An update on vitamin D and human immunity

Biological Effects of CYP11A1-Derived Vitamin D and Lumisterol Metabolites in the Skin

Novel pathways of vitamin D3, lumisterol 3 (L3), and tachysterol 3 (T3) activation have been discovered, initiated by CYP11A1 and/or CYP27A1 in the case of L3 and T3. The resulting hydroxymetabolites enhance protection of skin against DNA damage and oxidative stress; stimulate keratinocyte differentiation; exert anti-inflammatory, antifibrogenic, and anticancer activities; and inhibit cell proliferation in a structure-dependent manner. They act on nuclear receptors, including vitamin D receptor, aryl hydrocarbon receptor, LXRα/β, RAR-related orphan receptor α/γ, and peroxisome proliferator-activated receptor-γ, with selectivity defined by their core structure and distribution of hydroxyl groups. They can activate NRF2 and p53 and inhibit NF-κB, IL-17, Shh, and Wnt/β-catenin signaling. Thus, they protect skin integrity and physiology.

Prediction of Osteoporotic Hip Fracture Outcome: Comparative Accuracy of 27 Immune-Inflammatory-Metabolic Markers and Related Conceptual Issues

Objectives: This study, based on the concept of immuno-inflammatory-metabolic (IIM) dysregulation, investigated and compared the prognostic impact of 27 indices at admission for prediction of postoperative myocardial injury (PMI) and/or hospital death in hip fracture (HF) patients. Methods: In consecutive HF patient (n = 1273, mean age 82.9 ± 8.7 years, 73.5% females) demographics, medical history, laboratory parameters, and outcomes were recorded prospectively. Multiple logistic regression and receiver-operating characteristic analyses (the area under the curve, AUC) were used to establish the predictive role for each biomarker. Results: Among 27 IIM biomarkers, 10 indices were significantly associated with development of PMI and 16 were indicative of a fatal outcome; in the subset of patients aged >80 years with ischaemic heart disease (IHD, the highest risk group: 90.2% of all deaths), the corresponding figures were 26 and 20. In the latter group, the five strongest preoperative predictors for PMI were anaemia (AUC 0.7879), monocyte/eosinophil ratio > 13.0 (AUC 0.7814), neutrophil/lymphocyte ratio > 7.5 (AUC 0.7784), eosinophil count < 1.1 × 109/L (AUC 0.7780), and neutrophil/albumin × 10 > 2.4 (AUC 0.7732); additionally, sensitivity was 83.1-75.4% and specificity was 82.1-75.0%. The highest predictors of in-hospital death were platelet/lymphocyte ratio > 280.0 (AUC 0.8390), lymphocyte/monocyte ratio < 1.1 (AUC 0.8375), albumin < 33 g/L (AUC 0.7889), red cell distribution width > 14.5% (AUC 0.7739), and anaemia (AUC 0.7604), sensitivity 88.2% and above, and specificity 85.1-79.3%. Internal validation confirmed the predictive value of the models. Conclusions: Comparison of 27 IIM indices in HF patients identified several simple, widely available, and inexpensive parameters highly predictive for PMI and/or in-hospital death. The applicability of IIM biomarkers to diagnose and predict risks for chronic diseases, including OP/OF, in the preclinical stages is discussed.

Effects of Vitamin D Supplementation on Cognitive Outcomes: A Systematic Review and Meta-Analysis

Clinical studies examining the effects of vitamin D on cognition have reported inconsistent results. To date, no comprehensive study has examined this effect on the basis of sample characteristics or intervention model-related factors. This systematic review and meta-analysis of randomized controlled trials investigated the effects of vitamin D supplementation on global cognitive function and specific cognitive domains. This review was preregistered in the PROSPERO database (CRD42021249908) and comprised 24 trials enrolling 7557 participants (mean age: 65.21 years; 78.54% women). The meta-analysis revealed that vitamin D significantly influenced global cognition (Hedges' g = 0.128, p = .008) but not specific cognitive domains. A subgroup analysis indicated that the effect size of vitamin D was stronger for vulnerable populations (Hedges' g = 0.414) and those with baseline vitamin D deficiency (Hedges' g = 0.480). On the basis of subgroup analyses in studies without biological flaws (Hedges' g = 0.549), we suggest that an intervention model should correct baseline vitamin D deficiency. Our results indicate that vitamin D supplementation has a small but significant positive effect on cognition in adults.

Design, synthesis, and biological activity of D-bishomo-1α,25-dihydroxyvitamin D3 analogs and their crystal structures with the vitamin D nuclear receptor

The biologically active metabolite of vitamin D3 - calcitriol - is a hormone involved in the regulation of calcium-phosphate homeostasis, immunological processes and cell differentiation, being therefore essential for the proper functioning of the human body. This suggests many applications of this steroid in the treatment of diseases such as rickets, psoriasis and some cancers. Unfortunately, using therapeutic doses of calcitriol is associated with high concentrations of this compound which causes hypercalcemia. For this reason, new calcitriol analogs are constantly sought, devoid of calcemic effects but maintaining its beneficial properties. In this study, we present the synthesis of vitamin D derivatives characterized by an enlarged (seven-membered) ring D. Preparation of the designed vitamin D compounds required separate syntheses of crucial building blocks (C/D-rings fragments with side chain and rings A) which were combined by different methods, including Wittig-Horner reaction and Suzuki coupling. Biological activities of the target vitamin D analogs were assessed both in vitro and in vivo, demonstrating their significant potency compared to the natural hormone. Furthermore, the successful crystallization of these compounds with the vitamin D receptor (VDR) enabled us to investigate additional molecular interactions with this protein.

Transcriptomics analysis highlights potential ways in human pathogenesis in Leishmania braziliensis infected with the viral endosymbiont LRV1

The parasite Leishmania (Viannia) braziliensis is widely distributed in Brazil and is one of the main species associated with human cases of different forms of tegumentary leishmaniasis (TL) such as cutaneous leishmaniasis (CL) and mucosal leishmaniasis (ML). The mechanisms underlying the pathogenesis of TL are still not fully understood, but it is known that factors related to the host and the parasite act in a synergistic and relevant way to direct the response to the infection. In the host, macrophages have a central connection with the parasite and play a fundamental role in the defense of the organism due to their ability to destroy intracellular parasites and present antigens. In the parasite, some intrinsic factors related to the species or even the strain analyzed are fundamental for the outcome of the disease. One of them is the presence of Leishmania RNA Virus 1 (LRV1), an endosymbiont virus that parasitizes some species of Leishmania that triggers a cascade of signals leading to a more severe TL phenotype, such as ML. One of the strategies for understanding factors associated with the immune response generated after Leishmania/host interaction is through the analysis of molecular patterns after infection. Thus, the gene expression profile in human monocyte-derived macrophages obtained from healthy donors infected in vitro with L. braziliensis positive (LbLRV1+) and negative (LbLRV1-) for LRV1 was evaluated. For this, the microarray assay was used and 162 differentially expressed genes were identified in the comparison LbLRV1+ vs. LbLRV1-, 126 upregulated genes for the type I and II interferons (IFN) signaling pathway, oligoadenylate synthase OAS/RNAse L, non-genomic actions of vitamin D3 and RIG-I type receptors, and 36 down-regulated. The top 10 downregulated genes along with the top 10 upregulated genes were considered for analysis. Type I interferon (IFNI)- and OAS-related pathways results were validated by RT-qPCR and Th1/Th2/Th17 cytokines were analyzed by Cytometric Bead Array (CBA) and enzyme-linked immunosorbent assay (ELISA). The microarray results validated by RT-qPCR showed differential expression of genes related to IFNI-mediated pathways with overexpression of different genes in cells infected with LbLRV1+ compared to LbLRV1- and to the control. No significant differences were found in cytokine levels between LbLRV1+ vs. LbLRV1- and control. The data suggest the activation of gene signaling pathways associated with the presence of LRV1 has not yet been reported so far. This study demonstrates, for the first time, the activation of the OAS/RNase L signaling pathway and the non-genomic actions of vitamin D3 when comparing infections with LbLRV1+ versus LbLRV1- and the control. This finding emphasizes the role of LRV1 in directing the host's immune response after infection, underlining the importance of identifying LRV1 in patients with TL to assess disease progression.

