Association between the serum level of vitamin D and systemic sclerosis in a Chinese population: a case control study

Vitamin D and Autoimmune Rheumatic Diseases

Vitamin D is a steroid hormone with potent immune-modulating properties. It has been shown to stimulate innate immunity and induce immune tolerance. Extensive research efforts have shown that vitamin D deficiency may be related to the development of autoimmune diseases. Vitamin D deficiency has been observed in patients with rheumatoid arthritis (RA) and has been shown to be inversely related to disease activity. Moreover, vitamin D deficiency may be implicated in the pathogenesis of the disease. Vitamin D deficiency has also been observed in patients with systemic lupus erythematosus (SLE). It has been found to be inversely related to disease activity and renal involvement. In addition, vitamin D receptor polymorphisms have been studied in SLE. Vitamin D levels have been studied in patients with Sjogren's syndrome, and vitamin D deficiency may be related to neuropathy and the development of lymphoma in the context of Sjogren's syndrome. Vitamin D deficiency has been observed in ankylosing spondylitis, psoriatic arthritis (PsA), and idiopathic inflammatory myopathies. Vitamin D deficiency has also been observed in systemic sclerosis. Vitamin D deficiency may be implicated in the pathogenesis of autoimmunity, and it may be administered to prevent autoimmune disease and reduce pain in the context of autoimmune rheumatic disorders.

Involvement of the secosteroid vitamin D in autoimmune rheumatic diseases and COVID-19

Evidence supporting the extra-skeletal role of vitamin D in modulating immune responses is centred on the effects of its final metabolite, 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃, also known as calcitriol), which is regarded as a true steroid hormone. 1,25(OH)₂D₃, the active form of vitamin D, can modulate the innate immune system in response to invading pathogens, downregulate inflammatory responses and support the adaptive arm of the immune system. Serum concentrations of its inactive precursor 25-hydroxyvitamin D₃ (25(OH)D₃, also known as calcidiol) fluctuate seasonally (being lowest in winter) and correlate negatively with the activation of the immune system as well as with the incidence and severity of autoimmune rheumatic diseases such as rheumatoid arthritis, systemic lupus erythematosus and systemic sclerosis. Thus, a low serum concentration of 25(OH)D₃ is considered to be a risk factor for autoimmune rheumatic diseases and vitamin D₃ supplementation seems to improve the prognosis; moreover, long-term vitamin D₃ supplementation seems to reduce their incidence (i.e. rheumatoid arthritis). In the setting of COVID-19, 1,25(OH)₂D₃ seems to downregulate the early viral phase (SARS-CoV-2 infection), by enhancing innate antiviral effector mechanisms, as well as the later cytokine-mediated hyperinflammatory phase. This Review provides an update of the latest scientific and clinical evidence concerning vitamin D and immune response in autoimmune rheumatic diseases and COVID-19, which justify the need for monitoring of serum 25(OH)D₃ concentrations and for appropriate supplementation following clinical trial-based approaches.

Micronutrient Deficiencies in Systemic Sclerosis: A Scoping Review

Purpose

The primary aim is to identify the micronutrient deficiencies commonly reported in SSc. The exploratory aim is to evaluate associations between micronutrient deficiencies and SSc clinical manifestations.

Patient and Methods

We conducted a scoping review of all published reports on SSc and nutrition in PubMed from its inception to August 2020. Clinical trials, observational studies, meta-analyses, and case series (with ≥20 cases) containing data on nutritional deficiency and SSc were included. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) for reporting our findings. Two reviewers (ADN and ERV) studied the titles and abstracts of all search results with pre-specified inclusion and exclusion criteria.

Results

Among 790 retrieved publications, 35 full-length articles and 3 abstracts met the inclusion/exclusion criteria. Included studies took place across multiple geographic locations and included patients with both diffuse and limited cutaneous SSc. Vitamin D deficiency was the most commonly reported deficiency described in SSc, followed by vitamin B12, vitamin B9, selenium, zinc, and iron. In addition, some small studies found deficiencies in vitamins B1, B6, C, E, and A. While some studies reported associations between specific micronutrient deficiencies and SSc disease features (eg, interstitial lung disease was commonly associated with vitamin D deficiency and elevated homocysteine [Hcy]), the evidence to support these associations was not robust.

Conclusion

Micronutrient deficiencies are common in SSc and are associated with specific SSc features. Routine screening for micronutrient deficiencies may lead to early detection of malnutrition. Future studies are needed to understand how interventions to replete micronutrient deficiencies affect patient outcomes in SSc.

