Vitamin D: a novel player in endothelial function and dysfunction

Prolonged clinical remission of type 1 diabetes sustained by calcifediol and low-dose basal insulin: a case report

Herein, we describe an unusually prolonged duration (31 months) of the clinical remission phase in a 22-year-old Italian man with new-onset type 1 diabetes. Shortly after the disease diagnosis, the patient was treated with calcifediol (also known as 25-hydroxyvitamin D3 or calcidiol), coupled with low-dose basal insulin, to correct hypovitaminosis D and to exploit the anti-inflammatory and immunomodulatory properties of vitamin D. During the follow-up period, the patient retained a substantial residual β-cell function and remained within the clinical remission phase, as evidenced by an insulin dose-adjusted glycated hemoglobin value <9. At 24 months, we detected a peculiar immunoregulatory profile of peripheral blood cells, which may explain the prolonged duration of the clinical remission sustained by calcifediol as add-on treatment to insulin.

VITAMIN D DEFICIENCY AS AN INDEPENDENT PREDICTOR OF CARDIOVASCULAR DISEASE

Context

In addition to traditional risk factors for cardiovascular diseases, there are new risk factors with potentially relevant prognostic, such as vitamin D deficiency.

Objective

The study aims to analyze the relationship between vitamin D deficiency and the occurrence of cardiovascular disease, in patients who already have at least one cardiovascular risk factor.

Design

It is a prospective, observational study. Follow- up time was 24 months.

Subjects and methods

A total of 77 patients were included in the study, aged over 18 years, who had at least one cardiovascular risk factor. Their vitamin D levels were measured and they were monitored for a period of 2 years, in order to see which one developed cardiovascular diseases.

Results

Of the 77 patients, 56 (72.7%) had serum deficient levels of vitamin D and the mean serum level was 16 ng/mL (± 8.6 ng/mL). Statistically significant differences were observed only in the case of dyslipidemia (p=0.0334). The evolution to cardiovascular disease occurred in 39 of the cases (50.6%). The only independent risk factors for progression to cardiovascular disease demonstrated in this study were serum vitamin D (OR = 0.9024, 95% CI: 0.83-0.97 and age (OR = 1.1313, 95% CI: 1.05-1.21).

Conclusion

The results shows that patients with cardiovascular risk factors and advanced age are at a higher risk of developing cardiovascular disease, if they also have vitamin D deficiency.

Vitamin D deficiency on admission to the emergency department is a mortality predictor for patients with septic shock treated with early protocol-driven resuscitation bundle therapy

BACKGROUND

Vitamin D is an important immune modulator and is associated with susceptibility to infection. However, past studies have reported inconsistent results regarding the association between vitamin D deficiency and mortality in patients with sepsis, and early-stage data regarding septic shock are limited. This study aimed to determine the relationship between vitamin D deficiency on admission to the emergency department (ED) and mortality in patients with septic shock.

METHODS

We analyzed prospectively collected data on adult patients with septic shock who were treated with protocol-driven resuscitation bundle therapy in the ED between September 2019 and February 2021. Septic shock was defined by the sepsis-3 definition and vitamin D deficiency was defined as a 25-hydroxyvitamin D <20 ng/ml. The primary outcome was 30-day mortality.

RESULTS

A total of 302 patients were included, 236 (78.1%) patients had vitamin D deficiency; it was significantly higher in non-survivors than in survivors (89.3% vs. 73.9%, P = 0.004). Mortality was higher in vitamin D deficient patients than in non-deficient patients (31.8% vs. 13.6%, P = 0.004). In multivariate analysis, vitamin D deficiency (odds ratio [OR], 2.43; 95 % confidence interval [CI], 1.03-5.74), hyperlactatemia (OR, 3.65; 95 % CI, 1.95-6.83), Sequential Organ Failure Assessment scores (OR, 1.22; 95% CI, 1.09-1.36), and albumin levels (OR, 0.39; 95% CI, 0.21-0.73) were significantly associated with 30-day mortality.

CONCLUSIONS

Vitamin D deficiency was prevalent in patients with septic shock visiting the ED and was associated with mortality.

Very low calorie ketogenic diet combined with physical interval training for preserving muscle mass during weight loss in sarcopenic obesity: A pilot study

Background

The prevalence of sarcopenic obesity (SO) is increasing worldwide, posing important challenges to public health and national health care system, especially during the COVID pandemic. In subjects with SO, it is essential to reduce body weight, and to preserve lean mass, to avoid worsening of muscle function. Adequate nutrition and correct physical activity is essential to counteract SO progression. Very Low Calorie Ketogenic Diet (VLCKD), a well-established nutritional intervention for obesity, has been also indicated for the treatment of SO. To date, the effects of physical training during VLCKD have not been investigated.

Aim

This pilot study aims to determine the efficacy of VLCKD combined with interval training, compared to a VLCKD alone, on weight-loss, body composition, and physical performance in participants with SO.

Materials and methods

Twenty-four participants with SO, aged between 50 and 70 years, who met the inclusion criteria, accepted to adhere to a VLCKD (<800 Kcal/die) and to give informed consent, were enrolled in the study. Twelve participants followed a structured VLCKD protocol (VLCKD group) and twelve followed the same VLCKD protocol combined with interval training (IT), twice per week (VLCKD + IT group). Data were collected at baseline (T0) and after 6-week of treatment (T6). Anthropometric indexes, body composition analysis by Bioelectrical Impedance Analysis (BIA), muscle strength and physical performance analysis were assessed at baseline and at the end of treatment.

Results

At the end of the study, body mass index (BMI), body weight, waist circumference, and hip circumference were significantly reduced in both VLCKD group and VLCKD + IT group. Interestingly, a significant improvement in muscle strength and physical performance was observed in both groups. A multiple comparison of delta variations in all parameters between groups was performed. No differences were observed for the majority of anthropometric and biochemical parameters, with the exception of fat free mass (FFM) and fat mass (FM): notably, participants who followed a VLCKD combined with IT preserved FFM (p < 0.001) and reduced FM (p = 0.001) to a greater extent than what observed in VLCKD group. Moreover, high density lipoprotein (HDL) cholesterol plasma levels were significantly higher in the VLCKD + IT group compared to the VLCKD group.

