Cardiovascular disease and vitamin D supplementation: trial analysis, systematic review, and meta-analysis

Effect of vitamin D supplementation on cardiovascular outcomes: an updated meta-analysis of RCTs

Objective

To evaluate the effect of vitamin D supplementation on cardiovascular outcomes.

Methods

After searching different databases, we retrieved and included randomized controlled trials on long-term supplementation of vitamin D (≥1-year intervention) and reporting cardiovascular outcomes. We calculated risk ratio (RR) with 95% confidence intervals (CI) for dichotomous outcomes.

Results

Compared to the control group, the vitamin D group was not associated with a statistically significant decrease in the incidence of major adverse cardiovascular events (MACE) [risk ratio=0.99; 95% CI: 0.94-1.03]. We found no difference between the vitamin D group and the control group for the outcomes of incidences of myocardial infarction, heart failure, coronary revascularization, cardiovascular death, and all-cause mortality. The heterogeneity was low for all outcomes.

Conclusion

According to our meta-analysis, vitamin D supplementation did not reduce major adverse cardiovascular events, other cardiovascular parameters, and all-cause mortality.

Vitamin D Supplementation: Shedding Light on the Role of the Sunshine Vitamin in the Prevention and Management of Type 2 Diabetes and Its Complications

As the incidence of type 2 diabetes mellitus (T2DM) continues to increase globally, researchers are keen to investigate various interventions to mitigate its impact. Among these, vitamin D supplementation has attracted significant attention due to its influence on insulin secretion from the pancreas and insulin receptors in body cells. A substantial body of evidence indicates that vitamin D supplementation can reduce low-grade inflammation, a critical factor in developing insulin resistance. In addition, vitamin D aids in sustaining low resting concentrations of reactive oxygen species and free radicals, normalizes Ca2+ signaling, diminishes the expression of cytokines that are pro-inflammatory, and enhances the production of cytokines that are anti-inflammatory. This review discusses the effects of vitamin D on the glycemic control of individuals with T2DM and evaluates the impact of vitamin D supplementation on glycemic markers in this population. The investigation employs a comprehensive analysis of the existing literature with a special focus on recent studies published in the past decade. Based on the findings in the literature, it can be concluded that vitamin D supplementation alongside anti-diabetic medications may enhance glycemic control and potentially reduce the risk of diabetic complications. The evidence supports the notion that vitamin D supplementation can be a valuable addition to pharmacological agents for the management of T2DM, potentially enhancing glycemic control and overall health outcomes in affected individuals.

A systematic review and meta-analysis of the linkage between low vitamin D and the risk as well as the prognosis of stroke

OBJECTIVE

The research intended to probe the connection between the risk of stroke and serum vitamin D levels.

METHODS

Three electronic databases (Cochrane Library, EMBASE, PubMed) were searched according to the subject terms from inception until July 29, 2022, and retrieved researches were screened on the basis of inclusion and exclusion criteria. Two investigators conducted the quality assessment and data extraction. Using Stata 16.0 software, a meta-analysis was conducted on the extracted data.

FINDINGS

In total, 27 studies with 45,302 participants were included. Among these studies, 20 focused on stroke risk, while 7 examined stroke prognosis. According to the meta-analysis findings, it was observed that a higher stroke risk is connected to reduced levels of serum vitamin D. This association was reflected in a combined relative risk (RR) of 1 .28 (95% confidence interval (CI): 1.15-1.42) and a worse prognosis after stroke (RR = 2.95, 95% CI: 1.90-4.60). Additional analysis indicated that no apparent relationship between a decrease in vitamin D and the probability of experiencing a hemorrhagic stroke was found. The RR found was 1.93 (95% CI: 0.95-3.95). On the other hand, it was observed that a reduction in serum vitamin D levels was linked to an elevated likelihood of developing an ischemic stroke. The RR identified was 1.72 (95% CI: 1.78-2.03). Moreover, a lower level of vitamin D in the bloodstream was associated with a more unfavorable prognosis for individuals who suffered from a stroke. The RR for this correlation was 2.95 (95% CI: 1.90-4.60). However, further research is required to confirm the above-mentioned findings.

CONCLUSION

In conclusion, lower concentration vitamin D was found to be related to an increased risk of stroke, which could mainly be reflected in ischemic stroke patients but not in patients with hemorrhagic stroke. A lower serum vitamin D level was correlative with the poor prognosis of stroke.

The Power of Vitamin D: Is the Future in Precision Nutrition through Personalized Supplementation Plans?

In the last few decades, vitamin D has undeniably been one of the most studied nutrients. Despite our ability to produce vitamin D through sunlight exposure, its presence in several natural food sources and fortified foods, and its widespread availability as a dietary supplement, vitamin D deficiency is a serious public health problem, affecting nearly 50% of the global population. Low serum levels of vitamin D are being associated with increased susceptibility to numerous health conditions, including respiratory infections, mental health, autoimmune diseases, and different cancer types. Although the association between vitamin D status and health is well-established, the exact beneficial effects of vitamin D are still inconclusive and indefinite, especially when considering the prevention and treatment of different health conditions and the determination of an appropriate dosage to exert those beneficial effects in various population groups. Therefore, further research is needed. With constant improvements in our understanding of individual variations in vitamin D metabolism and requirements, in the future, precision nutrition and personalized supplementation plans could prove beneficial.

Long-Term Effect of Randomization to Calcium and Vitamin D Supplementation on Health in Older Women : Postintervention Follow-up of a Randomized Clinical Trial

BACKGROUND

Although calcium and vitamin D (CaD) supplementation may affect chronic disease in older women, evidence of long-term effects on health outcomes is limited.

OBJECTIVE

To evaluate long-term health outcomes among postmenopausal women in the Women's Health Initiative CaD trial.

DESIGN

Post hoc analysis of long-term postintervention follow-up of the 7-year randomized intervention trial of CaD. (ClinicalTrials.gov: NCT00000611).

SETTING

A multicenter (n = 40) trial across the United States.

PARTICIPANTS

36 282 postmenopausal women with no history of breast or colorectal cancer.

INTERVENTION

Random 1:1 assignment to 1000 mg of calcium carbonate (400 mg of elemental calcium) with 400 IU of vitamin D3 daily or placebo.

MEASUREMENTS

Incidence of colorectal, invasive breast, and total cancer; disease-specific and all-cause mortality; total cardiovascular disease (CVD); and hip fracture by randomization assignment (through December 2020). Analyses were stratified on personal supplement use.

RESULTS

For women randomly assigned to CaD versus placebo, a 7% reduction in cancer mortality was observed after a median cumulative follow-up of 22.3 years (1817 vs. 1943 deaths; hazard ratio [HR], 0.93 [95% CI, 0.87 to 0.99]), along with a 6% increase in CVD mortality (2621 vs. 2420 deaths; HR, 1.06 [CI, 1.01 to 1.12]). There was no overall effect on other measures, including all-cause mortality (7834 vs. 7748 deaths; HR, 1.00 [CI, 0.97 to 1.03]). Estimates for cancer incidence varied widely when stratified by whether participants reported supplement use before randomization, whereas estimates on mortality did not vary, except for CVD mortality.

LIMITATION

Hip fracture and CVD outcomes were available on only a subset of participants, and effects of calcium versus vitamin D versus joint supplementation could not be disentangled.

CONCLUSION

Calcium and vitamin D supplements seemed to reduce cancer mortality and increase CVD mortality after more than 20 years of follow-up among postmenopausal women, with no effect on all-cause mortality.

PRIMARY FUNDING SOURCE

National Heart, Lung, and Blood Institute of the National Institutes of Health.

Vitamin D and cardiovascular diseases: A narrative review

Cardiovascular diseases (CVD) and vitamin D deficiency are becoming highly prevalent among general populations. Despite plausible biological mechanisms for the role of vitamin D in cardio-protection, a cause-and-effect relationship has not yet been established. The interest in vitamin D as a potential therapeutic target to attenuate cardiovascular risk has been raised. The question about the benefit of vitamin D supplementation for cardiovascular outcomes cannot be answered certainly for the moment. The association between hypovitaminosis D and CVD has been proven by some studies while other studies deny any such link. The present narrative review gives a comprehensive overview of studies on the potential impact of hypovitaminosis D on CVD. The potential role of vitamin D supplementation in the management of CVD is also evaluated. Particular emphasis is paid to those studies that achieve a high level of scientific evidence.

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

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

Vitamin D and Cardiovascular Diseases: From Physiology to Pathophysiology and Outcomes

Vitamin D is rightly recognized as an essential key factor in the regulation of calcium and phosphate homeostasis, affecting primary adequate bone mineralization. In the last decades, a more complex and wider role of vitamin D has been postulated and demonstrated. Cardiovascular diseases have been found to be strongly related to vitamin D levels, especially to its deficiency. Pre-clinical studies have suggested a direct role of vitamin D in the regulation of several pathophysiological pathways, such as endothelial dysfunction and platelet aggregation; moreover, observational data have confirmed the relationship with different conditions, including coronary artery disease, heart failure, and hypertension. Despite the significant evidence available so far, most clinical trials have failed to prove any positive impact of vitamin D supplements on cardiovascular outcomes. This discrepancy indicates the need for further information and knowledge about vitamin D metabolism and its effect on the cardiovascular system, in order to identify those patients who would benefit from vitamin D supplementation.