Association of vitamin D with disease severity in infants with bronchiolitis

Vitamin D's role in immune system regulation and its contribution to host defenses against respiratory infections may have implications for bronchiolitis pathophysiology. This cross-sectional study aimed to determine the association between the clinical severity of bronchiolitis and serum vitamin D levels in infants. Infants aged 1 month to 12 months, diagnosed with bronchiolitis, and healthy controls attending routine immunization were enrolled. Baseline characteristics were recorded, including clinical details, bronchiolitis severity, and course during hospital stay. Bronchiolitis severity score (BSS) was used to score the severity. A 1-2 ml serum sample was obtained for vitamin D levels estimation. The median age of cases (n = 64; 65.6% male) was 5 [3, 8] months, and that of the control group (n = 30) was 3 [2, 9] months. No statistically significant differences were observed between the two groups in age, gender, weight, mode of delivery, family history of atopy/asthma, feeding pattern, smoke exposure, and daily vitamin D supplementation. The median vitamin D levels were not significantly different between the groups (p = 0.68). Among infants with bronchiolitis, 62.5% had vitamin D insufficiency (≤ 20 ng/ml). A significantly higher median BSS indicates that infants with vitamin D insufficiency exhibited more severe disease (p = 0.019). Although a negative correlation between BSS and vitamin D levels was noted, it did not reach statistical significance [rs = (-)0.17; p = 0.16].

CONCLUSION

 Infants with Vitamin D insufficiency experienced more severe bronchiolitis with elevated BSS scores. It highlights the potential role of vitamin D deficiency in severe bronchiolitis.

WHAT IS KNOWN

• Vitamin D level is low in infants with bronchiolitis.

WHAT IS NEW

• Infant with low vitamin D level experienced more severe bronchiolitis.

The Prognostic Significance of Vitamin D Deficiency in Korean Patients With Multiple Myeloma

BACKGROUND

Vitamin D deficiency is relatively common among patients with multiple myeloma. The prognostic significance of vitamin D deficiency in Asian patients with multiple myeloma remains unevaluated. This study aimed to assess the prognostic value of vitamin D levels in this Korean patient population.

METHODS

From September 2017 to May 2020, 98 patients were enrolled in the study. Vitamin D deficiency was defined as 25-hydroxyvitamin D level of less than 10 ng/mL.

RESULTS

Thirty-six patients (36.7%) had vitamin D deficiency. These patients had significantly lower 2-year progression-free survival rates (44.8% vs. 66.9%, P = .008) and overall survival (OS) rates (2-year OS 47.2% vs. 74.2%, P = .024) compared with those without deficiency. Furthermore, patients who received vitamin D supplementation showed a trend towards improved OS compared with those who did not, with a 2-year OS rate of 51.9% vs. 33.3% (P = .14).

CONCLUSION

These findings suggest that vitamin D levels are a significant prognostic factor in patients with multiple myeloma.

Vitamin D and Aging: Central Role of Immunocompetence

The pro-hormone vitamin D3 is an important modulator of both innate and adaptive immunity since its biologically active metabolite 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) regulates via the transcription factor VDR (vitamin D receptor) the epigenome and transcriptome of human immune cells and controls in this way the expression of hundreds of vitamin D target genes. Since the myeloid linage of hematopoiesis is epigenetically programmed by VDR in concert with the pioneer factors PU.1 (purine-rich box 1) and CEBPα (CCAAT/enhancer binding protein α), monocytes, macrophages, and dendritic cells are the most vitamin D-sensitive immune cell types. The central role of the immune system in various aging-related diseases suggests that immunocompetence describes not only the ability of an individual to resist pathogens and parasites but also to contest non-communicative diseases and the process of aging itself. In this review, we argue that the individual-specific responsiveness to vitamin D relates to a person's immunocompetence via the epigenetic programming function of VDR and its ligand 1,25(OH)2D3 during hematopoiesis as well as in the periphery. This may provide a mechanism explaining how vitamin D protects against major common diseases and, in parallel, promotes healthy aging.

Exploring the causal role of gut microbiota in giant cell arteritis: a Mendelian randomization analysis with mediator insights

Background

Giant Cell Arteritis (GCA) is a complex autoimmune condition. With growing interest in the role of gut microbiota in autoimmune diseases, this research aimed to explore the potential causal relationship between gut microbiota and GCA, and the mediating effects of specific intermediaries.

Methods

Using a bidirectional two-sample Mendelian randomization (MR) design, we investigated associations between 191 microbial taxa and GCA. A two-step MR technique discerned the significant mediators on this relationship, followed by Multivariable MR analyses to quantify the direct influence of gut microbiota on GCA and mediation effect proportion, adjusting for these mediators.

Results

Nine taxa displayed significant associations with GCA. Among them, families like Bacteroidales and Clostridiaceae1 had Odds Ratios (OR) of 1.48 (p=0.043) and 0.52 (p=5.51e-3), respectively. Genera like Clostridium sensu stricto1 and Desulfovibrio showed ORs of 0.48 (p=5.39e-4) and 1.48 (p=0.037), respectively. Mediation analyses identified 25 hydroxyvitamin D level (mediation effect of 19.95%), CD14+ CD16- monocyte counts (mediation effect of 27.40%), and CD4+ T cell counts (mediation effect of 28.51%) as significant intermediaries.

Conclusion

Our findings provide invaluable insights into the complex interplay between specific gut microbiota taxa and GCA. By highlighting the central role of gut microbiota in influencing GCA risk and long-term recurrence, and their interactions with vital immune mediators, this research paves the way for potential therapeutic interventions in GCA management.

Encapsulation of vitamin D3 using rhamnolipids-based nanostructured lipid carriers

This work had as main objective to encapsulate vitamin D3 (VD3) into nanostructured lipid carriers (NLCs) using rhamnolipids as surfactant. Glycerol monostearate and medium chain triglycerides with 2.625 % of VD3 were used as lipid materials. The three formulations of NLCs with VD3 (NLCs + VD3) were composed by 99 % of aqueous phase, 1 % of lipid phase and 0.05 % of surfactant. The difference between them was the ratio of solid:liquid in lipid phase. The NLCs + VD3 sizes ranged between 92.1 and 108.1 nm. The most stable formulation maintaining their caracteristics for 60 days at 4 °C. The NLCs + VD3 cytotoxicity demonstrated that concentrations of 0.25 mg/mL or lower up had a good biocompatibility in vitro. During the in vitro digestion, formulations with lower sizes and higher content on solid lipid had higher lipolysis rate and consequently higher VD3 bioaccessibility. The rhamnolipids-based NLCs are a good option for the encapsulation of VD3.

The Role of Vitamin D and Its Molecular Bases in Insulin Resistance, Diabetes, Metabolic Syndrome, and Cardiovascular Disease: State of the Art

In the last decade, an increasing awareness was directed to the role of Vitamin D in non-skeletal and preventive roles for chronic diseases. Vitamin D is an essential hormone in regulating calcium/phosphorous balance and in the pathogenesis of inflammation, insulin resistance, and obesity. The main forms of vitamin D, Cholecalciferol (Vitamin D3) and Ergocalciferol (Vitamin D2) are converted into the active form (1,25-dihydroxyvitamin D) thanks to two hydroxylations in the liver, kidney, pancreas, and immune cells. Some anti-inflammatory cytokines are produced at higher levels by vitamin D, while some pro-inflammatory cytokines are released at lower levels. Toll-Like Receptor (TLR) expression is increased, and a pro-inflammatory state is also linked to low levels of vitamin D. Regardless of how it affects inflammation, various pathways suggest that vitamin D directly improves insulin sensitivity and secretion. The level of vitamin D in the body may change the ratio of pro- to anti-inflammatory cytokines, which would impact insulin action, lipid metabolism, and the development and function of adipose tissue. Many studies have demonstrated an inverse relationship between vitamin D concentrations and pro-inflammatory markers, insulin resistance, glucose intolerance, metabolic syndrome, obesity, and cardiovascular disease. It is interesting to note that several long-term studies also revealed an inverse correlation between vitamin D levels and the occurrence of diabetes mellitus. Vitamin D supplementation in people has controversial effects. While some studies demonstrated improvements in insulin sensitivity, glucose, and lipid metabolism, others revealed no significant effect on glycemic homeostasis and inflammation. This review aims to provide insight into the molecular basis of the relationship between vitamin D, insulin resistance, metabolic syndrome, type 1 and 2 diabetes, gestational diabetes, and cardiovascular diseases.

Some genetic differences in patients with rheumatoid arthritis

OBJECTIVE

Vitamin D is important for bone and cartilage metabolism. Changes in vitamin D blood level may be related to pathological disorders such as rheumatoid arthritis (RA). The main aim of this study is to investigate the association between RA and the vitamin D receptor (VDR) genes FokI and TaqI polymorphisms. One hundred RA patients and fifty healthy matched controls were assessed for VDR FokI and TaqI genotyping. Intact parathyroid hormone (PTH) and calcium (Ca) levels were measured, categorized, and compared between the cases and control groups.