Vitamin D in Systemic Sclerosis: A Review

(1) Background: In the present paper we aimed to review the evidence about the potential implication of vitamin D in the pathogenesis and management of systemic sclerosis (SSc); (2) Methods: we performed a review of the literature looking for studies evaluating the potential role of vitamin D and its analogs in SSc. We searched the PubMed, Medline, Embase, and Cochrane libraries using the following strings: (vitamin D OR cholecalciferol) AND (systemic sclerosis OR scleroderma). We included cohort studies, case-control studies, randomized controlled trials, and observational studies. (3) Results: we identified nine pre-clinical and 21 clinical studies. Pre-clinical data suggest that vitamin D and its analogs may suppress fibrogenesis. Clinical data are concordant in reporting a high prevalence of hypovitaminosis D and osteoporosis in SSc patients; data about the association with clinical manifestations and phenotypes of SSc are, conversely, far less consistent; (4) Conclusions: in vitro data suggest that vitamin D may play an antifibrotic role in SSc, but clinical data confirming this finding are currently lacking. Hypovitaminosis D is common among SSc patients and should be treated to reduce the risk of osteoporosis.

An Update on the Effects of Vitamin D on the Immune System and Autoimmune Diseases

Vitamin D intervenes in calcium and phosphate metabolism and bone homeostasis. Experimental studies have shown that 1,25-dihydroxyvitamin D (calcitriol) generates immunologic activities on the innate and adaptive immune system and endothelial membrane stability. Low levels of serum 25-hydroxyvitamin D (25(OH)D) are associated with an increased risk of developing immune-related diseases such as psoriasis, type 1 diabetes, multiple sclerosis, and autoimmune diseases. Various clinical trials describe the efficacy of supplementation of vitamin D and its metabolites for treating these diseases that result in variable outcomes. Different disease outcomes are observed in treatment with vitamin D as high inter-individual difference is present with complex gene expression in human peripheral blood mononuclear cells. However, it is still not fully known what level of serum 25(OH)D is needed. The current recommendation is to increase vitamin D intake and have enough sunlight exposure to have serum 25(OH)D at a level of 30 ng/mL (75 nmol/L) and better at 40–60 ng/mL (100–150 nmol/L) to obtain the optimal health benefits of vitamin D.

Role of Vitamin D in Systemic Sclerosis: A Systematic Literature Review

Background

Systemic sclerosis (SSc) is a chronic multisystem autoimmune condition defined by a complex pathobiology, comprising excessive fibrosis of skin and internal organs, peripheral vasculopathy with endothelial cell dysfunction, inadequate vascular repair and neovascularization, and aberrant immunity. Vitamin D is a steroid hormone with pleiotropic effects beyond its traditional role in calcium and bone homeostasis. Since vitamin D has immunomodulatory, cardioprotective, and antifibrotic properties, it could potentially interfere with SSc pathogenesis. Suboptimal vitamin D levels are classically recognized in scleroderma, irrespective of clinical and serological phenotype.

Aim

This systematic review is aimed at investigating and clarifying the role of vitamin D in SSc and emphasizing the association of vitamin D status with different clinical settings.

Methods and Results

A systematic online search was performed, using PubMed databases to collect articles on the topic of vitamin D in SSc. The final analysis included 40 eligible articles.

Conclusions

Hypovitaminosis D is common in SSc patients and could be associated with clinical and serologic patterns of the disease. Intervention for low serum vitamin D levels in SSc pathogenesis remains controversial, as well as the significance of vitamin D supplementation in such patients.

Dualities of the vitamin D in systemic sclerosis: a systematic literature review

BACKGROUND

Systemic sclerosis (SSc) is a chronic disease characterized by autoimmunity, vasculopathy, and visceral and cutaneous fibrosis. Vitamin D has several functions in the immunological system, and different studies have suggested a potential role in triggering autoimmune diseases. Patients with SSc may present with low serum levels of vitamin D, but the association between hypovitaminosis D and disease onset or any clinical manifestation is still obscure. Our goal was to verify the causal relationship between hypovitaminosis D and SSc onset or any particular clinical manifestation in the literature.

METHODS

A systematic literature review was performed through February 24th, 2021 on Pubmed, Lilacs/BIREME, and Cochrane databases. The eligible studies were read in full text, and, in the absence of exclusion criteria, were included in this review after consensus between two reviewers.

RESULTS

Forty articles met the eligibility criteria and the main results of each study are described. In most studies, SSc patients showed a higher prevalence of vitamin D deficiency and insufficiency compared to controls. Additionally, in some reports serum levels of vitamin D were inversely correlated with the severity of SSc. Oral supplementation did not seem to affect serum levels of vitamin D. Four of the included studies were with experimental models.

CONCLUSION

In conclusion, vitamin D deficiency seems to have a role in susceptibility to SSc, as well as in the clinical manifestations of the disease.