Cardiovascular and Cerebrovascular Outcomes With Vitamin D Supplementation: A Systematic Review and Meta-Analysis

Vitamin D supplementation has seen a sharp increase in the primary healthcare setting but its efficacy in decreasing the risk of cardiovascular and cerebrovascular events is yet to be reliably established. We aim to determine whether vitamin D supplementation can significantly impact the risk of cardiovascular and cerebrovascular events. An extensive literature search of PubMed, Embase, and Cochrane CENTRAL was conducted from inception till August 2023 to include all the articles comparing vitamin D and placebo. Cardiovascular and cerebrovascular outcomes were presented as risk ratios (RR) with 95% confidence intervals (CIs) and pooled using a random effects model. Thirty-six trials consisting of 493,389 participants were included in our analysis. Our pooled analysis demonstrated no significant difference between vitamin D supplementation and placebo for the risk of cardiovascular mortality (RR 1.01, 95% CI 0.94-1.08; P = 0.80), stroke or cerebrovascular events (RR 1.03, 95% CI 0.95-1.11; P = 0.48), myocardial infarction (MI) (RR 0.98, 95% CI 0.91-1.06; P = 0.65), cerebrovascular mortality (RR 1.00, 95% CI 0.68-1.46; P = 0.99), arrhythmias (RR 0.98, 95% CI 0.66-1.44; P = 0.90) and hemorrhagic or ischemic stroke. There was no significant heterogeneity between the studies in any analysis. There was no significant difference in the risk of cardiovascular and cerebrovascular outcomes with vitamin D supplementation or placebo. Additional large high-powered studies focused on high-risk and vitamin D-deficient populations are required to resolve the current discrepancy in the literature and provide a definitive conclusion to this end.

Vitamin D Supplementation and Cardiovascular Disease Risks in More Than 134000 Individuals in 29 Randomized Clinical Trials and 157000 Individuals in 30 Prospective Cohort Studies: An Updated Systematic Review and Meta-analysis

BACKGROUND

According to the findings from observational studies and clinical trials assessing the effect of vitamin D supplements on cardiovascular diseases (CVDs), there are still contradictory results. This systematic review aimed to assess the effect of vitamin D supplements on CVDs considering cohort studies and clinical trials. Study Design: A systematic review.

METHODS

MEDLINE/PubMed, Science Direct, Embase, and Cochrane Library databases were reviewed by two reviewers independently until 2022. The study effect is risk ratio (RR) and 95% confidence interval (CI) according to Mantel Haenszel's random-effects model. Then, Stata version 14 was used for statistical analysis.

RESULTS

In clinical trial studies, the incidence of CVDs among the vitamin D-consuming group was not significantly different from that in the placebo group (RR: 0.99, 95% CI: 0.95-1.03; P=0.77; I 2=0%). CVD mortality was also not significantly different between the two groups (RR: 0.97, 95% CI: 0.90-1.05; P=0.72; I2=0%). In cohort studies, circulating 25 (OH) D increased the risk of CVD incidence by 31% (RR: 1.31, 95% CI: 1.19-1.45) and CVD mortality by 37% (RR: 1.37, 95% CI: 1.17-1.61).

CONCLUSION

According to current evidence from clinical trials, vitamin D supplementation should not be recommended for CVD prevention. However, there is a direct association between vitamin D deficiency and the incidence of CVDs as well as its mortality. According to the results of clinical trial studies carrying higher levels of scientific evidence, it can be concluded that vitamin D supplementation does not exert a significant effect on the incidence, mortality, and reduction of CVDs.

Associations of Serum Vitamin D Concentration with Cardiovascular Risk Factors and the Healthy Lifestyle Score

Vitamin D status is reportedly associated with risk factors for cardiovascular disease (CVD), although conflicting data have been generated. The healthy lifestyle score (HLS) was formulated as a primary approach toward preventing CVD; however, data on the association between the HLS and vitamin D status remain insufficient. This study aimed to investigate the associations of CVD risk factors and the HLS with serum 25-hydroxyvitamin D concentration in adults who participated in a national survey. HLS components, including body mass index, smoking status, alcohol consumption, physical activity, and dietary pattern, as well as other risk factors, including diabetes mellitus (DM), hypertension (HTN), and dyslipidemia (DL), were fitted in multiple linear regression models to determine their association with vitamin D status. DM, HTN, and DL were inversely associated whereas a balanced dietary pattern, alcohol consumption, and physical activity were positively associated with serum vitamin D concentration (p < 0.01). Furthermore, a strong association was observed between the total HLS and serum vitamin D concentration (p for trend <0.01); the regression coefficient estimate (95% confidence interval) for the highest score was 1.41 (0.65, 2.17) (p < 0.01) compared with that for the lowest. These findings suggest that CVD risk factors and the HLS may reflect vitamin D status.

Comparative Analysis of Dietary and Supplemental Intake of Calcium and Vitamin D among Canadian Older Adults with Heart Disease and/or Osteoporosis in 2004 and 2015

Despite the role of calcium and vitamin D in osteoporosis and heart disease, little research has examined changes in the intake of calcium and vitamin D among individuals with these conditions over time. Using data from the 2004 and 2015 Canadian Community Health Surveys, we investigated changes in dietary and supplemental intake of calcium and vitamin D among Canadian older adults aged ≥ 50 years, both with and without heart disease and/or osteoporosis, between 2004 and 2015. Notable declines in dietary calcium intake occurred, particularly among non-supplement users. Surprisingly, individuals with osteoporosis and heart disease, who are at higher nutritional risk, were less likely to use calcium supplements in 2015 compared to 2004. Among calcium supplement users, those with osteoporosis or both conditions experienced significant reductions in their usual calcium intake in 2015, with an increased proportion failing to meet recommended intake levels. Conversely, vitamin D supplement users experienced a substantial rise in vitamin D intake in 2015. In 2015, only a small proportion of supplement users did not meet the recommended vitamin D intake levels. These findings underscore the importance of public health initiatives to facilitate safe increases in calcium and vitamin D intake for older adults, particularly those with heart disease and osteoporosis.

Vitamin D Deficiency and Its Association With Cardiovascular Diseases Among Patients Attending a Private Tertiary Sector Cardiovascular Heart Clinic in Nairobi

BACKGROUND

Vitamin D deficiency is a common condition that affects approximately 30-50% of the worldwide population. Vitamin D deficiency is associated with an increased risk of cardiometabolic diseases and is considered a cardiovascular risk factor globally.  Methods: This is a retrospective cross-sectional study that aimed to identify the prevalence of vitamin D deficiency and its associations with the cardiovascular disease (CVD) risk profile of patients presenting for cardiac evaluation at Primecare Heart Clinic, a private heart clinic in Nairobi, Kenya, between January 1, 2020 and January 31, 2022.

RESULTS

Females with vitamin D deficiency composed 58.87% of the study participants. The average 10-year Framingham CVD risk level of the vitamin D-deficient participants was 7.09%. Participants with vitamin D deficiency that were older and had low serum high-density lipoprotein C (HDL-C) levels and high systolic blood pressure (BP) had a higher risk of CVDs. Male participants were at five times higher risk of CVDs. Vitamin D-deficient patients who were older and had a low HDL cholesterol level and high systolic BP are at a high risk of CVDs. The two-way analysis of variance (ANOVA) test value was 345.6992, and the p-value was 0.002884.

CONCLUSION

Our study demonstrated that a low level of vitamin D was associated with a higher Framingham cardiovascular risk score and cardiovascular risk in patients. Nonetheless, this is a retrospective study, which is a major limitation of this study.

Vitamin D Supplementation and Its Impact on Mortality and Cardiovascular Outcomes: Systematic Review and Meta-Analysis of 80 Randomized Clinical Trials

BACKGROUND

The impact of vitamin D supplementation on cardiovascular outcomes and mortality risk reduction remains unclear due to conflicting study findings.

METHODS

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs), published between 1983 and 2022, that reported the effect of vitamin D supplementation in adults versus placebo or no treatment on all-cause mortality (ACM), cardiovascular mortality (CVM), non-cardiovascular mortality (non-CVM), and cardiovascular morbidities. Only studies with a follow-up period longer than one year were included. The primary outcomes were ACM and CVM. Secondary outcomes were non-CVM, myocardial infarction, stroke, heart failure, and major or extended adverse cardiovascular events. Subgroup analyses were performed according to low-, fair- and good-quality RCTs.