RESULTS

We found that the FokI genotype frequencies for the RA cases and control groups were FF:Ff:ff = 46%:52%:2% and 50%:50%:0%, respectively (P = 0.76). The TaqI genotype frequencies for the RA cases and control groups were TT:Tt:tt = 45%:44%:11% and 42%:42%:16%, respectively (P = 0.69). A statistically significant high serum PTH level was associated with the ff genotype (p = 0.03), and a significantly low serum Ca level was associated with the TT genotype (p = 0.003). In comparison with controls, no influence of VDR FokI and TaqI genotypes on RA susceptibility or risk was demonstrated.

The Effect of Vit-D Supplementation on the Side Effect of BioNTech, Pfizer Vaccination and Immunoglobulin G Response Against SARS-CoV-2 in the Individuals Tested Positive for COVID-19: A Randomized Control Trial

Background

Vitamin D participates in the biological function of the innate and adaptive immune system and inflammation. We aim to specify the effectiveness of the vitamin D supplementation on the side effects BioNTech, Pfizer vaccination, and immunoglobulin G response against severe acute respiratory syndrome coronavirus 2 in subjects tested positive for coronavirus disease 2019 (COVID-19).

Methods

In this multi-center randomized clinical trial, 498 people tested positive for COVID-19 were divided into 2 groups, receiving vitamin D capsules or a placebo (1 capsule daily, each containing 600 IU of vitamin D) over 14-16 weeks. Anthropometric indices and biochemical parameters were measured before and after the second dose of vaccination.

Result

Fourteen to 16 weeks after supplementation, the intervention group had an immunoglobulin G (IgG) increase of 10.89 ± 1.2 g/L, while the control group had 8.89 ± 1.3 g/L, and the difference was significant between both groups (p = 0.001). After the second dose of vaccination, the supplement group significantly increased their 25-hydroxy vitamin D from initially 28.73 ± 15.6 ng/mL and increased to 46.48 ± 27.2 ng/mL, and the difference between them was significant. Those with a higher body mass index (BMI) had the most of symptoms, and the difference of side effects according to BMI level was significantly different. In 8 weeks after supplementation obese participants had the lowest IgG levels than overweight or normal subjects. The proportion of all types of side effects on the second dose was significantly diminished compared with the first dose in the intervention group.

Conclusion

Supplementation of 600 IU of vitamin D3 can reduce post-vaccination side effects and increase IgG levels in participants who received BioNTech, Pfizer vaccine.

Trial Registration

ClinicalTrials.gov Identifier: NCT05851313.

Maternal and Fetal Effects of Gestational Vitamin D Concentration

Most (90%) vitamin D synthesis occurs in the skin using sunlight (ultraviolet rays), and 10% is obtained through food. Vitamin D is an essential nutrient for skeletal growth and maintenance, cell proliferation and differentiation, and immune function. This study investigated whether maternal serum vitamin D concentrations induce maternofetal effects. Hematological analysis, serological changes, and precision fetal ultrasound findings were analyzed by maternal vitamin D concentration in gestational weeks 22-25 to ascertain direct effects on fetal growth. Bone density-vitamin D concentration correlation was analyzed. No hematologic or serological effect of maternal vitamin D concentration was detected; however, the sexually transmitted infection and cross-infection rates were inversely proportional to maternal vitamin D concentration. No significant correlation between vitamin D concentration and vertebral and femoral BMD was detected. For fetal growth, biparietal diameter, head circumference, abdominal circumference, femur length, and humerus length were analyzed. Humerus (p < 0.05) and femur (p < 0.001) lengths were higher in the vitamin D-sufficient group than in the vitamin D-deficient group. Vitamin D concentration did not positively affect hematologic changes and bone density; maternal vitamin D concentration essentially affected fetal bone growth. Vitamin D inhibits sexually transmitted infections in mothers and promotes fetal bone growth. Prevention of vitamin D deficiency, supplementation, or outdoor activities is recommended.

Prevention of COVID-19 with oral vitamin D supplemental therapy in essential healthcare teams (PROTECT): protocol for a multicentre, triple-blind, randomised, placebo-controlled trial

INTRODUCTION

In the COVID-19 pandemic, healthcare workers (HCWs) were at high risk of infection due to their exposure to COVID infections. HCWs were the backbone of our healthcare response to this pandemic; every HCW withdrawn or lost due to infection had a substantial impact on our capacity to deliver care. Primary prevention was a key approach to reduce infection. Vitamin D insufficiency is highly prevalent in Canadians and worldwide. Vitamin D supplementation has been shown to significantly decrease the risk of respiratory infections. Whether this risk reduction would apply to COVID-19 infections remained to be determined. This study aimed to determine the impact of high-dose vitamin D supplementation on incidence of laboratory-confirmed COVID-19 infection rate and severity in HCWs working in high COVID incidence areas.

METHODS AND ANALYSIS

PROTECT was a triple-blind, placebo-controlled, parallel-group multicentre trial of vitamin D supplementation in HCWs. Participants were randomly allocated in a 1:1 ratio in variable block size to intervention (one oral loading dose of 100 000 IU vitamin D₃+10 000 IU weekly vitamin D₃) or control (identical placebo loading dose+weekly placebo). The primary outcome was the incidence of laboratory-confirmed COVID-19 infection, documented by RT-qPCR on salivary (or nasopharyngeal) specimens obtained for screening or diagnostic purposes, as well as self-obtained salivary specimens and COVID-19 seroconversion at endpoint. Secondary outcomes included disease severity; duration of COVID-19-related symptoms; COVID-19 seroconversion documented at endpoint; duration of work absenteeism; duration of unemployment support; and adverse health events. The trial was terminated prematurely, due to recruitment difficulty.

ETHICS AND DISSEMINATION

This study involves human participants and was approved by the Research Ethics Board (REB) of the Centre hospitalier universitaire (CHU) Sainte-Justine serving as central committee for participating institutions (#MP-21-2021-3044). Participants provided written informed consent to participate in the study before taking part. Results are being disseminated to the medical community via national/international conferences and publications in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

https://clinicaltrials.gov/ct2/show/NCT04483635.

Combined Effect of Omega-3 Fatty Acid and Vitamin D 3 on Oxidized LDL-C and Non-HDL-C Levels in People With Vitamin D Deficiency: A Randomized Controlled Trial

ABSTRACT

The present randomized clinical trial (RCT) was conducted on Jordanian participants with vitamin D deficiency (VDD) with no other medical conditions, to evaluate the combined effect of 1,25-dihydroxy vitamin D 3 (Vit.D 3 ) and omega-3 fatty acid (n-3FA) supplements (D+) on oxidized low-density lipoprotein (Ox-LDL) and non-high-density lipoprotein cholesterol (non-HDL-C) levels as common predictors of cardiovascular diseases (CVDs). Participants were randomized into 4 groups as follows: a control group (C) that received no supplementations, a Vit.D 3 group that received 50,000 IU of Vit.D 3 every week, an n-3FA group that received 300 mg of omega-3 fatty acid every day, and a D+ group that received a combination of both supplements, with the same dosage administered by the previous groups but with a 4-6-hour time interval between Vit.D 3 and n-3FA administration to avoid any possible interaction. All supplementations were administered orally for 8 weeks. Forty-seven participants were allocated to each group. Twenty-six in the control group, 37 participants in the Vit.D 3 group, 37 participants in the n-3FA group, and 46 participants in the D+ group completed the study to the end. The D+ supplementations significantly increased non-HDL-C (118.99 ± 60.98 to 155.26 ± 43.36 mg/dL, P << 0.05) but decreased Ox-LDL-C levels (69.29 ± 37.69 to 52.81 ± 17.30 pg/mL, P = 0.03). The stepwise regression showed that the serum LDL-C level was the main independent variable involved in the elevation of non-HDL levels (R 2 = 0.837) observed at the end of the trial in the D+ group. The groups that were supplemented with either Vit.D 3 alone or n-3FA alone had an insignificant decrease in the level of Ox-LDL-C. In conclusion, despite the observed hyperlipidemic effect, the combination treatment is recommended by the research team because the decrease in Ox-LDL may offset the hyperlipidemic effect.

High prevalence and risk factors for osteoporosis in 1839 patients with systemic sclerosis: a systematic review and meta-analysis

OBJECTIVES

Osteoporosis is prevalent in patients with systemic sclerosis (SSc). Updated evidence is required to complement the previous systematic review on this topic to provide best practices. This systematic review and meta-analysis aimed to quantitatively synthesize data from studies concerning the prevalence and risk factors for osteoporosis among patients with SSc.

