The Impact of Vitamin D in the Treatment of Essential Hypertension

Health benefits of fish and fish by-products-a nutritional and functional perspective

Fish is the primary marine source that provides adequate nutrition to the human body. Fish production is increasing every year, contributing to a sustainable economy, as they provide a significant source of income and food: This review highlights the potential health benefits, industrial applications, and toxicity of various fish species Globally, fish possess various bioactive compounds; this efficacy makes them a more edible source to consume worldwide. A wide range of bioactive compounds, primary macronutrients, micronutrients, vitamins, and minerals are present in various fish types that are essential in preventing different human disorders. The nutritional value of fish helps to provide exceptional health benefits against different human ailments. Fish are excellent sources of protein, peptides, and polyunsaturated fatty acids, particularly eicosapentaenoic acid (EPA), Alpha-linolenic acid (ALA), omega-6 fatty acids, and docosahexaenoic acid (DHA), omega-3 fatty acids that influence human health positively. Fish and their by-products are also excellent sources for developing various nutraceutical and functional foods to fight against multiple human disorders. The by-products of fish exert significant effects against infection, viral attack, cardiovascular diseases, immune disorders, oxidative stress, inflammation, neurological diseases, and other physiological complications. Few fish species are contaminated with harmful substances that cause potential risks to children's and adults' bodies. Additionally, the therapeutic use of fish and their by-products unveils the potential nutritional benefits to reduce the burden on public health by managing dietary issues such as food security, protein deficiency, and other nutritional-related problems.

A Personalized Approach to Vitamin D Supplementation in Cardiovascular Health Beyond the Bone: An Expert Consensus by the Italian National Institute for Cardiovascular Research

Vitamin D is increasingly recognized for its role in cardiovascular health beyond its well-established effects on bone metabolism. This review synthesizes findings from observational studies, interventional trials, and meta-analyses to clarify the mechanisms through which vitamin D impacts cardiovascular health, including its influence on vascular function, inflammation, and metabolic pathways. Additionally, this review emphasizes the importance of a personalized approach to vitamin D supplementation, integrating individual cardiovascular risk profiles, baseline vitamin D levels, and comorbid conditions, such as hypertension and diabetes. While current evidence supports the association between low vitamin D levels and increased cardiovascular mortality, this work contributes novel insights by proposing tailored strategies for supplementation, particularly for high-risk subgroups. Practical recommendations for implementing these strategies in clinical practice are also discussed, providing a framework for optimizing cardiovascular outcomes through individualized vitamin D management.

Correlation between vitamin D metabolic pathway-related gene polymorphisms and cardiovascular disease

Vitamin D plays important roles in various physiological processes such as cardiovascular health, calcium balance regulation, bone health, immune system support, neurological function regulation, muscle function maintenance, and anti-inflammatory effects. Therefore, maintaining its adequate levels is essential for overall health. Genetic polymorphisms in vitamin D metabolic pathways have become a key factor affecting the susceptibility and progression of cardiovascular disease (CVD). This article reviews the relationship between gene polymorphisms in vitamin D metabolic pathways and vitamin D levels or CVD. It is emphasized that the polymorphisms of key genes such as GC, VDR, CYP2R1, CYP24A1 and CYP27B1 are related to the pathogenesis of CVD. These polymorphisms can regulate serum levels of vitamin D, thereby affecting the susceptibility, comorbidities and clinical manifestations of CVD. Despite the progress made, there are still inconsistencies and gaps in the literature. Thus, it is necessary to conduct large-scale, multicenter studies to verify these findings and deepen our understanding of the intricate interactions between gene polymorphisms in vitamin D metabolic pathways and CVD.

Seasonal variation in vascular function: a systematic review and recommendations for future research

Vascular function serves as a prognostic marker for cardiovascular disease and may exhibit seasonal variations due to lifestyle and environmental factors. Our systematic review aimed to determine whether seasonal variations in vascular function are present. We conducted a search of five databases (MEDLINE via PubMed, CINAHL, Web of Science, Cochrane Library, and Biomed Central) to identify evidence of seasonal variations in vascular function. Studies were eligible for inclusion if they assessed vascular function in adult humans during two or more seasons and were published in English. Of the 20,420 studies screened, 12 were eligible and none were excluded due to bias. Nine studies reported significant seasonal variations in vascular function, whereas three studies found no significant seasonal variations. The seasonality of vascular function remains unclear. However, current literature indicates that vascular dysfunction may exhibit a seasonal pattern, with vascular function reduced in the winter. Seasonal variations in endothelial function necessitate further exploration, particularly concerning factors such as exercise, temperature, light exposure, and air pollution. Future research should adopt standardised protocols, involve diverse and larger populations, employ longitudinal designs to minimise confounding factors, systematically measure and adjust for environmental variables, and accurately assess the impact of seasonal variation on vascular function.

The Role of Vitamin D Metabolism Genes and Their Genomic Background in Shaping Cyclosporine A Dosage Parameters after Kidney Transplantation

Background: Kidney transplantation is followed by immunosuppressive therapy involving calcineurin inhibitors (CNIs) such as cyclosporin A. However, long-term high CNIs doses can lead to vitamin D deficiency, and genetic variations influencing vitamin D levels can indirectly impact the necessary CNIs dosage. This study investigates the impact of genetic variations of vitamin D binding protein (DBP) rs2282679 and CYP2R1 hydroxylase rs10741657 polymorphisms on the cyclosporin A dosage in kidney transplant recipients. Additional polymorphisims of genes that are predicted to influence the pharmacogenetic profile were included. Methods: Gene polymorphisms in 177 kidney transplant recipients were analyzed using data mining techniques, including the Random Forest algorithm and Classification and Regression Trees (C&RT). The relationship between the concentration/dose (C/D) ratio of cyclosporin A and genetic profiles was assessed to determine the predictive value of DBP rs2282679 and CYP2R1 rs10741657 polymorphisms. Results: Polymorphic variants of the DBP (rs2282679) demonstrated a strong predictive value for the cyclosporin A C/D ratio in post-kidney transplantation patients. By contrast, the CYP2R1 polymorphism (rs10741657) did not show predictive significance. Additionally, the immune response genes rs231775 CTLA4 and rs1800896 IL10 were identified as predictors of cyclosporin A response, though these did not result in statistically significant differences. Conclusions:DBP rs2282679 polymorphisms can significantly predict the cyclosporin A C/D ratio, potentially enhancing the accuracy of CNI dosing. This can help identify patient groups at risk of vitamin D deficiency, ultimately improving the management of kidney transplant recipients. Understanding these genetic influences allows for more personalized and effective treatment strategies, contributing to better long-term outcomes for patients.

Lower extremity arterial plaque in patients with type 2 diabetes mellitus: A cross-sectional study of 25-(OH)D3 and other risk factors

OBJECTIVE

The occurrence of chronic vascular complications in individuals with type 2 diabetes mellitus(T2DM) is influenced by multiple factors. This study aims to analyze the correlation between serum 25-(OH)D3 levels and other risk factors with the formation and severity of arterial plaques in the lower extremities, and explore its role in clinical diagnosis and treatment.

METHODS

A total of 628 Chinese patients with T2DM were included in this study. Based on the intima-media thickness (IMT) and plaque echogenicity measured by lower extremity vascular ultrasound, the patients were divided into the no plaque group(NP), low-risk plague group(LP), moderate-risk plague group(MP), and severe-risk plague group(SP). Based on 25-(OH)D3 levels, patients were categorized as vitamin D deficient group (VDD，25-(OH)D3 ≤ 20 ng/mL), vitamin D insufficient group (VDI，25-(OH)D3 between>20 ng/mL and < 30 ng/mL), and vitamin D sufficient group (VDS，25-(OH)D3 ≥ 30 ng/mL). The correlation between the severity of lower extremity arterial plaques and serum 25-(OH)D3 levels was analyzed, as well as the risk factors for lower extremity arterial plaque formation in patients with T2DM.

