Immunomodulatory Role of Vitamin D: A Review

The effect of vitamin D supplementation and vaginal probiotics on fertility in women with recurrent implantation failure: A randomized clinical trial

Recurrent implantation failure (RIF) is a significant obstacle in assisted reproductive technology, affecting approximately 10 % of couples undergoing in vitro fertilization (IVF). Emerging evidence suggests that vaginal probiotics and vitamin D supplementation may improve reproductive outcomes. This randomized clinical trial evaluated the effects of these interventions on fertility in women with RIF and thin endometrium (<6 mm). A total of 112 women with a history of RIF were randomized into four groups: vaginal probiotics, vitamin D supplementation, a combination of both, or standard IVF treatment (control). The primary outcome was the pregnancy rate, confirmed by β-hCG testing and ultrasound. Secondary outcomes included changes in Th1/Th2 ratio, natural killer (NK) cell activity, and cytokine profiles. The combination group demonstrated the highest pregnancy rate (46.4 %), which was significantly higher compared with the probiotics ((14.2 %), p = 0.008), vitamin D ((17.8 %), p = 0.002), and control groups ((10.7 %), p = 0.003). Only the combination therapy significantly reduced the Th1/Th2 ratio (p < 0.001) and NK cell activity (p < 0.001), while significantly increasing IL-4 and TGF-β and decreasing IFN-γ levels (all p < 0.001). These findings suggest that combined vaginal probiotics and vitamin D supplementation may improve pregnancy outcomes by modulating the immune responses in women with RIF. This dual intervention may represent a promising strategy for enhancing fertility in this population of RIF patients.

Vitamin D and Colorectal Cancer Prevention: Immunological Mechanisms, Inflammatory Pathways, and Nutritional Implications

Vitamin D plays a crucial role in the regulation of the immune system, with immunomodulatory effects that are key in the prevention of colorectal cancer (CRC). Over the past decades, research has shown that this steroid hormone impacts much more than bone health, significantly influencing immune responses. Vitamin D enhances immune organ functions such as the spleen and lymph nodes, and boosts T-cell activity, which is essential in defending the body against tumors. Additionally, vitamin D mitigates inflammatory responses closely linked to cancer development, reducing the inflammation that contributes to CRC. It acts via vitamin D receptors (VDRs) expressed on immune cells, modulating immune responses. Adequate vitamin D levels influence gene expression related to inflammation and cell proliferation, inhibiting tumor development. Vitamin D also activates mechanisms that suppress cancer cell survival, proliferation, migration, and metastasis. Low levels of vitamin D have been associated with an increased risk of CRC, with deficiency correlating with higher disease incidence. Lifestyle factors, such as a diet high in red meat and calories but low in fiber, fruits, and vegetables, as well as physical inactivity, contribute significantly to CRC risk. Insufficient calcium and vitamin D intake are also linked to disease occurrence and poorer clinical outcomes. Maintaining optimal vitamin D levels and adequate dietary intake is crucial in preventing CRC and improving patient prognosis. This review explores the role of vitamin D in immune regulation and summarizes findings from randomized clinical trials assessing the effects of vitamin D supplementation on CRC outcomes.

Relation between vitamin D deficiency and Pseudomonas aeruginosa colonization in patients with bronchiectasis

BACKGROUND

The relationship between vitamin D deficiency and Pseudomonas aeruginosa (P. aeruginosa) colonization in bronchiectasis patients is not well understood.

METHODS

This study was conducted at Shanghai Pulmonary Hospital from June 2014 to May 2018. Serum 25-hydroxyvitamin D levels were measured in patients with bronchiectasis, and clinical data including sputum culture results were collected. To investigate the relationship between vitamin D levels and P. aeruginosa colonization, we conducted correlation analysis and logistic regression. Additionally, in vitro experiments with bone marrow-derived macrophages (BMDMs) infected with P. aeruginosa strain PAO1 were performed to further explore the influence of vitamin D on the bacterial infection and inflammatory response.

RESULTS

Among the 195 patients with bronchiectasis, 83.1% (162/195) were vitamin D deficient. A significant negative correlation was observed between serum vitamin D levels and the BSI (Bronchiectasis Severity Index) score. Patients with vitamin D deficiency showed higher rates of P. aeruginosa colonization compared to those with adequate vitamin D levels. Female gender and vitamin D deficiency were identified as risk factors for P. aeruginosa colonization in patients with bronchiectasis. Additionally, serum interleukin (IL)-1β levels were significantly elevated in the vitamin D-deficiency group. In vitro experiments, 1,25-dihydroxyvitamin D [1,25D] was shown to inhibit PAO1 phagocytosis in BMDMs and to suppress IL-1β secretion.

CONCLUSIONS

Vitamin D deficiency was strongly associated with an increased risk of P. aeruginosa colonization in patients with bronchiectasis. Furthermore, vitamin D demonstrated protective effects by reducing P. aeruginosa survival in cells and modulating the inflammatory dysregulation induced by the bacterium.