Conclusion

This pilot study confirms that VLCKD is effective in terms of body weight reduction, particularly FM; moreover, the combination of VLCKD and interval training could determine a better preservation of FFM.

Vitamin D attenuates endothelial dysfunction in streptozotocin induced diabetic rats by reducing oxidative stress

Diabetes mellitus (DM) is associated with micro- and macrovascular complications and increased cardiovascular risk. Vitamin D deficiency is the most common nutrient deficiency in the world. This study aimed to examine the effects of diabetes on the endothelial function and the role of vitamin D supplementation. Male Wistar rats (n = 30) were randomly assigned to three groups; control untreated, diabetic untreated, and diabetic groups treated with vitamin D at a dose of 12.5 μg/kg body weight, dissolved in 0.3 ml olive oil orally for 10 weeks. Compared to the control group, the serum glucose, serum asymmetric dimethylarginine (ADMA), aortic malondialdehyde (MDA) levels, endothelin-1 (ET-1) level, inducible nitric oxide synthase (iNOS) activity in diabetic rats were increased, whereas aortic superoxide dismutase (SOD) activity, nitric oxide (NO) levels, and constitutive NOS (cNOS) activity were decreased. Administration of vitamin D to diabetic rats resulted in a decrease of serum glucose, serum ADMA, a decrease of aortic MDA levels, ET-1 and iNOS activity, an increase of aortic SOD activity, NO levels, and cNOS activity. Vitamin D administration attenuated diabetic induced endothelial dysfunction by reducing oxidative stress. These results indicate that chronic vitamin D treatment might be useful in preventing diabetic vascular complications associated with endothelial dysfunction.

The Efficacy of Vitamin D Supplementation in the Treatment of Fibromyalgia Syndrome and Chronic Musculoskeletal Pain

Fibromyalgia syndrome (FMS) and chronic widespread musculoskeletal pain (CMP) are diffuse suffering syndromes that interfere with normal activities. Controversy exists over the role of vitamin D in the treatment of these diseases. We carried out a systematic literature review of randomized controlled trials (RCT) to establish whether vitamin D (25OHD) deficiency is more prevalent in CMP patients and to assess the effects of vitamin D supplementation in pain management in these individuals. We searched PubMed, Physiotherapy Evidence Database (PEDro), and the Cochrane Central Register of Controlled Trials (CENTRAL) for RCTs published in English from 1 January 1990 to 10 July 2022. A total of 434 studies were accessed, of which 14 satisfied the eligibility criteria. In our review three studies, of which two had the best-quality evidence, a correlation between diffuse muscle pain and 25OHD deficiency was confirmed. Six studies, of which four had the best-quality evidence, demonstrated that appropriate supplementation may have beneficial effects in patients with established blood 25OHD deficiency. Eight studies, of which six had the best-quality evidence, demonstrated that 25OHD supplementation results in pain reduction. Our results suggest a possible role of vitamin D supplementation in alleviating the pain associated with FMS and CMP, especially in vitamin D-deficient individuals.

BNT162b2 mRNA COVID-19 Vaccine Does Not Impact the Honeymoon Phase in Type 1 Diabetes: A Case Report

Type 1 diabetes (T1D), which is caused by the autoimmune destruction of insulin-secreting pancreatic beta cells, represents a high-risk category requiring COVID-19 vaccine prioritization. Although COVID-19 vaccination can lead to transient hyperglycemia (vaccination-induced hyperglycemia; ViHG), its influence on the course of the clinical remission phase of T1D (a.k.a. “honeymoon phase”) is currently unknown. Recently, there has been an increasing concern that COVID-19 vaccination may trigger autoimmune phenomena. We describe the case of a 24-year-old young Italian man with T1D who received two doses of the BNT162b2 mRNA (Pfizer-BioNTech) COVID-19 vaccine during a prolonged honeymoon phase. He experienced a transient impairment in glucose control (as evidenced by continuous glucose monitoring) that was not associated with substantial changes in stimulated C-peptide levels and islet autoantibody titers. Nonetheless, large prospective studies are needed to confirm the safety and the immunometabolic impact of the BNT162b2 vaccine in T1D patients during the honeymoon phase. Thus far, T1D patients who are going to receive COVID-19 vaccination should be warned about the possible occurrence of transient ViHG and should undergo strict postvaccination surveillance.

Protective effect of vitamin D on imidacloprid-induced testicular injury in rats

INTRODUCTION

The degenerative effects of imidacloprid via oxidative stress are known. Irisin is a recently discovered peptide with energy regulator and antioxidant effects. In addition, the antioxidant potential of Vitamin D has been reported in previous studies. The current study was performed to investigate the effect of Vitamin D on testis morphology and irisin immunoreactivity in imidacloprid-treated rats.

MATERIAL AND METHODS

Thirty-two Wistar albino male rats were divided into groups: control (n = 6), corn oil (n = 6), Vitamin D (n = 6), imidacloprid (n = 7) and imidacloprid + Vitamin D (n = 7). Testis tissues were used to evaluate the histopathological, biochemical and immunohistochemical changes. Oxidative state in testis tissue was determined with total antioxidant and oxidant status markers, total antioxidant status (TAS) and total oxidant status (TOS) respectively.

RESULTS

In microscopic examination, degenerative changes in the seminiferous tubule epithelium, interstitial edema and increased irisin immunoreactivity were observed in animals given imidacloprid. Also increased TOS and decreased TAS levels were measured in these animals. It was observed that Vitamin D improved the testicular damage histopathologically when compared to the imidacloprid group. However, increase in TAS levels and decrease in both TOS levels and irisin immunoreactivity were found insignificant in animals given Vitamin D.

CONCLUSIONS

In the present study it was observed that Vitamin D ameliorated testis injury caused by imidacloprid. Furthermore, imidacloprid was found to increase the immunoreactivity of irisin. In the light of our findings, we conclude that the use of Vitamin D could be beneficial against testicular damage caused by imidacloprid.