RESULTS

Eighty RCTs were assessed, including 82,210 participants receiving vitamin D supplementation and 80,921 receiving placebo or no treatment. The participants' mean (SD) age was 66.1 (11.2) years, and 68.6% were female. Vitamin D supplementation was associated with a lower risk of ACM (OR: 0.95 [95%CI 0.91-0.99] p = 0.013), was close to statistical significance for a lower risk of non-CVM (OR: 0.94 [95%CI 0.87-1.00] p = 0.055), and was not statistically associated with a lower risk of any cardiovascular morbi-mortality outcome. Meta-analysis of low-quality RCTs showed no association with cardiovascular or non-cardiovascular morbi-mortality outcomes.

CONCLUSIONS

The emerging results of our meta-analysis present evidence that vitamin D supplementation appears to decrease the risk of ACM (especially convincing in the fair- and good-quality RCTs), while not showing a decrease in the specific cardiovascular morbidity and mortality risk. Thus, we conclude that further research is warranted in this area, with well-planned and executed studies as the basis for more robust recommendations.

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.

Low serum 25-hydroxyvitamin D (vitamin D) level among children with ventricular septal defect: how big is the risk for pulmonary hypertension?

INTRODUCTION

Ventricular septal defect is the most common CHD, leading to pulmonary hypertension. Significantly lower 25-hydroxyvitamin D level was reported in children with CHD compared with healthy controls. The current study aimed to investigate the correlation between 25-hydroxyvitamin D level and pulmonary hypertension in children with ventricular septal defect.

METHODS

A cross-sectional study was conducted on ventricular septal defect paediatric patients from January to June, 2019. Serum 25-hydroxyvitamin D was measured using electrochemiluminescence. Pulmonary hypertension was defined as mean pulmonary artery systolic pressure > 20 mmHg for children >3 months of age at sea level, measured by Doppler echocardiography.

RESULTS

From forty-four subjects, the majority of the subjects were female (56.8%) with normal nutritional status and perimembranous ventricular septal defect. Bivariate analysis showed that 25-hydroxyvitamin D level was associated with pulmonary hypertension (p < 0.01), type and size of ventricular septal defect (p = 0.02), and heart failure (p < 0.01). Higher 25-hydroxyvitamin D level was correlated with better nutritional status (p = 0.04, r = 0.26), and lower 25-hydroxyvitamin D level was correlated with the occurence of perimembranous ventricular septal defect (p = 0.01, r = -0.39), larger defect size (p < 0.01, r = -0.70), history of pneumonia (p = 0.02, r = -0.31), and heart failure (p < 0.01, r = -0.64). Subjects with 25-hydroxyvitamin D deficiency had prevalence ratio of 24.0 times for pulmonary hypertension. Higher pulmonary artery pressure was correlated to the occurence perimembranous ventricular septal defect (p = 0.01, r = 0.47), larger defect size (p < 0.01, r = 0.78), history of pneumonia (p = 0.01, r = 0.38), and heart failure (p < 0.01, r = 0.75).

CONCLUSION

Children with ventricular septal defect who had low 25-hydroxyvitamin D level posed a higher risk of having pulmonary hypertension.

Vitamin D supplementation and risk of stroke: A meta-analysis of randomized controlled trials

Background

Previous observational studies have supported the hypothesis that vitamin D supplementation protects against stroke. However, several current intervention studies contradict this observation. Therefore, we conducted a meta-analysis to investigate further the association between vitamin D supplementation and the risk of stroke.

Methods

This meta-analysis was conducted in accordance with the PRISMA statement and included all the randomized controlled trials (RCTs) that analyzed the relationship between vitamin D supplementation and the risk of stroke. A literature search strategy was established, and the following Medical Search Terms (MeSH) were used: “vitamin D,” “Calcitriol,” “Calcifediol,” “Cholecalciferol,” “25-Hydroxyvitamin D 2,” “ergocalciferols,” “stroke,” and stroke-derived terms. We searched for articles published before January 2022 in several databases, namely, PubMed, Web of Science, EMBASE, and The Cochrane Library. We also reviewed references included in relevant published meta-analyses and searched the http://www.ClinicalTrials.gov website for additional RCTs. The Q test and I2 were utilized to assess the degree of heterogeneity among the studies. Review Manager 5.3 and STATA16.0 software programs were used to assess the literature quality and perform statistical analyses.

Results

In total, twenty-four RCTs (86,202 participants) were included. There was no statistical heterogeneity among the RCTs (I2 = 0.0%, P = 0.94) included in this meta-analysis. We determined that vitamin D supplementation was not associated with a reduced risk of stroke compared with the placebo (RR = 1.02, 95% CI: 0.93–1.13, P = 0.65). In total, 10 studies only included women, and 14 studies included women and men among the 24 RCTs. Therefore, we performed a subgroup analysis based on sex. After the subgroup analysis, the effect remained statistically insignificant (mixed-sex group: RR = 1.06, 95% CI: 0.93–1.22, P = 0.37, women group: RR = 0.98, 95% CI: 0.86–1.13, P = 0.80). The results were generally comparable, based on age, body mass index (BMI), follow-up period, baseline 25-hydroxyvitamin D (25(OH)D) levels, the designated endpoint, latitude, vitamin D dosage, type of vitamin D administered, and an absence or presence of concurrent calcium supplementation (P &gt; 0.05).

Conclusion

Our study revealed that additional vitamin D supplementation did not reduce the risk of stroke. Therefore, additional RCTs of similar design should not be encouraged to assess any association between vitamin D supplementation and reduced stroke risk.

Vitamin D and Multiple Health Outcomes: An Umbrella Review of Observational Studies, Randomized Controlled Trials, and Mendelian Randomization Studies

Observational studies, randomized controlled trials (RCTs), and Mendelian randomization (MR) studies have yielded inconsistent results on the associations of vitamin D concentrations with multiple health outcomes. In the present umbrella review we aimed to evaluate the effects of low vitamin D concentrations and vitamin D supplementation on multiple health outcomes. We summarized current evidence obtained from meta-analyses of observational studies that examined associations between vitamin D concentrations and multiple health outcomes, meta-analyses of RCTs that investigated the effect of vitamin D supplementation on multiple health outcomes, and MR studies that explored the causal associations of vitamin D concentrations with various diseases (international prospective register of systematic reviews PROSPERO registration number CRD42018091434). A total of 296 meta-analyses of observational studies comprising 111 unique outcomes, 139 meta-analyses of RCTs comprising 46 unique outcomes, and 73 MR studies comprising 43 unique outcomes were included in the present umbrella review. Twenty-eight disease outcomes were identified by both meta-analyses of observational studies and MR studies. Seventeen of these reported disease outcomes had consistent results, demonstrating that lower concentrations of vitamin D were associated with a higher risk for all-cause mortality, Alzheimer's disease, hypertension, schizophrenia, and type 2 diabetes. The combinations of consistent evidence obtained by meta-analyses of observational studies and MR studies together with meta-analyses of RCTs showed that vitamin D supplementation was associated with a decreased risk for all-cause mortality but not associated with the risk for Alzheimer's disease, hypertension, schizophrenia, or type 2 diabetes. The results indicated that vitamin D supplementation is a promising strategy with long-term preventive effects on multiple chronic diseases and thus has the potential to decrease all-cause mortality. However, the current vitamin D supplementation strategy might not be an efficient intervention approach for these diseases, suggesting that new strategies are highly needed to improve the intervention outcomes.

Association of Vitamin D Supplementation with Cardiovascular Events: A Systematic Review and Meta-Analysis

BACKGROUND

low vitamin D status has been associated with an increased incidence of cardiovascular events. However, whether vitamin D supplementation would reduce the incidence of cardiovascular events remains unclear.

PURPOSE

To perform a systematic review and meta-analysis of the effect of vitamin D supplementation on the mortality and incidence of cardiovascular events.

DATA SOURCES

We searched Medline, Embase, and the Cochrane Central Register of Controlled Trials from their inception until 3 May 2022.

STUDY SELECTION

Two authors searched for randomized clinical trials that reported vitamin D supplementation's effect on cardiovascular events outcomes.

DATA EXTRACTION

Two authors conducted independent data extraction.

DATA SYNTHESIS

We identified 41,809 reports; after exclusions, 18 trials with a total of 70,278 participants were eligible for analysis. Vitamin D supplementation was not associated with the mortality of cardiovascular events (RR 0.96, 95% CI 0.88-1.06, I2 = 0%), the incidence of stroke (RR 1.05, 95% CI 0.92-1.20, I2 = 0%), myocardial infarction (RR 0.97, 95% CI 0.87-1.09, I2 = 0%), total cardiovascular events (RR 0.97, 95% CI 0.91-1.04, I2 = 27%), or cerebrovascular events (RR 1.01, 95% CI 0.87-1.18, I2 = 0%).

LIMITATION

Cardiovascular events were the secondary outcome in most trials and thus, might be selectively reported.

CONCLUSION

In this meta-analysis of randomized clinical trials, vitamin D supplementation was not associated with a lower risk of cardiovascular events than no supplementation. These findings do not support the routine use of vitamin D supplementation in general.

