renin angiotensin aldosterone system (RAAS) mediators.

Objectives

To evaluate whether supplementation with calcifediol affects equilibrium concentrations of selected mediators of the RAAS. We hypothesized that vitamin D supplementation will decrease concentration of circulating RAAS mediators in dogs with CKD.

Animals

Six client‐owned adult dogs with IRIS Stage 2 and 3 CKD.

Methods

Prospective study. Serum 25‐hydroxyvitamin D (25[OH]D), 1,25‐dihydroxyvitamin D (1,25[OH]₂D), 24,25‐dihydroxyvitamin D (24,25[OH]₂D), RAAS mediators (angiotensin I/II/III/IV/1‐5/1‐7, and aldosterone), and surrogate angiotensin converting enzyme (ACE) activity (calculated by the ratio of angiotensin II to angiotensin I) were evaluated at baseline, after 3 months of calcifediol supplementation, and 2 months after discontinuing administration of supplement.

Results

All serum vitamin D metabolite concentrations increased significantly by month 3 (P < .001): 25(OH)D (median 250 ng/mL; range, 204‐310), compared to baseline (median 43.2 ng/mL; range, 33.8‐58.3 ng/mL); 1,25(OH)₂D (median 66.1 pg/mL; range, 57.3‐88.1 pg/mL) compared to baseline (median 35.2 pg/mL; range, 29.3‐56.7 pg/mL); 24,25(OH)₂D (median 68.4 ng/mL; range, 22.1‐142.0 ng/mL) compared to baseline (median 14.4 ng/mL; range, 9.0‐21.3 ng/mL). Calculated ACE activity was significantly lower at month 3 (median 0.5; range, 0.4‐1.0) compared to baseline (median 0.7; range, 0.6‐1.3; P = .01). There were no significant differences in any of the evaluated RAAS variables at any other time‐point.

Conclusions and Clinical Importance

Short‐term calcifediol supplementation in this small group of CKD dogs appeared to decrease ACE activity.

Exposure to airborne particulate matter induces renal tubular cell injury in vitro: the role of vitamin D signaling and renin-angiotensin system

Background

Exposure to air pollution can interfere with the vitamin D endocrine system. This study investigated the effects of airborne particulate matter (PM) on renal tubular cell injury in vitro and explored the underlying mechanisms.

Methods

HK-2 human renal proximal tubule cells were treated with PM with or without 1,25(OH)₂D₃ analog, 19-Nor-1,25(OH)₂D₂ (paricalcitol, 10 nM) for 48 h. The dose- and time-dependent cytotoxicity of PM with or without paricalcitol was determined via cell counting kit-8 assay. Cellular oxidative stress was assessed using commercially available enzyme-linked immunosorbent assay kits. The protein expression of vitamin D receptor (VDR), cytochrome P450(CYP)27B1, CYP24A1, renin, angiotensin converting enzyme (ACE), angiotensin II type 1 receptor (AT1), nuclear factor erythroid 2-related factor 2 (Nrf2), nuclear factor-kB (NF-kB), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 was determined.

Results

PM exposure decreased HK-2 cell viability in a dose- and time-dependent manner. The activities of superoxide dismutase and malondialdehyde in HK-2 cells increased significantly in the group exposed to PM. PM exposure decreased VDR and Nrf2, while increasing CYP27B1, renin, ACE, AT1, NF-kB, TNF-α, and IL-6. The expression of VDR, CYP27B1, renin, ACE, AT1, and TNF-α was reversed by paricalcitol treatment. Paricalcitol also restored the cell viability of PM-exposed HK-2 cells.

Conclusion

Our findings indicate that exposure to PM induces renal proximal tubular cell injury, concomitant with alteration of vitamin D endocrine system and renin angiotensin system. Vitamin D could attenuate renal tubular cell damage following PM exposure by suppressing the renin-angiotensin system and by partially inhibiting the inflammatory response.