Vitamin D and immuno-pathology of COVID-19: many interactions but uncertain therapeutic benefits

Introduction: COVID-19 pandemic has caused huge loss of human lives and extensive socio-economic damages. The immuno-pathology of this disease is neither clearly understood nor there are effective drugs for severe cases of COVID-19. Repurposing of available drugs for the treatment of COVID-19 is imperative.Areas Covered: This review has gathered the evidence from PubMed, Google Scholar, WHO, and other reliable websites on COVID-19 and summarized the existing knowledge of the immuno-pathology of COVID-19. We elucidated how vitamin D through its diverse actions on immune effector cells, epithelial cells, or renin-angiotensin-aldosterone system could have a modulatory role on the pathogenic mechanisms of COVID-19. The epidemiological evidence associating vitamin D deficiency with the severity and incidence of COVID-19 is also presented. However, the evidence of clinical benefit to patients of COVID-19 from randomized controlled trials with vitamin D has not come as yet.Expert opinion: It is now established that fatality of COVID-19 is primarily determined by hyperactivation of the host's innate immune system in response to SARS-CoV-2 invasion, and thus the research on the immuno-modulatory and other roles of vitamin D against viral infections should be pursued vigorously. This would be also useful for future pandemics caused by other novel viruses.

Cytokine storm modulation in COVID-19: a proposed role for vitamin D and DPP-4 inhibitor combination therapy (VIDPP-4i)

A dysregulated immune response characterized by the hyperproduction of several pro-inflammatory cytokines (a.k.a. 'cytokine storm') plays a central role in the pathophysiology of severe coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this Perspective article we discuss the evidence for synergistic anti-inflammatory and immunomodulatory properties exerted by vitamin D and dipeptidyl peptidase-4 (DPP-4) inhibitors, the latter being a class of antihyperglycemic agents used for the treatment of Type 2 diabetes, which have also been reported as immunomodulators. Then, we provide the rationale for investigation of vitamin D and DPP-4 inhibitor combination therapy (VIDPP-4i) as an immunomodulation strategy to ratchet down the virulence of SARS-CoV-2, prevent disease progression and modulate the cytokine storm in COVID-19.

Combination of vitamin D and dipeptidyl peptidase-4 inhibitors (VIDPP-4i) as an immunomodulation therapy for autoimmune diabetes

Type 1 diabetes (T1D) and latent autoimmune diabetes in adults (LADA) represent the most common types of autoimmune diabetes and are characterized by different age of onset, degrees of immune-mediated destruction of pancreatic beta cells and rates of disease progression towards insulin dependence. Several immunotherapies aimed to counteract autoimmune responses against beta cells and preserve beta-cell function are currently being investigated, particularly in T1D. Preliminary findings suggest a potential role of combination therapy with vitamin D and dipeptidyl peptidase-4 (DPP-4) inhibitors (VIDPP-4i) in preserving beta-cell function in autoimmune diabetes. This manuscript aims to provide a comprehensive overview of the immunomodulatory properties of vitamin D and DPP-4 inhibitors, as well as the rationale for investigation of their combined use as an immunomodulation therapy for autoimmune diabetes.

Low Vitamin D Status at Admission as a Risk Factor for Poor Survival in Hospitalized Patients With COVID-19: An Italian Retrospective Study

OBJECTIVE

Preliminary findings suggest a relationship between lower serum 25-hydroxyvitamin D [25(OH)D] levels and incidence and severity of COVID-19. The aim of this study was to evaluate the relationship between vitamin D status at admission and different markers of inflammation, coagulation, and sepsis in hospitalized patients with COVID-19.

METHOD

We conducted a retrospective study on 137 consecutive patients with SARS-CoV-2 infection and available data on serum 25(OH)D levels, who were admitted to our Institution between March 1 and April 30, 2020. Patients were divided into two groups: survivors (n = 78; 57%) and non-survivors (n = 59; 43%).

RESULTS

At admission, all patients showed hypovitaminosis D. Median total serum 25(OH)D levels at admission were significantly higher in survivors than non-survivors (12 ng/mL vs 8 ng/mL; p < 0.01). Non-survivors exhibited significantly higher median levels of white blood cell (WBC) count, neutrophil-to-lymphocyte count ratio (NLR), high-sensitivity C-reactive protein (hsCRP), ferritin, interleukin 6 (IL-6), D-dimer, fibrinogen, and procalcitonin (PCT) compared to survivors at three different time points during hospitalization. In a multivariate analysis performed by a logistic regression model, serum 25(OH)D levels were significantly inversely associated with risk of COVID-19-related in-hospital mortality (odds ratio, 0.91; 95% confidence interval, 0.85-0.98; p = 0.01). According to receiver operating characteristic curve analysis, hsCRP, NLR, ferritin, and D-dimer were the best predictive biomarkers for poor prognosis of COVID-19, whereas IL-6, PCT, fibrinogen, 25(OH)D, WBC count, and tumor necrosis factor alpha (TNF-α) may serve as supportive biomarkers for worse clinical course of the disease.

CONCLUSIONS

We found a markedly high prevalence (100%) of hypovitaminosis D in patients admitted to hospital with COVID-19, suggesting a possible role of low vitamin D status in increasing the risk of SARS-CoV-2 infection and subsequent hospitalization. The inverse association between serum 25(OH)D levels and risk of in-hospital mortality observed in our cohort suggests that a lower vitamin D status upon admission may represent a modifiable and independent risk factor for poor prognosis in COVID-19.

Association between Vitamin D and Heart Failure Mortality in 10,974 Hospitalized Individuals

A broad range of chronic conditions, including heart failure (HF), have been associated with vitamin D deficiency. Existing clinical trials involving vitamin D supplementation in chronic HF patients have been inconclusive. We sought to evaluate the outcomes of patients with vitamin D supplementation, compared with a matched cohort using real-world big data of HF hospitalization. This study was based on the Diagnosis Procedure Combination database in the Japanese Registry of All Cardiac and Vascular Datasets (JROAD-DPC). After exclusion criteria, we identified 93,692 patients who were first hospitalized with HF between April 2012 and March 2017 (mean age was 79 ± 12 years, and 52.2% were male). Propensity score (PS) was estimated with logistic regression model, with vitamin D supplementation as the dependent variable and clinically relevant covariates. On PS-matched analysis with 10,974 patients, patients with vitamin D supplementation had lower total in-hospital mortality (6.5 vs. 9.4%, odds ratio: 0.67, p < 0.001) and in-hospital mortality within 7 days and 30 days (0.9 vs. 2.5%, OR, 0.34, and 3.8 vs. 6.5%, OR: 0.56, both p < 0.001). In the sub-group analysis, mortalities in patients with age < 75, diabetes, dyslipidemia, atrial arrhythmia, cancer, renin-angiotensin system blocker, and β-blocker were not affected by vitamin D supplementation. Patients with vitamin D supplementation had a lower in-hospital mortality for HF than patients without vitamin D supplementation in the propensity matched cohort. The identification of specific clinical characteristics in patients benefitting from vitamin D may be useful for determining targets of future randomized control trials.