Associations Between Vitamin D Levels and Risk of Heart Failure: A Bidirectional Mendelian Randomization Study

Background

Although studies suggest that concentrations of serum 25-hydroxyvitamin D (25(OH)D) are lower in individuals with Heart Failure (HF), the beneficial effects of vitamin D supplementation are controversial. Therefore, in this study, we aimed to determine whether there is a causal relationship between serum Vitamin D (VD) levels and HF.

Methods

We obtained genetic instruments from the largest available genome-wide association study (GWAS) of European descent for 25(OH)D (443, 734 individuals) to investigate the association with HF (47,309 cases, 930,014 controls), and vice versa. Two-sample bidirectional Mendelian Randomization (MR) analysis was performed to infer the causality. In addition to the primary analysis using inverse variance-weighted (IVW) MR, we applied five additional methods to control for pleiotropy [MR-Egger, weighted median, Maximum-likelihood, MR-robust adjusted profile score (MR-RAPS) and MR-pleiotropy residual sum and outlier (MR-PRESSO)] and compared their respective MR estimates. We also performed a sensitivity analysis to ensure that our results were robust.

Results

Mendelian randomized analysis showed that increased serum 25(OH)D was associated with a lower risk of HF in the IVW method (odds ratio [OR] = 0. 81;95%CI, 0.70–0.94, P = 0.006). In the reverse MR analyses, the genetic predisposition to HF was negatively correlated with serum 25(OH)D level (OR = 0. 89;95%CI, (0.82–0.97), P = 0.009).

Conclusion

Our study revealed the possible causal role of 25(OH)D on decreasing the risk for HF. Meanwhile, reverse MR analysis suggested that HF may be associated with lower vitamin D levels, it could be the potential implications for dietary recommendations.

Hypovitaminosis D and cardiovascular outcomes: A systematic review and meta-analysis

Background

The relation between blood vitamin D levels and the risk of cardiovascular outcomes is debatable. To our knowledge this is the first comparative meta-analysis of more than 100,000 patients' data with the aim to inspect the relevance of low vitamin D levels with adverse cardiovascular events.

Methods

Online databases including PubMed, Embase and Cochrane Central were queried to compare the cardiovascular outcomes among hypovitaminosis D (HVD) and control group. The outcomes assessed included differences in major adverse cardiovascular events (MACE), mortality, myocardial infarction, and heart failure. Unadjusted odds ratios (OR) were calculated using a random-effect model with a 95% confidence interval (CI) and P less than 0.05 as a statistical significance.

Results

A total of 8 studies including 426,039 patients were included in this analysis. HVD group was associated with a higher incidence of MACE (OR 1.92, 95% CI 1.24 to 2.98, p = 0.003), while there was no significant association of HVD and all-cause mortality (OR 1.77, 95% CI 0.75 to 4.17, p = 0.19), risk of myocardial infarction (OR 0.69, 95% CI 0.39 to 1.24, p = 0.22), and heart failure (OR 1.20, 95% CI 0.34 to 4.25, p = 0.78).

Conclusions

This meta-analysis suggested that low blood levels of vitamin D are associated with MACE, but no such difference in all-cause mortality, myocardial infarction or heart failure was observed. Appropriate supplementation of vitamin D in selected populations might be cardioprotective in nature and warrants extensive trials.

Low Vitamin D Status Is Associated with Increased Risk of Mortality in Korean Men and Adults with Hypertension: A Population-Based Cohort Study

Background Recent randomized controlled trials (RCTs) have shown no effect of vitamin D supplementation on cardiovascular disease, cancer events and mortality or all-cause mortality in Western populations. However, there has been a lack of research on populations with low vitamin D status, including Asians. In addition, there have been indications that an individual’s sex or hypertension status may affect the relationship between vitamin D status and mortality. In this study, we retrospectively assessed the association between vitamin D status and all-cause, cardiovascular, and cancer mortality in Koreans using a national database, and stratified participants according to sex and hypertension status. Methods Participants in the Korean Health and Nutrition Examination Survey 2008−2014, who consented to their data being synthesized with mortality data (up to December 2019), were included (n = 22,742; mean follow-up: 8.9 years). Participants’ level of serum 25-hydroxyvitamin D (25(OH)D) was measured by radioimmunoassay and categorized as <12, 12−19.9, and ≥20 ng/mL. A Cox proportional hazard model was used to assess the risk of mortality. Results In the total sample, risk of all-cause, cancer, and cardiovascular mortality was greater in adults with a serum 25(OH)D level below 12 and 12−19.9 ng/mL than those with ≥20 ng/mL. Men and adults with hypertension, who had low vitamin D status, had a higher risk of cancer and cardiovascular mortality, but not women or adults without hypertension. Similar results were observed when various cutoffs for 25(OH)D were employed, or extrinsic deaths were excluded. Conclusions Vitamin D status below 20 ng/mL is associated with a higher risk of mortality in Korean adults, especially in men and those with hypertension, on the basis of data from a nationally representative sample. Further RCTs on Asian adults with low vitamin D status are warranted.

The role of vitamin D in cardiovascular disease and COVID-19

Patients with pre-existing cardiovascular disease (CVD) are at high risk for adverse outcomes with coronavirus disease 2019 (COVID-19). Further, COVID-19 infection is associated with numerous cardiovascular (CV) complications including arrhythmia, myocardial injury, cardiomyopathy, and thrombotic events. Increased susceptibility to COVID-19 and CV complications related to COVID-19 may be in part related to immune dysregulation and inflammation associated with CV disease which is exacerbated with viral infection. Vitamin D plays a major role in immune function and exerts anti-inflammatory effects, which may prove important in the context of CVD and COVID-19. To date, studies have shown minimal benefit for vitamin D supplementation in patients with COVID-19, though there are no studies specific to patients with CVD and related complications. Further, given that vitamin D has important protective effects on the CV system, including augmentation of myocardial contractility and anti-thrombotic effects, it is unknown if supplementation with vitamin D can mitigate CVD complications associated with COVID-19.

Calcifediol (25OH Vitamin D3) Deficiency: A Risk Factor from Early to Old Age

Vitamin D deficiency is the main cause of nutritional rickets in children and osteomalacia in adults. There is consensus that nutritional access to vitamin D can be estimated by measuring serum concentrations of 25OHD and vitamin D deficiency can thus be considered as calcifediol deficiency. However, the threshold for vitamin D/calcifediol sufficiency remains a matter of debate. Vitamin D/calcifediol deficiency has been associated with musculoskeletal effects but also multiple adverse extra-skeletal consequences. If these consequences improve or if they can be treated with vitamin D supplementation is still unclear. Observational studies suggest a higher infection risk in people with low calcifediol levels. There is also a consistent association between serum calcifediol and cardiovascular events and deaths, but large-scale, long-term intervention studies did not show any benefit on cardiovascular outcomes from supplementation, at least not in subjects without clear vitamin D deficiency. Cancer risk also did not change with vitamin D treatment, although there are some data that higher serum calcifediol is associated with longer survival in cancer patients. In pregnant women, vitamin D supplementation decreases the risk of pre-eclampsia, gestational diabetes mellitus, and low birth weight. Although preclinical studies showed that the vitamin D endocrine system plays a role in certain neural cells as well as brain structure and function, there is no evidence to support a beneficial effect of vitamin D in neurodegenerative diseases. Vitamin D supplementation may marginally affect overall mortality risk especially in elderly subjects with low serum calcifediol concentrations.

Vitamin D, respiratory infections, and chronic disease: Review of meta-analyses and randomized clinical trials

BACKGROUND

Observational studies have suggested associations of vitamin D deficiency (VDD) with respiratory tract infections, impaired bone health, and myriad chronic diseases.

OBJECTIVE

To assess potential causal relationships between vitamin D supplementation and a reduced risk of these conditions, a review of the evidence across available meta-analyses of randomized control trials (RCTs) and RCTs was performed.

METHOD

PubMed, Embase, Cochrane Library, and Web of Science were searched from their inception to March 2021. We included only RCTs and meta-analyses of RCTs focusing on the association between vitamin D and respiratory disease, bone health, cardiovascular disease (CVD), diabetes mellitus, and cancer.

RESULTS

A total of 107 RCTs and 62 meta-analysis of RCTs were included. Although most RCTs did not support benefits of vitamin D supplementation, suggestive evidence for benefit was found in populations at greater risk of VDD and for acute respiratory infections, fractures in institutionalized older adults, type 2 diabetes among patients with prediabetes, and cancer mortality. In contrast, no compelling evidence for benefit was found for other respiratory conditions, fractures in community-dwelling adults, falls, cancer incidence, or CVD.

CONCLUSIONS

Current evidence from RCTs and meta-analyses of RCTs is inconsistent regarding the effects of vitamin D supplementation on respiratory infections and chronic diseases. Individuals most likely to benefit are those with baseline VDD or with selected high-risk conditions. Public health initiatives are needed to eliminate VDD globally, and future research will be enhanced by a 'precision prevention' approach to identify those most likely to benefit from vitamin D supplementation.