The Role of Vitamin D in SARS-CoV-2 Infection and Acute Kidney Injury

Vitamin D has been described as an essential nutrient and hormone, which can cause nuclear, non-genomic, and mitochondrial effects. Vitamin D not only controls the transcription of thousands of genes, directly or indirectly through the modulation of calcium fluxes, but it also influences the cell metabolism and maintenance specific nuclear programs. Given its broad spectrum of activity and multiple molecular targets, a deficiency of vitamin D can be involved in many pathologies. Vitamin D deficiency also influences mortality and multiple outcomes in chronic kidney disease (CKD). Active and native vitamin D serum levels are also decreased in critically ill patients and are associated with acute kidney injury (AKI) and in-hospital mortality. In addition to regulating calcium and phosphate homeostasis, vitamin D-related mechanisms regulate adaptive and innate immunity. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections have a role in excessive proinflammatory cell recruitment and cytokine release, which contribute to alveolar and full-body endothelial damage. AKI is one of the most common extrapulmonary manifestations of severe coronavirus disease 2019 (COVID-19). There are also some correlations between the vitamin D level and COVID-19 severity via several pathways. Proper vitamin D supplementation may be an attractive therapeutic strategy for AKI and has the benefits of low cost and low risk of toxicity and side effects.

Vitamin D for Recovery of COVID-19 in Patients With Chronic Kidney Disease

The severity of coronavirus disease 2019 (COVID-19) is determined not only by viral damage to cells but also by the immune reaction in the host. In addition to therapeutic interventions that target the viral infection, immunoregulation may be helpful in the management of COVID-19. Vitamin D exerts effects on both innate and adaptive immunity and subsequently modulates immune responses to bacteria and viruses. Patients with chronic kidney disease (CKD) frequently have vitamin D deficiency and increased susceptibility to infection, suggesting a potential role of vitamin D in this vulnerable population. In this paper, we review the alterations of the immune system, the risk of COVID-19 infections and mechanisms of vitamin D action in the pathogenesis of COVID-19 in CKD patients. Previous studies have shown that vitamin D deficiency can affect the outcomes of COVID-19. Supplementing vitamin D during treatment may be protective against COVID-19. Future studies, including randomized control trials, are warranted to determine the effect of vitamin D supplementation on the recovery from COVID-19 in CKD patients.

Plasma renin, aldosterone, and urinary prostaglandin E2 levels in children with hypocalcemia due to vitamin D deficiency rickets

We investigated the effect of hypocalcemia on plasma renin, aldosterone, and urine PGE₂ levels in children with vitamin D deficiency rickets (VDDR). In the study group, 25 patients with VDDR-induced hypocalcemia were treated with a single dose of 150,000-300,000 IU cholecalciferol and 50 mg/kg/day elemental Ca for 10 days. On any day between 21th and 30th days after the treatment, the patients' clinical, biochemical and radiologic findings were re-evaluated. The healthy children with the same sex and similar age as the study group comprised the control group. Plasma sodium (Na), potassium (K), calcium (Ca), phosphorus (P), alkaline phosphatase (ALP), parathyroid hormone (PTH), 25- hydroxy vitamin D (25OHD), renin, aldosterone; and urinary Ca, creatinine (Cr) and prostaglandin E₂ (PGE₂) levels were measured in both the study (pre-treatment and post-treatment) and the control group. Plasma Ca, P, 25OHD and renin levels and urinary PGE₂/Cr ratio in the post-treatment group were significantly higher than those in the pre-treatment group while K, ALP, and PTH concentrations were significantly lower. Plasma ALP and PTH levels in pre-treatment group were significantly higher than in the control group while Ca, P, 25OHD, aldosterone and renin concentrations and urinary PGE₂/Cr ratio were significantly lower. Post-treatment plasma Ca level was significantly decreased in normal limits compared to the control group while other biochemical parameters were not different from the control group. Plasma Ca concentration was positively correlated with renin level and urinary PGE₂/Cr ratio. The findings suggest that hypocalcemia may inhibit the production of renin, aldosterone and PGE₂ and a blunt aldosterone secretion may develop even after recovery from hypocalcemia.