RESULTS

The levels of 25-(OH)D3 in patients with arterial plaques were significantly lower than those in the NP (p = 0.002). Additionally, with the increasing severity of lower extremity arterial plaques, 25-(OH)D3 levels also decreased significantly (p = 0.01). The proportion of patients with sufficient 25-(OH)D3 levels was highest in NP, while the proportion of deficient and insufficient groups was higher in LP (p<0.001). Multivariate logistic regression analysis showed that low levels of 25-(OH)D3 were an independent risk factor for lower extremity arterial plaques in T2DM patients. Compared to patients with 25-(OH)D3>20 ng/mL, the odds ratios for the formation of moderate-risk plaques were 2.525 (95 % CI: 1.45-4.39) in patients with 25-(OH)D3 ≤ 20 ng/mL, and 2.893 (95 % CI: 1.59-5.26) for the formation of high-risk plaques.

CONCLUSION

Serum 25-(OH)D3 levels may be correlated with the occurrence and severity of lower extremity arterial plaques in patients with T2DM. Low serum 25-(OH)D3 concentration is a risk factor for lower extremity vascular lesions.

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.

Association of Vitamin D Genetic Risk Score with Noncommunicable Diseases: A Systematic Review

Background and Aims: The genetic risk score (GRS) is an important tool for estimating the total genetic contribution or susceptibility to a certain outcome of interest in an individual, taking into account their genetic risk alleles. This study aims to systematically review the association between the GRS of low vitamin D with different noncommunicable diseases/markers. Methods: The article was first registered in PROSPERO CRD42023406929. PubMed and Embase were searched from the time of inception until March 2023 to capture all the literature related to the vitamin D genetic risk score (vD-GRS) in association with noncommunicable diseases. This was performed using comprehensive search terms including "Genetic Risk Score" OR "Genetics risk assessment" OR "Genome-wide risk score" AND "Vitamin D" OR 25(HO)D OR "25-hydroxyvitamin D". Results: Eleven eligible studies were included in this study. Three studies reported a significant association between vD-GRS and metabolic parameters, including body fat percentage, body mass index, glycated hemoglobin, and fasting blood glucose. Moreover, colorectal cancer overall mortality and the risk of developing arterial fibrillation were also found to be associated with genetically deprived vitamin D levels. Conclusions: This systematic review highlights the genetic contribution of low-vitamin-D-risk single nucleotides polymorphisms (SNPs) as an accumulative factor associated with different non-communicable diseases/markers, including cancer mortality and the risk of developing obesity, type 2 diabetes, and cardiovascular diseases such as arterial fibrillation.

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

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

The benefits of Vitamin D in the COVID-19 pandemic: biochemical and immunological mechanisms

In December 2019, a new infectious complication called CoronaVirus Infectious Disease-19, briefly COVID-19, caused by SARS-COV-2, is identified in Wuhan, China. It spread all over the world and became a pandemic. In many individuals who had suffered SARS-COV-2 infection, cytokine storm starts through cytokine overproduction and leads to Acute Respiratory Syndrome (ARS), organ failure, and death. According to the obtained evidence, Vitamin D (VitD) enhances the ACE2/Ang(1-7)/MasR pathway activity, and it also reduces cytokine storms and the ARS risk. Therefore, VitD intake may be beneficial for patients with SARS-COV-2 infection exposed to cytokine storm but do not suffer hypotension. In the present review, we have explained the effects of VitD on the renin-angiotensin system (RAS) function and angiotensin-converting enzyme2 (ACE2) expression. Furthermore, we have reviewed the biochemical and immunological effects of VitD on immune function in the underlying diseases and its role in the COVID-19 pandemic.

Single Nucleotide Polymorphisms in the Vitamin D Metabolic Pathway and Their Relationship with High Blood Pressure Risk

High blood pressure (HBP) is the leading risk factor for cardiovascular disease (CVD) and all-cause mortality worldwide. The progression of the disease leads to structural and/or functional alterations in various organs and increases cardiovascular risk. Currently, there are significant deficiencies in its diagnosis, treatment, and control. Vitamin D is characterized by its functional versatility and its involvement in countless physiological processes. This has led to the association of vitamin D with many chronic diseases, including HBP and CVD, due to its involvement in the regulation of the renin-angiotensin-aldosterone system. The aim of this study was to evaluate the effect of 13 single nucleotide polymorphisms (SNPs) related to the vitamin D metabolic pathway on the risk of developing HBP. An observational case-control study was performed, including 250 patients diagnosed with HBP and 500 controls from the south of Spain (Caucasians). Genetic polymorphisms in CYP27B1 (rs4646536, rs3782130, rs703842, and rs10877012), CYP2R1 rs10741657, GC rs7041, CYP24A1 (rs6068816, and rs4809957), and VDR (BsmI, Cdx2, FokI, ApaI, and TaqI) were analyzed by real-time PCR using TaqMan probes. Logistic regression analysis, adjusted for body mass index (BMI), dyslipidemia, and diabetes, showed that in the genotypic model, carriers of the GC rs7041 TT genotype were associated with a lower risk of developing HBP than the GG genotype (odds ratio (OR) = 0.44, 95% confidence interval (CI): 0.41-0.77, p = 0.005, TT vs. GG). In the dominant model, this association was maintained; carriers of the T allele showed a lower risk of developing HBP than carriers of the GG genotype (OR = 0.69, 95% CI: 0.47-1.03; TT + TG vs. GG, p = 0.010). Finally, in the additive model, consistent with previous models, the T allele was associated with a lower risk of developing HBP than the G allele (OR = 0.65, 95% CI: 0.40-0.87, p = 0.003, T vs. G). Haplotype analysis revealed that GACATG haplotypes for SNPs rs1544410, rs7975232, rs731236, rs4646536, rs703842, and rs10877012 were associated with a marginally significant lower risk of developing HBP (OR = 0.35, 95% CI: 0.12-1.02, p = 0.054). Several studies suggest that GC 7041 is associated with a lower active isoform of the vitamin D binding protein. In conclusion, the rs7041 polymorphism located in the GC gene was significantly associated with a lower risk of developing HBP. This polymorphism could therefore act as a substantial predictive biomarker of the disease.

The Association Between Vitamin D Level and Chest Pain, Anxiety, and Fatigue in Patients With Coronary Artery Disease

This study sought to assess the association between vitamin D deficiency (VDD) and chest pain, anxiety, and fatigue in patients with coronary artery disease (CAD). A cross-sectional study was conducted to collect data from a sample of 90 participants with CAD. Serum 25OHD3 was measured using a radioimmunoassay procedure. Chest pain was assessed using the Numeric Pain Rating Scale, anxiety using the Anxiety Subscale, and fatigue by the General Fatigue subscale. The majority of participants (80%) had VDD. Results showed that the level of vitamin D was significantly negatively associated with chest pain (r = -.43, p = .00); anxiety (r = -.466, p = .00); and fatigue (r = -.25, p = .018). Findings suggest the role of VDD in heightened central sensitivity in cardiac-related symptoms such as chest pain, anxiety, and fatigue. Patients with CAD should be monitored for VDD so that the condition can be corrected.

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

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

Association of CYP2R1 and VDR Polymorphisms with Metabolic Syndrome Components in Non-Diabetic Brazilian Adolescents

Associations between vitamin D deficiency and metabolic syndrome (MS) have been reported; however, the underlying biological mechanisms remain controversial. The aim of this study was to investigate the associations of CYP2R1 and VDR variants with MS and MS components in non-diabetic Brazilian adolescents. This cross-sectional study included 174 adolescents who were classified as overweight/obese. Three CYP2R1 variants and four VDR variants were identified by allelic discrimination. The CYP2R1 polymorphisms, rs12794714 (GG genotype) (odds ratio [OR] = 3.54, 95% confidence interval [CI] = 1.24–10.14, p = 0.023) and rs10741657 (recessive model—GG genotype) (OR = 3.90, 95%CI = 1.18–12.92, p = 0.026) were significantly associated with an increased risk of MS and hyperglycemia, respectively. The AG + GG genotype (dominant model) of the rs2060793 CYP2R1 polymorphism was associated with hyperglycemia protection (OR = 0.28, 95%CI = 0.08–0.92, p = 0.037). Furthermore, the CC genotype (recessive model) of the rs7975232 VDR polymorphism was significantly associated with a risk of hypertension (OR = 5.91, 95%CI = 1.91–18.32, p = 0.002). In conclusion, the CYP2R1 rs12794714 polymorphism could be considered a possible new molecular marker for predicting the risk of MS; CYP2R1 rs10741657 polymorphism and VDR rs7975232 polymorphism are associated with an increased risk of diabetes and hypertension in adolescents with overweight/obesity.