METHODS

We searched PubMed, EMBASE, Web of Science, and ScienceDirect databases for potential studies published from inception to May 31, 2022. Eligibility screening, data extraction, and quality assessment of the retrieved articles were conducted independently by two reviewers. Then meta-analyses were performed to determine osteoporosis prevalence and risk factors in patients with SSc. Meta-regression analysis was conducted to explore the sources of heterogeneity.

RESULTS

The pooled prevalence of osteoporosis in patients with SSc was 27% (95% CI, 24-31), with moderate heterogeneity (I² = 61.6%). Meta-regression revealed no significant difference among all variables. And the presence of SSc increased the likelihood of having osteoporosis (OR = 3.05, 95% CI, 2.32-4.01) compared to controls. These significant risk factors for osteoporosis in SSc patients were age > 50 years (OR = 2.94, 95% CI, 1.52-5.68), menopause (OR = 3.90; 95% CI, 1.94-7.84), aging (MD = 8.40; 95% CI,6.10-10.71) and longer disease duration (MD = 4.78; 95% CI,1.83-7.73). However, female (OR = 1.45; 95% CI, 0.75-2.77), pulmonary arterial hypertension (OR = 0.50; 95% CI, 0.17-1.54), and diffuse cutaneous SSc (OR = 1.05; 95% CI, 0.75-1.48) were not significant risk factors for osteoporosis in SSc patients.

CONCLUSIONS

Osteoporosis was highly prevalent in patients with SSc, and the prevalence seemed to be high and similar in many countries. The age > 50 years, menopause, aging, and longer disease duration were identified as risk factors for osteoporosis in patients with SSc.

The Effect of Weekly 50,000 IU Vitamin D3 Supplements on the Serum Levels of Selected Cytokines Involved in Cytokine Storm: A Randomized Clinical Trial in Adults with Vitamin D Deficiency

This research aimed to evaluate the effects of high-dose cholecalciferol (VD₃) supplements (50,000 IU/week) on selected circulating cytokines associated with cytokine storms in adults with vitamin D deficiency. This clinical trial, based in Jordan, included 50 participants receiving vitamin D₃ supplements (50,000 IU/week) for 8 weeks; the exact number was assigned to the control group. Interleukin-6 (IL-6), interleukin-1β (IL-1β), interleukin-10 (IL-10), tumor necrotic factor-α (TNF-α), and leptin were measured in serum at baseline and 10 weeks (wash out: 2 weeks). Our results revealed that vitamin D₃ supplementation significantly increased the serum levels of 25OHD, IL-6, IL-10, IL-1β, and leptin compared with baseline. In contrast, the serum level of TNF-α insignificantly increased in the group receiving vitamin D₃ supplementation. Although the observations of this trial may refer to a potential negative effect of VD₃ supplementation during cytokine storms, further trials are required to clarify the potential benefits of VD₃ supplement during cytokine storms.

Vitamin D as a Shield against Aging

Aging can be seen as a physiological progression of biomolecular damage and the accumulation of defective cellular components, which trigger and amplify the process, toward whole-body function weakening. Senescence initiates at the cellular level and consists in an inability to maintain homeostasis, characterized by the overexpression/aberrant expression of inflammatory/immune/stress responses. Aging is associated with significant modifications in immune system cells, toward a decline in immunosurveillance, which, in turn, leads to chronic elevation of inflammation/oxidative stress, increasing the risk of (co)morbidities. Albeit aging is a natural and unavoidable process, it can be regulated by some factors, like lifestyle and diet. Nutrition, indeed, tackles the mechanisms underlying molecular/cellular aging. Many micronutrients, i.e., vitamins and elements, can impact cell function. This review focuses on the role exerted by vitamin D in geroprotection, based on its ability to shape cellular/intracellular processes and drive the immune response toward immune protection against infections and age-related diseases. To this aim, the main biomolecular paths underlying immunosenescence and inflammaging are identified as biotargets of vitamin D. Topics such as heart and skeletal muscle cell function/dysfunction, depending on vitamin D status, are addressed, with comments on hypovitaminosis D correction by food and supplementation. Albeit research has progressed, still limitations exist in translating knowledge into clinical practice, making it necessary to focus attention on the role of vitamin D in aging, especially considering the growing number of older individuals.

The Role of Microbiota-Derived Vitamins in Immune Homeostasis and Enhancing Cancer Immunotherapy

Not all cancer patients who receive immunotherapy respond positively and emerging evidence suggests that the gut microbiota may be linked to treatment efficacy. Though mechanisms of microbial contributions to the immune response have been postulated, one likely function is the supply of basic co-factors to the host including selected vitamins. Bacteria, fungi, and plants can produce their own vitamins, whereas humans primarily obtain vitamins from exogenous sources, yet despite the significance of microbial-derived vitamins as crucial immune system modulators, the microbiota is an overlooked source of these nutrients in humans. Microbial-derived vitamins are often shared by gut bacteria, stabilizing bioenergetic pathways amongst microbial communities. Compositional changes in gut microbiota can affect metabolic pathways that alter immune function. Similarly, the immune system plays a pivotal role in maintaining the gut microbiota, which parenthetically affects vitamin biosynthesis. Here we elucidate the immune-interactive mechanisms underlying the effects of these microbially derived vitamins and how they can potentially enhance the activity of immunotherapies in cancer.

Stage of infection with Mycobacterium avium subsp. paratuberculosis impacts expression of Rab5, Rab7, and CYP27B1 in macrophages within the ileum of naturally infected cows

Introduction

Macrophages are the preferential target of Mycobacterium avium subsp. paratuberculosis (MAP), the etiologic agent of ruminant paratuberculosis. Uptake of pathogens by intestinal macrophages results in their trafficking through endosomal compartments, ultimately leading to fusion with an acidic lysosome to destroy the pathogen. MAP possesses virulence factors which disrupt these endosomal pathways. Additionally, levels of serum vitamin D₃ have proven relevant to host immunity. Dynamics of endosomal trafficking and vitamin D₃ metabolism have been largely unexplored in bovine paratuberculosis.

Methods

This study aimed to characterize expression of early and late endosomal markers Rab5 and Rab7, respectively, within CD68+ macrophages in frozen mid-ileum sections harvested from cows at different stages of natural paratuberculosis infection. Additionally, factors of vitamin D₃ signaling and metabolism were characterized through expression of vitamin D₃ activating enzyme 1α-hydroxylase (CYP27B1), vitamin D₃ inactivating enzyme 24-hydroxylase (CYP24A1), and vitamin D₃ receptor (VDR) within CD68+ ileal macrophages.

Results and discussion

Cows with clinical paratuberculosis had significantly greater macrophage and MAP burden overall, as well as intracellular MAP. Total expression of Rab5 within macrophages was reduced in clinical cows; however, Rab5 and MAP colocalization was significantly greater in this group. Intracellular Rab7 colocalization with MAP was not detected in subclinical or Johne's Disease negative (JD-) control cows but was present in clinical cows. Additionally, macrophage CYP27B1 expression was significantly reduced in clinical cows. Taken together, the results from this study show disparate patterns of expression for key mediators in intracellular MAP trafficking and vitamin D metabolism for cows at different stages of paratuberculosis.

Vitamin D supplementation and cardiac tissue inflammation in obese rats

OBJECTIVE

The current study was aimed to evaluate the effects of active form of vitamin D on TGF- β, NF-κB and MCP-1 in heart tissue of obese rats.

METHODS

Forty rats were allocated into groups of normal diet and high fat diet for sixteen weeks; then each group was divided into two groups that received either 500 IU/kg vitamin D or placebo for five weeks. Biochemical parameters were assessed by ELISA kits.

RESULTS

Vitamin D reduced TGF-β in obese rats supplemented with vitamin D compared with other groups (P = 0.03). Moreover, vitamin D reduced MCP-1 concentrations in the heart tissues of both vitamin D administered groups compared to placebo one (P = 0.002). NF-κB in the heart of HFD + vitamin D group was significantly lower (P = 0.03). Current study also showed that vitamin D improves glycemic status and reduce insulin resistance significantly in HFD group (P = 0.008).

CONCLUSION

Vitamin D was a potential anti- inflammatory mediator of cardiovascular disease and markers of glycemic status in obese rats. Further investigations are needed to better identify the therapeutic role of this vitamin in CVD and to elucidate the underlying mechanisms.