Unveiling the Link: The Potential Roles of Vitamin D in Keloid Pathophysiology

Keloid disease, a fibroproliferative skin disorder, is characterised by scar tissue growth that extends beyond the original wound boundaries. Despite advancements, current treatments, particularly surgical excision, often result in high recurrence rates, ranging from 45% to 100%. Recent investigations into the role of vitamin D (vit D) in keloids present a promising avenue for novel therapeutic strategies. Studies have highlighted the multifaceted involvement of vit D, including its immunomodulatory effects and influence on key processes such as fibroblast activity, collagen production and extracellular matrix dynamics. Additionally, emerging research has explored the potential impact of vit D on epithelial-to-mesenchymal transition and endothelial dysfunction, both of which are implicated in keloid formation and progression. This review consolidates the current evidence linking vitamin D deficiency to keloid pathogenesis, shedding light on potential mechanisms and therapeutic targets. By elucidating the intricate interplay between vit D signalling and keloid development, this study paves the way for innovative treatment approaches that may enhance patient outcomes and mitigate the burden of this challenging dermatological condition.

Vitamin D can mitigate sepsis-associated neurodegeneration by inhibiting exogenous histone-induced pyroptosis and ferroptosis: Implications for brain protection and cognitive preservation

BACKGROUND

Sepsis-induced neurodegeneration and cognitive dysfunction remain critical challenges worldwide. Vitamin D was reported to reduce neuronal injury and neurotoxicity and its deficiency was associated with neurocognitive disorders. This study investigates the mechanisms by which vitamin D exerts neuroprotective potential against damage-associated molecular patterns (DAMPs), specifically extracellular histones, in sepsis-related brain dysfunction.

METHODS

The cultured mouse hippocampal neuronal HT22 cells were exposed to 20 µg/ml exogenous histone for 24 h to induce pyroptosis and ferroptosis in the presence or absence of the active form of vitamin D, calcitriol (1 nM). A cecal ligation and puncture mouse sepsis model was used to evaluate histone release and pyroptosis/ferroptosis biomarkers in the brain together with neurobehavioral performance with or without calcitriol treatment (1 µg/kg, i.p. injection) at 24 h or 1 week after sepsis onset.

RESULTS

In vitro, histone exposure triggered both pyroptosis and ferroptosis in neuronal cells, which was significantly suppressed by calcitriol treatment with the reduced expression of caspase-1 by 38 %, GSDMD by 30 %, ACSL4 by 33 %, and the increased expression of GPX4 by 35 % (n = 6, P < 0.05). Similarly, in vivo, calcitriol treatment inhibited both neuronal pyroptosis and ferroptosis by reducing expression of pyroptosis marker, GSDMD/NeuN (11.6 ± 1.2 % vs. 19.4 ± 1.1 %) and increasing expression of ferroptosis marker, GPX4/NeuN (21.4 ± 1.7 % vs. 13.5 ± 1.1 %), in the brain of septic mice (n = 6, P < 0.01). In addition, calcitriol increased survival rate (72 % vs. 41 %) and ameliorated cognitive dysfunction of septic mice (n = 8-13, P < 0.05).

CONCLUSIONS

This study demonstrates that vitamin D exerts a neuroprotective effect against sepsis by attenuating histone-induced pyroptosis and ferroptosis. These findings highlight the potential therapeutic role of vitamin D supplementation in mitigating brain dysfunction associated with sepsis which needs for further investigation.

An Observational Study on the Analysis of Vitamin D Deficiency in COVID-19 Patients With No Comorbidities: A Retrospective Analysis

INTRODUCTION

 Vitamin D deficiency is an important problem when facing a viral disease. Vitamin D deficiency is widely prevalent in India and plays an important role in immunoregulation. The deficiency can lead to severe viral infections.

AIMS AND OBJECTIVES

Vitamin D deficiency should be considered an independent risk factor in assessing the severity of COVID-19 infection. This study aims to establish this link. Our study is conducted with young individuals with no comorbidities. This has been done to exclusively evaluate vitamin D deficiency as an independent risk factor.

METHODS

 A retrospective record-based analysis was done on all patients with COVID-19 infection admitted at Max Smart Hospital, Saket, Delhi, from 1st September 2020 to 30th April 2022. Data gathering was done from 18th May 2023 to 30th May 2023. Vitamin D assay was checked as a part of routine care for all patients. The patients were divided into two groups. They consisted of vitamin D-sufficient and vitamin D-deficient patients. The primary endpoint was evaluated based on the outcomes, duration of stay, and severity of disease in these two groups.