Independent Association of 25[OH]D Level on Reduced Glutathione and TNF-α in Patients ‎with Diabetes and/or Hypertension

Purpose

Oxidative and inflammatory pathways play a significant role in the pathophysiology of a wide variety of non-communicable diseases such as type 2 diabetes mellitus (T2DM) and hypertension. However, the effect of serum 25-hydroxyvitamin D ‎‎(25[OH]D) on these pathways is still controversial. To evaluate the association of 25[OH]D on ‎antioxidant and pro-inflammatory biomarkers, reduced glutathione (GSH) and tumor ‎necrosis factor (TNF)-α, in T2DM and hypertensive patients.

Patients and Methods

This is a cross-sectional study of a consecutive sample of patients attending the the Family Medicine clinic at King Abdullah bin Abdulaziz University Hospital (KAAUH). Participants were screened for eligibility according to the following ‎criteria: aged above 18 years and diagnosed with T2DM and/or hypertension for at least one ‎year. Patients receiving any kind of vitamin D or calcium supplements within the last three ‎months were excluded, as were those with a history of ‎renal failure, cancer, liver, thyroid, or any other chronic inflammatory diseases.

Results

In total 424 T2DM and/or ‎hypertensive patients (mean age 55±12 years) were recruited. In addition to routine ‎physical and laboratory examinations, levels of serum 25[OH]D, GSH and TNF-α were ‎measured. The prevalence of 25[OH]D deficiency (<50 nmol/L) was 35.1%, which was ‎independent from GSH and TNF-α levels. In T2DM, hypertensive and patients having ‎both diseases, GSH levels were 349.3±19, 355.4±19 and 428.8±20 μmol/L, ‎respectively. Uncontrolled T2DM and hypertension patients showed significantly higher ‎GSH compared with the controlled group. ‎Males showed slightly higher level ‎of TNF-α compared with females and uncontrolled hypertensive patients had relatively ‎higher TNF-α level when evaluated against controlled hypertensive patients. ‎

Conclusion

25[OH]D level is independent of oxidative stress and inflammation, ‎assessed by levels of GSH and TNF-α, respectively, in T2DM and hypertensive Saudi ‎patients. ‎

Relationship between serum 25-hydroxyvitamin D and target organ damage in children with essential hypertension

Researchers have shown that 25-hydroxyvitamin D (25[OH] D), a kind of active vitamin D in the human body, plays a role in cardiovascular disease (CVD). Low serum 25(OH) D levels have been found to be associated with elevated blood pressure (BP) in adults. However, measurement of 25(OH) D in hypertensive children has not been documented. The aim of this study was to investigate the relationship between 25(OH) D and target organ damage (TOD) in children with essential hypertension. We recruited a total of 346 children with essential hypertension and analyzed the correlation between serum 25(OH) D and TOD. Serum 25(OH) D concentration was significantly lower in the TOD than in the no-TOD group (t = 2.416, P = 0.016), as well as significantly lower in the two-organ damage than in the single-organ damage group (t = 3.140, P = 0.002). Pearson's correlation coefficient (PCC) indicated that serum 25(OH) D levels were negatively correlated with left ventricular mass index (LVMI; r = -0.110, P = 0.041) and albuminuria (r = -0.120, P = 0.026). Linear- regression analysis showed that 25(OH) D was a risk factor for left ventricular hypertrophy (LVH; β ± s.e. =-0.074 ± 0.036; 95% confidence interval [CI], - 0.145 to -0.003; P < 0.001) and renal damage (β ± s.e.= -0.018 ± 0.008; 95% CI, - 0.035 to -0.002; P = 0.004). In total, our data revealed that serum 25(OH) D was independently associated with hypertensive cardiac and renal damage, meaning that it was a risk factor for LVH and albuminuria in childhood hypertension.

The effect of combined magnesium and vitamin D supplementation on vitamin D status, systemic inflammation, and blood pressure: A randomized double-blinded controlled trial

OBJECTIVE

Poor vitamin D and magnesium status is observed in individuals who are overweight and obese (Owt/Ob) and is often associated with a heightened risk of cardiovascular disease. Magnesium is a cofactor that assists vitamin D metabolism. We aimed to determine the efficacy of a combined magnesium and vitamin D regimen compared with vitamin D only on increasing serum 25-hydroxyvitamin D (25OHD) concentrations and the effects of these supplements on cardiometabolic outcomes.

METHODS

This 12-week double-blinded randomized controlled trial had three treatment arms: magnesium + vitamin D (MagD; 360 mg magnesium glycinate + 1000 IU vitamin D 3 × daily), vitamin D only (VitD; 1000 IU vitamin D 3 × daily), and placebo. A total of 95 Owt/Ob participants were randomized into one of these three study arms. Anthropometry, dietary intake, concentrations of serum 25OHD, serum parathyroid hormone (PTH), serum inflammatory markers, and blood pressure were obtained at baseline and week 12.

RESULTS

The MagD group experienced the greatest increase in serum 25OHD concentrations (6.3 ± 8.36 ng/mL; P < 0.05). There was a decrease in systolic blood pressure (7.5 ± 8.26 mmHg; P < 0.05) for individuals who had a baseline systolic blood pressure of >132 mmHg in the MagD group. There were no statistically significant treatment effects on serum PTH concentrations and markers of inflammation.

CONCLUSIONS

A combined MagD treatment may be more effective in increasing serum 25OHD concentrations compared with VitD supplementation alone in Owt/Ob individuals.

Status of Vitamin D Receptor Gene Polymorphism and 25-Hydroxy Vitamin D Deficiency with Essential Hypertension

Essential hypertension (EH) is a multifactorial and complex disease with high rate of incidence and associated co-morbidities. Previous studies do not provide unanimous results for the risk of hypertension and association with Fok I genotype frequency and serum vitamin D levels. Hence, this study was undertaken to determine the status of Fok I vitamin D receptor (VDR) gene polymorphism along with vitamin D levels and blood pressure in patients with EH. Four hundred (200 controls and 200 cases of essential hypertension) participants from general Indian population were enrolled in this study. Peripheral blood samples were collected for genotyping Fok I-VDR gene polymorphism using PCR-RFLP method whereas 25-OH vitamin D levels in serum were quantified using high performance liquid chromatography (HPLC). Significantly reduced 25-OH vitamin D levels were observed in patients with EH (24.04 ± 8.62 vs 50.46 ± 15.46) compared to control subjects (p = 0.0001). Homozygous recessive genotype 'ff' frequency was increased by 8.06 fold (CI: 3.71-17.47, p = 0.0001) in patients with EH compared to dominant 'FF' genotype frequency. In conclusion, recessive 'ff' genotype frequency correlates with reduced serum vitamin D levels and results in significantly increased systolic and diastolic blood pressures leading to predisposition of EH.

Vitamin D status, genetic factors, and risk of cardiovascular disease among individuals with type 2 diabetes: a prospective study

BACKGROUND

The presence of a threshold effect has been proposed, suggesting that beneficial effects from vitamin D supplementation may only be present when vitamin D concentration was below a particular threshold.

OBJECTIVES

To investigate the associations of serum 25-hydroxyvitamin D [25(OH)D] concentrations and genetic factors with risks of total and subtypes of CVD in individuals with type 2 diabetes (T2D), among whom vitamin D deficiency or insufficiency is particularly common.

METHODS

This prospective study included 15,103 individuals with T2D, initially free of CVD and with serum 25(OH)D measurements in UK Biobank. Incidence of total and subtypes of CVD, including ischemic heart disease (IHD) and stroke, were ascertained via electronic health records. Weighted genetic risk scores (GRSs) were constructed for IHD and stroke, respectively.

RESULTS

The mean (standard deviation) of serum 25(OH)D concentration was 43.4 (20.4) nmol/L, and 65.7% participants had vitamin D below 50 nmol/L. During a median of 11.2 years of follow-up, 3,534 incident CVD events were documented. Compared with individuals with 25(OH)D <25 nmol/L, participants with 25(OH)D ≥75 nmol/L had an HR of 0.75 (0.64, 0.88) for CVD, 0.69 (0.56, 0.84) for IHD, and 0.74 (0.52, 1.06) for stroke. Participants with 25(OH)D ≥50 nmol/L and low GRS, as compared with individuals with 25(OH)D <25 nmol/L and high GRS, had a 50% (39%, 65%) lower risk of IHD. No significant interactions between serum 25(OH)D and the GRSs and genetic variants in vitamin D receptor (VDR) were demonstrated.