Impact of Zinc, Vitamins C and D on Disease Prognosis among Patients with COVID-19 in Bangladesh: A Cross-Sectional Study

Vitamin C, (ascorbic acid), vitamin D (cholecalciferol) and zinc (zinc sulfate monohydrate) supplements are important in immunity against coronavirus disease-2019 (COVID-19). However, a limited number of studies have been conducted on the association of vitamins and supplements with the reduced risks of COVID-19 infection. This study aims to evaluate the association of vitamins and supplements as treatment options to reduce the severity of COVID-19. Data were collected from 962 participants from 13 December 2020 to 4 February 2021. The presence of COVID-19 was confirmed by qRT-PCR. The Chi-square test and multivariate regression analyses were conducted. The ratio of uptake of vitamin C:vitamin D:zinc was 1:1:0.95. Uptake of vitamin C, vitamin D and zinc were significantly associated with the reduced risk of infection and severity of COVID-19 (OR: 0.006 (95% CI: 0.03-0.11) (p = 0.004)) and (OR: 0.03 (95% CI: 0.01-0.22) (p = 0.005)). The tendency of taking supplements was associated with the presence of infection of COVID-19 (p = 0.001), age (p = 0.02), sex (p = 0.05) and residence (p = 0.04). The duration of supplementation and medication was significantly associated with reduced hospitalization (p = 0.0001). Vitamins C, D and zinc were not significantly (p = 0.9) associated with a reduced risk of severity when taken through the diet. Hospitalization (p = 0.000001) and access to health facilities (p = 0.0097) were significantly associated with the survival period of the participants. Participants with better access to health facilities recovered early (OR: 6.21, 95% CI 1.56-24.7). This study will add knowledge in the field of treatment of COVID-19 by using vitamins and zinc supplements.

Behavioral and Dietary Habits That Could Influence Both COVID-19 and Non-Communicable Civilization Disease Prevention-What Have We Learned Up to Now?

The massive expansion of the new coronavirus SARS-CoV-2 has urged countries to introduce lockdowns and set restrictive actions worldwide. The focus of the studies was to determine how COVID-19 induces damage to the lungs in order to find an alternative or adjuvant therapy that could lead to preventing COVID-19 or at least ameliorating it. This paper aims to survey the literature and provide new insights into behavioral and dietary habits that could influence the prevention of COVID-19. Maintaining an adequate mental health status, sleep, and taking moderate exercise are often disrupted in the conditions of lockdown and are followed by weakened immunity. Mediterranean and vegetarian diets are superior to other eating patterns in terms of immunity boosting and fighting COVID-19. Our study showed how adequate hydration, green tea intake, and supplementation with vitamins D, C, and E can increase our chances of avoiding the infection and even help us sleep better. Another focus of the research was on determining what level of hygiene really increases one's chances of not contracting SARS-CoV-2, but this seems a little counter-intuitive at first. Since an immunocompromised state is a familiar predisposing factor for all contagious diseases, maintaining healthy behavioral and dietary habits could be a crucial step in boosting immunity and preventing COVID-19.

Combined use of lactoferrin and vitamin D as a preventive and therapeutic supplement for SARS-CoV-2 infection: Current evidence

Lactoferrin is a multifunctional protein that exhibits anti-inflammatory, immune regulating and anti-infective properties. One of its receptor sites is located on severe acute respiratory syndrome coronavirus 2. The binding of lactoferrin with heparin sulfate proteoglycans may prevent the first contact between the virus and host cells, thus preventing subsequent infection. Given that lactoferrin may act as a natural mucosal barrier, an intranasal treatment together with its oral intake can be hypothesized to prevent the spread, infection and inflammation caused by coronavirus disease 2019 (COVID-19). Moreover, the literature reports that vitamin D plays an essential role in promoting immune response. With its anti-inflammatory and immunoregulatory properties, vitamin D is critical for activating the immune system’s defenses, improving immune cell function. Different studies also demonstrate that lactoferrin is a potential activator of the vitamin D receptor. In this sense, the combined use of lactoferrin (through an association of oral intake and a nasal spray formulation) and vitamin D could represent a valuable therapy for COVID-19 treatment and prevention. However, further randomized clinical trials are needed before recommending/prescribing them.

Influence of vitamin D supplementation on immune function of healthy aging people: A pilot randomized controlled trial

OBJECTIVES

This study aims to investigate the influence of vitamin D supplementation on immune function of healthy older adults.

MATERIALS AND METHODS

Designed as a randomized controlled trial, 21 participants (55-85 years) completed the study during May-November 2018 in Coventry, England. The participants were randomized into vitamin D or the control group, stratified by age, gender and body mass index. The vitamin D group (n = 12) took vitamin D3 tablets of 1,000 IU/day for 12 weeks plus vitamin D education leaflet, while the control group (n = 9) were only provided with the leaflet. At baseline, 6 and 12 weeks, plasma 25(OH)D levels and immunological and metabolic parameters including phagocytic activity of granulocytes and monocytes, tumor necrosis factor, interleukin 6, lymphocyte subsets and fasting blood glucose and lipid were measured. Dietary vitamin D intake was analyzed at baseline and week 12. Data were presented as mean ± SD. Two-way repeated measures ANOVA and independent t-test were used to analyze the data.

RESULTS

At baseline, 42.9% of the participants were vitamin D deficiency (25(OH)D < 25 nmol/L), only 10% achieved a level of 25(OH)D > 50 nmol/L. Overweight/obese participants (n = 9) had significantly lower mean plasma 25(OH)D concentration (22.3 ± 8.7 nmol/L) than normal weight participants (48.1 ± 34.3 nmol/L) (P = 0.043). There was a significant increase in plasma 25(OH)D concentration in vitamin D group compared with that in control group (P = 0.002) during the intervention period. The plasma 25(OH)D concentration in vitamin D group was increased at 6 weeks (from 38.4 ± 37.0 nmol/L at baseline to 51.0 ± 38.2 nmol/L) with little change observed between 6 and 12 weeks (51.8 ± 36.4 nmol/L). The plasma creatinine concentration in vitamin D group was significantly decreased compared with the control group (P = 0.036) (79.8 ± 7.0 μmol/L at baseline vs 75.1 ± 5.4 μmol/L at week 12). No significant effect of vitamin D supplementation was determined on immunological parameters.

CONCLUSION

Vitamin D deficiency is common among the aging population in the UK even during the summertime. Vitamin D supplementation at 1,000 IU/day for 12 weeks significantly increased plasma 25(OH)D concentration but showed no effect on metabolic and immunological parameters except decreased plasma creatinine.

Evaluation of Vitamin D Levels in Pediatric Patients With Recurrent Aphthous Stomatitis

BACKGROUND

Recurrent aphthous stomatitis is one of the most common oral mucosal diseases. It is characterized by recurrent painful attacks. Its etiology is unknown. Vitamin D (vit D) is a steroid vitamin with immunomodulatory and anti-inflammatory effects. It is thought that oral cavity diseases may occur in vitamin D deficiency. This study aimed to investigate vit D levels in pediatric patients with recurrent aphthous stomatitis.

METHODS

In this retrospective study, 86 children with recurrent aphthous stomatitis and 71 age-matched healthy children were included in the study. The 25-hydroxyvitamin D levels examined with the enzyme immune assay were recorded for both groups.

RESULTS

Serum vit D level was 12±4.5 ng/ml in the group with aphthous stomatitis and 31±7 ng/ml in the healthy group. A statistically significant difference was found in vit D levels between the two groups (p<0.001).

CONCLUSIONS

Vit D levels were significantly low in children with recurrent aphthous stomatitis. Our findings suggest that low vit D levels may be associated with recurrent aphthous stomatitis.

Nutrition, Immunosenescence, and Infectious Disease: An Overview of the Scientific Evidence on Micronutrients and on Modulation of the Gut Microbiota

The immune system is key to host defense against pathogenic organisms. Aging is associated with changes in the immune system, with a decline in protective components (immunosenescence), increasing susceptibility to infectious disease, and a chronic elevation in low-grade inflammation (inflammaging), increasing the risk of multiple noncommunicable diseases. Nutrition is a determinant of immune cell function and of the gut microbiota. In turn, the gut microbiota shapes and controls the immune and inflammatory responses. Many older people show changes in the gut microbiota. Age-related changes in immune competence, low-grade inflammation, and gut dysbiosis may be interlinked and may relate, at least in part, to age-related changes in nutrition. A number of micronutrients (vitamins C, D, and E and zinc and selenium) play roles in supporting the function of many immune cell types. Some trials report that providing these micronutrients as individual supplements can reverse immune deficits in older people and/or in those with insufficient intakes. There is inconsistent evidence that this will reduce the risk or severity of infections including respiratory infections. Probiotic, prebiotic, or synbiotic strategies that modulate the gut microbiota, especially by promoting the colonization of lactobacilli and bifidobacteria, have been demonstrated to modulate some immune and inflammatory biomarkers in older people and, in some cases, to reduce the risk and severity of gastrointestinal and respiratory infections, although, again, the evidence is inconsistent. Further research with well-designed and well-powered trials in at-risk older populations is required to be more certain about the role of micronutrients and of strategies that modify the gut microbiota-host relationship in protecting against infection, especially respiratory infection.