Association of vitamin D status with COVID-19 and its severity : Vitamin D and COVID-19: a narrative review

Vitamin D is associated with biological activities of the innate and adaptive immune systems, as well as inflammation. In observational studies, an inverse relationship has been found between serum 25-hydroxyvitamin D (25(OH)D) concentrations and the risk or severity of coronavirus disease 2019 (COVID-19). Several mechanisms have been proposed for the role of vitamin D in COVID-19, including modulation of immune and inflammatory responses, regulation of the renin-angiotensin-aldosterone system, and involvement in glucose metabolism and cardiovascular system. Low 25(OH)D concentrations might predispose patients with COVID-19 to severe outcomes not only via the associated hyperinflammatory syndrome but also by worsening preexisting impaired glucose metabolism and cardiovascular diseases. Some randomized controlled trials have shown that vitamin D supplementation is beneficial for reducing severe acute respiratory syndrome coronavirus 2 RNA positivity but not for reducing intensive care unit admission or all-cause mortality in patients with moderate-to-severe COVID-19. Current evidence suggests that taking a vitamin D supplement to maintain a serum concentration of 25(OH)D of at least 30 ng/mL (preferred range 40-60 ng/mL), can help reduce the risk of COVID-19 and its severe outcomes, including mortality. Although further well designed studies are warranted, it is prudent to recommend vitamin D supplements to people with vitamin D deficiency/insufficiency during the COVID-19 pandemic according to international guidelines.

Early pregnancy vitamin D status is associated with blood pressure in children: an Odense Child Cohort study

BACKGROUND

Blood pressure in childhood tracks into later life. Vitamin D status in adults is associated with blood pressure, but the impact of vitamin D status in pregnancy and childhood on blood pressure still needs investigation.

OBJECTIVE

We investigated whether fetal rather than current vitamin D status is associated with blood pressure in children.

METHODS

In a prospective observational study within the population-based Odense Child Cohort (OCC), we examined serum 25-hydroxyvitamin D2+3 [s-25(OH)D] in early and late pregnancy, cord blood, and at 5 y age, and the associations with systolic and diastolic blood pressure (SBP/DBP) in the 5-y-old children (n = 1,677). Multiple regression models were adjusted for maternal country of origin, parity, smoking during pregnancy, 5-y height, and weight. Two-stage mixed effect modeling was performed, integrating all s-25(OH)D data from pregnancy and cord blood.

RESULTS

The median (IQR) s-25(OH)D in early pregnancy, late pregnancy, the umbilical cord, and at 5 y was 65.5 (50.7-78.5), 78.5 (60.3- 95.8), 45.4 (31.1- 60.7), and 71.9 (54.6- 86.5) nmol/L, respectively. The mean ±SD 5-y SBP/DBP was 101.0/63.8 (7.1/5.9) mmHg. In adjusted analyses, a 10 nmol/L increase of s-25(OH)D in early pregnancy associated with a 0.3/0.2 mmHg lower SBP/DBP at 5 y (P < 0.05). Optimal s-25(OH)D (>75 nmol/L) in early pregnancy was associated with lower 5-y SBP and DBP, β (95% CI) -1.45 (-2.6, -0.3), and -0.97 (-1.9, -0.1), compared with reference s-25(OH)D (50-74.9 nmol/L). Two-stage analysis combining early pregnancy, late pregnancy, and cord s-25(OH)D data showed an inverse association with 5-y SBP and DBP for boys (P < 0.025) with significant sex-difference for DBP (Pinteraction = 0.004). No associations were found between s-25(OH)D and 5-y BP above the 90th percentile.

CONCLUSION

Early pregnancy s-25(OH)D concentrations, especially >75 nmol/L, were inversely associated with 5-y blood pressure in the offspring. A novel identified protective effect of optimal vitamin D levels in early pregnancy on offspring BP is suggested.