RESULTS

 A total of 137 patients who met the inclusion criteria were included in the study. On presentation, 75.2% of patients had mild disease, 10.9% were classified as having moderate severity, and 13.9% had severe disease. The mean duration of hospital stay was 6.94±2.96 days. Vitamin D levels were normal in 31.4% (n=43) and vitamin D deficiency was noted in 68.6% (n=94) of patients. Vitamin D deficiency was reported in 64.9% (n=61, p-value=0.011) in the age group of <50 years and 35.1% (n=33, p-value=0.011) in the >50 years group. It was more frequently seen in male patients (67%, n=63, p-value=0.023) as compared to female patients (33%, n=31, p-value=0.023). Vitamin D deficiency was found in 74.5% (n=70, p-value=0.553) of patients with mild disease, 12.8% (n=12, p-value=0.553) with moderate-severity disease, and 12.8% (n=12, p-value=0.553) with severe disease. None of the patients with normal vitamin D levels required ICU admission on presentation. In the deficient group, 2.1% (n=2, p-value=0.335) of patients required ICU admission. The mean duration of hospital stay in the deficient group was 6.72±2.96 days (p-value=0.204). There was no mortality reported in this study.

CONCLUSION

 Our study does show an increased incidence of moderate and severe disease in patients with vitamin D deficiency. This is in line with the evidence presented by several observational studies and meta-analyses. A specific randomized controlled trial focused on evaluating vitamin deficiency and the incidence of viral illness may be warranted to further evaluate this topic. Vitamin D deficiency is an easily correctable factor.

Nutritional Status Impact on Hip Fracture Patients in a Rural Environment

(1) Background: Hip fractures are highly prevalent traumatic events with significant functional consequences, particularly among the older population. These fractures are associated with increased mortality, postoperative complications, and functional dependence. Medical and nutritional factors such as malnutrition and sarcopenia are crucial for predicting functional outcomes and mortality in these patients. This study aimed to assess the nutritional status, vitamin D levels, and sarcopenia, as well as their relationship with mortality, mean hospital stay, and 30-day-readmission rate, in patients with hip fracture who underwent surgery in a rural hospital setting. (2) Methods: A longitudinal retrospective study involving 124 patients who underwent hip fracture surgery in 2021 was conducted. Sociodemographic, surgical, and nutritional data, including vitamin D, albumin, and blood urea nitrogen (BUN) levels, were collected. (3) Results: The average age of the sample was 89.1 years, with a postoperative 30-day-mortality rate of 8.1% and an average hospital stay of 10.4 days. Vitamin D deficiency was present in 79.7% of patients, and a high prevalence of malnutrition was indicated by low albumin and elevated BUN levels. Elevated BUN levels and low vitamin D levels were associated with higher mortality. (4) Conclusions: Adequate nutritional assessment in patients with hip fracture is vital for identifying the risks of complications and mortality. Understanding the current nutritional status and its associated complications will aid in developing strategies to improve health and reduce complications in the future.

Vitamin D treatment distinctly modulates cytokine production by peripheral blood mononuclear cells among patients with chronic cardiac and indeterminate clinical forms of Chagas disease

INTRODUCTION

Chagas disease is caused by the protozoan Trypanosoma cruzi and is clinically divided into acute and chronic phases. Chronic Chagas cardiomyopathy is the most studied manifestation of the disease. Vitamin D deficiency has been suggested as a risk factor for cardiovascular disease. No studies demonstrate the action of this hormone in the cells of patients with chronic Chagas heart disease.

OBJECTIVE

To evaluate the in vitro immunomodulatory effect of vitamin D on peripheral blood mononuclear cells of patients with the different chronic clinical forms of Chagas disease. Evaluating vitamin D's in vitro effect on blood cells by producing cytokines.

METHODS

Thirteen patients of the undetermined form (IND), 13 of the mild cardiac form (CARD1) and 14 of the severe cardiac form (CARD2) of Chagas disease, and 12 with idiopathic heart disease (CARDid) were included. The cells obtained from peripheral blood were treated in vitro with vitamin D (1 × 10-7 M) for 24 h and cytokines were dosed in the culture supernatant.

RESULTS

Although it was not possible to demonstrate statistically significant differences between the groups studied, our data showed that the cells treated with vitamin D modify (p < .05) the production of interferon-γ (IFN-γ) (decrease in IND), tumor necrosis factor-α (TNF-α) (decreased in CARD1 and CARDid), interleukin (IL)-6 (increased in all groups), and IL-10 (decreased in CARD1, CARD2, and CARDid) when compared to untreated cells.

CONCLUSION

In vitro treatment with vitamin D distinctly modulated the production of cytokines by mononuclear cells of peripheral blood among patients with chronic and indeterminate cardiac clinical forms of Chagas disease.

