Modulation of the sympathetic nervous system in youngsters by vitamin-D supplementation

The Efficacy of Vitamins in the Prevention and Treatment of Cardiovascular Disease

Vitamins are known to affect the regulation of several biochemical and metabolic pathways that influence cellular function. Adequate amounts of both hydrophilic and lipophilic vitamins are required for maintaining normal cardiac and vascular function, but their deficiencies can contribute to cardiovascular abnormalities. In this regard, a deficiency in the lipophilic vitamins, such as vitamins A, D, and E, as well as in the hydrophilic vitamins, such as vitamin C and B, has been associated with suboptimal cardiovascular function, whereas additional intakes have been suggested to reduce the risk of atherosclerosis, hypertension, ischemic heart disease, arrhythmias, and heart failure. Here, we have attempted to describe the association between low vitamin status and cardiovascular disease, and to offer a discussion on the efficacy of vitamins. While there are inconsistencies in the impact of a deficiency in vitamins on the development of cardiovascular disease and the benefits associated with supplementation, this review proposes that specific vitamins may contribute to the prevention of cardiovascular disease in individuals at risk rather than serve as an adjunct therapy.

The Possible Influence of Vitamin D Levels on the Development of Atrial Fibrillation-An Update

Atrial fibrillation (AF) is a severe and most common supraventricular arrhythmia in humans, which, if left untreated or treated ineffectively, can lead to ischemic stroke or heart failure. It has been suggested that serum vitamin D (VitD) deficiency may be one of the critical factors influencing the onset of AF, especially in the period after cardiac surgery, such as coronary artery bypass grafting. Several papers have indicated that VitD supplementation reduces the risk of AF, significantly reducing the proportion of patients between the control and study groups in both the pre- and postoperative periods. Factors that increase the risk of AF from VitD deficiency are also further indicated, and these are age, gender, weight, season or comorbidities. In addition, the cardiodepressive mechanism of VitD is not fully understood; however, it is suggested that it acts through at least two pathways. The first indicates a direct effect of VitD on atrial muscle degradation, while the second is related to the modulation of cardiovascular depression factors. Despite many reports showing correlations between no VitD concentrations on the development of AF, this topic is still widely debated and the results from these papers are still subject to doubt. Therefore, this review aims at describing in detail the problem of correlation between VitD deficiency and the development of AF associated mainly with the postoperative period, i.e., after cardiac surgery, especially pathogenesis, and results of this correlation, taking into account recent studies, limitations and future perspectives. Due to the fact that this is still a topical problem, we believe that the collection of the latest reports and a detailed description of the problem is most appropriate in this case.

Understanding the Role of Vitamin D in Heart Failure

Vitamin D is now believed to have a significant role in cardiac signal transduction and regulation of gene expression, and thus influences normal cardiomyocyte function. It has been reported to provide cardioprotection through its anti-inflammatory, anti-apoptotic and anti-fibrotic actions; and to prevent cardiac remodeling, Ca 2 + -handling defects, and abnormal electrophysiological patterns. A vitamin D deficient state has been associated in the pathogenesis of heart failure; however, while many clinical studies report a benefit of vitamin D to heart function, other clinical studies are inconsistent with these findings. These uncertainties have led to a discord in the recommendation of vitamin D supplementation for the treatment of heart failure or as a preventive agent in patients deemed to be at risk for cardiac dysfunction. Accordingly, this article is intended to describe some of the mechanisms/sites of action of vitamin D in different animal models of heart failure, as well as to review the clinical observations and challenges in the interpretation and understanding of the clinical relevance of vitamin D in relation to heart function.

Vitamin D: A Role Also in Long COVID-19?