A Potential Linking between Vitamin D and Adipose Metabolic Disorders

Vitamin D has been discovered centuries ago, and current studies have focused on the biological effects of vitamin D on adipogenesis. Besides its role in calcium homeostasis and energy metabolism, vitamin D is also involved in the regulation of development and process of metabolic disorders. Adipose tissue is a major storage depot of vitamin D. This review summarized studies on the relationship between vitamin D and adipogenesis and furthermore focuses on adipose metabolic disorders. We reviewed the biological roles and functionalities of vitamin D, the correlation between vitamin D and adipose tissue, the effect of vitamin D on adipogenesis, and adipose metabolic diseases. Vitamin D is associated with adipogenesis, and vitamin D supplements can reduce the burden caused by metabolic diseases. The review provides new insights and basis for medical therapy on adipose metabolic diseases.

Influence of Vitamin D on Islet Autoimmunity and Beta-Cell Function in Type 1 Diabetes

Type 1 diabetes (T1D) is a chronic autoimmune disease leading to immune-mediated destruction of pancreatic beta cells, resulting in the need for insulin therapy. The incidence of T1D is increasing worldwide, thus prompting researchers to investigate novel immunomodulatory strategies to halt autoimmunity and modify disease progression. T1D is considered as a multifactorial disease, in which genetic predisposition and environmental factors interact to promote the triggering of autoimmune responses against beta cells. Over the last decades, it has become clear that vitamin D exerts anti-inflammatory and immunomodulatory effects, apart from its well-established role in the regulation of calcium homeostasis and bone metabolism. Importantly, the global incidence of vitamin D deficiency is also dramatically increasing and epidemiologic evidence suggests an involvement of vitamin D deficiency in T1D pathogenesis. Polymorphisms in genes critical for vitamin D metabolism have also been shown to modulate the risk of T1D. Moreover, several studies have investigated the role of vitamin D (in different doses and formulations) as a potential adjuvant immunomodulatory therapy in patients with new-onset and established T1D. This review aims to present the current knowledge on the immunomodulatory effects of vitamin D and summarize the clinical interventional studies investigating its use for prevention or treatment of T1D.

Association between vitamin D and risk of cardiovascular disease in Chinese rural population

Previous studies have suggested that vitamin D is associated with cardiovascular disease (CVD), however, the relationship between vitamin D levels and CVD risk is still unclear. The purpose of this study was to assess the relationship of serum concentration of 25-hydroxyvitamin D (25(OH)D) with CVD in rural residents of Henan province of China. Basic information and medical history were gathered through face-to-face surveys from July 2013 to August 2015, and biochemical indicators were gathered in a laboratory setting. Logistic and restricted cubic splines regression analyses were used to estimate odd ratios (ORs) and 95% confidence intervals (95%CI) of CVD. A total of 1078 participants were included, the mean serum 25(OH)D concentration was determined to be 25 ± 18 ng/ml, with 54.45% of the participants presenting vitamin D deficiency [25(OH)D < 20 ng/mL]. Moreover, the prevalence of CVD was 59.28% in the vitamin D deficient group, which was higher than in the insufficient (48.55%) and sufficient groups (52.78%). After adjusting for potential confounders, compared with the deficient group, the ORs (95%CI) of CVDs were 0.68 (0.50, 0.91) in the insufficient group and 0.81 (0.56, 1.16) in the sufficient group. A nonlinear (U-shaped) association was observed between the risk of CVD and 25(OH)D concentration. Further research suggested that the risk of CVD was higher in males than in females. In conclusion, a U-shape association between serum levels of 25(OH)D and the risk of CVD was identified in our study, suggesting a nonlinear relationship between vitamin D with the prevalence of CVD.

Relationship between low levels of circulating TRAIL and atheromatosis progression in patients with chronic kidney disease

Background

Chronic kidney disease (CKD) patients experience a high risk of cardiovascular disease (CV); however, the factors involved in CV-related morbidity and mortality in these patients have not been fully defined. Tumor necrosis factor related apoptosis-inducing ligand (TRAIL) is a cytokine, which exhibits pleiotropic activities on endothelial, vascular smooth muscle and inflammatory cells, with relevant effects on atheromatous plaque formation. On this basis, the present study aims to investigate the role of TRAIL in atheromatosis progression in CKD patients.

Methods

Circulating TRAIL levels were measured in 378 CKD patients belonging to the Spanish National Observatory of Atherosclerosis in Nephrology (NEFRONA) study. All patients were free of previous CV events. Carotid and femoral B-mode ultrasound was performed to detect the presence of plaque at baseline and after 24 months of follow-up.

Results

The lowest levels of TRAIL at baseline were significantly (p<0.05) associated with the appearance, after 24 months of follow-up, of at least two new atheromatous plaques in all territories and of one new plaque in the carotid artery, even after adjusting for CV risk factors. In addition, the patients with low levels of TRAIL at baseline were characterized by the presence of at least one hypoechoic plaque in the carotid artery. This association was significant (p<0.05) even after adjusting for CKD stage.

Conclusions

Overall, the results of our study suggest TRAIL as an assertable independent prognostic biomarker for atheromatosis plaque formation in CKD patients. This observation further supports the potential role of TRAIL for the prevention/treatment of CV disease.

Effect of vitamin D on ventricular remodelling in heart failure: a meta-analysis of randomised controlled trials

OBJECTIVES

The level of vitamin D is considered to be associated with the development and progression of heart failure (HF). However, it is still unclear whether supplementation of vitamin D could improve ventricular remodelling in patients with HF. This study aimed to systematically evaluate the influence and safety of additional vitamin D supplementation on ventricular remodelling in patients with HF.

DESIGN

This study is a meta-analysis of randomised controlled trials (RCTs).

SETTING

The PubMed, EMBASE, CNKI, Cochrane library, Web of Science databases and grey literature were searched for RCTs regarding the effect of vitamin D on ventricular remodelling in patients with HF (from database creation to October 2017). RevMan V.5.3 software was employed for data analysis.