The relationship between subclinical hypothyroidism and vitamin D

Aim: Vitamin D (vitD) is primarily responsible for bone formation and mineralization. However, in recent years, it has been suggested that vitD may play a role as an immune modulator in the development of numerous diseases, including autoimmune diseases. It has been observed that there is an association between chronic autoimmune thyroiditis (AIT) and vitD levels. This study aims to investigate whether there are differences in the levels of 25-hydroxy vitamin D [25(OH)D], calcium, and phosphorus in patients with subclinical hypothyroidism (SCH) due to AIT, in patients with antibody-negative subclinical hypothyroidism (ANSCH), and in healthy control subjects. Material and Method: Data from 50 newly diagnosed patients with SCH (35 of whom AIT) and 50 euthyroid and antibody-negative healthy controls who presented to the Department of Endocrinology and Internal Medicine at our hospital between 2018 and 2020 were retrospectively reviewed. Calcium, phosphorus, and 25(OH)D levels of patients and controls were compared. Results: Serum 25(OH)D levels were significantly lower in patients compared to controls (16.2±7.8 ng/ml and 20.4±8.2 ng/ml, respectively; p=0.024). Serum levels of calcium (p=0.081) and phosphorus (p=0.712) did not differ between groups. In a subgroup analysis, patients with AIT had significantly lower 25(OH)D values than controls (p=0.009). Compared to controls, 25(OH)D levels were comparable in the ANSCH group (p=0.096). 25(OH)D level was higher in the AIT group than in the ANSCH group (p=0.01). Conclusion: Our results show that patients with SCH have lower 25(OH)D levels than healthy controls. However, this difference is significant in patients with AIT. It is recommended to screen for vitD deficiency in patients with SCH due to AIT.

Molecular mechanisms and therapeutic target of NETosis in diseases

Evidence shows that neutrophils can protect the host against pathogens in multiple ways, including the formation and release of neutrophil extracellular traps (NETs). NETs are web‐like structures composed of fibers, DNA, histones, and various neutrophil granule proteins. NETs can capture and kill pathogens, including bacteria, viruses, fungi, and protozoa. The process of NET formation is called NETosis. According to whether they depend on nicotinamide adenine dinucleotide phosphate (NADPH), NETosis can be divided into two categories: “suicidal” NETosis and “vital” NETosis. However, NET components, including neutrophil elastase, myeloperoxidase, and cell‐free DNA, cause a proinflammatory response and potentially severe diseases. Compelling evidence indicates a link between NETs and the pathogenesis of a number of diseases, including sepsis, systemic lupus erythematosus, rheumatoid arthritis, small‐vessel vasculitis, inflammatory bowel disease, cancer, COVID‐19, and others. Therefore, targeting the process and products of NETosis is critical for treating diseases linked with NETosis. Researchers have discovered that several NET inhibitors, such as toll‐like receptor inhibitors and reactive oxygen species scavengers, can prevent uncontrolled NET development. This review summarizes the mechanism of NETosis, the receptors associated with NETosis, the pathology of NETosis‐induced diseases, and NETosis‐targeted therapy.

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.

Health Status of Afghan Refugees in Europe: Policy and Practice Implications for an Optimised Healthcare

Four decades of civil war, violence, and destabilisation have forced millions of Afghans to flee their homes and to move to other countries worldwide. This increasing phenomenon may challenge physicians unfamiliar with the health status of this population, which may be markedly different from that of the host country. Moreover, several factors during their migration, such as transport in closed containers, accidental injuries, malnutrition, and accommodation in detention centres and refugee camps have a major influence on the health of refugees. By taking into account the variety of the specific diseases among migrant groups, the diversity of the origins of refugees and asylum seekers, and the increasing numbers of Afghan refugees, in this review we focus on the population of Afghans and describe their health status with the aim of optimising our medical approach and management. Our literature review shows that the most prevalent reported infections are tuberculosis and other respiratory tract infections and parasitic diseases, for example leishmaniasis, malaria, and intestinal parasitic infections. Anaemia, hyperlipidaemia, arterial hypertension, diabetes, smoking, overweight, malnutrition, low socioeconomic status, and poor access to healthcare facilities are additional risk factors for non-communicable diseases among Afghan refugees. With regards mental health issues, depression and post-traumatic stress disorder (PTSD) are the most common diagnoses and culture shock and the feeling of being uprooted modulate their persistence. Further research is needed in order to provide us with extensive, high-quality data about the health status of Afghan refugees. The main objective of this review is to identify protective factors which could ensure key health concepts and good clinical practice.

COVID-19 disease and autoimmune disorders: A mutual pathway

Coronavirus disease 2019 (COVID-19) is a real challenge for humanity with high morbidity and mortality. Despite being primarily a respiratory illness, COVID-19 can affect nearly every human body tissue, causing many diseases. After viral infection, the immune system can recognize the viral antigens presented by the immune cells. This immune response is usually controlled and terminated once the infection is aborted. Nevertheless, in some patients, the immune reaction becomes out of control with the development of autoimmune diseases. Several human tissue antigens showed a strong response with antibodies directed against many severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) proteins, such as SARS-CoV-2 S, N, and autoimmune target proteins. The immunogenic effects of SARS-CoV-2 are due to the sizeable viral RNA molecules with interrupted transcription increasing the pool of epitopes with increased chances of molecular mimicry and interaction with the host immune system, the overlap between some viral and human peptides, the viral induced-tissue damage, and the robust and complex binding between sACE-2 and SARS-CoV-2 S protein. Consequently, COVID-19 and its vaccine may trigger the development of many autoimmune diseases in a predisposed patient. This review discusses the mutual relation between COVID-19 and autoimmune diseases, their interactive effects on each other, the role of the COVID-19 vaccine in triggering autoimmune diseases, the factors affecting the severity of COVID-19 in patients suffering from autoimmune diseases, and the different ways to minimize the risk of COVID-19 in patients with autoimmune diseases.

Vitamin D Levels and Length of Hospitalization in Indian Patients With COVID-19: A Single-Center Prospective Study

Introduction

The role of vitamin D deficiency in increasing susceptibility or modifying outcomes in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) illness is unclear, and data about the association is scant in low- and middle-income countries. We set out to investigate any correlation between baseline vitamin D status and the length of hospital stay in laboratory-confirmed SARS-CoV-2 patients in India.

Methods

Two hundred patients with SARS-CoV-2 infection requiring admission in a North Indian 1200-bedded tertiary care hospital were recruited prospectively from November 2020 to March 2021. Baseline serum 25 hydroxyvitamin D [25(OH)D] levels were measured within 24 hours of admission using chemiluminescent immunoassay. Patients were managed as per hospital management protocol for COVID-19. The primary outcome was the length of hospital stay; secondary outcomes were comparative clinical severity between two groups, rate of requirement of mechanical ventilation and/or non-invasive ventilation (NIV), and mortality. Vitamin D deficiency (VDD) was defined as baseline vitamin D levels of <30 ng/ml.

Results 

Of the 200 recruited patients, 57.5% (n = 115) patients were vitamin D deficient, and the overall median length of hospital stay was around 12 days (IQR: 8-15 days). There was no statistically significant difference in the length of hospital stay between patients with normal serum vitamin D (VDS) and those with VDD, median LOS being 12 days (95% CI: 10, 12 days) in VDD cases and 11 days (95% CI: 10,13 days) in VDS cases (p = 0.176). No association between baseline 25(OH)D and any of the secondary outcomes could be established.

Conclusions

In Indian patients, baseline vitamin D levels are not associated with the length of hospital stay, need for mechanical ventilation, or mortality.