High-dose versus standard-dose vitamin D supplementation in older adults with COVID-19 (COVIT-TRIAL): A multicenter, open-label, randomized controlled superiority trial

BACKGROUND

Vitamin D supplementation has been proposed as a treatment for Coronavirus Disease 2019 (COVID-19) based on experimental data and data from small and uncontrolled observational studies. The COvid19 and VITamin d TRIAL (COVIT-TRIAL) study was conducted to test whether a single oral high dose of cholecalciferol (vitamin D3) administered within 72 hours after the diagnosis of COVID-19 improves, compared to standard-dose cholecalciferol, the 14-day overall survival among at-risk older adults infected with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2).

METHODS AND FINDINGS

This multicenter, randomized, controlled, open-label, superiority trial involved collaboration of 9 medical centers in France. Patients admitted to the hospital units or living in nursing homes adjacent to the investigator centers were eligible if they were ≥65 years, had SARS-CoV-2 infection of less than 3 days, and at least 1 COVID-19 worsening risk factor (among age ≥75 years, SpO2 ≤94%, or PaO2/FiO2 ≤300 mm Hg). Main noninclusion criteria were organ failure requiring ICU, SpO2 ≤92% despite 5 L/min oxygen, life expectancy <3 months, vitamin D supplementation >800 IU/day during the preceding month, and contraindications to vitamin D supplements. Eligible and consenting patients were randomly allocated to either a single oral high-dose (400,000 IU) or standard-dose (50,000 IU) cholecalciferol administered under medical supervision within 72 hours after the diagnosis of COVID-19. Participants and local study staff were not masked to the allocated treatment, but the Steering Committee and the Data and Safety Monitoring Board were masked to the randomization group and outcome data during the trial. The primary outcome was 14-day overall mortality. Between April 15 and December 17, 2020, of 1,207 patients who were assessed for eligibility in the COVIT-TRIAL study, 254 met eligibility criteria and formed the intention-to-treat population. The median age was 88 (IQR, 82 to 92) years, and 148 patients (58%) were women. Overall, 8 (6%) of 127 patients allocated to high-dose cholecalciferol, and 14 (11%) of 127 patients allocated to standard-dose cholecalciferol died within 14 days (adjusted hazard ratio = 0.39 [95% confidence interval [CI], 0.16 to 0.99], P = 0.049, after controlling for randomization strata [i.e., age, oxygen requirement, hospitalization, use of antibiotics, anti-infective drugs, and/or corticosteroids] and baseline imbalances in important prognostic factors [i.e., sex, ongoing cancers, profuse diarrhea, and delirium at baseline]). The number needed to treat for one person to benefit (NNTB) was 21 [NNTB 9 to ∞ to number needed to treat for one person to harm (NNTH) 46]. Apparent benefits were also found on 14-day mortality due to COVID-19 (7 (6%) deaths in high-dose group and 14 (11%) deaths in standard-dose group; adjusted hazard ratio = 0.33 [95% CI, 0.12 to 0.86], P = 0.02). The protective effect of the single oral high-dose administration was not sustained at 28 days (19 (15%) deaths in high-dose group and 21 (17%) deaths in standard-dose group; adjusted hazard ratio = 0.70 [95% CI, 0.36 to 1.36], P = 0.29). High-dose cholecalciferol did not result in more frequent adverse effects compared to the standard dose. The open-label design and limited study power are the main limitations of the study.

CONCLUSIONS

In this randomized controlled trial (RCT), we observed that the early administration of high-dose versus standard-dose vitamin D3 to at-risk older patients with COVID-19 improved overall mortality at day 14. The effect was no longer observed after 28 days.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04344041.