PARTICIPANTS

Seven RCTs with a total of 465 patients, including 235 cases in the vitamin D group and 230 cases in the control group, were included.

PRIMARY AND SECONDARY OUTCOME MEASURES

Left ventricular end-diastolic dimension (LVEDD), left ventricular ejection fraction (LVEF) and the incidence of adverse reactions.

RESULTS

Compared with the control group, a decrease in the LVEDD (mean difference (MD)=-2.31 mm, 95% CI -4.15 to -0.47, p=0.01) and an increase in the LVEF (MD=4.18%, 95% CI 0.36 to 7.99, p=0.03) were observed in the vitamin D group. Subgroup analysis also revealed a reduced LVEDD in adults (>18 years) and adolescents (<18 years) of the vitamin D group relative to that in those of the control group. High-dose vitamin D (>4000 IU/day) was more effective at reducing the LVEDD than low-dose vitamin D (<4000 IU/day). Moreover, vitamin D supplementation was more effective at reducing the LVEDD and increasing the LVEF in patients with reduced ejection fraction than in patients without reduced ejection fraction.

CONCLUSION

Vitamin D supplementation inhibits ventricular remodelling and improves cardiac function in patients with HF.

TRIAL REGISTRATION NUMBER

CRD42017073893.

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

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

Effect of combined vitamin D receptor activator and lanthanum carbonate on serum fibroblast growth factor 23 level in predialysis patients (CVD-LAF study): design and method

BACKGROUND

Whether vitamin D receptor activator (VDRA) use is beneficial in chronic kidney disease (CKD) is unclear, because it is possible that VDRA increases serum fibroblast growth factor 23 (FGF23) levels. We will conduct a randomized controlled trial in predialysis patients to determine the effect of VDRA alone or in combination with lanthanum carbonate (LC) on serum FGF23 levels.

METHODS

This is a single-center, open-label, randomized controlled trial. Enrollment will commence February 1, 2018, using the following inclusion criteria: (1) age ≥ 20 years, (2) CKD with an estimated glomerular filtration rate of 10-45 mL/min/1.73 m², (3) serum adjusted calcium level < 9.5 mg/dL, (4) serum phosphate level 4.0-6.0 mg/dL, and (5) serum intact parathyroid hormone (PTH) level ≥ 60 pg/mL. Study patients will be randomized 1:1 to receive alfacalcidol alone or in combination with LC. The initial dose of alfacalcidol will be 0.25-0.5 µg once a day according to serum adjusted calcium level. The initial dose of LC will be 250 mg once a day. We will measure serum intact and C-terminal FGF23 at 0, 4, 8, 12, 24, and 52 weeks. The primary outcome will be serum FGF23 level at 24 weeks compared with baseline.

DISCUSSION

This study aims to determine whether low-dose oral VDRA increases serum FGF23 level and whether the combination of VDRA and LC inhibits this increase. The results will be useful in the management of CKD-mineral and bone disorder in predialysis patients.

TRIAL REGISTRATION

UMIN000030503. Registered 20 January 2018.

Vitamin D and regulation of vascular cell function

Vitamin D deficiency is linked to pathogenesis of many diseases including cardiovascular, cancer, and various eye diseases. In recent years, important roles for vitamin D in regulation of immune function, inflammation, angiogenesis, and aging have been demonstrated. Thus, vitamin D and its analogs have been evaluated for the treatment of various types of cancer and chronic diseases. We have previously shown that the active form of vitamin D [1,25(OH)₂D₃] is a potent inhibitor of angiogenesis. This activity is consistent with the important role proposed for vitamin D and its analogs in the mitigation of tumor growth through inhibition of angiogenesis. Here, we review the important nutritional value of vitamin D and the abnormalities linked to its deficiency. We will explore its potential role as a regulator of angiogenesis and vascular cell function and the role vitamin D receptor (VDR) expression plays in these activities during vascular development and neovascularization. Our studies have established an important role for 1,25(OH)₂D₃ and VDR in the regulation of perivascular supporting cell function. In addition, the interaction of 1,25(OH)₂D₃ and VDR is essential for these activities and inhibition of neovascularization. Delineating the signaling pathways involved and identification of genes that are the target of 1,25(OH)₂D₃ regulation in vascular cells will allow us to identify novel pathways that are targets for regulation of vascular function and angiogenesis.

The Associations of Endotoxemia With Systemic Inflammation, Endothelial Activation, and Cardiovascular Outcome in Kidney Transplantation

OBJECTIVE

Cardiovascular disease is the leading cause of death in kidney transplant recipients (KTRs), yet incompletely accountable by traditional risk factors. Inflammation is an unconventional cardiovascular risk factor, with gut-derived endotoxemia potentially driving inflammation and endothelial disease. Comparable data are lacking in kidney transplantation. This study investigated the associations of endotoxemia with inflammation, endothelial activation, and 5-year cardiovascular events in KTRs. Determinants of endotoxemia were also explored.

DESIGN AND METHODS

This is a single-center cross-sectional study with prospective follow-up from a prevalent cohort of 128 KTRs.

MAIN OUTCOME MEASURES

Demographic, nutritional and clinical predictors of inflammation (high-sensitivity C-reactive protein [hsCRP]), endothelial activation (sE-selectin), and endotoxemia (endotoxin) were assessed. Follow-up data on 5-year cardiovascular event rates were collected.

RESULTS

Endotoxemia (P = .03), reduced 25-hydroxyvitamin D (P = .04), high fructose intake (P < .001), decreased fiber intake (P < .001), and abdominal obesity (P = .002) were independently associated with elevated hsCRP. In turn, endotoxemia (P = .007) and increasing hsCRP (P = .02) were both independently associated with raised sE-selectin. Furthermore, endotoxemia predicted increased cardiovascular event rate (P = .02), independent of hsCRP and a global measure of cardiovascular risk estimated by a validated algorithm of 7-year risk for major adverse cardiac events in kidney transplantation. Determinants of endotoxemia included reduced 25-hydroxyvitamin D (P < .001), hypertriglyceridemia (P < .001), increased fructose intake (P = .01), and abdominal obesity (P = .01).