The Role of Vitamin D in SARS-CoV-2 Infection and Acute Kidney Injury

Vitamin D has been described as an essential nutrient and hormone, which can cause nuclear, non-genomic, and mitochondrial effects. Vitamin D not only controls the transcription of thousands of genes, directly or indirectly through the modulation of calcium fluxes, but it also influences the cell metabolism and maintenance specific nuclear programs. Given its broad spectrum of activity and multiple molecular targets, a deficiency of vitamin D can be involved in many pathologies. Vitamin D deficiency also influences mortality and multiple outcomes in chronic kidney disease (CKD). Active and native vitamin D serum levels are also decreased in critically ill patients and are associated with acute kidney injury (AKI) and in-hospital mortality. In addition to regulating calcium and phosphate homeostasis, vitamin D-related mechanisms regulate adaptive and innate immunity. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections have a role in excessive proinflammatory cell recruitment and cytokine release, which contribute to alveolar and full-body endothelial damage. AKI is one of the most common extrapulmonary manifestations of severe coronavirus disease 2019 (COVID-19). There are also some correlations between the vitamin D level and COVID-19 severity via several pathways. Proper vitamin D supplementation may be an attractive therapeutic strategy for AKI and has the benefits of low cost and low risk of toxicity and side effects.

Effect of serum vitamin D on metabolic associated fatty liver disease: a large population-based study

BACKGROUND

Several studies have revealed that serum vitamin D is an important factor for metabolic associated fatty liver disease (MAFLD), but there had been no consistent conclusion.

METHODS

Of 427,507 subjects who underwent health examination, 83,625 who met the inclusion criteria were included in a cross-sectional analysis. Clinical and laboratory data were collected for analysis. MAFLD was diagnosed by abdominal imaging.

RESULTS

Multivariate linear regression models discovered a negative association between serum vitamin D and MAFLD (OR: 0.92, 95% CI: 0.90 to 0.94, p = .001), after adjusting for other well-identified risk factors. The same result was found when serum vitamin D was handled as a categorical variable (quartile, Q1-Q4) (Q4 vs. Q1, OR: 0.82, 95% CI: 0.77 to 0.87, p < .001), and a significant linear trend was observed (p for trend <.001). After analysis, a nonlinear relationship was detected between serum vitamin D and MAFLD, with an inflection point of 2.23 (44.6 nmol/L or 17.84 ng/mL). The effect sizes and the confidence intervals on the left and right sides of the inflection point were 1.16 (1.06 to 1.28) and 0.89 (0.86 to 0.91), respectively. All interactions with MAFLD were not significant for age, sex, diabetes, hypertension, smoking and body mass index (p for interaction = .110, .558, .335, .195, .616 and .401, respectively).

CONCLUSIONS

There was a nonlinear relationship between serum vitamin D and MAFLD. When the serum vitamin D level was ≥44.6 nmol/L (17.84 ng/mL), a negative correlation between serum vitamin D and MAFLD was detected. Below this level, serum vitamin D might promote the progression of MAFLD.

Host and Clostridioides difficile-Response Modulated by Micronutrients and Glutamine: An Overview

Changes in intestinal microbiota are integral to development of Clostridioides difficile (C. difficile)—associated nosocomial diarrhea. Certain diets, especially Western diets, increase susceptibility to C. difficile infection (CDI). Here, we discuss recent findings regarding how nutrients modulate response of the host and C. difficile during infection. Calcium has a role in the sporulation and germination process. Selenium is effective in reducing the total amount of C. difficile toxin A (TcdA) and toxin B (TcdB) and in decreasing its cytotoxicity. In addition, selenium phosphate synthetase deficiency reduces C. difficile growth and spore production. On the other hand, iron has a dual role in C. difficile growth. For instance, high intracellular levels can generate reactive hydroxyl radicals, whereas low levels can reduce its growth. In humans, zinc deficiency appears to be related to the recurrence of CDI, in contrast, in the CDI model in mice a diet rich in zinc increased the toxin's activity. Low vitamin D levels contribute to C. difficile colonization, toxin production, and inflammation. Furthermore, glutamine appears to protect intestinal epithelial cells from the deleterious effects of TcdA and TcdB. In conclusion, nutrients play an important role in modulating host and pathogen response. However, further studies are needed to better understand the mechanisms and address some controversies.

Tuberculosis and Autoimmunity

Tuberculosis remains a common and dangerous chronic bacterial infection worldwide. It is long-established that pathogenesis of many autoimmune diseases is mainly promoted by inadequate immune responses to bacterial agents, among them Mycobacterium tuberculosis. Tuberculosis is a multifaceted process having many different outcomes and complications. Autoimmunity is one of the processes characteristic of tuberculosis; the presence of autoantibodies was documented by a large amount of evidence. The role of autoantibodies in pathogenesis of tuberculosis is not quite clear and widely disputed. They are regarded as: (1) a result of imbalanced immune response being reactive in nature, (2) a critical part of TB pathogenicity, (3) a beginning of autoimmune disease, (4) a protective mechanism helping to eliminate microbes and infected cells, and (5) playing dual role, pathogenic and protective. There is no single autoimmunity-mechanism development in tuberculosis; different pathways may be suggested. It may be excessive cell death and insufficient clearance of dead cells, impaired autophagy, enhanced activation of macrophages and dendritic cells, environmental influences such as vitamin D insufficiency, and genetic polymorphism, both of Mycobacterium tuberculosis and host.

Calcifediol for Use in Treatment of Respiratory Disease

Calcifediol is the prohormone of the vitamin D endocrine system (VDES). It requires hydroxylation to move to 1,25(OH)2D3 or calcitriol, the active form that exerts its functions by activating the vitamin D receptor (VDR) that is expressed in many organs, including the lungs. Due to its rapid oral absorption and because it does not require first hepatic hydroxylation, it is a good option to replace the prevalent deficiency of vitamin D (25 hydroxyvitamin D; 25OHD), to which patients with respiratory pathologies are no strangers. Correcting 25OHD deficiency can decrease the risk of upper respiratory infections and thus improve asthma and COPD control. The same happens with other respiratory pathologies and, in particular, COVID-19. Calcifediol may be a good option for raising 25OHD serum levels quickly because the profile of inflammatory cytokines exhibited by patients with inflammatory respiratory diseases, such as asthma, COPD or COVID-19, can increase the degradation of the active metabolites of the VDES. The aim of this narrative revision is to report the current evidence on the role of calcifediol in main respiratory diseases. In conclusion, good 25OHD status may have beneficial effects on the clinical course of respiratory diseases, including COVID-19. This hypothesis should be confirmed in large, randomized trials. Otherwise, a rapid correction of 25(OH)D deficiency can be useful for patients with respiratory disease.

Effect of Vitamin D on Graft-versus-Host Disease

The different cell subsets of the immune system express the vitamin D receptor (VDR). Through the VDR, vitamin D exerts different functions that influence immune responses, as previously shown in different preclinical models. Based on this background, retrospective studies explored the impacts of vitamin D levels on the outcomes of patients undergoing allogeneic hematopoietic stem-cell transplantation, showing that vitamin D deficiency is related to an increased risk of complications, especially graft-versus-host disease. These results were confirmed in a prospective cohort trial, although further studies are required to confirm this data. In addition, the role of vitamin D on the treatment of hematologic malignancies was also explored. Considering this dual effect on both the immune systems and tumor cells of patients with hematologic malignancies, vitamin D might be useful in this setting to decrease both graft-versus-host disease and relapse rates.

The role of Th17 cells/IL-17A in AD, PD, ALS and the strategic therapy targeting on IL-17A

Neurodegenerative diseases are a group of disorders characterized by progressive loss of certain populations of neurons, which eventually lead to dysfunction. These diseases include Alzheimer’s disease (AD), Parkinson’s disease (PD), and amyotrophic lateral sclerosis (ALS). Immune pathway dysregulation is one of the common features of neurodegeneration. Recently, there is growing interest in the specific role of T helper Th 17 cells and Interleukin-17A (IL-17A), the most important cytokine of Th 17 cells, in the pathogenesis of the central nervous system (CNS) of neurodegenerative diseases. In the present study, we summarized current knowledge about the function of Th17/IL-17A, the physiology of Th17/IL-17A in diseases, and the contribution of Th17/IL-17A in AD, PD, and ALS. We also update the findings on IL-17A-targeting drugs as potentially immunomodulatory therapeutic agents for neurodegenerative diseases. Although the specific mechanism of Th17/IL-17A in this group of diseases is still controversial, uncovering the molecular pathways of Th17/IL-17A in neurodegeneration allows the identification of suitable targets to modulate these cellular processes. Therapeutics targeting IL-17A might represent potentially novel anti-neurodegeneration drugs.