Vitamin D and its possible relationship to neuroprotection in COVID-19: evidence in the literature

Abstract:

Vitamin D is a hormone involved in the regulation of important biological processes such as signal transduction, immune response, metabolic regulation and also in the nervous and vascular systems. To date, coronavirus disease 2019 (COVID-19) infection does not have a specific treatment, however various drugs have been proposed, including those that attenuate the intense inflammatory response and recently the use of vitamin D, in clinical trials, as part of the treatment of COVID-19 has provided promising results. It has been observed in some clinical studies that the use of cholecalciferol (vitamin D3) and its two metabolites the circulating form, calcidiol or calcifediol (25-hydroxycalciferol, 25-(OH)-D) and the active form, calcitriol (1,25-(OH)2-D), in different doses, improve the clinical manifestations, prognosis and survival of patients infected with COVID-19 probably because of its anti-inflammatory, antiviral and lung-protective action. In relation to the central nervous system (CNS) it has been shown, in clinical studies, that vitamin D is beneficial in some neurological and psychiatric conditions because of its anti-inflammatory and antioxidant properties, modulation of neurotransmitters actions, regulation of calcium homeostasis between other mechanisms. It has been showed that COVID-19 infection induces CNS complications such as headache, anosmia, ageusia, neuropathy, encephalitis, stroke, thrombosis, cerebral hemorrhages, cytotoxic lesions and psychiatric conditions and it has been proposed that the use of dietary supplements, as vitamin and minerals, can be adjuvants in this disease. In this review the evidence of possible role of vitamin D, and its metabolites, as protector against the neurological manifestations of COVID-19 was summarized.

Vitamin D receptor deficiency increases systolic blood pressure by upregulating the renin‑angiotensin system and autophagy

The vitamin D receptor (VDR) may regulate blood pressure via multiple pathways. The present study investigated the underlying mechanism by which VDR deficiency increases blood pressure. A total of 16 8-week-old male littermate mice were randomly divided into the VDR knockout and wild-type groups (VDR^-/- and VDR^+/+, respectively). Blood pressure was measured using a four-channel PowerLab data acquisition and ADI software analysis system. After euthanasia, vascular smooth muscle cells (VSMCs) were isolated from the VDR^-/- and VDR^+/+ mice. Oxidative stress, renin-angiotensin system (RAS) activation and autophagy markers were measured in the isolated VSMCs using reverse transcription-quantitative PCR (RT-qPCR), western blotting and transmission electron microscopy (TEM) assays. Mean systolic pressure was significantly higher in the VDR^-/- mice compared with the VDR^+/+ mice. RT-qPCR and western blotting analyses indicated that RAS markers (angiotensin II and II type 1 receptor) were significantly upregulated, oxidative stress was increased (evidenced by reduced superoxide dismutase and peroxiredoxin-4) and autophagy was activated (upregulation of autophagy related protein 7, Beclin 1 and microtubule-associated proteins 1A/1B light chain 3A) in the VDR^-/- VSMCs compared with the VDR^+/+ VSMCs. TEM demonstrated that there were more autophagy bodies in the VDR^-/- VSMCs compared with the VDR^+/+ VSMCs. In conclusion, VDR deficiency was associated with high blood pressure. The mechanism underlying the increase in blood pressure caused by VDR deficiency may involve activation of the RAS, as well as increased oxidative stress and autophagy of VSMCs.

Chronic diseases, chest computed tomography, and laboratory tests as predictors of severe respiratory failure and death in elderly Brazilian patients hospitalized with COVID-19: a prospective cohort study

BACKGROUND

The primary risk factors for severe respiratory failure and death in the elderly hospitalized with COVID-19 remain unclear.

OBJECTIVE

To determine the association of chronic diseases, chest computed tomography (CT), and laboratory tests with severe respiratory failure and mortality in older adults hospitalized with COVID-19.

METHOD

This was a prospective cohort with 201 hospitalized older adults with COVID-19. Chronic diseases, chest CT, laboratory tests, and other data were collected within the first 48 h of hospitalization. Outcomes were progression to severe respiratory failure with the need of mechanical ventilation (SRF/MV) and death.