CONCLUSIONS

Endotoxemia in KTRs contributes to inflammation, endothelial activation, and increased cardiovascular events. This study highlights the clinical relevance of endotoxemia in KTRs, suggesting future interventional targets.

Vitamin D: not just the bone. Evidence for beneficial pleiotropic extraskeletal effects

Vitamin D is a fat-soluble vitamin and a steroid hormone that plays a central role in maintaining calcium-phosphorus and bone homeostasis in close interaction with parathyroid hormone, acting on its classical target tissues, namely, bone, kidney, intestine, and parathyroid glands. However, vitamin D endocrine system regulates several genes (about 3 % of the human genome) involved in cell differentiation, cell-cycle control, and cell function and exerts noncalcemic/pleiotropic effects on extraskeletal target tissues, such as immune and cardiovascular system, pancreatic endocrine cells, muscle, and adipose tissue. Several studies have demonstrated the role of vitamin D supplementation in the prevention/treatment of various autoimmune diseases and improvement of glucose metabolism, muscle, and adipose tissue function. Hence, this review aims to elucidate the effects of vitamin D on extraskeletal target tissues and to investigate the potential therapeutic benefit of vitamin D supplementation among a broad group of pathological conditions, especially with regard to metabolic and autoimmune diseases. In addition, we focused on the best daily intakes and serum levels of vitamin D required for extraskeletal benefits which, even if still controversial, appear to be higher than those widely accepted for skeletal effects.

High Levels of Hemoglobin Promote Carotid Adventitial Vasa Vasorum Neoangiogenesis in Chronic Kidney Disease

Chronic kidney disease (CKD) patients, characterized by traditional and nontraditional risk factors, are prone to develop atheromatosis and thus cardiovascular events and mortality. The angiogenesis of the adventitial vasa vasorum (aVV) surrounding the carotid has been described as the atheromatosis initiator. Therefore, the aim of the study was to (1) evaluate if the carotid aVV in CKD patients increases in comparison to its physiological value of healthy patients; (2) explore which traditional or nontraditional risk factor including inflammation, bone and mineral metabolism, and anemia could be related to the aVV angiogenesis. CKD patients without previous cardiovascular events (44, stages 3-4; 37, stage 5D) and 65 healthy subjects were compared. The carotid aVV and the intima-media thickness (cIMT) were evaluated by ultrasound. CKD patients at stages 3-4 showed higher aVV of the right carotid artery even after adjusting for age. Importantly, a multiple linear regression model showed hemoglobin levels > 12.5 g/dL as the factor for an estimated higher aVV of the right carotid artery. In conclusion, the association of hemoglobin with higher aVV could suggest the role of high hemoglobin in the higher incidence of adverse cardiovascular outcomes in CKD patients.

Vitamin D and inflammation: evaluation with neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio

INTRODUCTION

Association of vitamin D, inflammation and endothelial dysfunction, beside the classic bone metabolism disorders, may explain the pathogenesis of numerous diseases associated with vitamin D deficiency. While large numbers of reports support the relationship of vitamin D with inflammation, several reports fail to confirm this relationship. Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are novel and inexpensive markers of inflammation that can be studied in all centers. The goal of this study was to investigate the association between 25-hydroxy vitamin D (25(OH)D) and inflammation with the novel inflammatory markers NLR and PLR.

MATERIAL AND METHODS

This study was performed retrospectively. Results of the simultaneously performed 25(OH)D, parathyroid hormone, albumin, calcium, phosphorus, alkaline phosphatase and creatinine level measurements and complete blood count were recorded. The data of 4120 patients were included in the study.

RESULTS

Between vitamin D deficient and non-deficient groups there were significant differences in PLR (p < 0.001) and NLR (p = 0.001). Vitamin D had a significant negative correlation with PLR (p < 0.001) and NLR (p < 0.001). Multiple regression analysis indicated that 25(OH)D was independently and negatively correlated with PLR (OR = 0.994, 95% CI 0.991-0.998, p = 0.02).

CONCLUSIONS

Platelet-to-lymphocyte ratio and NLR were significantly associated with 25(OH)D levels, and PLR was found to be an independent predictor of 25(OH)D levels. Our study revealed an inverse association of vitamin D levels and inflammation with these inexpensive and universally available markers.

Inflammatory markers and cardiovascular risks among overweight-obese Emirati women

BACKGROUND

The prevalence of abdominal obesity among women in UAE is exceptionally high. However, its impact on cardiovascular health has not been adequately investigated. The aims of this study were to investigate: (1) correlations between inflammatory and oxidative biomarkers vs. anthropometric and metabolic measures; (2) rates of dyslipidemia, diabetes, and hypertension and (3) risks of cardiovascular disease.

METHODS

One hundred ten "healthy" overweight/obese Emirati women attending nutrition counselling clinics were randomly recruited. All participants had completed questionnaire, physical examination and laboratory assessment.

RESULTS

The participants' mean ± SD of age, body mass-index, waist circumference were 39 ± 9 years, 34 ± 6 kg/m(2) and 100 ± 13 cm respectively. Among the studied women 45 % met diagnostic criteria for metabolic syndrome showing a positive correlation of hsCRP with BMI (p = 0.002), body fat (p = 0.002) and waist circumference (p = 0.018). There was positive correlation of IL-6 with waist circumference (p = 0.019) and adiponectin with HDL (p = 0.007). Prevalence of HDL <1.3 mmol/L or triglycerides ≥1.7 mmol/L were 82 %, dysglycemia 31 %, and hypertension 27 and 37 % of women had either 'high' or 'moderate' calculated cardiovascular 10-year risk score.

CONCLUSION

The levels of inflammatory and oxidative stress markers were highly prevalent among overweight/obese Emirati women and this may predispose to increasing cardiovascular risks at relatively young age. Thus effective strategies to impact cardiovascular burden and conducting outcome studies assessing the increased risk of cardiovascular disease and addressing obesity prevention among women are urgently needed.

Predialysis Vitamin D Receptor Activator Treatment and Cardiovascular Events after Dialysis Initiation: A Multicenter Observational Study

BACKGROUND

Vitamin D receptor activator (VDRA) administration has been linked with a reduced incidence of cardiovascular disease (CVD). However, it is unclear whether VDRA administration during the predialysis stage is associated with CVD incidence after dialysis initiation in patients with chronic kidney disease. Therefore, we examined the association between VDRA use and CVD events.