Joint Associations between Plasma 25-Hydroxyvitamin D, Glycemic Status, and First Stroke in General Hypertensive Adults: Results from the China Stroke Primary Prevention Trial (CSPPT)

BACKGROUND

Associations between vitamin D and stroke remain inconsistent. One major risk factor for stroke is high blood glucose, but the role it plays in this association is not well studied.

OBJECTIVES

We aimed to evaluate the individual association between plasma 25-hydroxyvitamin D [25(OH)D] and risk of first stroke stratified by fasting blood glucose (FBG), and the joint associations between plasma 25(OH)D, glycemic status, and first stroke in hypertensive adults.

METHODS

This study was a nested, case-control design utilizing data from the China Stroke Primary Prevention Trial (CSPPT). This analysis included 591 first stroke cases (of which 475 were ischemic stroke, 114 were hemorrhagic stroke, and 2 were uncertain type) and 591 matched controls. The age range of the study population was 45-75 y. The normal FBG (NFG) group had FBG <5.6 mmol/L,  and the impaired FBG (IFG) group had FBG ≥5.6 mmol/L and <7.0 mmol/L. Diabetes was defined as participants with FBG ≥7 mmol/L or who were receiving treatment with hypoglycemic agents. ORs (95% CIs) were calculated using unconditional logistic regression models.

RESULTS

Multivariable adjusted models revealed an inverse association between quartiles of 25(OH)D and risk of first stroke among participants with NFG, but the opposite trend was observed for those with IFG or diabetes. The largest ORs (>2) were observed among patients with diabetes, compared with the reference group of NFG and high 25(OH)D. Those with NFG and low 25(OH)D (OR = 1.73, 95% CI: 1.22 to 2.44) or those with IFG and high 25(OH)D (OR = 1.74, 95% CI: 1.14 to 2.67) both had a higher risk of total stroke. There was a significant interaction between 25(OH)D and a combined group of IFG and diabetes (P = 0.001). Similar results were observed for ischemic stroke.

CONCLUSIONS

In a hypertensive population, the relation between plasma 25(OH)D and risk of first stroke was significantly modified by FBG. This trial was registered at https://www.clinicaltrials.gov as NCT00794885.

The cost-effectiveness analysis of a nationwide vitamin D supplementation program among Iranian adolescents for adulthood cardiovascular diseases prevention

OBJECTIVE

This study aimed to evaluate a national vitamin D supplementation program's cost-effectiveness among Iranian adolescents to prevent cardiovascular diseases (CVDs) in adulthood.

STUDY DESIGN

A cost-effectiveness analytical study.

METHODS

A decision tree model was adopted to evaluate the cost per quality-adjusted life-year (QALY) of monthly intake of nine pearls of 50,000 IU vitamin D for nine months to prevent CVD a one-year horizon compared to no intervention. The analysis was conducted in Iranian adolescents in first or second high school grades of 47 climatically different Iran regions.

RESULTS

Our analytical analysis estimated the 1090$ cost per QALY gained of the monthly intake of 50,000 IU vitamin D for nine months among adolescents over a one-year horizon. Based on the incremental cost-effectiveness ratio (ICER) threshold of 1032-2666, vitamin D supplementation was cost-effective for adolescents to prevent adulthood CVD. It means that vitamin D supplementation costs were substantially less than the costs of CVD treatments compared to the no intervention.

CONCLUSIONS

Based on these findings, the national program of vitamin D supplementation in adolescents would be cost effective to prevent CVD development in adulthood. From an economic perspective, vitamin D supplementation, especially in adolescents with vitamin D deficiency, would be administrated.

The Effect of Vitamin D on Coronary Atherosclerosis: A Propensity Score Matched Case-Control Coronary CTA Study

Background: Vitamin D supplementation may be associated with lower cardiovascular (CV) events, but the data are controversial. It remains speculative whether vitamin D supplementation has a direct effect on coronary atherosclerosis. We therefore set out to assess the influence of vitamin D supplementation on the coronary atherosclerosis profile quantified by coronary computed tomography angiography (CTA) in a retrospective case–control cohort study. Methods: 176 patients (age: 62.4 ± 10.4) referred to coronary CTA for clinical indications were included. A total of 88 patients receiving vitamin D supplementation (mean duration 65.3 ± 81 months) were 1:1 propensity score matched with 88 controls for age, gender, smoking, arterial hypertension, positive family history, dyslipidemia, and diabetes. Coronary stenosis severity (CAD-RADS^TM), mixed plaque burden (weighted for non-calcified), high-risk-plaque (HRP) features, and plaque density (HU) were quantified by CTA. Serum 25-hydroxyvitamin D (OH)-levels were measured in 138 patients and categorized into four groups (0: <20 ng/mL; 1: 20–40 ng/mL; 2: 40–60 ng/mL; and 3: >60 ng/mL) and compared with CTA. Results: The prevalence of atherosclerosis by CTA was similar in both groups (75.6% versus 74.3%, p = 0.999), >50% coronary stenosis was slightly higher in controls (p = 0.046), but stenosis severity score (CAD-RADS) was not different (p = 0.106). Mixed plaque burden (weighted for non-calcified) was lower in patients receiving vitamin D supplementation (p = 0.002) and high-risk-plaque prevalence was markedly lower (3.8% versus 32%, p < 0.001). CT plaque density (HU) was higher (p < 0.001) in the vitamin D group. Patients with serum vitamin D (OH) levels >60 ng/mL had higher plaque density (p = 0.04), indicating more calcified and less vulnerable plaque. Conclusions: In this retrospective case–control cohort study, vitamin D supplementation was associated with less high-risk plaque, less non-calcified plaque burden, and a higher calcified plaque independent of CV risk factors.

The role of biofactors in the prevention and treatment of age-related diseases

The present demographic changes toward an aging society caused a rise in the number of senior citizens and the incidence and burden of age-related diseases (such as cardiovascular diseases [CVD], cancer, nonalcoholic fatty liver disease [NAFLD], diabetes mellitus, and dementia), of which nearly half is attributable to the population ≥60 years of age. Deficiencies in individual nutrients have been associated with increased risks for age-related diseases and high intakes and/or blood concentrations with risk reduction. Nutrition in general and the dietary intake of essential and nonessential biofactors is a major determinant of human health, the risk to develop age-related diseases, and ultimately of mortality in the older population. These biofactors can be a cost-effective strategy to prevent or, in some cases, even treat age-related diseases. Examples reviewed herein include omega-3 fatty acids and dietary fiber for the prevention of CVD, α-tocopherol (vitamin E) for the treatment of biopsy-proven nonalcoholic steatohepatitis, vitamin D for the prevention of neurodegenerative diseases, thiamine and α-lipoic acid for the treatment of diabetic neuropathy, and the role of folate in cancer epigenetics. This list of potentially helpful biofactors in the prevention and treatment of age-related diseases, however, is not exhaustive and many more examples exist. Furthermore, since there is currently no generally accepted definition of the term biofactors, we here propose a definition that, when adopted by scientists, will enable a harmonization and consistent use of the term in the scientific literature.

Vitamin D and Vascular Disease

Cardiovascular disease (CVD) is a major cause of morbidity and mortality worldwide. Vitamin D deficiency has been identified as a potential risk factor for a number of diseases unrelated to the classical skeletal pathophysiology, such as cancer and CVD, but the effects of vitamin D supplementation are less clear. Purpose of this narrative review is to discuss the evidence suggesting an association between vitamin D status and CVD as well as the results of supplementation studies. Vitamin D deficiency has been associated with CVD risk factors such as hypertension, dyslipidemia and diabetes mellitus as well as with cardiovascular events such as myocardial infarction, stroke and heart failure. While vitamin D deficiency might contribute to the development of CVD through its association with risk factors, direct effects of vitamin D on the cardiovascular system may also be involved. Vitamin D receptors are expressed in a variety of tissues, including cardiomyocytes, vascular smooth muscle cells and endothelial cells. Moreover, vitamin D has been shown to affect inflammation, cell proliferation and differentiation. While observational studies support an association between low plasma vitamin D levels and increased risk of CVD, Mendelian randomization studies do not support a causal association between the two. At present, high quality randomized trials do not find evidence of significant effects on CVD endpoints and do not support supplementation of vitamin D to decrease CVD events.

Protective Effects of 1,25 Dihydroxyvitamin D3 against High-Glucose-Induced Damage in Human Umbilical Vein Endothelial Cells Involve Activation of Nrf2 Antioxidant Signaling

AIM

To explore the protective effects and related mech-anisms of 1,25 dihydroxyvitamin D3 (1,25(OH)2D3) on en-dothelial dysfunction under hyperglycemic conditions.

METHODS

Cultured human umbilical vein endothelial cells (HUVECs) were treated with normal glucose (glucose concentration of 5.5 mmol/L), high glucose (glucose concentration of 33 mmol/L), and high glucose plus 1,25(OH)2D3, respectively. Cell viability and apoptosis, intracellular reactive oxygen species (ROS) and nitric oxide (NO) contents, antioxidant enzyme activities, proinflammatory cytokine mRNA levels, and expression levels of proteins involved were measured.