RESULTS

The mean age was 72.7 ± 9.2 years, and 63.2% were men. SRF/MV occurred in 16.9% (p < 0.001), and death occurred in 8%. In the adjusted regression analyses, lung involvement over 50% [odds ratio (OR): 3.09 (1.03-9.28; 0.043)], C-reactive protein (CRP) > 80 ng/mL [OR: 2.97 (0.99-8.93; 0.052)], Vitamin D < 40 ng/mL [OR: 6.41 (1.21-33.88; 0.029)], and hemoglobin < 12 g/mL [OR: 3.32 (1.20-9.20; 0.020)] were independent predictors for SFR/MV, while chronic atrial fibrillation [OR: 26.72 (3.87-184.11; 0.001)], cancer history [OR:8.32 (1.28-53.91; 0.026)] and IL-6 > 40 pg/mL [OR:10.01 (1.66-60.13; 0.012)] were independent predictors of death.

CONCLUSION

In hospitalized older adults with COVID-19, tomographic pulmonary involvement > 50%, anemia, vitamin D below 40 ng/mL, and CRP above 80 mg/L were independent risk factors for progression to SRF/MV. The presence of chronic atrial fibrillation, previous cancer, IL-6 > 40 pg/mL, and anemia were independent predictors of death.

Bone and mineral metabolism in patients with primary aldosteronism: A systematic review and meta-analysis

PURPOSE

Patients with primary aldosteronism (PA) tend to exhibit a high prevalence of osteoporosis (OP) that may vary by whether PA is unilateral or bilateral, and responsive to PA treatment. To explore relationships between bone metabolism, PA subtypes, and treatment outcomes, we performed a systematic review and meta-analysis.

METHODS

The PubMed, Embase, and Cochrane databases were searched for clinical studies related to PA and bone metabolism markers. Articles that met the criteria were screened and included in the systematic review; the data were extracted after evaluating their quality. R software (ver. 2022-02-16, Intel Mac OS X 11.6.4) was used for the meta-analysis.

RESULTS

A total of 28 articles were subjected to systematic review, of which 18 were included in the meta-analysis. We found that PA patients evidenced a lower serum calcium level (mean difference [MD] = -0.06 mmol/L, 95% confidence interval [CI]: -0.10 ~ -0.01), a higher urine calcium level (MD = 1.29 mmol/24 h, 95% CI: 0.81 ~ 1.78), and a higher serum parathyroid hormone (PTH) level (MD = 2.16 pmol/L, 95% CI: 1.57 ~ 2.75) than did essential hypertension (EH) subjects. After medical treatment or adrenal surgery, PA patients exhibited a markedly increased serum calcium level (MD = -0.08 mmol/L, 95% CI: -0.11 ~ -0.05), a decreased urine calcium level (MD = 1.72 mmol/24 h, 95% CI: 1.00 ~ 2.44), a decreased serum PTH level (MD = 2.67 pmol/L, 95% CI: 1.73 ~ 3.62), and an increased serum 25-hydroxyvitamin D (25-OHD) level (MD = -6.32 nmol/L, 95% CI: -11.94 ~ -0.70). The meta-analysis showed that the ser um PTH level of unilateral PA patients was significantly higher than that of bilateral PA patients (MD = 0.93 pmol/L, 95% CI: 0.36 ~ 1.49) and the serum 25-OHD lower than that of bilateral PA patients (MD = -4.68 nmol/L, 95% CI: -7.58 ~ 1.77). There were, however, no significant differences between PA and EH patients of 25-OHD, or BMD of femoral neck and lumbar spine. BMDs of the femoral neck or lumbar spine did not change significantly after treatment. The meta-analytical results were confirmed via sensitivity and subgroup analyses.

CONCLUSION

Excess aldosterone was associated with decreased serum calcium, elevated urinary calcium, and elevated PTH levels; these effects may be enhanced by low serum 25-OHD levels. The risks of OP and fracture might be elevated in PA patients, especially unilateral PA patients, but could be reduced after medical treatment or adrenal surgery. In view, however, of the lack of BMD changes, such hypothesis needs to be tested in further studies.