Exploring the Role of Vitamin D, Vitamin D-Dependent Proteins, and Vitamin D Receptor Gene Variation in Lung Cancer Risk

Lung cancer has an unfavorable prognosis with a rate of low overall survival, caused by the difficulty of diagnosis in the early stages and resistance to therapy. In recent years, there have been new therapies that use specific molecular targets and are effective in increasing the survival chances of advanced cancer. Therefore, it is necessary to find more specific biomarkers that can identify early changes in carcinogenesis and allow the earliest possible treatment. Vitamin D (VD) plays an important role in immunity and carcinogenesis. Furthermore, the vitamin D receptor (VDR) regulates the expression of various genes involved in the physiological functions of the human organism. The genes encoding the VDR are extremely polymorphic and vary greatly between human populations. To date, there are significant associations between VDR polymorphism and several types of cancer, but the data on the involvement of VDR polymorphism in lung cancer are still conflicting. Therefore, in this review, our aim was to investigate the relationship between VDR single-nucleotide polymorphisms in humans and the degree of risk for developing lung cancer. The studies showcased different gene polymorphisms to be associated with an increased risk of lung cancer: TaqI, ApaI, BsmI, FokI, and Cdx2. In addition, there is a strong positive correlation between VD deficiency and lung cancer development. Still, due to a lack of awareness, the assessment of VD status and VDR polymorphism is rarely considered for the prediction of lung cancer evolution and their clinical applicability, despite the fact that studies have shown the highest risk for lung cancer given by TaqI gene polymorphisms and that VDR polymorphisms are associated with more aggressive cancer evolution.

Vitamin D: An Essential Nutrient in the Dual Relationship between Autoimmune Thyroid Diseases and Celiac Disease-A Comprehensive Review

Autoimmune thyroid diseases (AITD) are among the most frequent autoimmune disorders, with a multifactorial etiology in which both genetic and environmental determinants are probably involved. Celiac disease (CeD) also represents a public concern, given its increasing prevalence due to the recent improvement of screening programs, leading to the detection of silent subtypes. The two conditions may be closely associated due to common risk factors, including genetic setting, changes in the composition and diversity of the gut microbiota, and deficiency of nutrients like vitamin D. This comprehensive review discussed the current evidence on the pivotal role of vitamin D in modulating both gut microbiota dysbiosis and immune system dysfunction, shedding light on the possible relevance of an adequate intake of this nutrient in the primary prevention of AITD and CeD. While future technology-based strategies for proper vitamin D supplementation could be attractive in the context of personalized medicine, several issues remain to be defined, including standardized assays for vitamin D determination, timely recommendations on vitamin D intake for immune system functioning, and longitudinal studies and randomized controlled trials to definitely establish a causal relationship between serum vitamin D levels and the onset of AITD and CeD.

Vitamin D and monoclonal gammopathy of undetermined significance (MGUS) among U.S. Black women

PURPOSE

Risk factors for monoclonal gammopathy of undetermined significance (MGUS), the asymptomatic precursor to multiple myeloma, are largely unknown. We hypothesized that low vitamin D levels might be associated with higher MGUS prevalence in a national cohort of U.S. Black women.

METHODS

We screened archived serum samples (collected 2014-2017) from 3896 randomly selected participants in the Black Women's Health Study ages 50-79 for evidence of MGUS; samples had been assayed for 25-hydroxyvitamin D [25(OH)D] shortly after blood draw. We used logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI) for the association between 25(OH)D level and MGUS status, adjusting for age, body mass index, and season of blood draw.

RESULTS

We identified 334 MGUS cases (8.6%) in the study population. The adjusted OR comparing women with vitamin D deficiency (25(OH)D < 20 ng/mL) to those with 25(OH)D levels ≥ 30 ng/mL was 1.27 (95% CI: 0.95, 1.72).

CONCLUSION

MGUS was more prevalent among Black women with vitamin D deficiency compared to those with 25(OH)D ≥ 30 ng/mL; however, the association was not statistically significant. Future prospective studies are warranted to clarify the possible association between vitamin D and MGUS.

Circulating vitamin D level before initiating chemotherapy impacts on the time-to-outcome in metastatic colorectal cancer patients: systematic review and meta-analysis

BACKGROUND

Vitamin D (VD) is implicated in various health conditions, including colorectal cancer (CRC). To investigate potential relationships between pre-chemotherapy VD levels and the time-to-outcome in metastatic CRC patients, we conducted a systematic review and meta-analysis.

METHODS

Following the PRISMA 2020 guidelines, we performed thorough searches in PubMed/MEDLINE and Scopus/ELSEVIER databases (covering the years 2002 to 2022). Inclusion criteria mandated studies to report on individuals aged 18 years and above with histologically confirmed stage IV CRC. Additionally, studies needed to provide data on VD levels before chemotherapy, along with hazard ratios (HR) and 95% confidence intervals (CIs) for overall survival (OS) and/or progression-free survival (PFS). Five articles were identified with the aim of establishing a combined risk estimate for death and progression based on pre-chemotherapy VD levels. Heterogeneity among studies and publication bias were evaluated using Tau2, I2 statistics, and a Funnel plot.