Association of Systemic Sclerosis and Periodontitis with Vitamin D Levels

The aim of the present study was to analyze the association among systemic sclerosis (SSc), periodontitis (PT); we also evaluated the impact of PT and SSc on vitamin D levels. Moreover, we tested the association with potential confounders. A total of 38 patients with SSc, 40 subjects with PT, 41 subjects with both PT and SSc, and 41 healthy controls were included in the study. The median vitamin D levels in PT subject were 19.1 (17.6-26.8) ng/mL, while SSc + PT group had vitamin d levels of 15.9 (14.7-16.9) ng/mL, significantly lower with respect to SSc patients (21.1 (15.4-22.9) ng/mL) and to healthy subjects (30.5 (28.8-32.3) ng/mL) (p < 0.001). In all subjects, vitamin D was negatively associated with c-reactive protein (CRP) (p < 0.001) and with probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), and plaque score (PI) (p < 0.001 for all parameters) and positively related to the number of teeth (p < 0.001). Moreover, univariate regression analysis demonstrated an association among high low-density lipoproteins (LDL) cholesterol (p = 0.021), CRP (p = 0.014), and PT (p < 0.001) and reduced levels of vitamin D. The multivariate regression analysis showed that PT (p = 0.011) and CRP (p = 0.031) were both predictors of vitamin D levels. Subjects with PT and SSc plus PT had significant lower vitamin D values with respect to SSc and to healthy subjects. In addition, PT seems negatively associated with levels of vitamin D in all analyzed patients.

Vitamin D and connective tissue diseases

OBJECTIVE AND DESIGN

Recently, many studies have shown that the biologically active form of vitamin D-1,25(OH)₂ D-is involved in many biological processes, including immune system modulation, and patients affected by various autoimmune diseases, such as connective tissue diseases (CTD), showed low levels of vitamin D. It is not clear if vitamin D deficiency is involved in the pathogenesis of autoimmune diseases or it is a consequence.

MATERIAL

We carried out a review of literature to summarize the existing connections between 25-OH vitamin D and CTD.

METHODS

We searched for articles on PubMed by keywords: vitamin D, connective tissue diseases, systemic lupus erythematosus, Sjogren's syndrome, systemic sclerosis, undifferentiated connective tissue disease.

RESULTS

The relationship between vitamin D and CTD is still not very clear, despite many studies having been performed and some data suggest a connection between these diseases and 25-OH vitamin D levels.

CONCLUSIONS

The limitations of the study, such as the heterogeneity of patients, methods used to measure vitamin D serum concentration and other biases, do not lead to unequivocal results to demonstrate a direct link between low vitamin D serum levels and autoimmune diseases. Further studies are needed to resolve conflicting results.

Associations of Vitamin D Receptor Single Nucleotide Polymorphisms with Susceptibility to Systemic Sclerosis

BACKGROUND

This study aims to evaluate whether the Vitamin D receptor (VDR) gene polymorphisms were associated with systemic sclerosis (SSc) in a Chinese Han population.

METHODS

Using a hospital-based case-control study including 100 SSc patients and 100 healthy controls. Single nucleotide polymorphisms (SNPs) in the VDR region were genotyped by the improved multiplex ligase detection reaction (i MLDR) method. Haplotypes were also constructed after linkage disequilibrium (LD) analysis.

RESULTS

Eight SNPs (rs731236 (TaqI), rs2228570 (FokI), rs7975232 (ApaI), rs1544410 (BsmI), rs11574010 (Cdx2), rs739837 (BglI), rs757343 (Tru9I) and rs11168267) were included. There were significant differences between SSc patients and healthy individuals in ApaI and BglI genotype (both adjusted p = 0.008). Through the genotyping, significantly association of SSc were found for: dominant model of ApaI and BglI (both OR (95% CI) = 1.80 (1.03,3.16), p = 0.040). Furthermore, the elevation of erythrocyte sedimentation rate (ESR) had a higher percentage of BglI GT genotype frequency (p = 0.034) and dominant model of ApaI (p = 0.016) in SSc. There was high linkage disequilibrium was detected in BglI and ApaI polymorphisms (r² = 1.0, D' = 1.0), Tru9I and rs11168267 (r² = 0.926, D' = 0.969), respectively. No significant difference were found in these four haplotypes (all p >0.05). The correlation between VD levels and VDR gene polymorphisms was not statistically significant.

CONCLUSIONS

Our preliminary study indicates the ApaI and BglI genotype may possibly have a role in the pathogenesis of SSc patients. Dominant model of ApaI and BglI GT genotype frequency may be associated with the increased risk of ESR.