RESULTS

High glucose decreased HUVEC viability, promoted ROS production and apoptosis, and reduced NO generation, which was associated with decreased activities of antioxidant enzymes and increased levels of proinflam-matory cytokines. 1,25(OH)2D3 treatment enhanced HUVEC viability, attenuated ROS generation and apoptosis, and -increased NO production, which was accompanied by -enhanced antioxidant enzyme activities and reduced -proinflammatory factors. Mechanically, 1,25(OH)2D3 promoted nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) in a vitamin D receptor (VDR)-dependent manner, and Nrf2 siRNA abolished the antioxidative and -anti-inflammatory effects of 1,25(OH)2D3.

CONCLUSIONS

1,25(OH)2D3 attenuates high-glucose-induced endothelial oxidative injury through upregulation of the Nrf2 antioxidant pathway in a VDR-dependent manner.

MicroRNA‑378d inhibits Glut4 by targeting Rsbn1 in vitamin D deficient ovarian granulosa cells

Vitamin D (VD) is not only associated with bone growth and development, but is also closely associated with numerous other pathological conditions. The present study aimed to investigate the effect of microRNA (miRNA/miR)-378d on ovarian granulosa cells by regulating the round spermatid basic protein 1 (Rsbn1) in the absence of VD. The abnormal expression of miRNAs in ovarian tissues of the VD-deficient mouse was analyzed using transcriptome sequencing. miR-378d, glucose transporter 4 (Glut4) and aromatase (Cyp19a) expression levels were examined via reverse transcription-quantitative (RT-q)PCR and western blotting. The expression levels of Rsbn1, Glut4 and Cyp19a were detected in transfected mouse ovarian granulosa cells. The targeting regulation between miR-378d and Rsbn1 was verified using double reporter gene assay and functional rescue experiments. Among the 672 miRNAs that were differentially expressed, cluster analysis revealed that 17 were significantly upregulated and 16 were significantly downregulated. Moreover, miR-378d showed significant upregulation, which was further verified via RT-qPCR. It was identified that the protein expression level of Rsbn1 was significantly downregulated. Furthermore, Glut4 mRNA expression was significantly decreased in the mimic group but markedly increased in the inhibitor group. By contrast, the mRNA expression levels of Rsbn1 and Cyp19a did not demonstrate any significant difference. The western blotting results indicated that the protein expression levels of Rsbn1 and Glut4 were decreased and increased, respectively, while Cyp19a did not show any significant change. In addition, the double reporter gene experiments confirmed that Rsbn1 was the target gene of miR-378d. Collectively, the present results demonstrated that miR-378d was abnormally overexpressed in the ovarian tissues of the VD-deficient mice, and that miR-378d could inhibit Glut4 production by targeting Rsbn1, which may lead to insulin resistance.

Potential role of hypovitaminosis D and vitamin D supplementation during COVID-19 pandemic

Vitamin D deficiency is a pandemic disorder affecting over 1 billion of subjects worldwide and displaying a broad spectrum of implications on cardiovascular and inflammatory disorders. Since the initial reports of the association between hypovitaminosis D and COVID-19, Vitamin D has been pointed as a potentially interesting treatment for SARS-CoV-2 infection. We provide an overview on the current status of vitamin D deficiency, the mechanisms of action of vitamin D and the current literature on the topic, with a special focus on the potential implications for COVID-19 pandemic.

Association between vitamin D deficiency and serum Homocysteine levels and its relationship with coronary artery disease

Homocysteine (Hcy) elevation and vitamin D deficiency have emerged as potential markers of coronary artery disease (CAD). However, even tough hypovitaminosis D has been suggested to interfere with Hcy catabolism, no study has so far addressed the interaction of vitamin D and Hcy and their impact on CAD, that was the aim of present study. A cohort of consecutive patients undergoing coronary angiography in a single center were included and analyzed within the year 2019. Significant CAD was defined as at least 1 vessel stenosis > 50%, while severe CAD as left main and/or three-vessel disease. Hcy and vitamin D levels were assesssed at admission. We included 3150 patients undergoing coronary angiography at our centre, who were divided according to the quartiles values of vitamin D. Patients with lower levels of Vitamin D displayed a higher cardiovascular risk profile and a higher prevalence of CAD. We observed an inverse linear relationship between lower levels of vitamin D and higher Hcy (r = − 0.092, p < 0.001) and a higher prevalence of hyperhomocysteinemia in patients with lower quartiles values of vitamin D (p < 0.001). By forward conditional regression model, low vitamin D appeared as independent predictors of Homocysteine levels above the median (OR[95%CI] = 1.79[1.37–2.33], p < 0.001). In addition, patients with low vitamin D (below the median) and increased Hcy displayed a non-significantly higher rate of CAD (81% vs 77.7%, p = 0.13, adjusted OR[95%CI] = 1.16[0.88–1.54], p = 0.29) but a significant increase in the rate of severe left main/3-vessel CAD (37.4% vs 30.5%, p = 0.005, adjusted OR[95%CI] = 1.29[1.02–1.67], p = 0.04). Among patients with vitamin D levels above the median, Hcy levels did not impact on the prevalence and extent of CAD (77.7 vs 77.2%, p = 0.81, adjusted OR[95%CI] = 0.94[0.73–1.20], p = 0.60 for CAD and 31.8% vs 27.7%, p = 0.08, adjusted OR[95%CI] = 0.97[0.75–1.25], p = 0.81 for severe left main/3-vessel CAD). No significant interaction between Hcy and vitamin D with CAD or severe CAD was observed. The present study shows an independent inverse linear relationship between vitamin D and Hcy values. Moreover, the association of Hcy with the extent of CAD was significant only among patients with hypovitaminosis D, and not in the cohort of subjects with vitamin D levels above the median, suggesting that a normal vitamin D status can prevent the deleterious effects of hyperhomocysteinemia on coronary atherosclerosis, a hypothesis that certainly needs further confirmation in larger randomized trials.

Vitamin D/VDR attenuate cisplatin-induced AKI by down-regulating NLRP3/Caspase-1/GSDMD pyroptosis pathway

Vitamin D/Vitamin D receptor (VDR) has been shown to inhibit the NF-κB-mediated inflammatory effects. Up-regulation of the NLRP3(Recombinant NLR Family, Pyrin Domain Containing Protein 3)/Caspase-1/GSDMD (Gasdermin D) pathway through NF-κb is one of the key mechanisms leading to pyroptosis. This study aims to explore the effects of vitamin D/VDR on the pyroptosis pathway in cisplatin induced acute kidney injury (AKI) models. Our results showed that in wide type mice, renal function loss, tissue injury and cell death induced by cisplatin were alleviated by pretreatment of high-dose paricalcitol(a VDR agonist) accompanied with up-regulated VDR and decreased expression of NLRP3, GSDMD-N, Cleaved-Caspase-1 and mature Interleukin- 1β (features of pyroptosis). While, in VDR knock out mice, cisplatin induced more severer renal injury and further increased pyroptosis related protein than the wild type mice and the effect of paricalcitol were also eliminated. In tubular cell specific VDR-over expressing mice, those renal injury index as well as pyroptosis phenotype were significantly reduced by low-dose paricalcitol pretreatment with upregulated VDR expression compared with WT mice. In vitro data using gain and lose function experiments in Human tubular epithelial cell (HK-2) were consistent with the observation as in vivo work. Our further experiments in both animal and cell culture work has found that the level of IκBα(Inhibitor of NF-κB) were decreased and the nuclear level of NF-κB p65 of renal tubular cells were increased after cisplatin injury while VDR activation by paricalcitol could reverse up-regulation of nuclear NF-κB p65 with reduced cell pyroptosis. These data suggested that vitamin D/VDR could alleviate cisplatin-induced acute renal injury partly by inhibiting NF-κB-mediated NLRP3/Caspase-1/GSDMD pyroptosis.

Prognostic impact of Vitamin D deficiency in patients with coronary artery disease undergoing percutaneous coronary intervention

BACKGROUND

Whether Vitamin D deficiency represents an independent predictor of mortality and major cardiovascular events or rather the mirror of a more advanced clinical condition with increased comorbidities is still debated. We aimed at assessing the impact of vitamin D levels on the long-term outcomes among patients with coronary artery disease (CAD) undergoing percutaneous coronary intervention.

METHODS

Consecutive patients from a single centre were included. Vitamin D levels were measured at admission by chemiluminescence immunoassay kit LIAISON® Vitamin D assay (Diasorin Inc). Severe deficiency was defined for 25(OH)D < 10 ng/ml. The primary study endpoint was overall mortality. Secondary endpoints were cardiovascular mortality, recurrent acute coronary syndrome or major cardiovascular events (a composite of death, recurrent MI and target vessel revascularization) at the longest available follow-up.

