Vitamin D as a Nutri-Epigenetic Factor in Autoimmunity-A Review of Current Research and Reports on Vitamin D Deficiency in Autoimmune Diseases

Investigating the comparative effect of vitamin D level with the type of complications in Henoch Schönlein purpura and Kawasaki disease

INTRODUCTION AND OBJECTIVES

Henoch Schönlein purpura (HSP) and Kawasaki disease (KD) are two main inflammatory diseases among childhood vasculitis. Considering the anti-inflammatory effects of 25-hydroxyvitamin D3, we decided to investigate the association of serum 25-hydroxy vitamin D3 level with the type and severity of these conditions.

MATERIALS AND METHODS

The present study was performed as a historical cohort of 254 affected children with KD and HSP vasculitis. The required data were extracted, using a researcher-made questionnaire from patients' electronic file, and then they were analyzed after collecting information of the patients.

RESULTS

In HSP group, 54% of participants were boys. Similarly, in KD group, boys were more affected than girls. The comparative 25-hydroxyvitamin vitamin D3 level in HSP patients with and without renal involvement (P=0.02), hematuria (P=0.14), and in two groups with and without heart disease, and also with and without coronary artery dilatation in KD patients (P<0.001) were significant.

DISCUSSION AND CONCLUSIONS

The findings showed that insufficient level of vitamin D3 were significantly associated with the exacerbation of complications of both diseases, and therefore it seems that vitamin D deficiency can be an effective predictive factor of severity in HSP and KD patients.

VDR Gene Single Nucleotide Polymorphisms and Autoimmunity: A Narrative Review

The vitamin D/Vitamin D receptor (VDR) axis is crucial for human health as it regulates the expression of genes involved in different functions, including calcium homeostasis, energy metabolism, cell growth and differentiation, and immune responses. In particular, the vitamin D/VDR complex regulates genes of both innate and adaptive immunity. Autoimmune diseases are believed to arise from a genetic predisposition and the presence of triggers such as hormones and environmental factors. Among these, a role for Vitamin D and molecules correlated to its functions has been repeatedly suggested. Four single nucleotide polymorphisms (SNPs) of the VDR gene, ApaI, BsmI, TaqI, and FokI, in particular, have been associated with autoimmune disorders. The presence of particular VDR SNP alleles and genotypes, thus, was observed to modulate the likelihood of developing diverse autoimmune conditions, either increasing or reducing it. In this work, we will review the scientific literature suggesting a role for these different factors in the pathogenesis of autoimmune conditions and summarize evidence indicating a possible VDR SNP involvement in the onset of these diseases. A better understanding of the role of the molecular mechanisms linking Vitamin D/VDR and autoimmunity might be extremely useful in designing novel therapeutic avenues for these disorders.

Evidence That Increasing Serum 25(OH)D Concentrations to 30 ng/mL in the Kingdom of Saudi Arabia and the United Arab Emirates Could Greatly Improve Health Outcomes

Accumulating evidence supports the potential protective effects of vitamin D against chronic diseases such as Alzheimer’s disease, autoimmune diseases, cancers, cardiovascular disease (ischaemic heart disease and stroke), type 2 diabetes, hypertension, chronic kidney disease, stroke, and infectious diseases such as acute respiratory tract diseases, COVID-19, influenza, and pneumonia, as well as adverse pregnancy outcomes. The respective evidence is based on ecological and observational studies, randomized controlled trials, mechanistic studies, and Mendelian randomization studies. However, randomized controlled trials on vitamin D supplementation have largely failed to show benefits, probably due to poor design and analysis. In this work, we aim to use the best available evidence on the potential beneficial effects of vitamin D to estimate the expected reduction in incidence and mortality rates of vitamin D-related diseases in the Kingdom of Saudi Arabia and the United Arab Emirates if minimum serum 25(OH)D concentrations were to be raised to 30 ng/mL. Estimated reductions by 25% for myocardial infarction incidence, 35% for stroke incidence, 20 to 35% for cardiovascular disease mortality, and 35% for cancer mortality rates depicted a promising potential for raising serum 25(OH)D. Methods to increase serum 25(OH)D concentrations at the population level could include food fortification with vitamin D3, vitamin D supplementation, improved dietary vitamin D intake, and sensible sun exposure.

Guidelines for Preventing and Treating Vitamin D Deficiency: A 2023 Update in Poland

Introduction: All epidemiological studies suggest that vitamin D deficiency is prevalent among the Polish general population. Since vitamin D deficiency was shown to be among the risk factors for many diseases and for all-cause mortality, concern about this problem led us to update the previous Polish recommendations. Methods: After reviewing the epidemiological evidence, case-control studies and randomized control trials (RCTs), a Polish multidisciplinary group formulated questions on the recommendations for prophylaxis and treatment of vitamin D deficiency both for the general population and for the risk groups of patients. The scientific evidence of pleiotropic effects of vitamin D as well as the results of panelists' voting were reviewed and discussed. Thirty-four authors representing different areas of expertise prepared position statements. The consensus group, representing eight Polish/international medical societies and eight national specialist consultants, prepared the final Polish recommendations. Results: Based on networking discussions, the ranges of total serum 25-hydroxyvitamin D concentration indicating vitamin D deficiency [<20 ng/mL (<50 nmol/L)], suboptimal status [20-30 ng/mL (50-75 nmol/L)], and optimal concentration [30-50 ng/mL (75-125 nmol/L)] were confirmed. Practical guidelines for cholecalciferol (vitamin D₃) as the first choice for prophylaxis and treatment of vitamin D deficiency were developed. Calcifediol dosing as the second choice for preventing and treating vitamin D deficiency was introduced. Conclusions: Improving the vitamin D status of the general population and treatment of risk groups of patients must be again announced as healthcare policy to reduce a risk of spectrum of diseases. This paper offers consensus statements on prophylaxis and treatment strategies for vitamin D deficiency in Poland.

Vitamin D-Related Genes and Thyroid Cancer-A Systematic Review

Vitamin D, formerly known for its role in calcium-phosphorus homeostasis, was shown to exert a broad influence on immunity and on differentiation and proliferation processes in the last few years. In the field of endocrinology, there is proof of the potential role of vitamin D and vitamin D-related genes in the pathogenesis of thyroid cancer-the most prevalent endocrine malignancy. Therefore, the study aimed to systematically review the publications on the association between vitamin D-related gene variants (polymorphisms, mutations, etc.) and thyroid cancer. PubMed, EMBASE, Scopus, and Web of Science electronic databases were searched for relevant studies. A total of ten studies were found that met the inclusion criteria. Six vitamin D-related genes were analyzed (VDR-vitamin D receptor, CYP2R1-cytochrome P450 family 2 subfamily R member 1, CYP24A1-cytochrome P450 family 24 subfamily A member 1, CYP27B1-cytochrome P450 family 27 subfamily B member 1, DHCR7-7-dehydrocholesterol reductase and CUBN-cubilin). Moreover, a meta-analysis was conducted to summarize the data from the studies on VDR polymorphisms (rs2228570/FokI, rs1544410/BsmI, rs7975232/ApaI and rs731236/TaqI). Some associations between thyroid cancer risk (VDR, CYP24A1, DHCR7) or the clinical course of the disease (VDR) and vitamin D-related gene polymorphisms were described in the literature. However, these results seem inconclusive and need validation. A meta-analysis of the five studies of common VDR polymorphisms did not confirm their association with increased susceptibility to differentiated thyroid cancer. Further efforts are necessary to improve our understanding of thyroid cancer pathogenesis and implement targeted therapies for refractory cases.