CONCLUSIONS

Higher serum 25(OH)D concentrations were significantly associated with lower risks of total CVD and IHD among patients with T2D, regardless of genetic susceptibility and genetic variants in VDR. Risk reductions tended to plateau at serum 25(OH)D levels around 50 nmol/L. These findings suggest that maintaining adequate vitamin D status and avoiding deficiency may help to prevent CVD complications among patients with T2D.

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

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

The influence of CYP2R1 polymorphisms and gene-obesity interaction with hypertension risk in a Chinese rural population

BACKGROUND AND AIMS

Several studies have reported that variants in CYP2R1 have been linked with an increased risk of hypertension. However, the interaction between CYP2R1 variants and environmental factors on the susceptibility of hypertension remained unclear. Therefore, this study evaluated the influence of CYP2R1 polymorphisms on hypertension susceptibility, and explored the interaction effect of CYP2R1 variations and obesity on the disease.

METHODS AND RESULTS

We included 766 incident hypertension cases matched with non-hypertension controls in a 1:1 ratio by sex, age (within 3 years). Two loci in CYP2R1 gene (rs10766197 and rs12794714) were genotyped by TaqMan probe assays. The concentration of 25-hydroxyvitamin-D was determined by human enzyme-linked immunosorbent assay (ELISA) kits. The associations of CYP2R1 polymorphisms and risks of vitamin D deficiency (VDD) were analyzed by logistic regression. Multifactor dimensionality reduction (MDR) was used to analyze the gene-environment interaction. Multiple logistic regression was used to examine the effect of CYP2R1 gene variations, and the interaction between CYP2R1 variation and obesity on hypertension susceptibility. The results showed that rs10766197 (GG vs. AA) and rs12794714 (GG vs. AA) polymorphisms were both associated with an increased risk of VDD (OR = 1.49, 95% confidence interval (CI) = 1.08-2.05 and OR = 1.63, 95% CI = 1.19-2.25, respectively), after adjustment for potential risk factors. We also found that rs12794714 polymorphism was significantly associated with elevated risk of hypertension under the dominant model (OR = 1.26, 95% CI = 1.01-1.56). In addition, the interactions between rs12794714 with both general obesity (OR = 3.93, 95% CI = 2.72-5.68) and central obesity (OR = 3.22, 95% CI = 2.29-4.52) have significant effects on hypertension susceptibility.

CONCLUSIONS

The study provided further evidence that CYP2R1 variation was associated with a higher risk of hypertension in Chinese rural population. The interaction between CYP2R1 rs12794714 and obesity may increase the risk of hypertension.

Association between Vitamin D Deficiency and Levels of Renin and Angiotensin in Essential Hypertension

OBJECTIVE

The present study aims to investigate the relationship between vitamin D deficiency and renin-angiotensin-aldosterone levels in patients with essential hypertension.

METHODS

The present study observed two groups of patients from Urumqi, Xinjiang, China, from April 2017 to March 2018. There were two subject groups: the hypertension group (80 patients with essential hypertension selected by random cluster sampling) and the control group (76 healthy adults). The 25-hydroxyvitamin D (25(OH)D or vitamin D) levels were measured through electrolytes; fasting blood glucose, blood lipids, and other biochemical indicators were detected using immune chemiluminescence; and plasma renin activity and angiotensin II concentrations were detected with radio-immunity.

RESULTS

Comparison between the hypertension group and control group showed statistically significant differences in the systolic pressure and levels of 25(OH)D, renin, and triglycerides (P < 0.05). The correlation analysis showed that 25(OH)D was negatively correlated with renin (r = -0.185; P=0.021) and positively correlated with systolic pressure (r = -0.105; P=0.035). There were no statistically significant differences in diastolic pressure, fasting blood glucose, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides between the two groups.

CONCLUSIONS

The results of the present study show that vitamin D deficiency is common in Urumqi, Xinjiang, China and vitamin D levels are negatively correlated with renin levels. Vitamin D plays an important role in regulating blood pressure by affecting renin levels through the renin-angiotensin-aldosterone system.

Role of Vitamin D in Cardiovascular Diseases

Vitamin D represents a group of secosteroids involved in the calcium and phosphate metabolism. The active form of vitamin D, 1,25-dihydroxylcalciferol, exerts its biological mechanisms via the VDR (vitamin D receptor) which acts as a regulator of several target genes. Hypovitaminosis D is associated with many diseases, which are not only limited to the metabolism of the skeleton, but growing evidence links the deficit of vitamin D to cardiovascular, metabolic, immune, and neoplastic diseases. In regard to the cardiovascular system, current evidence shows the presence of VDR in endothelial cells. Moreover, both in vitro and animal experimental models demonstrated that the deficit of vitamin D can promote endothelial dysfunction and atherosclerosis development. Vitamin D can interfere with vascular functions also by affecting the production of vasodilator mediators. VDR is also expressed in left ventricle cardiomyocytes, and hypovitaminosis D can relate to cardiac hypertrophy and heart failure. Randomized clinical trials (RCT) designed to prove the therapeutic role of vitamin D supplementation have been inconclusive to date. The aim of this review is to highlight the main interactions between vitamin D metabolism and cardiovascular diseases; thus, focusing on pathogenic mechanisms and related clinical manifestations.

Association Between Aldosterone and Parathyroid Hormone Levels in Patients With Adrenocortical Tumors

OBJECTIVE

Patients with primary aldosteronism (PA) can present with high PTH levels and negative calcium balance, with some studies speculating that aldosterone could directly stimulate PTH secretion. Either adrenalectomy or mineralocorticoid receptor blockers could reduce PTH levels in patients with PA. The aim of this study was to assess the relationship between aldosterone levels and parathyroid hormone (PTH)-vitamin D-calcium axis in a cohort of patients with PA, compared with patients with nonsecreting adrenocortical tumors in conditions of vitamin D sufficiency.

METHODS

We enrolled a series of 243 patients retrospectively, of whom 66 had PA and 177 had nonsecreting adrenal tumors, and selected those with full mineral metabolism evaluation and 25(OH) vitamin D levels >20 ng/mL at the time of initial endocrine screening. The final cohort was composed of 26 patients with PA and 39 patients, used as controls, with nonsecreting adrenal tumors. The relationships between aldosterone, PTH levels, and biochemistries of mineral metabolism were assessed.

RESULTS

Aldosterone was positively associated with PTH levels (r = 0.260, P < .05) in the whole cohort and in the PA cohort alone (r = 0.450; P = .02). In the multivariate analysis, both aldosterone concentrations and urinary calcium excretion were significantly related to PTH levels, with no effect of 25(OH) vitamin D or other parameters of bone metabolism.

CONCLUSION

PTH level is associated with aldosterone, probably independent of 25(OH) vitamin D levels and urinary calcium. Whether aldosterone interacts directly with the parathyroid glands remains to be established.

Rewinding sarcopenia: a narrative review on the renin-angiotensin system

BACKGROUND AND AIMS

The purpose of this review was two-fold. First, we aimed to provide an in-depth glance on the relationship between renin-angiotensin system (RAS) dysregulation and sarcopenia. Second, we aimed to touch upon potential treatments of sarcopenia (including RAS blockers, vitamin D, and exercise) in light of the pertinent literature.

METHODS

Currently available research regarding the effects of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers on knee extensor strength, grip strength, chair stand test, gate speed together with the effects of exercise on muscle mass, strength, physical performance, blood pressure and cognitive tests (particularly in older adults) was reviewed.

RESULTS

Although some studies have shown favorable effects of ACEIs on muscle strength and/or physical function tests, some studies have reported no/negative association in between. The favorable impact of exercise on reducing blood pressure is shown, and exercise treatment is widely recommended in the relevant literature. Different types of exercises (aerobic, resistance, dancing, music movement, water-based, golf, knitting activities or multicomponent exercises) have shown improvement in cognitive functions as well.