Coronavirus disease 2019 (COVID-19) has quickly become a global pandemic. Reports from different parts of the world indicate that a significant proportion of people who have recovered from COVID-19 are suffering from various health problems collectively referred to as “long COVID-19”. Common symptoms include fatigue, shortness of breath, cough, joint pain, chest pain, muscle aches, headaches, and so on. Vitamin D is an immunomodulatory hormone with proven efficacy against various upper respiratory tract infections. Vitamin D can inhibit hyperinflammatory reactions and accelerate the healing process in the affected areas, especially in lung tissue. Moreover, vitamin D deficiency has been associated with the severity and mortality of COVID-19 cases, with a high prevalence of hypovitaminosis D found in patients with COVID-19 and acute respiratory failure. Thus, there are promising reasons to promote research into the effects of vitamin D supplementation in COVID-19 patients. However, no studies to date have found that vitamin D affects post-COVID-19 symptoms or biomarkers. Based on this scenario, this review aims to provide an up-to-date overview of the potential role of vitamin D in long COVID-19 and of the current literature on this topic.

Vitamin D Deficiency and Vasovagal Syncope in Children and Adolescents

Aims: To investigate the association of vitamin D deficiency with cardiovascular autonomic nervous system function in children and adolescents with vasovagal syncope (VVS). Methods: This study recruited 76 pediatric patients with VVS and 15 healthy children. The 25-hydroxyvitamin D levels in serum among the participants were evaluated. Heart rate variability analysis including SDNN, rMSSD, and SDANN was tested in patients with VVS. The correlation between indices of time-domain analysis and serum vitamin D status of the children with VVS was investigated. Results: In this work, 25-hydroxyvitamin D levels in serum among VVS cases remarkably decreased compared with those among healthy controls (48.76 ± 19.25 vs. 67.62 ± 15.46 nmol/L, p < 0.01). The vitamin D deficient patients with VVS exhibited a lower rMSDD value compared to the non-deficient group with VVS (45.56 ± 16.87 vs. 61.90 ± 20.38 ms, p < 0.001, respectively). Pearson correlation analysis indicated that serum 25-hydroxyvitamin D levels had positive correlation with rMSDD values (r = 0.466, p < 0.001). Conclusions: As suggested by our data, VVS children and adolescents with vitamin D deficiency may have cardiac autonomic dysfunction and cardiac vagal tone decreases with the reduction in vitamin D level.

Is there any link between vitamin D deficiency and vasovagal syncope?

BACKGROUND

This study aimed to investigate serum 25[OH]D levels between patients with vasovagal syncope (VVS) diagnosed with head-up tilt table test (HUTT) and age-matched healthy people.

METHODS

The study included 75 consecutive patients (32.3 ± 10.7 years), who presented with syncope and underwent HUTT and 52 healthy controls (32.9 ± 14.1 years). HUTT patients were divided into two groups according to whether there was syncope response to the test. Patients underwent cardiac, psychiatric, and neurological investigation. Serum 25[OH]D levels were measured by chemiluminescent microparticle immunoassay method.

RESULTS

There was no difference between the two groups in terms of age, gender, body mass index (BMI), echocardiographic findings (P > .05). Mean serum 25[OH]D (24.5 ± 6.3 vs 20.1 ± 8.8 ng/mL, P = .003) and vitamin B12 levels (436.4 ± 199.2 vs 363.1 ± 107.6 pg/mL, P = .009) was lower in syncope patients when compared to the control group. In correlation analyses, syncope was shown as correlated with the vitamin D (r = -264, P = .003) and vitamin B12 levels (r = -233, P = .009). But, multivariate regression analyses showed that only vitamin D increased risk of syncope [OR: 0.946, 95% CI (0.901-0.994)]. There was no difference in terms of age, gender, BMI, echocardiographic findings between the in HUTT positive (n = 45) and negative groups (n = 29). Only vitamin D level was significantly lower in HUTT positive group (17.5 ± 7.7 vs 24.4 ± 9.1 ng/mL, P = .002). There was no difference among in the vasovagal subgroups in terms of vitamin D level and other features.

CONCLUSION

Vitamin D and B12 levels were reasonably low in syncope patients, but especially low Vitamin D levels were associated with VVS diagnosed in HUTT.