RESULTS

Although no significant heterogeneity was observed in time-to-outcome among the selected studies, variations in technical assessments and serum VD concentration measurements were noted. The pooled analysis, involving 1712 patients for OS and 1264 patients for PFS, revealed a 47% increased risk of death (HR: 1.47, 95% CI: 1.21-1.79) and a 38% increased risk of progression (HR: 1.38, 95% CI: 1.13-1.70) for patients with lower VD levels, as indicated by fixed-effects models.

CONCLUSIONS

Our results emphasize the adverse effects of low VD concentration on the time-to-outcome in metastatic CRC patients. This underscores the importance of investigating VD supplementation as an innovative approach in this clinical setting to enhance patient outcomes.

Vitamin D and Its Role on the Fatigue Mitigation: A Narrative Review

Vitamin D has historically been associated with bone metabolism. However, over the years, a growing body of evidence has emerged indicating its involvement in various physiological processes that may influence the onset of numerous pathologies (cardiovascular and neurodegenerative diseases, rheumatological diseases, fertility, cancer, diabetes, or a condition of fatigue). This narrative review investigates the current knowledge of the pathophysiological mechanisms underlying fatigue and the ways in which vitamin D is implicated in these processes. Scientific studies in the databases of PubMed, Scopus, and Web of Science were reviewed with a focus on factors that play a role in the genesis of fatigue, where the influence of vitamin D has been clearly demonstrated. The pathogenic factors of fatigue influenced by vitamin D are related to biochemical factors connected to oxidative stress and inflammatory cytokines. A role in the control of the neurotransmitters dopamine and serotonin has also been demonstrated: an imbalance in the relationship between these two neurotransmitters is linked to the genesis of fatigue. Furthermore, vitamin D is implicated in the control of voltage-gated calcium and chloride channels. Although it has been demonstrated that hypovitaminosis D is associated with numerous pathological conditions, current data on the outcomes of correcting hypovitaminosis D are conflicting. This suggests that, despite the significant involvement of vitamin D in regulating mechanisms governing fatigue, other factors could also play a role.

Evaluation of the Impact of Serum Vitamin D Levels on the Scoring Atopic Dermatitis Index in Pediatric Atopic Dermatitis

Atopic dermatitis (AD) is a chronic and recurrent inflammatory skin condition characterized by itching, eczematous plaques, and dry skin. Despite ongoing research, its exact cause remains elusive. In this study, we aimed to explore the factors that influence the severity of AD in children and assess the relationship between serum vitamin D levels and the disease's severity. We enrolled 96 AD patients in our investigation, evaluated their clinical condition using the Scoring Atopic Dermatitis (SCORAD) index, and compared them to a group of 90 healthy controls. Our analysis revealed that serum vitamin D levels and eosinophil counts significantly impacted the SCORAD index (p < 0.001). According to standardized regression coefficients, for each incremental unit in serum vitamin D levels, the SCORAD index exhibited a decrease of 0.449 units. Similarly, a one-unit increase in eosinophil count resulted in a 0.009 unit increase in the SCORAD index. It is worth noting that the influence of serum vitamin D levels on disease severity surpasses that of eosinophil counts and atopic conditions. In our patient cohort, we uncovered a negative correlation (r = -0.419, p < 0.001) between serum vitamin D levels and the SCORAD index. Our findings suggest that low serum vitamin D levels may have a more substantial impact on AD severity than atopic conditions and eosinophilia. Furthermore, we observed a negative association between the severity of AD and serum 25(OH)D3 levels.

Osteoporosis and dermatoporosis: a review on the role of vitamin D

Osteoporosis (OP) and Dermatoporosis (DP) are expressions of the aging process at the skin and bone levels, respectively. Both conditions are associated with increased morbidity for elderly people, and this requires necessary interventions. They share many common risk factors; among these, vitamin D (VD) deficiency appears to have a role. VD is involved in either disease with many mechanisms, among which immunomodulation. VD deficiency has been linked to OP because it inhibits the body's capacity to absorb calcium and maintain optimal bone health. Available evidence suggests that proper vitaminosis D also appears to be vital in preventing skin age-related issues. DP is often seen in elderly individuals, particularly those with long-term sun exposure and a history of chronic sun damage. VD deficiency can be linked to DP, since its involvement in collagen production, epidermal barrier function, inflammation regulation, wound healing, and sun protection. Aim of this review is to summarize the most updated existing evidence on the role of VD in the development of fragility syndromes such as DP and OP and the possible benefits of VD supplementation as a simple and harmful weapon against aging.

Vitamin D level in patients with systemic lupus erythematosus: its relationship to disease course and bone mineral density

OBJECTIVE

To determine vitamin D levels in patients with SLE and evaluate their relationship to bone mineral density (BMD) and the disease course.

METHODS

The study included 101 patients with SLE and 29 individuals in the control group. The study participants were tested for vitamin D level, erythrocyte sedimentation rate (ESR), C reactive protein (CRP), interleukin (IL)-6, osteocalcin (OC) and collagen type I C-terminal telopeptide (CTX), and the dual-energy X-ray absorptiometry was provided to assess BMD in the lumbar spine and the hip.