CONCLUSION

Classical RAS activity results in deleterious effects not only on the cardiovascular but also on the neuromusculoskeletal system. Therefore, treatments targeting inhibition of the classical RAS activity seem to be important in the management of several age-related pathologies, including sarcopenia. As such, ACEIs, vitamin D, exercise, and healthy diet can have prominent effects not only on the modulation of RAS but also on physical and cognitive functions and sarcopenia as well.

Vitamin D3 potentiates the nephroprotective effects of vildagliptin-metformin combination in a rat model of metabolic syndrome

The current study was conducted to investigate the nephroprotective effects of vildagliptin-metformin combination in an experimental model of fructose/salt-induced metabolic syndrome (MetS). A major aim was to evaluate the potential capacity of vitamin D3 to potentiate the pleiotropic nephroprotective effects of vildagliptin-metformin combination. MetS was induced in adult male Wistar rats by adding fructose (10%) to everyday drinking water and salt (3%) to the diet for 6 weeks. Along with the same concentrations of fructose/salt feeding, MetS rats were then treated orally with either vildagliptin (10 mg/kg/day)-metformin (200 mg/kg/day) combination, vitamin D3 (10 μg/kg/day), or the triple therapy for a further 6 weeks. The incidence of MetS was confirmed 6 weeks after fructose/salt consumption, when the rats exhibited significant weight gain, dyslipidemia, hyperuricemia, insulin resistance, hyperinsulinemia, and impaired glucose tolerance. At the end of the 12-week experimental period, MetS rats displayed significantly deteriorated renal function, enhanced intrarenal oxidative stress and inflammation together with exaggerated renal histopathological damages and interstitial fibrosis. The study has corroborated antioxidant, anti-inflammatory, and antifibrotic effects of vildagliptin-metformin combination, vitamin D3, and the triple collaborative therapy, conferring renoprotection in the setting of MetS. Due attention has been paid to the crucial role of dipeptidyl peptidase-4 inhibition and sirtuin-1/5' adenosine monophosphate-activated protein kinase activation as novel therapeutic targets to optimize renoprotection. The apparent potentiating effect, evoked upon coadministration of vitamin D3 with vildagliptin-metformin combination, may provide a cornerstone for further clinical investigations.

An LC-MS/MS Method for Analysis of Vitamin D Metabolites and C3 Epimers in Mice Serum: Oral Supplementation Compared to UV Irradiation

INTRODUCTION

The most common forms of vitamin D in human and mouse serum are vitamin D3 and vitamin D2 and their metabolites. The aim of this study is to determine whether diet and sunlight directly affect the circulating concentrations of vitamin D metabolites in a mouse model. We investigated the serum concentrations of eight vitamin D metabolites-vitamin D (vitamin D3 + vitamin D2), 25OHD (25OHD3 + 25OHD2), 1α25(OH)2D (1α25(OH)2D2, and 1α25(OH)2D3)-including their epimer, 3-epi-25OHD (3-epi-25OHD3 and 3-epi-25OHD2), and a bile acid precursor 7alpha-hydroxy-4-cholesten-3-one (7αC4), which is known to cause interference in liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis.

METHOD

The LC-MS/MS method was validated according to FDA-US guidelines. The validated method was used for the analysis of mouse serum samples. Forty blood samples from mice were collected and divided into three groups. The first group, the DDD mice, were fed a vitamin D-deficient diet (25 IU VD3/kg of diet) and kept in the dark; the second group, the SDD mice, were maintained on a standard-vitamin D diet (1000 IU VD3) and kept in the dark; and the third group, SDL, were fed a standard-vitamin D diet (1000 IU VD3) but kept on a normal light/dark cycle. LC-MS/MS was used for the efficient separation and quantitation of all the analytes.

RESULTS

The validated method showed good linearity and specificity. The intraday and interday precision were both <16%, and the accuracy across the assay range was within 100 ± 15%. The recoveries ranged between 75 and 95%. The stability results showed that vitamin D metabolites are not very stable when exposed to continuous freeze-thaw cycles; the variations in concentrations of vitamin D metabolites ranged between 15 and 60%. The overlapping peaks of vitamin D, its epimers, and its isobar (7αC4) were resolved using chromatographic separation. There were significant differences in the concentrations of all metabolites of vitamin D between the DDD and SDL mice. Between the groups SDD (control) and SDL, a significant difference in the concentrations of 3-epi-25OHD was noted, where C3 epimer was about 30% higher in SDL group while no significant differences were noted in the concentrations of vitamin D, 25OHD, 1α25(OH)2D, and 7αC4 between SDD and SDL group.

CONCLUSIONS

A validated method, combined with a simple extraction technique, for the sensitive LC-MS/MS determination of vitamin D metabolites is described here. The method can eliminate the interferences in LC-MS/MS analysis caused by the overlapping epimer and isobar due to them having the same molecular weights as 25OHD. The validated method was applied to mouse serum samples. It was concluded that a standard-vitamin D diet causes an increase in the proportion of all the vitamin D metabolites and C3 epimers and isobar, while UV light has no pronounced effect on the concentrations of the majority of the vitamin D metabolites except 3-epi-25OHD. Further studies are required to confirm this observation in humans and to investigate the biochemical pathways related to vitamin D's metabolites and their epimers.

Prevalence of Low Level of Vitamin D Among COVID-19 Patients and Associated Risk Factors in India - A Hospital-Based Study

Background

The world is facing the most challenging pandemic in the 21st century. The developed and developing countries are facing the burden equally and no proven treatment options available. Recent studies suggest the plausibility of vitamin D therapy and prophylaxis for COVID-19, in the setting where the deficiency is more prevalent. Though evaluation of vitamin D status is not a routine in India, the present study focuses on the level of Vitamin d among COVID-19 patients.

Methods

The study was a hospital-based cross-sectional to find the status of vitamin D among COVID-19 patients in a tertiary care hospital, Patna, Bihar, India. The demographic, comorbidity data were taken, and the level of vitamin D was measured by a chemiluminescence-based immunoassay analyzer. The analysis compared the level of deficiency and insufficiency among different groups of COVID-19 patients. The role of DM and HTN as risk factors for mortality was compared.

Results

Among the total study participants (156), 42.31% were obese and 17.31% were severe as per clinical severity. The total prevalence of vitamin D deficiency was 58.97% and insufficiency was 89.1%. The prevalence was found high among male (61.02%), overweight (65.52%), and severe (62.96%) patients. The severity increases with advanced age (p<0.05) and important risk factors for mortality are DM, HTN, and advanced age.

Conclusion

The level of vitamin D can be assessed for the prognosis of COIVD-19 patients and help to modify the treatment protocol. Appropriate therapeutic/preventive intervention of vitamin D can alter the course and severity of COVID-19.

Health implication of vitamin D on the cardiovascular and the renal system

Vitamin D regulates the calcium and phosphorus balance in the body. The activated form of vitamin D (1 α,25-dihydroxyvitamin D) binds to vitamin D receptor which regulates genes that control cell proliferation, differentiation and apoptosis. In the cardiovascular system, the vitamin D receptor is present in cardiomyocytes and the arterial wall. A clear correlation between vitamin D level and cardiovascular diseases is established. Vitamin D deficiency affects the renin-angiotensin system leading to ventricular hypertrophy and eventually to stroke. While clinical trials highlighted the positive effects of vitamin D supplements on cardiovascular disease these still need to be confirmed. This review outlines the association between vitamin D and cardiovascular and renal disease summarising the experimental data of selective cardiovascular disorders.

Relationship between 25-hydroxyvitamin D and microalbuminuria in patients with newly diagnosed essential hypertension

Purpose: Vitamin D deficiency is known that associated with hypertension. Microalbuminuria (MAU) is associated with increased cardiovascular morbidity and mortality. This study aimed to evaluate the relationship between 25-hydroxyvitamin D (25(OH)D) and MAU in newly diagnosed essential hypertension (NDEH) patients. Methods: A total of 116 patients with a diagnosis of NDEH were enrolled in the study. The diagnosis of hypertension was based on ABPM. Patients were divided into 2 groups according to 25(OH)D levels: Group 1: (25(OH)D)>20 ng/mL was defined as Vitamin D sufficiently (VDS), while Group 2: (25(OH)D)<20 ng/mL was defined Vitamin D deficiently (VDD). The relationship between 25(OH)D and MAU was analyzed. The results were analyzed using the SPSS program version 21. Results: The mean age of the patients was 58.4 ± 14.7 years and 60 (51.7%) of them were female. The prevalence of MAU was 18.9% and Vitamin D deficiency was 61.2% in NDEH. Linear regression analysis showed that 25(OH)D was independently related to MAU [β 0.643, 95% confidence interval 1.173-1.631, p = .011]. Besides, male gender, C-reactive protein, non-dipper hypertension, and diastolic blood pressure were independent risk factors associated with MAU in the multivariate analysis (p < .05). Conclusion: Vitamin D deficiency is highly prevalent in NDEH patients. This study showed that the level of microalbuminuria was significantly higher in patients with 25(OH)D deficiency compared to patients with normal 25(OH)D levels. Vitamin D deficiency is independently related to microalbuminuria in NDEH.