Role of Vitamin D Beyond the Skeletal Function: A Review of the Molecular and Clinical Studies

The classical function of Vitamin D, which involves mineral balance and skeletal maintenance, has been known for many years. With the discovery of vitamin D receptors in various tissues, several other biological functions of vitamin D are increasingly recognized and its role in many human diseases like cancer, diabetes, hypertension, cardiovascular, and autoimmune and dermatological diseases is being extensively explored. The non-classical function of vitamin D involves regulation of cellular proliferation, differentiation, apoptosis, and innate and adaptive immunity. In this review, we discuss and summarize the latest findings on the non-classical functions of vitamin D at the cellular/molecular level and its role in complex human diseases.

Vitamin D levels in systemic sclerosis patients: a meta-analysis

PURPOSE

This study aimed to investigate the association between vitamin D and systemic sclerosis (SSc) by meta-analysis.

METHODS

A comprehensive search was performed through June 12, 2017. Pooled standardized mean difference (SMD) was used to estimate the mean vitamin D difference between case and control groups (or between diffused- and limited-type SSc). Pooled risk ratios (RRs) with 95% confidence intervals (CIs) were used to assess the impact of vitamin D level on clinical characteristics of SSc patients. All statistical analyses were performed using Revman 5.0 software.

RESULTS

The search yielded six studies with a total of 554 SSc patients and 321 healthy controls. The meta-analysis showed that SSc patients suffered from decreased vitamin D levels (SMD =-8.72 ng/mL; 95% CI: -10.11 to -7.32) compared with healthy controls. The meta-analysis results of three studies with 240 SSc patients (93 diffused-type and 147 limited-type SSc patients) showed that diffused-type SSc patients exhibited lower vitamin D levels (SMD =-4.71 ng/mL; 95% CI: -8.98 to -0.44) compared with limited-type SSc patients. However, vitamin D level was not found to be associated with Rodnan score (SMD =-2.29 ng/mL, 95% CI: -8.49 to 3.91, P=0.47), systolic pulmonary pressure (SMD =-1.68 ng/mL, 95% CI: -10.79 to 7.43, P=0.72), gastrointestinal ulcer (RR =1.01, 95% CI: 0.53-1.93, P=0.98), or pulmonary involvement (RR =1.01, 95% CI: 0.36-2.86, P=0.99) in SSc patients.

CONCLUSION

SSc patients exhibited lower vitamin D levels compared with healthy controls. Vitamin D levels in diffused-type SSc patients were significantly lower than those in limited-type SSc patients. The severity of clinical features was not associated with the extent of vitamin D deficit. Therefore, we hypothesize that SSc patients, especially diffused type, have lower vitamin D levels, and that the decrease of vitamin D levels might not be an accelerating factor of SSc severity.

Serum 25-OH vitamin D levels in systemic sclerosis: analysis of 140 patients and review of the literature

Hypovitaminosis D is increasingly reported in autoimmune diseases. We investigated the 25-OH-vitamin D (25-OH-vitD) levels in systemic sclerosis (SSc) patients, in correlation with disease's features. We measured the 25-OH-vitD serum levels in 140 consecutive patients (F/M 126/15; mean age 61 ± 15.1 years), 91 without (group A) and 49 with (group B) 25-OH-cholecalciferol supplementation. Patients of group A invariably showed low 25-OH-vitD levels (9.8 ± 4.1 ng/ml vs. 26 ± 8.1 ng/ml of group B); in particular, 88/91 (97%) patients showed vitamin D deficiency (<20 ng/ml), with very low vitamin D levels (<10 ng/ml) in 40 (44%) subjects. Only 15/49 (30.6%) patients of group B reached normal levels of 25-OH-vitD (≥30 ng/ml), whereas vitamin D deficiency persisted in 12/49 (24.5%) individuals. Parathormone levels inversely correlated with 25-OH-vitD (r = -0.3, p < 0.0001). Of interest, hypovitaminosis D was statistically associated with autoimmune thyroiditis (p = 0.008), while calcinosis was more frequently observed in patients of group A (p = 0.057). Moreover, we found significantly higher percentage of serum anticentromere antibodies in group B patients with 25-OH-vitD level ≥30 ng/ml (8/15 vs. 6/34; p = 0.017). In literature, hypovitaminosis D is very frequent in SSc patients. An association with disease duration, calcinosis, or severity of pulmonary involvement was occasionally recognized. Hypovitaminosis D is very frequent in SSc and severe in a relevant percentage of patients; furthermore, less than one third of supplemented subjects reached normal levels of 25-OH-vitD. The evaluation of 25-OH-vitD levels should be included in the routine clinical work-up of SSc. The above findings expand previous observations and may stimulate further investigations.