RESULTS

The mean serum vitamin D level was 18.98±0.88 ng/mL, and women had 25.42% lower vitamin D levels than men (p<0.05). There was no correlation between vitamin D levels and patient's age or disease course. There was a significant inverse correlation between vitamin D levels and cumulative dose of glucocorticoids (r=-0.26) and serum inflammatory markers, particularly CRP (r=-0.39), IL-6 (r=-0.37) and ESR (r=-0.15). Vitamin D level was associated with the bone turnover markers (BTMs). In women of reproductive age with vitamin D deficiency, BMD of the lumbar spine and the hip was 9.5-23.1% higher than in those with no vitamin deficiency, respectively, and the mean lumbar spine Z-score in women of reproductive age with vitamin D insufficiency and deficiency was significantly 2.0 and 2.9 times lower than in patients with normal vitamin D level.

CONCLUSIONS

Hypovitaminosis D is quite common in patients with SLE and is associated with high inflammatory activity (SLE Disease Activity Index, ESR, CRP, IL-6), severity of organ damage (Damage Index), cumulative dose of glucocorticoids, BTM changes (decrease in OC, increase in CTX) and BMD decline. Vitamin D status was not associated with the patient's age or disease course.

Vitamin D and miRNA-155 in Behçet's Disease: Possible Association with the Disease and Disease Activity

Background

Vitamin D (vit D) controls inflammation and immunity. In Behçet's disease (BD), microRNA-155 is recognized as a significant immune response regulator. We aimed to investigate the role of vit D on immunomodulation and downregulation of inflammatory pathways associated with BD and detect the role of miRNA-155 in BD.

Methods

miRNA-155 expression by Real Time -Polymerase Chain Reaction (RT-PCR), and vit D, nuclear factor Kappa-light-chain-enhancer of activated B cells (NF-κB), and Tumor necrosis fact of TNF-α) expression by Enzyme Linked Immunosorbent Assay (ELISA) were assessed.

Results

BD patients had a significantly higher relative expression of microRNA-155 (P< 0.001), it was significantly related to vascular manifestations (P< 0.001). Vit D relative expression was significantly low in BD (P< 0.001). There was a significant rise in miRNA-155 in the active group compared to the inactive group (P< 0.001). A significant decrease in vit D levels (IU) was found in inactive and active individuals suffering from BD when compared to controls (P< 0.001). A significant rise was found in vit D levels in inactive BD cases (P< 0.001). A significant positive correlations were found between miRNA-155, NF-κB, TNF-α, and negative correlations with vit D relative expression in BD patients.

Conclusions

miRNA-155 relative expression is higher in BD is significantly related to vascular manifestations. It may have a relationship to disease activity. Vitamin D relative expression is significantly low in BD patients, which can significantly influence immunomodulatory BD therapy. Vitamin D deficiency linked to active BD.

Vitamin D/vitamin D receptor pathway in non-alcoholic fatty liver disease

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide, but underlying mechanisms are not fully understood. In recent years, a growing body of evidence has emphasized the therapeutic role of vitamin D in NAFLD, but the specific mechanism remains to be investigated.

AREAS COVERED

This review summarized the roles of vitamin D/VDR (vitamin D receptor) pathway in different types of liver cells (such as hepatocytes, hepatic stellate cells, liver macrophages, T lymphocytes, and other hepatic immune cells) in case of NAFLD. Meanwhile, the effects of pathways in the gut-liver axis, adipose tissue-liver axis, and skeletal muscle-liver axis on the development of NAFLD were further reviewed. Relevant literature was searched on PubMed for the writing of this review.

EXPERT OPINION

The precise regulation of regional vitamin D/VDR signaling pathway based on cell-specific or tissue-specific function will help clarify the potential mechanism of vitamin D in NAFLD, which may provide new therapeutic targets to improve the safety and efficacy of vitamin D based drugs.

Circulating Vitamin D Level and Its Impact on Mortality and Recurrence in Stage III Colorectal Cancer Patients: A Systematic Review and Meta-Analysis

BACKGROUND

Vitamin D (VD) has been implicated in several diseases, including colorectal cancer (CRC). This study aimed to determine whether there is an association between VD levels and time-to-outcome in stage III CRC patients through a systematic review and meta-analysis.

METHODS

The study adhered to the PRISMA 2020 statement. Articles were searched in PubMed/MEDLINE and Scopus/ELSEVIER. Four articles were selected, with the primary objective of providing a pooled estimate of the risk of death specifically in stage III CRC patients based on pre-operative VD levels. Study heterogeneity and publication bias were analyzed using Tau2 statistics and funnel plots.