Lessons Learned from Hereditary 1,25-Dihydroxyvitamin D-Resistant Rickets Patients on Vitamin D Functions

We summarize here lessons learned from studies on skeletal and extra-skeletal functions of vitamin D in hereditary 1,25-dihydroxyvitamin D-resistant rickets (HVDRR) patients with a mutant, nonfunctioning vitamin D receptor (VDR). During childhood, HVDRR patients are dependent on intestinal VDR, demonstrate low intestinal fraction calcium absorption, and have a bone calcium accretion rate that leads to hypocalcemia and rickets. After puberty, there is recovery in intestinal calcium absorption and in bone calcium accretion and structure. HVDRR monocytes and lymphocytes show impairment in the expression of antimicrobial proteins and demonstrate a proinflammatory cytokine profile. However, HVDRR patients do not exhibit increased rates of infections or inflammatory diseases. Vitamin D deficiency is associated with asthmatic exacerbations. Surprisingly, HVDRR patients do not usually develop asthma. They have normal allergic tests and lung functions and are protected against provoked bronchial hyperactivity. HVDRR patients have decreased IL-5 levels in their exhaled breath condensate. Given that IL-5 is a key cytokine in the development of airway inflammation and hyperactivity and that VDR is important for IL-5 generation, it is plausible that low lung IL-5 protects HVDRR patients from asthma. Vitamin D metabolites have suppressive effects on the renin angiotensin system. However, no HVDRR patient showed hypertension or echocardiographic pathology, and their renin angiotensin metabolites were normal. The VDR is expressed throughout the reproductive system, suggesting a role in reproduction. However, the reproductive history of HVDRR patients is normal despite the lack of a normal VDR. HVDRR patients provide a unique opportunity to study the role of the VDR and the role of vitamin D in various human systems.

VDR Gene Polymorphisms in Healthy Individuals with Family History of Premature Coronary Artery Disease

AIM

The gene encoding the vitamin D receptor (VDR) is considered in many studies to be a good candidate responsible for susceptibility to several diseases such as coronary artery disease (CAD). Epidemiological data show that cardiovascular disease is one of the major health problems in Polish society. Basic studies show that genetic factors play a significant role in the pathogenesis of CAD. We conducted this clinical study to determine if the VDR gene polymorphisms TaqI (rs731236), ApaI (rs7975232), and FokI (rs2228570) could predispose healthy individuals to an increased risk of premature CAD (P-CAD) incidents.

METHODS

We genotyped 845 subjects in a cohort consisting of 386 healthy volunteers with a documented P-CAD incident in their first-degree relatives and 459 healthy volunteers without family history (FH) of P-CAD. TaqI, ApaI, and FokI polymorphisms in VDR were genotyped using TaqMan assays and the endpoint genotyping method (qPCR). Statistical analyses were performed using the Power Analysis Software STATISTICA v.13.3.

RESULTS

Although no statistical significance was found for TaqI and ApaI genotype frequencies, the AA genotype of FokI polymorphism was significantly more frequent in the study group compared to the control group (24.61% vs. 16.99%). The results of logistic regression analysis suggested a significant association between FokI polymorphism and FH of P-CAD in heathy people under the recessive model (OR: 1.26 (1.07-1.49, p = 0.007)); however, the frequency of VDR haplotypes did not differ significantly between the control and study populations.

CONCLUSIONS

FokI polymorphism is may be associated with FH of P-CAD. FokI polymorphism may predispose to the development of P-CAD among healthy people over the next years.

The Blockade of TACE-Dependent EGF Receptor Activation by Losartan-Erlotinib Combination Attenuates Renal Fibrosis Formation in 5/6-Nephrectomized Rats Under Vitamin D Deficiency

Chronic kidney disease (CKD) has been considered a major public health issue. In addition to cardiovascular diseases and infections, hypovitaminosis D has been considered a non-traditional aggravating factor for CKD progression. Interstitial fibrosis is a hallmark of CKD strongly correlated with deterioration of renal function. Transforming growth factor β (TGF-β) is the major regulatory profibrotic cytokine in CKD. Many injurious stimuli converge on the TGF-β pathway, which has context-dependent pleiotropic effects and interacts with several related renal fibrosis formation (RFF) pathways. Epidermal growth factor receptor (EGFR) is critically involved in CKD progression, exerting a pathogenic role in RFF associated with TGF-β-related fibrogenesis. Among others, EGFR pathway can be activated by a disintegrin and a metalloproteinase known as tumor necrosis factor α-converting enzyme (TACE). Currently no effective therapy is available to completely arrest RFF and slow the progression of CKD. Therefore, we investigated the effects of a double treatment with losartan potassium (L), an AT1R antagonist, and the tyrosine kinase inhibitor erlotinib (E) on the alternative pathway of RFF related to TACE-dependent EGFR activation in 5/6-nephrectomized rats under vitamin D deficiency (D). During the 90-day protocol, male Wistar rats under D, were submitted to 5/6 nephrectomy (N) on day 30 and randomized into four groups: N+D, no treatment; N+D+L, received losartan (50 mg/kg/day); N+D+E, received erlotinib (6 mg/kg/day); N+D+L+E received losartan+erlotinib treatment. N+D+L+E data demonstrated that the double treatment with losartan+erlotinib not only blocked the TACE-dependent EGF receptor activation but also prevented the expression of TGF-β, protecting against RFF. This renoprotection by losartan+erlotinib was corroborated by a lower expression of ECM proteins and markers of phenotypic alteration as well as a lesser inflammatory cell infiltrate. Although erlotinib alone has been emerging as a renoprotective drug, its association with losartan should be considered as a potential therapeutic strategy on the modulation of RFF.

High-dose Cholecalciferol Supplementation Reducing Morning Blood Pressure in Normotensive DM1 Patients

BACKGROUND

Vitamin D (VD) deficiency has been related to several endocrine metabolic and cardiovascular diseases. The effect of VD supplementation on blood pressure (BP) in patients with diabetes is controversial.

OBJECTIVE

The aim of this study was to evaluate high-dose vitamin D supplementation effects on blood pressure of normotensive patients with diabetes mellitus 1 (DM1) patients by 24-hour ambulatory blood pressure monitoring (ABPM).

METHODS

We performed a clinical trial including 35 DM1 normotensive patients, who received doses of 4,000 or 10,000 IU/day of cholecalciferol for 12 weeks according to previous VD levels. They underwent 24-hour ABPM, along with glycated hemoglobin, creatine, lipids profile and PCRus dosage before and after VD supplementation.

RESULTS

We found an expressive reduction of systolic and diastolic morning blood pressures (117±14 vs 112±14, p<0,05; 74±9 vs 70±10 mmHg, p<0,05, respectively) with no changes in other pressoric markers. Besides, we noticed a relationship between levels of VD after supplementation and diastolic morning blood pressure (r= -0,4; p<0.05).

CONCLUSION

Our study suggests an association between supplementation of high doses of vitamin D and the reduction of morning blood pressure in normotensive DM1 patients.