RESULTS

We included a total of 705 patients, that were divided according to vitamin D tertiles (<12.7; 12.7-21.59; ≥21.6 ng/ml). Lower levels of Vitamin D were associated with renal failure (p=0.03), more severe coronary disease (p=0.001), diabetes mellitus and previous CABG (p<0.001), lower ejection fraction (p=0.02), acute presentation (p=0.04), use of statins (p=0.02), diuretics, nitrates and clopidogrel (p<0.001) and RASI (p=0.008). An inverse association was documented with BMI, glycemia, total cholesterol (p<0.001), creatinine and WBC (p=0.001). At a median follow-up of 996.5 [377-1552] days, 3.8% of the patients died. Vitamin D deficiency was significantly associated with overall mortality (7.6% vs 2.9% vs 0.4%, adjusted HR[95%CI]=3.6[1.43-8.9], p=0.006), MACE (adjusted HR[95%CI]=1.32[1.07-1.63], p=0.01) and the composite of death and MI (adjusted HR[95%CI]=1.3[1.03-1.65], p=0.03). A similarly increased risk was confirmed for all major higher-risk subsets of patients, with no significant interaction according to age, gender, diabetes mellitus or chronic kidney disease.

CONCLUSION

Among patients undergoing percutaneous coronary interventions, lower levels of vitamin D are associated with an over 3-fold increased risk of mortality and major cardiovascular events. Future larger studies are certainly warranted in order to define the prognostic implications of cholecalciferol supplementation among high-risk patients with established coronary artery disease.

The VITamin D and OmegA-3 TriaL (VITAL): Do Results Differ by Sex or Race/Ethnicity?

Whether vitamin D or marine omega-3 (n-3) fatty acid supplementation reduces risk of cancer or cardiovascular disease (CVD) in general populations at usual risk for these outcomes is relatively unexplored in randomized trials. The primary goal of the VITamin D and OmegA-3 TriaL (VITAL), a nationwide, randomized, placebo-controlled, 2 × 2 factorial trial of vitamin D₃ (2000 IU/day) and marine n-3 fatty acids (1 g/day) in the primary prevention of cancer and CVD among 25 871 US men aged ≥50 years and women aged ≥55 years, was to fill these knowledge gaps. Studying the influence of sex and race/ethnicity on treatment-related outcomes was a prespecified goal; such analyses help ensure that important effects are not missed and contribute to the foundation for developing targeted recommendations for supplement use. To enable investigation of potential sex- and race-specific treatment effects, trial investigators enrolled an even balance of men (n = 12 786) and women (n = 13 085) and oversampled African Americans (n = 5106). Significant or suggestive variation in intervention effects according to sex, race/ethnicity, and other participant characteristics was observed for some, though not all, outcomes. Additional research is needed to determine which individuals may be most likely to derive a net benefit from vitamin D or n-3 fatty acid supplementation. (VITAL clinicaltrials.gov identifier: NCT01169259).

Herbal or Dietary Supplement Use and Hypertensive Medications: Does the Combination Relate to Medication Adherence and Blood Pressure Control?

Introduction: Medication nonadherence contributes to poor blood pressure control and increases cardiovascular disease risk in patients with hypertension. Identifying modifiable risk factors for low or nonadherence to antihypertensive medication is needed. Studies that have examined the relationship between herbal or dietary supplement (HDS) use and antihypertensive medication nonadherence provide inconsistent findings. Data from the National Health and Nutrition Examination Survey were used to examine the association between HDS use, current use of prescribed antihypertensive medication, and blood pressure status. Methods: The study sample included hypertensive adults (n = 5,478) who have been told by a health professional to take prescribed medication for their health condition. Respondents were classified as either HDS users or HDS nonusers. Depending on the kind of supplement used, HDS users were further divided into three mutually exclusive groups: hypertension HDS users, nonhypertension HDS users, and those who used both kinds of supplements. Supplements groupings were based on reports in the literature. Blood pressure status definition was based on Eighth Joint National Committee (JNC 8) recommendations. Adjusted odds ratios (aORs) and 95% confidence intervals (95% CIs) were obtained from logistic models. Results: Overall HDS use prevalence was 62%. Current medication use did not significantly differ between patients reporting no HDS use and those reporting HDS use (aOR: 1.45; 95% CI: 0.78-2.69). No observable differences were found in current medication use between patients reporting no HDS use and those taking nonhypertension HDS or both kinds of supplements. Use of hypertension HDS was associated with improved blood pressure (aOR: 1.90; 95% CI: 1.07-3.36) compared with no HDS use. Conclusion: In a nationally representative U.S. sample, HDS use did not compromise current use of prescribed medication and was associated with improved blood pressure control. More research is needed to better understand why HDS use is associated with better blood pressure control.

The Association of Vitamin D and Vitamin K Status with Subclinical Measures of Cardiovascular Health and All-Cause Mortality in Older Adults: The Hoorn Study

BACKGROUND

A low vitamin D and K status has been associated with increased cardiovascular disease (CVD) risk but the evidence of their combined effect on cardiovascular health is limited.

OBJECTIVES

Our study aimed to investigate the prospective association of vitamin D and K status with subclinical measures of cardiovascular health and all-cause mortality among a population of Dutch Caucasians.

METHODS

We performed an observational prospective study on 601 participants of the Hoorn Study (mean ± SD age: 70 ± 6 y, 50.4% women, BMI: 27.2 ± 4.0 kg/m2), of whom 321 underwent an echocardiogram in 2000-2001 and 2007-2009. Vitamin D and K status was assessed at baseline by serum 25-hydroxyvitamin D [25(OH)D] and plasma desphospho-uncarboxylated matrix-gla protein (dp-ucMGP)-high concentrations indicate low vitamin K status. Vital status was assessed from baseline until 2018. We studied the association of categories of 25(OH)D (stratified by the clinical cutoff of 50 mmol/L) and dp-ucMGP (stratified by the median value of 568 pmol/L) with echocardiographic measures using linear regression and with all-cause mortality using Cox regression, adjusted for confounders.

RESULTS

Compared with markers of normal vitamin D and K status, markers of low vitamin D and K status were prospectively associated with increased left ventricular mass index (5.9 g/m2.7; 95% CI: 1.8, 10.0 g/m2.7). Participants with low vitamin D and K status were also at increased risk of all-cause mortality with an HR of 1.64 (95% CI: 1.12, 2.39) compared with normal vitamin D and K status.

CONCLUSIONS

A combination of low vitamin D and K status is associated with adverse cardiac remodeling and increased risk of all-cause mortality in men and women. Future studies should investigate whether vitamin D and K supplementation could help to improve cardiovascular health and to decrease CVD risk.

The relationship between circulating vitamin D3 and subclinical atherosclerosis in an elderly Asian population

The current evidence regarding the association between vitamin D deficiency and cardiovascular diseases/metabolic disorders is contradictory and inconclusive. In this large-scale observational study, we investigated the relationship between the serum 25-hydroxy vitamin D3 [25(OH)D] concentration and subclinical atherosclerosis in an elderly Asian population. In the I-Lan longitudinal study (ILAS), 1798 elderly, aged 50 and older, were enrolled. For each subject, serum 25-hydroxy vitamin D3 [25(OH)D] concentration and demographic data were recorded. The participants were divided into two groups according to their serum 25(OH)D level (sufficient, > 20 ng/mL and deficient, ≤ 20 ng/mL). Carotid intima-media thickness (cIMT) was measured at bilateral common carotid arteries. Subclinical atherosclerosis was defined as a mean cIMT > 0.81 mm. The mean subject age was 64 ± 9 years old, and 604 (33.6%) were identified as having serum 25(OH)D level ≤ 20 ng/mL. Subjects with serum 25(OH)D level ≤ 20 ng/mL were younger, more likely to be female and smoker, and had a higher incidence of hypertension, dyslipidemia, and metabolic syndrome, compared to those with serum 25(OH)D level > 20 ng/mL. Additionally, patients with serum 25(OH)D level ≤ 20 ng/mL were associated with a lower risk of subclinical atherosclerosis (crude OR: 0.63, 95% CI 0.50–0.81, p < 0.001), according to univariate analysis. However, after adjusting for gender and age, serum 25(OH)D level ≤ 20 ng/mL was not a significant risk factor for subclinical atherosclerosis. Serum 25(OH)D level ≤ 20 ng/mL was not an independent risk factor for subclinical atherosclerosis in this large elderly Asian population. Association observed in the univariate analysis may be confounded by gender or comorbidities.

Vitamin D Provides Benefit Based on the Proinflammatory Effects of Homocysteine in Elderly Patients With Type 2 Diabetes Mellitus

PURPOSE

It is unclear whether vitamin D provides any benefit against the pro-inflammatory effects of homocysteine in elderly patients with type 2 diabetes mellitus (T2DM).

METHODS

We compared lymphocyte counts for CD3, CD19, CD4, and CD8 subsets between elderly (age ≥65 years) T2DM patients (n = 5098) and nondiabetes control subjects (n = 20,590) based on the serum concentrations of homocysteine and total vitamin D (calcidiol + calcifediol [total vitamin D, TVD]; <20, 20-30, and >30 ng/mL).