METHODS

This multicenter observational study included 1,516 patients; they were divided into 2 groups: those who did and did not receive oral VDRA for at least 3 months before dialysis initiation. The CVD incidence was compared between these groups. Factors that impacted CVD incidence were extracted through a multivariate analysis. Subgroups were created based on prior CVD history and serum CRP levels.

RESULTS

The incidence of CVD was significantly lower in the VDRA group (log-rank test, p = 0.014). Stepwise multivariate analyses identified age, gender, diabetes, CVD history, calcium-channel blockers, beta-blockers, loop diuretics, anti-platelet agents, phosphate binders, VDRA, erythropoiesis stimulating agents, and cardiothoracic ratio as factors affecting CVD incidence. In the group with no CVD history, VDRA use was associated with a low incidence of CVD (HR 0.35). In the group with serum CRP levels <1.0 mg/dl, VDRA use was associated with a low incidence of CVD (HR 0.47).

CONCLUSION

Administration of VDRA during predialysis was associated with a low incidence of CVD onset after dialysis initiation.

Vitamin D protects endothelial cells from irradiation-induced senescence and apoptosis by modulating MAPK/SirT1 axis

PURPOSE

Radiotherapy toxicity is related to oxidative stress-mediated endothelial dysfunction. Here, we investigated on radioprotective properties of Vitamin D (Vit.D) on human endothelial cells (HUVEC).

METHODS

HUVEC, pre-treated with Vit.D, were exposed to ionizing radiation (IR): ROS production, cellular viability, apoptosis, senescence and western blot for protein detection were performed. The role of MAPKs pathway was investigated by using U0126 (10 μM) MEKs/ERKs-, SB203580 (2.5 μM) p38-inhibitor or by over/expressing MKK6 p38-upstream activator.

RESULTS

Vit.D reduced IR-induced ROS production protecting proliferating and quiescent HUVEC from cellular apoptosis or senescence, respectively, by regulating MAPKs pathways. In proliferating HUVEC, Vit.D prevented IR-induced apoptosis by activating ERKs while in quiescent HUVEC counteracted IR-induced senescence by inhibiting the p38-IR-induced activation. MEKs&ERKs inhibition in proliferating or MKK6/mediated p38 activation in quiescent HUVEC, respectively, reverted anti-apoptotic or anti-senescent Vit.D properties. SirT1 protein expression levels were up-regulated by Vit.D. ERKs inhibition blocked Vit.D-induced SirT1 protein up-regulation in proliferating cells. In quiescent HUVEC cells, p38 inhibition counteracted the IR-induced SirT1 protein down-regulation, while MKK6 transfection abrogated the Vit.D positive effects on SirT1 protein levels after irradiation. SirT1 inhibition by sirtinol blocked the Vit.D radioprotective effects.

CONCLUSION

Vit.D protects HUVEC from IR induced/oxidative stress by positively regulating the MAPKs/SirT1 axis.

Vitamin D Supplementation in the Treatment of Chronic Heart Failure: A Meta-analysis of Randomized Controlled Trials

BACKGROUND

In recent years, there has been growing evidence that vitamin D deficiency is associated with the development and progression of chronic heart failure (CHF).

HYPOTHESIS

Additional supplementation of vitamin D may have protective effects in patients with CHF.

METHODS

We searched PubMed, Embase, and Cochrane databases through June 2015 and included 7 randomized controlled trials that investigated the effects of vitamin D on cardiovascular outcomes in patients with CHF. Then, we performed a meta-analysis of clinical trials to confirm whether vitamin D supplementation is beneficial in CHF patients. The weighted mean difference (WMD) and 95% confidence interval (CI) were calculated using fixed- or random-effects models.

RESULTS

Our pooled results indicated that additional supplementation of vitamin D was not superior to conventional treatment in terms of left ventricular ejection fraction, N-terminal pro-B-type natriuretic peptide, and 6-minute walk distance. Moreover, vitamin D supplementation was associated with significant decreases in the levels of tumor necrosis factor-α (WMD: -2.42 pg/mL, 95% CI: -4.26 to -0.57, P < 0.05), C-reactive protein (WMD: -0.72 mg/L, 95% CI: -1.42 to -0.02, P < 0.05), and parathyroid hormone (WMD: -13.44 pg/mL, 95% CI: -21.22 to -5.67, P < 0.05).

CONCLUSIONS

Vitamin D supplementation may decrease serum levels of parathyroid hormone and inflammatory mediators in CHF patients, whereas it has no beneficial effects on improvement of left ventricular function and exercise tolerance.

Serum parathyroid hormone and 25-hydroxyvitamin D concentrations and risk of incident heart failure: the Multi-Ethnic Study of Atherosclerosis

Background

Heart failure (HF) is common and is associated with high mortality. We aimed to determine associations of serum parathyroid hormone (PTH) and 25‐hydroxyvitamin D (25[OH]D) with incident HF and left ventricular mass.

Methods and Results

Among 6459 participants in the community‐based Multi‐Ethnic Study of Atherosclerosis, all of whom were free of prevalent clinical cardiovascular disease, we measured serum concentrations of PTH and 25(OH)D at the baseline examination. In longitudinal analyses, we tested associations of PTH and 25(OH)D with incident HF events, adjudicated by a panel of physicians. In cross‐sectional analyses of a subset of 4763 participants, we tested associations of PTH and 25(OH)D with left ventricular mass, measured by cardiac magnetic resonance imaging at baseline. Multivariable Cox proportional hazard and linear regression models were adjusted for demographics, physical examination measures, comorbidity, kidney function, and other mineral metabolism markers. Mean age was 62 years and 53% of participants were female. There were 180 incident HF events over a median (interquartile range) follow‐up time of 8.46 (7.67 to 8.63) years. Compared with participants with PTH <65 pg/mL, PTH ≥65 pg/mL was associated with a 50% greater risk of incident HF (95% CI: 3% to 210%) and a 5.3 g higher left ventricular mass (95% CI: 2.6, 7.9 g). In contrast, there was no association of 25(OH)D with risk of incident HF or elevated left ventricular mass.

Conclusions

In a racially/ethnically diverse population without prevalent cardiovascular disease, higher serum PTH concentration was associated with increased left ventricular mass and increased risk of incident HF. Further studies should be pursued to determine whether PTH excess may be a modifiable risk factor for HF.