Vitamin D and cardiovascular health

The principal source of vitamin D in humans is its biosynthesis in the skin through a chemical reaction dependent on sun exposure. In lesser amounts, the vitamin can be obtained from the diet, mostly from fatty fish, fish liver oil and mushrooms. Individuals with vitamin D deficiency, defined as a serum level of 25 hydroxyvitamin D < 20 ng/dl, should be supplemented. Vitamin D deficiency is a prevalent global problem caused mainly by low exposure to sunlight. The main role of 1,25 dihydroxyvitamin D is the maintenance of calcium and phosphorus homeostasis. However, vitamin D receptors are found in most human cells and tissues, indicating many extra-skeletal effects of the vitamin, particularly in the immune and cardiovascular (CV) systems. Vitamin D regulates blood pressure by acting on endothelial cells and smooth muscle cells. Its deficiency has been associated with various CV risk factors and appears to be linked to a higher mortality and incidence of CV disease (CVD). Several mechanisms have been proposed relating vitamin D deficiency to CV risk factors such as renin-angiotensin-aldosterone system activation, abnormal nitric oxide regulation, oxidative stress or altered inflammatory pathways. However, in the latest randomized controlled trials no benefits of vitamin D supplementation for CVD have been confirmed. Although more work is needed to establish the protective role of vitamin D in this setting, according to current evidences vitamin D supplements should not be recommended for CVD prevention.

Non-classical effects of vitamin D: Non-bone effects of vitamin D

Our understanding of vitamin D has improved considerably in recent years. The role of vitamin D in preventing osteoporotic fractures is now well-established. However, an important controversy has emerged in the last decade concerning the effects of the active form of vitamin D (1,25-dihydroxy-vitamin D) on tissues other than bone (non-classical effects). The demonstration that the vitamin D receptor (VDR) is ubiquitously, expressed combined with increasing observational data supporting a relationship between the level of 25-hydroxy-vitamin D in the serum and chronic metabolic disorders, cardiovascular disease and neoplasms, have led to its redefinition as a steroid hormone and the proposal of its use in preventing and/or treating those diseases. This article is an update on the different non-bone or non-classical effects of "vitamin-hormone D", and its potential preventive or therapeutic role in certain diseases, however, this review is not exhaustive. The different modalities of substitution or supplementation proposed in France by the Groupe de Recherche et d'Information sur les Ostéoporoses (GRIO) are also summarised.

Association between vitamin D and cardioprotection in adult patients

OBJECTIVE

To conduct a review of articles which have evaluated the relationship between vitamin D and cardioprotection in adult.

METHODS

A literature search was performed in the Pubmed and Scielo databases. The results were extracted from primary and secondary sources and will be presented in the form of a bibliographic review.

RESULTS

Twenty-three articles were identified from the electronic search that reported on physiological mechanisms relating the vitamin D axis and the cardiovascular system through receptors. Of the ten studies that evaluated the therapeutic effect of vitamin D in cardiovascular diseases, none reported significant results.

CONCLUSION

The articles assessed in this review did not demonstrate a cardioprotective effect of vitamin D, despite the epidemiological correlation of vitamin D deficiency with a higher prevalence of cardiovascular diseases.

Dietary vitamin D interacts with high phosphate-induced cardiac remodeling in rats with normal renal function

BACKGROUND

Vitamin D (VD) and phosphate (Pi) load are considered as contributors to cardiovascular disease in chronic kidney disease and the general population, but interactive effects of VD and Pi intake on the heart are not clearly illustrated.

METHODS

We fed normal male rats with three levels of dietary VD (100, 1100 or 5000 IU/kg chow) and Pi (0.2, 0.6 or 1.6%) (3X3 design) for 8 weeks and examined renal and cardiac function and histology.

RESULTS

High dietary Pi decreased plasma and renal Klotho and plasma 25-hydroxyvitamin D, and increased plasma Pi, fibroblast growth factor 23 and parathyroid hormone without affecting renal function, while low Pi increased plasma and renal Klotho. Both low and high VD diets enhanced high Pi-reduced Klotho expression. Low dietary VD reduced-plasma Klotho was rescued by a low Pi diet. High dietary Pi reduced-cardiac ejection fraction was not modified by a low or high VD diet, but the dietary VD effects on cardiac pathologic changes were more complex. High dietary Pi-induced cardiac hypertrophy was attenuated by a low VD and exacerbated by a high VD diet. In contrast, high dietary Pi -induced cardiac fibrosis was magnified by a low VD and attenuated by a high VD diet.

CONCLUSIONS

High Pi diet induces hypertrophy and fibrosis in left ventricles, a low VD diet accelerates high Pi-induced fibrosis, and a high VD diet exacerbated high Pi -induced hypertrophy. Therefore, cardiac phosphotoxicity is exacerbated by either high or low dietary VD in rats with normal kidney function.

Impact of Vitamin D Deficiency on COVID-19-A Prospective Analysis from the CovILD Registry

The novel Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is a global health concern. Vitamin D (VITD) deficiency has been suggested to alter SARS-CoV-2 susceptibility and the course of disease. Thus, we aimed to investigate associations of VITD status to disease presentation within the CovILD registry. This prospective, multicenter, observational study on long-term sequelae includes patients with COVID-19 after hospitalization or outpatients with persistent symptoms. Eight weeks after PCR confirmed diagnosis, a detailed questionnaire, a clinical examination, and laboratory testing, including VITD status, were evaluated. Furthermore, available laboratory specimens close to hospital admission were used to retrospectively analyze 25-hydroxyvitamin D levels at disease onset. A total of 109 patients were included in the analysis (60% males, 40% females), aged 58 ± 14 years. Eight weeks after the onset of COVID-19, a high proportion of patients presented with impaired VITD metabolism and elevated parathyroid hormone (PTH) levels. PTH concentrations were increased in patients who needed intensive care unit (ICU) treatment, while VITD levels were not significantly different between disease severity groups. Low VITD levels at disease onset or at eight-week follow-up were not related to persistent symptom burden, lung function impairment, ongoing inflammation, or more severe CT abnormalities. VITD deficiency is frequent among COVID-19 patients but not associated with disease outcomes. However, individuals with severe disease display a disturbed parathyroid-vitamin-D axis within their recovery phase. The proposed significance of VITD supplementation in the clinical management of COVID-19 remains elusive.

Effect of daily 2000 IU versus 800 IU vitamin D on blood pressure among adults age 60 years and older: a randomized clinical trial

BACKGROUND

Observational studies report higher blood pressure (BP) among individuals with lower 25-hydroxyvitamin D concentration. Whether dosage of vitamin D supplementation has a differential effect on BP control remains unclear.

OBJECTIVE

The study aimed to determine if daily vitamin D supplementation with 2000 IU is more effective than 800 IU for BP control among older adults.

METHODS

This randomized, double-blind, ancillary trial of the Zurich Multiple Endpoint Vitamin D Trial in Knee Osteoarthritis enrolled adults aged ≥60 y who underwent elective surgery due to severe knee osteoarthritis. Participants were randomly assigned to receive high dose (2000 IU) or standard dose (800 IU) daily vitamin D3 for 24 mo. Outcomes included daytime and 24-h mean systolic BP. BP variability and serum 25-hydroxyvitamin D concentration were examined in a post hoc and observational analysis.

RESULTS

Of the 273 participants randomly assigned, 250 participants completed a follow-up 24-h ambulatory BP monitoring (mean age: 70.4 ± 6.4 y; 47.2% men). The difference in daytime mean systolic BP reduction between the 2000 IU (n = 123) and 800 IU (n = 127) groups was not statistically significant (-2.75 mm Hg vs. -3.94 mm Hg; difference: 1.18 mm Hg; 95% CI: -0.68, 3.05; P = 0.21), consistent with 24-h mean systolic BP. However, systolic BP variability was significantly reduced with 2000 IU (average real variability: -0.37 mm Hg) compared to 800 IU vitamin D3 (0.11 mm Hg; difference: -0.48 mm Hg; 95% CI: -0.94, -0.01; P = 0.045). Independent of group allocation, maximal reductions in mean BP were observed at 28.7 ng/mL of achieved serum 25-hydroxyvitamin D concentrations.

CONCLUSIONS

While daily 2000 IU and 800 IU vitamin D3 reduced mean systolic BP over 2 y to a small and similar extent, 2000 IU reduced mean systolic BP variability significantly more compared with 800 IU. However, without a placebo control group we cannot ascertain whether vitamin D supplementation effectively reduces BP.This trial was registered at www.clinicaltrials.gov as NCT00599807.