RESULTS

The selected studies showed significant heterogeneity regarding time-to-outcome, technical assessments, and serum VD concentration measures. The pooled analysis of 2628 and 2024 patients revealed a 38% and 13% increase in the risk of death (HR: 1.38, 95% CI: 0.71-2.71) and recurrence (HR: 1.13; 95% CI: 0.84-1.53), respectively, for random-effects models among patients with lower levels of VD.

CONCLUSIONS

Our findings suggest that a low concentration of VD has a significant negative impact on time-to-outcome in stage III CRC.

Role of in vitamin D in irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common chronic functional gastrointestinal disorder affecting 10%-22% of adults. Its development is closely related to the gut microbiota, and the inflammatory and immune responses triggered by the gut microbiota can lead to IBS. Vitamin D (VD) effectively treats IBS with fewer side effects by improving gut microbiota, immune regulation, and anti-inflammatory effects. In the future, it is necessary to carry out epidemiological studies on the relationship between VD and IBS, clinical studies on the efficacy of supplementing VD to improve IBS, and animal studies on the mechanism of VD improving IBS. Therefore, this paper discussed the relationship between VD and IBS.

COVID-19 and Multiple Sclerosis: A Complex Relationship Possibly Aggravated by Low Vitamin D Levels

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an exceptionally transmissible and pathogenic coronavirus that appeared at the end of 2019 and triggered a pandemic of acute respiratory disease, known as coronavirus disease 2019 (COVID-19). COVID-19 can evolve into a severe disease associated with immediate and delayed sequelae in different organs, including the central nervous system (CNS). A topic that deserves attention in this context is the complex relationship between SARS-CoV-2 infection and multiple sclerosis (MS). Here, we initially described the clinical and immunopathogenic characteristics of these two illnesses, accentuating the fact that COVID-19 can, in defined patients, reach the CNS, the target tissue of the MS autoimmune process. The well-known contribution of viral agents such as the Epstein-Barr virus and the postulated participation of SARS-CoV-2 as a risk factor for the triggering or worsening of MS are then described. We emphasize the contribution of vitamin D in this scenario, considering its relevance in the susceptibility, severity and control of both pathologies. Finally, we discuss the experimental animal models that could be explored to better understand the complex interplay of these two diseases, including the possible use of vitamin D as an adjunct immunomodulator to treat them.

Vitamin D3 Metabolism and Its Role in Temporomandibular Joint Osteoarthritis and Autoimmune Thyroid Diseases

The aim of this review was to present the metabolism of vitamin D3, as well as to discuss the role of vitamin D3 in bone metabolism, temporomandibular joint osteoarthritis (TMJ OA), and autoimmune thyroid diseases (AITD) on the basis of the literature. Vitamin D3 plays a significant role in human health, as it affects the calcium-phosphate balance and regulates the bone metabolism. Calcitriol impresses the pleiotropic effect on human biology and metabolism. Its modulative function upon the immune system is based on the reduction of Th1 cell activity and increased immunotolerance. Vitamin D3 deficiency may lead to an imbalance in the relationship between Th1/Th17 and Th2, Th17/Th reg, and is considered by some authors as one of the possible backgrounds of autoimmune thyroid diseases (AITD), e.g., Hashimoto's thyroiditis or Graves' disease. Moreover, vitamin D3, through its direct and indirect influence on bones and joints, may also play an important role in the development and progression of degenerative joint diseases, including temporomandibular joint osteoarthritis. Further randomized, double blind studies are needed to unequivocally confirm the relationship between vitamin D3 and abovementioned diseases and to answer the question concerning whether vitamin D3 supplementation may be used in the prevention and/or treatment of either AITD or OA diseases.

Vitamin D Deficit as Inducer of Adenotonsillar Hypertrophy in Children with Obstructive Sleep Apnea-A Prospective Case-Control Study

(1) Objective: This prospective case-control study aimed to assess the level of serum vitamin D comparing pediatric non-allergic patients with obstructive sleep apnea (OSA) and healthy controls. (2) Methods: The period of the enrollment was from November 2021 to February 2022. Children with uncomplicated OSA caused by adenotonsillar hypertrophy (ATH) were recruited. Allergy was excluded by skin prick test (SPT), and the determination of serum IgE level using ELISA test. Plasma concentration of 25-hydroxy vitamin D (25-OHD) was quantitatively determined; then, the vitamin D concentration in patients was compared with healthy controls matched for sex, age, ethnicity, and characteristics. (3) Results: Plasma 25-OHD levels were significantly lower in patients than in healthy subjects (mean 17 ng/mL, 6.27 DS, range 6-30.7 ng/mL, vs. mean 22 ng/mL, 9.45 DS, range 7-41.2 ng/ ml; p < 0.0005). The prevalence of children with vitamin D deficiency was significantly higher in the ATH group than controls. The plasma 25-OHD level did not change following the ATH clinical presentation (III or IV grade according to the Brodsky scale), while the different categories of 25-OHD status (insufficiency, deficiency, and adequacy) in the ATH group were statistically significantly different (p < 0.001) from healthy controls. (4) Conclusions: This study identified statistically significant differences between the ATH group and control regarding the plasma concentration of vitamin D; this data, despite not being directly linkable to the lymphoid tissue hypertrophy (p-value not significant), might suggest a negative effect of vitamin D deficit on the immune system.