Chemical synthesis, biological activities and action on nuclear receptors of 20S(OH)D3, 20S,25(OH)2D3, 20S,23S(OH)2D3 and 20S,23R(OH)2D3

New and more efficient routes of chemical synthesis of vitamin D₃ (D₃) hydroxy (OH) metabolites, including 20S(OH)D₃, 20S,23S(OH)₂D₃ and 20S,25(OH)₂D₃, that are endogenously produced in the human body by CYP11A1, and of 20S,23R(OH)₂D₃ were established. The biological evaluation showed that these compounds exhibited similar properties to each other regarding inhibition of cell proliferation and induction of cell differentiation but with subtle and quantitative differences. They showed both overlapping and differential effects on T-cell immune activity. They also showed similar interactions with nuclear receptors with all secosteroids activating vitamin D, liver X, retinoic acid orphan and aryl hydrocarbon receptors in functional assays and also as indicated by molecular modeling. They functioned as substrates for CYP27B1 with enzymatic activity being the highest towards 20S,25(OH)₂D₃ and the lowest towards 20S(OH)D₃. In conclusion, defining new routes for large scale synthesis of endogenously produced D₃-hydroxy derivatives by pathways initiated by CYP11A1 opens an exciting era to analyze their common and differential activities in vivo, particularly on the immune system and inflammatory diseases.

Vitamin D attenuates COVID-19 complications via modulation of proinflammatory cytokines, antiviral proteins, and autophagy

INTRODUCTION

Global emergence of coronavirus disease-19 (COVID-19) has clearly shown variable severity, mortality, and frequency between and within populations worldwide. These striking differences have made many biological variables attractive for future investigations. One of these variables, vitamin D, has been implicated in COVID-19 with rapidly growing scientific evidence.

AREAS COVERED

The review intended to systematically explore the sources, and immunomodulatory role of vitamin D in COVID-19. Search engines and data sources including Google Scholar, PubMed, NCBI, Scopus, and Web of Science were used for data collection. The search terms used were Vitamin D, COVID-19, immune system, and antiviral mechanism. Overall, 232 sources of information were collected and 188 were included in this review.

EXPERT OPINION

Interaction of vitamin D and vitamin D receptor (VDR) triggers the cellular events to modulate the immune system by regulation of many genes. Vitamin D operates as a double-edged sword against COVID-19. First, in macrophages, it promotes the production of antimicrobial and antiviral proteins like β-defensin 2 and cathelicidin, and these proteins inhibit the replication of viral particles and promote the clearance of virus from the cells by autophagy. Second, it suppresses cytokine storm and inflammatory processes in COVID-19.

The Expression of Inflammasomes NLRP1 and NLRP3, Toll-Like Receptors, and Vitamin D Receptor in Synovial Fibroblasts From Patients With Different Types of Knee Arthritis

Activated rheumatoid arthritis (RA) synovial fibroblasts (SFs) are among the most important cells promoting RA pathogenesis. They are considered active contributors to the initiation, progression, and perpetuation of the disease; therefore, early detection of RASF activation could advance contemporary diagnosis and adequate treatment of undifferentiated early inflammatory arthritis (EA). In this study, we investigated the expression of nucleotide-binding, oligomerization domain (NOD)-like receptor family, pyrin domain containing (NLRP)1, NLRP3 inflammasomes, Toll-like receptor (TLR)1, TLR2, TLR4, vitamin D receptor (VDR), and secretion of matrix metalloproteinases (MMPs) in SFs isolated from patients with RA, osteoarthritis (OA), EA, and control individuals (CN) after knee surgical intervention. C-reactive protein, general blood test, anticyclic citrullinated peptide (anti-CCP), rheumatoid factor (RF), and vitamin D (vitD) in patients’ sera were performed. Cells were stimulated or not with 100 ng/ml tumor necrosis factor alpha (TNF-α) or/and 1 nM or/and 0.01 nM vitamin D3 for 72 h. The expression levels of NLRP1, NLRP3, TLR1, TLR2, TLR4, and VDR in all examined SFs were analyzed by quantitative real-time PCR (RT-qPCR). Additionally, the secretion of IL-1β by SFs and MMPs were determined by ELISA and Luminex technology. The expression of NLRP3 was correlated with the levels of CRP, RF, and anti-CCP, suggesting its implication in SF inflammatory activation. In the TNF-α-stimulated SFs, a significantly lower expression of NLRP3 and TLR4 was observed in the RA group, compared with the other tested forms of arthritis. Moreover, upregulation of NLRP3 expression by TNF-α alone or in combination with vitD3 was observed, further indicating involvement of NLRP3 in the inflammatory responses of SFs. Secretion of IL-1β was not detected in any sample, while TNF-α upregulated the levels of secreted MMP-1, MMP-7, MMP-8, MMP-12, and MMP-13 in all patient groups. Attenuating effects of vitD on the expression of NLRP3, TLR1, and TLR4 suggest potential protective effects of vitD on the inflammatory responses in SFs. However, longer studies may be needed to confirm or fully rule out the potential implication of vitD in SF activation in inflammatory arthritis. Both VDR and NLRP3 in the TNF-α-stimulated SFs negatively correlated with the age of patients, suggesting potential age-related changes in the local inflammatory responses.

Potential role of 25(OH)D insufficiency in the dysfunction of glycolipid metabolism and cognitive impairment in patients with T2DM

PURPOSE

To investigate the changes of plasma 25(OH)D levels in type 2 diabetes mellitus (T2DM) patients and explore its role in the dysfunction of glucose and lipid metabolism and cognition.

METHODS

One hundred and thirty-two T2DM patients were enrolled and the demographic and clinical data were collected. The plasma concentration of 25(OH)D was detected and the patients were divided into two groups including a Vitamin D insufficient (VDI) group and a normal VD group according to the clinical diagnostic criterial of VDI with the plasma 25(OH)D level less than 29 ng/mL. The glycolipid metabolic and routine blood biochemical indices were detected, the plasma concentrations of C-reactive protein (CRP), interleukin-6 (IL-6), soluble myeloid soluble trigger receptor 1 (sTREM1) were measured. The cognitive function was assessed using the Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A). The depressive symptomatology was assessed using the Center for Epidemiological Survey Depression Scale (CES-D). Sleep quality was assessed using the Pittsburgh sleep quality index (PSQI).

RESULTS

There were 70 T2DM patients with VDI (70/132, 53.03%) in this study. The plasma concentrations of glycated hemoglobin (HbA1c), fasting plasma glucose (FPG), postprandial blood glucose (PBG), IL-6, and sTREM1 were remarkably increased in T2DM patients with VDI as compared with that with the normal VD, accompanied with an elevated BRIEF-A scores. There was no significant difference between groups with regard to the indices of blood lipid, liver function, and scores in CES-D and PSQI. Moreover, results of Pearson correlation test showed that the plasma 25(OH)D levels were negatively correlated with HbA1c, FPG, PBG, CRP, IL-6, sTREM1, CES-D sum scores, and PSQI sum scores, but positively correlated with the plasma levels of Serum creatinine (Scr). Furthermore, result of Receiver Operating Characteristic (ROC) curve analysis showed a predictive role of VDI levels in discriminating T2DM patients with higher cognitive impairments, with the sensitivity and specificity being 62.12% and 62.12%, respectively.

CONCLUSION

VDI is harmful for T2DM patients with a significant relation with the hyperglycosemia and cognitive dysfunction.

COVID-19 pneumonia patients with 25(OH)D levels lower than 12 ng/ml are at increased risk of death

Objectives

There is no consensus on specific serum 25-hydroxy vitamin D (25(OH) D) levels associated with higher risk of severe outcome in patients with coronavirus disease 2019 (COVID-19). According to the literature patients with serum 25(OH) D levels <12 ng/ml are clearly deficient at all ages. Our aim was to assess COVID-19 mortality in the settings of severe 25(OH) D deficiency. A cohort study of 357 patients with COVID-19 was conducted. Subjects were monitored until discharge or in-hospital death. At admission, severity parameters (C-reactive protein (CRP), IL-6, Charlson comorbidity index, etc.) were assessed. These parameters were compared regarding 25(OH) D levels threshold 12 ng/ml, where values below 12 ng/ml were considered absolute vitamin D deficiency.

Results

25(OH) D levels at the time of admission were independently associated with mortality (p <0.05). Nonsurvivors (N = 168) had lower 25(OH) D levels, SO2, higher age, CRP, viral load, and Charlson comorbidity index in comparison to survivors. Patients with serum 25(OH) D levels <12 ng/ml had higher mortality (55% vs 45 %), viral load (21.5 vs 23.1), and Charlson comorbidity index (5.3 vs 4.4) than those with serum 25(OH) D levels >12 ng/ml (p <0.05).

Conclusions

Patients with COVID-19 with serum 25(OH) D levels <12 ng/ml have higher mortality. Among other factors, severe vitamin D deficiency likely leads to poor outcome.