Obtaining and Investigation of the β-Cyclodextrin Inclusion Complex with Vitamin D 3 Oil Solution

Background. The research results of fat-soluble vitamin D 3 (cholecalciferol) encapsulation with β-cyclodextrin have been presented in this work. The vitamin D 3 inclusion complex with β-cyclodextrin was obtained under microwave radiation. The surface morphology of obtained clathrate inclusion complexes was described with the help of a scanning electron microscope. The thermographic measurement results on a differential scanning calorimeter have been presented. The activation energy of the β-cyclodextrin : vitamin D 3 clathrate complex thermal oxidative destruction reaction was calculated. The clathrate thermal destruction kinetic parameters were determined. The inclusion complex spectral properties were characterized by IR-Fourier and 1H and 13C NMR spectroscopy. The existence of β-cyclodextrin inclusion complex with vitamin D 3 in a 2 : 1 ratio was confirmed by the experimental results. The activation energy of thermal destruction of the inclusion complex of β-cyclodextrin with vitamin D 3 was calculated using four different methods.

Vitamin D Metabolites and Binding Protein Predict Preeclampsia in Women with Type 1 Diabetes

The risk for preeclampsia (PE) is enhanced ~4-fold by the presence of maternal type 1 diabetes (T1DM). Vitamin D is essential for healthy pregnancy. We assessed the total, bioavailable, and free concentrations of plasma 25-hydroxyvitamin D (25(OH)D), 1,25-dihydroxyvitamin D (1,25(OH)₂D), and vitamin D binding protein (VDBP) at ~12, ~22, and ~32 weeks’ gestation (“Visits” (V) 1, 2, and 3, respectively) in 23 T1DM women who developed PE, 24 who remained normotensive, and 19 non-diabetic, normotensive women (reference controls). 25(OH)D deficiency was more frequent in diabetic than non-diabetic women (69% vs. 22%, p < 0.05), but no measure of 25(OH)D predicted PE. By contrast, higher 1,25(OH)₂D concentrations at V2 (total, bioavailable, and free: p < 0.01) and V3 (bioavailable: p < 0.05; free: p < 0.01), lower concentrations of VDBP at V3 (p < 0.05), and elevated ratios of 1,25(OH)₂D/VDBP (V2, V3: p < 0.01) and 1,25(OH)₂D/25(OH)D (V3, p < 0.05) were all associated with PE, and significance persisted in multivariate analyses. In summary, in women with T1DM, concentrations of 1,25(OH)₂D were higher, and VDBP lower, in the second and third trimesters in women who later developed PE than in those who did not. 1,25(OH)₂D may serve as a new marker for PE risk and could be implicated in pathogenesis.

Meta-Analysis of the Association Between the rs228570 Vitamin D Receptor Gene Polymorphism and Arterial Hypertension Risk

The association between FokI polymorphism in the vitamin D receptor (VDR) gene and susceptibility to arterial hypertension (HT) is controversial. Thus, we evaluated the relation between FokI and HT according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using MEDLINE® (Medical Literature Analysis and Retrieval System Online)/PubMed, Scopus, and Cochrane Library CENTRAL databases. Data from case-control studies, including the number of participants, age, 25-hydroxyvitamin D concentrations, systolic and diastolic blood pressure values, FokI allele, and genotype frequency were extracted by 2 independent authors and OR was calculated with the 95% CI to assess the strength of the association between the FokI variant and odds of HT. In general and subgroup analyses, we used allelic (f compared with F), common (ff compared with FF + Ff), risk (ff + Ff compared with FF), and additive (ff compared with FF) models. Six case-control studies including 3140 cases and 3882 controls were reviewed in the meta-analysis. Global assessment revealed a correlation between FokI and reduced odds of HT in the additive/homozygote model (ff compared with FF; OR: 0.65; 95% CI: 0.45-0.94) and common/recessive model (ff compared with FF + Ff; OR: 0.75; 95% CI: 0.57-0.99). In Asian subjects, there was a significant reduction in the odds of HT in additive (ff compared with FF; OR: 0.84; 95% CI: 0.73-0.98) and risk models (ff + Ff compared with FF; OR: 0.87, 95% CI: 0.78-0.97), in particular, for Indians (South). In Africans, the statistically significant association occurred in the additive and common models. Allele f in the FokI polymorphism of the VDR gene was associated with reduced odds of HT in the general population based on the risk model. Thus, nutritional genomics can help understand the influence of nutrition on metabolic homeostasis pathways and the clinical consequences of hypertension. This study shows the need for healthy, anti-inflammatory, and antioxidant compounds to prevent or treat chronic complications.

Vitamin D-mitochondria cross-talk could modulate the signaling pathway involved in hypertension development: a translational integrative overview

Vitamin D deficiency is a worldwide pandemic and results in osteoporosis, hypertension, and other cardiovascular diseases. At the cellular level, it produces significant oxidative stress, inflammatory markers, and mitochondrial damage. There is increasing evidence about the role of vitamin D in the regulation of the renin-angiotensin-aldosterone system (RAAS). Moreover, there is evidence of involvement in cardiovascular complications, as well as in the immune system disorders. Vitamin D values below 25ng/mL are related to an increase in vascular tone mediated by smooth muscle contraction. Furthermore, it can produce direct effects on vascular smooth muscle cells, RAAS over-regulation, modulation of calcium metabolism, and secondary hyperparathyroidism. All this predisposes patients to develop hypertrophy of the left ventricle and vascular wall, causing hypertension. In this work, a review is presented of the main mechanisms involved in the development of hypertension due to vitamin D deficiency. Among them are the link established between the levels of extra-mitochondrial inorganic phosphate, its main regulatory hormones -such as vitamin D-, the cardiovascular system, reactive oxygen species, and mitochondrial metabolism. The role of the mitochondrial vitamin D receptor and the regulation of the respiratory chain could influence arterial remodelling since its activation would reduce oxidative damage and preserve cell life. However, there are aspects not yet understood about the intricate signalling network that appeared simple in experimental trials, but complex in clinical studies. In this way, the completion of new studies as VITAL, could clarify, and thus support or refute the possible benefits of vitamin D in hypertensive cardiovascular disease.

Vitamin D and Cardiovascular Risk: which Implications in Children?

Vitamin D (25OHD) pleiotropic effects are widely recognized and studied. Recently, vitamin D cardiovascular effects are gaining interest, especially in children, although the studies present conflicting data. Some randomized controlled trials (RCTs) have demonstrated that cardiovascular risk markers, such as lipid parameters, inflammation markers, blood pressure, and arterial stiffness, are unaffected by vitamin D supplementation. By contrast, other studies show that low vitamin D levels are associated with higher risk of cardiovascular disease (CVD) and mortality, and support that increased risk of these diseases occurs primarily in people with vitamin D deficiency. An update on these points in pediatric patients is certainly of interest to focus on possible benefits of its supplementation.

Evaluation of Vitamin D Fractions in Obese Hypertensive Patients

Vitamin D fractions can be involved in the pathogenesis of metabolic disorders, but their concentrations are rarely determined. The aim of this study was to evaluate the concentration of vitamin D fractions in obese hypertensive patients and to determine its associations with anthropometric parameters, glucose levels, and lipid profiles. A total of 85 obese hypertensive patients (OBHT) and 40 nonobese nonhypertensive subjects (NOBNHT) underwent biochemical measurements of lipid profiles, glycemia, 25-hydroxyvitamin D (25(OH)D), free vitamin D (free25(OH)D), vitamin D binding protein, albumin levels. Moreover, free25(OH)D and bioavailable25(OH)D (bio25(OH)D) concentrations were calculated. Blood pressure and anthropometric measurements were performed. Differences between groups (p < 0.001) were found for 25(OH)D (OBHT 40.25 ± 18.02 vs. NOBNHT 64.10 ± 22.29 nmol/L), free25(OH)D (9.77 (7.46; 11.49) vs. 13.80 (10.34; 16.82) pmol/L), bioavailable 25(OH)D (3.7 (2.8; 4.4) vs. 5.4 (4.2; 6.7) nmol/L), and calculated free25(OH)D (7.82 (5.54; 11.64) vs. 10.46(8.06;16.28) pmol/L, p = 0.002). The OBHT patients showed no relationship between vitamin D fractions concentration and glucose or lipids level, although it was associated with anthropometric parameters. In the NOBNHT group, vitamin D fractions correlated positively with HDL cholesterol and negatively with triglyceridemia and hip circumference. Vitamin D fractions were decreased in obese hypertensive subjects, and were associated with anthropometric parameters, but not with glucose level or lipid profiles; they thus cannot be considered as a predictive marker of metabolic disorders in this group of patients.