FINDINGS

Significant variation in CD19 (P = 0.019), CD4 (P = 0.015), and CD8 (P < 0.001) were associated with serum TVD in T2DM patients with homocysteine ≤15 μmol/L, whereas CD3 (P = 0.003) and CD8 (P = 0.019) varied in control subjects with homocysteine ≤15 μmol/L. In T2DM patients with high homocysteine (>15 μmol/L) levels, significant variation based on serum TVD occurred in CD19 only (P = 0.024), whereas CD3 (P = 0.016) and CD4 (P = 0.001) varied in control subjects with high homocysteine concentrations.

IMPLICATIONS

Serum TVD influences variation in CD3, CD19, CD4, and CD8 lymphocyte subsets based on the serum homocysteine concentration in elderly T2DM patients and nondiabetic individuals with moderate to high homocysteine concentrations. The effect of TVD is partially attenuated in individuals with high homocysteine concentrations, with greater attenuation occurring in patients with T2DM. Differences in the variation of lymphocyte subsets between nondiabetes subjects with moderate homocysteine concentrations and those with high homocysteine concentrations constitute a shift from CD8-positive cells to CD4-positive cells, suggesting a change in TH1/TH2 balance based on TVD and homocysteine concentrations that is absent in diabetes cases with high homocysteine concentrations.

Low vitamin D levels affect left ventricular wall thickness in severe aortic stenosis

BACKGROUND

Vitamin D [25(OH)D] deficiency and degenerative aortic stenosis represent emerging conditions, linked to a progressive ageing of the population and increased frailty. Previous studies have associated lower levels of 25 (OH)D to the pathogenesis of atherosclerosis and vascular calcifications. However, few studies have evaluated, so far, the impact of vitamin D deficiency in patients with aortic stenosis, which was therefore the aim of present study.

METHODS

Consecutive patients with severe degenerative aortic stenosis undergoing nonurgent coronary angiography were included. Aortic stenosis was defined as aortic valve area (AVA) less than 1 cm and/or mean gradient more than 40 mmHg. Indexed area and stroke volume or dobutamine stress evaluation were performed when indicated. Fasting samples were collected at admission for 25 (OH)D levels assessment.

RESULTS

We included 137 patients with severe degenerative aortic stenosis (48.9% men, mean age 78.4 ± 6.4 years) who were divided according to vitamin D median values (≥12.4 ng/ml). Patients with lower vitamin D had a more frequent history of coronary artery bypass graft (P = 0.02) and received more often angiotensin-converting enzyme-inhibitors (P = 0.03). Among them, 38.7% had vitamin D levels less than 10 ng/ml and only five patients were in therapy with vitamin D supplementation. We observed no significant relationship between vitamin D levels and echocardiographic parameters for the severity of aortic stenosis (AVA, peak and mean gradients, volumes, ejection fraction) except for a greater wall thickness in patients with lower vitamin D levels (r = -0.34, P = 0.03). Results did not change when excluding patients with renal failure or treated with vitamin D supplementation.

CONCLUSION

Among patients with severe degenerative aortic stenosis, vitamin D deficiency is common. We found a significant association between left ventricular wall thickness and vitamin D levels, suggesting a potential role of this hormone in modulating hypertrophic remodelling in these patients. However, future larger studies are certainly needed to confirm our findings and to define their prognostic implications.

Vitamin D Supplementation and Cardiovascular Disease Risks in More Than 83 000 Individuals in 21 Randomized Clinical Trials: A Meta-analysis

Importance

Observational studies have reported an association between low serum vitamin D levels and elevated risk of cardiovascular disease (CVD) events, but such studies cannot prove causation because of possible unmeasured confounding.

Objective

We conducted a meta-analysis of randomized clinical trials that tested the association of vitamin D supplementation with reduced CVD events and all-cause mortality.

Data Sources

Literature search through PubMed, the Cochrane Library, and Embase was completed by 2 reviewers from each database's inception to December 15, 2018.

Study Selection

Inclusion criteria were randomized clinical trials that reported the effect of long-term (≥1 year) vitamin D supplementation on CVD events and all-cause mortality. Studies that did not include cardiovascular outcomes were excluded.

Data Extraction and Synthesis

Data were abstracted independently by 2 authors. Random-effects models were used to report the risk ratios (RRs) and 95% CIs.

Main Outcomes and Measures

Major adverse cardiovascular events was the primary outcome, and rates of myocardial infarction, stroke or cerebrovascular accident, CVD mortality, and all-cause mortality were the secondary end points.

Results

Twenty-one randomized clinical trials were included (including 83 291 patients, of whom 41 669 received vitamin D and 41 622 received placebos). The mean (SD) age of trial participants was 65.8 (8.4) years; 61 943 (74.4%) were female. Only 4 trials had prespecified CVD as a primary end point. Vitamin D supplementation compared with placebo was not associated with reduced major adverse cardiovascular events (RR, 1.00 [95% CI, 0.95-1.06]; P = .85) nor the secondary end points of myocardial infarction (RR, 1.00 [95% CI, 0.93-1.08]; P = .92), stroke (RR, 1.06 [95% CI, 0.98-1.15]; P = .16), CVD mortality (RR, 0.98 [95% CI, 0.90-1.07]; P = .68), or all-cause mortality (RR, 0.97 [95% CI, 0.93-1.02]; P = .23). Results were generally consistent by sex, baseline 25-hydroxyvitamin D level, vitamin D dosage, formulation (daily vs bolus dosing), and presence or absence of concurrent calcium administration.

Conclusions and Relevance

In this updated meta-analysis, vitamin D supplementation was not associated with reduced major adverse cardiovascular events, individual CVD end points (myocardial infarction, stroke, CVD mortality), or all-cause mortality. The findings suggest that vitamin D supplementation does not confer cardiovascular protection and is not indicated for this purpose.

Health effects of vitamin and mineral supplements

Growing numbers of healthy people are taking dietary supplements but there is little evidence that they protect against non-communicable diseases, say Fang Fang Zhang and colleagues

A comparative pharmacogenomic analysis of three classic TCM prescriptions for coronary heart disease based on molecular network modeling

Traditional Chinese medicine (TCM) has evolved over several thousands of years, which has been shown to be efficacious in the treatment of ischemic heart disease. Three classical TCM prescriptions, namely Xuefu Zhuyu Decoction, Zhishi Xiebai Guizhi Decoction, and Gualou Xiebai Banxia Decoction, have been extensively used in the treatment of coronary heart disease (CHD). Based on molecular network modeling, we performed a comparative pharmacogenomic analysis to systematically determine the drug-targeting spectrum of the three prescriptions at molecular level. Wide-area target molecules of CHD were covered, which was a common feature of the three decoctions, demonstrating their therapeutic functions. Meanwhile, collective signaling involved metabolic/pro-metabolic pathways, driving and transferring pathways, neuropsychiatric pathways, and exocrine or endocrine pathways. These organized pharmacological disturbance was mainly focused on almost all stages of CHD intervention, such as anti-atherosclerosis, lipid metabolism, inflammation, vascular wall function, foam cells formation, platelets aggregation, thrombosis, arrhythmia, and ischemia-reperfusion injury. In addition, heterogeneity analysis of the global pharmacological molecular spectrum revealed that signaling crosstalk, cascade convergence, and key targets were tendentious among the three decoctions. After all, it is unadvisable to rank the findings on targeting advantages of the three decoctions. Comparative pharmacological evidence may provide an appropriate decoction scheme for individualized intervention of CHD.

Vitamin D supplementation, cardiac events and stroke: A systematic review and meta-regression analysis

INTRODUCTION

Observational data has suggested a link between vitamin D deficiency and coronary heart disease (CHD). However, randomized controlled trials (RCTs) have failed to show benefit. The objective of this study is to analyze the RCTs investigating vitamin D supplementation and the risk of CHD and stroke.

METHODS

All RCTs that compared vitamin D supplementation to placebo and evaluated nonfatal myocardial infarction (MI), cardiac mortality, stroke and CHD events (a composite of cardiac mortality, MI, unstable angina and revascularization) were included. Rate ratios (RR) were calculated for each endpoint and to test for heterogeneity of treatment effect (HTE) the Chi2 and I2 tests were used for younger vs. older participants, shorter vs. longer trial duration, vitamin D supplements with vs. without calcium, and daily vs. monthly dosages of vitamin D. A meta-regression was performed with baseline vitamin D concentration as the covariate.

RESULTS

22 RCTs were identified (n = 83,200). Vitamin D supplementation had no effect on nonfatal MI (RR 0.98, 95% confidence interval (CI) 0.89-1.08), cardiac death (RR 0.94, CI 0.84-1.06), CHD events (RR 1.00, CI 0.91-1.10), or stroke (RR, 0.97, CI 0.9-1.03). When performing the meta-regression with baseline circulating 25-hydroxyvitamin D (25(OH)D) concentrations as the covariate, vitamin D supplementation's treatment effect on CVD outcomes was not associated with baseline 25(OH)D.

CONCLUSION

Vitamin D did not reduce CHD and stroke. A linear relationship does not exist between baseline 25(OH)D and vitamin D supplementation's effect on CVD. Vitamin D levels should be checked and repleted in those with an absolute indication.