Vitamin D deficiency and cardiovascular disease: potential mechanisms and novel perspectives

Interest in contemporary vitamin D research has been sparked in recent years, stemming from the identification of vitamin D receptors in virtually all cells as well as the enzymatic machinery necessary to produce its active form. Both epidemiological and in-vitro studies have linked vitamin D deficiency to enigmatic diseases including cardiovascular disease; however, a clear mechanistic link remains missing. This review highlights conclusions of observational studies, in-vitro experiments and randomized-controlled trials that aimed to link deficiency of the sunshine vitamin to one of the leading causes of death in the world, cardiovascular disease. Furthermore, putative mechanisms viewed from a novel perspective are also discussed.

Potential pathophysiological role for the vitamin D deficiency in essential hypertension

Vitamin D deficiency has been indicated as a pandemic emerging public health problem. In addition to the well-known role on calcium-phosphorus homeostasis in the bone, vitamin D-mediated processes have been recently investigated on other diseases, such as infections, cancer and cardiovascular diseases. Recently, both the discovery of paracrine actions of vitamin D (recognized as “local vitamin D system”) and the link of vitamin D with renin-angiotensin-aldosterone system and the fibroblast growth factor 23/klotho pathways highlighted its active cardiovascular activity. Focusing on hypertension, this review summarizes the more recent experimental evidence involving the vitamin D system and deficiency in the cardiovascular pathophysiology. In particular, we updated the vascular synthesis/catabolism of vitamin D and its complex interactions between the various endocrine networks involved in the regulation of blood pressure in humans. On the other hand, the conflicting results emerged from the comparison between observational and interventional studies emphasize the fragmentary nature of our knowledge in the field of vitamin D and hypertension, strongly suggesting the need of further researches in this field.

Vitamin D and neurocognitive function

In recent years, emerging evidence has linked vitamin D not only to its known effects on calcium and bone metabolism, but also to many chronic illnesses involving neurocognitive decline. The importance of vitamin D₃ in reducing the risk of these diseases continues to increase due to the fact that an increasing portion of the population in developed countries has a significant vitamin D deficiency. The older population is at an especially high risk for vitamin D deficiency due to the decreased cutaneous synthesis and dietary intake of vitamin D. Recent studies have confirmed an association between cognitive impairment, dementia, and vitamin D deficiency. There is a need for well-designed randomized trials to assess the benefits of vitamin D and lifestyle interventions in persons with mild cognitive impairment and dementia.

The effect of acute administration of vitamin D on micro vascular endothelial function in Caucasians and South Asian Indians

BACKGROUND

Vitamin D is a modulator of the immune system. There is some limited evidence that it also increases local blood flow in response to stress.

MATERIAL AND METHODS

In the present study, we examined 20 age matched subjects; 10 whom were from India and 10 Caucasians from the United States. Subjects were administered 4000 IU of Vitamin D3 for 3 weeks at breakfast. The function of the endothelial cells was evaluated in 2 ways; first, the response to 4 minutes of vascular occlusion was measured with a laser Doppler flow meter and second, the blood flow response to local heat at 42°C for 6 minutes.

RESULTS

The results of the experiments showed that, as reported previously, the endothelial function in people from India was less than their Caucasian counterparts. The blood flow response to heat was reduced after 3 weeks administration of vitamin D in both groups and the response to vascular occlusion in the Caucasian group. But there was only a 20% reduction in the blood flow response to heat in the Caucasian group and a 50% reduction in the group from India.

CONCLUSIONS

Thus acute doses of vitamin D may increase vascular tone and reduce blood flow to tissue during stressors. Dosages administered for a longer duration may have beneficial effects on endothelial function but this was not examined here.

Maternal plasma 25-hydroxyvitamin D levels, angiogenic factors, and preeclampsia

OBJECTIVE

The objective of the study was to examine the associations of maternal plasma levels of 25-hydroxyvitamin D [25(OH)D] with angiogenesis and endothelial dysfunction indicators: soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF), intercellular adhesion molecule-1 (ICAM-1), vascular adhesion molecule-1 (VCAM-1), and risk of preeclampsia.

STUDY DESIGN

In this prospective cohort study (n = 697), maternal plasma 25(OH)D levels were measured at 12-18 and 24-26 weeks; sFlt-1, PlGF, ICAM-1, and VCAM-1 levels were measured at 24-26 weeks.

RESULTS

Maternal PlGF levels were significantly lower in women with 25(OH)D less than 50 nmol/L at 12-18 weeks (median, 449.5 vs 507.9 pg/mL, P = 0.04) and 24-26 weeks (median, 450.4 vs 522.5 pg/mL, P = 0.007). Both maternal 25(OH)D and PlGF levels were inversely associated with the risk of preeclampsia (both P < .05). However, based on a test of interaction, there was no evidence that the association between vitamin D and preeclampsia depended on the level of PlGF.

CONCLUSION

Maternal vitamin D deficiency is associated with low PlGF levels and increased preeclampsia risk. However, our data do not support the hypothesis that the association between vitamin D deficiency and preeclampsia is mediated by impaired angiogenesis.

The effect of vitamin D status on risk factors for cardiovascular disease

Vitamin-D-related pathways are implicated in various endocrine, inflammatory and endothelial functions. An estimated 1 billion people in the world have vitamin D deficiency or insufficiency, and undiagnosed vitamin D deficiency is common. Vitamin D deficiency is associated with substantial increases in the incidence of hypertension, hyperlipidaemia, myocardial infarction and stroke, as well as in diseases such as chronic kidney disease and type 2 diabetes. Low vitamin D levels also upregulate the renin-angiotensin-aldosterone system, increase inflammation and cause endothelial dysfunction. However, the role of vitamin D deficiency in cardiovascular morbidity and mortality is an emerging and hotly debated topic. Epidemiological studies suggest an association between low vitamin D levels and risk factors for cardiovascular disease, but a causal relationship has not been established, and clinical trials and meta-analyses have not demonstrated convincing evidence that vitamin D therapy improves cardiovascular outcomes. Some evidence suggests that vitamin D status is a biomarker of lifestyle, since unhealthy and sedentary lifestyles are associated with vitamin D insufficiency or deficiency and are also risk factors for cardiovascular complications.