Darkness hormone or daylight hormone in women with systemic lupus erythematosus?

INTRODUCTION

In this study, it was aimed to compare the effects of both melatonin and 25-hydroxyvitamin D3, defined as an immune modulator, on laboratory diagnostic criteria parameters and disease activity in patients with systemic lupus erythematosus (SLE).

METHODS

The study included 56 women with SLE and 40 healthy women (control group). Melatonin and 25-hydroxyvitamin D3 levels of patients and healthy individuals included in the study were examined. In addition, leukocytes, lymphocytes, platelets, C3, C4, anti-double-stranded DNA (Anti-dsDNA), antinuclear antibody, and SLE disease activity index (SLEDAI) were analyzed in women with SLE. Patients were divided into four subgroups according to SLEDAI.

RESULTS

Melatonin and 25-hydroxyvitamin D3 levels of women with SLE were lower than healthy women (p < 0.001). Both melatonin and 25-hydroxyvitamin D3 levels were not correlated with laboratory diagnostic criteria parameters. Only 25-hydroxyvitamin D3 levels were correlated with leukocyte levels (p < 0.01). There was no significant difference between the melatonin levels of the subgroups. The 25-hydroxyvitamin D3 levels of the subgroup without disease activity were higher than levels of the subgroups with disease activity (p < 0.05). There was a negative correlation between SLEDAI score and 25-hydroxyvitamin D3 levels (p < 0.05).

CONCLUSION

Women with SLE had lower melatonin and 25-hydroxyvitamin D3 levels than healthy women. On the other hand, parameters of laboratory diagnostic criteria of SLE disease were not related. Only 25-hydroxyvitamin D3 levels were inversely related leukocyte levels. SLE disease activity was not correlated with melatonin levels but negatively correlated with 25-hydroxyvitamin D3 levels. Key Points • Women with SLE have low levels of melatonin and 25-hydroxyvitamin D3. • Melatonin and 25-hydroxyvitamin D3 levels are not related to the laboratory diagnostic criteria parameters for SLE disease. • Low levels of melatonin and 25-hydroxyvitamin D3 may be a factor in the unbalanced immune system of SLE. • Supplementation of melatonin and 25-hydroxyvitamin D3 may be recommended for women patients with SLE.

Vitamin D Supplementation Practices among Multiple Sclerosis Patients and Professionals

Vitamin D serum level increase is associated with a reduction in clinical relapse rate, gadolinium-enhancing lesions, new or enlarging T2 lesions and new active lesions in the MRI in MS patients. However, current RCTs assessing the vitamin D supplementation therapeutic effect in MS provide inconclusive results. Experts recommend vitamin D measurements and implementations among patients with MS. This article discusses an observational study, performed without any intervention to evaluate the vitamin D status and practices among MS patients and professionals in the clinical setting. A total of 139 patients with MS treated by disease-modifying therapy were recruited and fulfilled the standardized questionnaire assessing the vitamin D supplementation practices and vitamin D level influencing factors such as education, insolation, smoking, obesity and current treatment. The collected data were then compared to the patients' vitamin D serum levels available in medical records at the baseline and after 12 months of observation. Professionals' practices and recommendations were also assessed. A total of 74.1% patients confirmed vitamin D supplementation, and all patients were administered cholecalciferol, taken orally. However, only 43.69% of the patients achieved an optimal vitamin D concentration (30-50 ng/mL). The lack of a doctor's recommendation was the most frequent reason for the absence of vitamin D supplementation. The most often recommended vitamin D daily dose was 4000 IU. There was no adverse effect of supplementation observed. Vitamin D status in patients with MS is currently better than in the general population, but still, a significant percentage of patients do not implement vitamin D.

Modulation of immunological responses by aqueous extract of Datura stramonium L. seeds on cyclophosphamide-induced immunosuppression in Wistar rats

BACKGROUND

Datura stramonium L. (Solanaceae) is used traditionally in west Africa to treat asthma, epilepsy, rheumatoid arthritis, filariasis microbial infections and conjunctivitis. This study investigated the immunomodulatory effects of aqueous seed extract of D. stramonium L. (ASEDS) on Wistar rats.

METHODS

Thirty Wistar albino rats (180-200 g) were randomized into 6 groups (n = 5). Group 1 received distilled water only. Rats in groups 2-6 were pretreated with 10 mg/kg body weight (b.w.) Cyclophosphamide orally for 27-days to induce immunosuppression. Thereafter, they received treatment orally for 28 days as follows: Group 2 (distilled water), group 3 (5 mg/kg b.w. Levamisole), groups 4-6 (60, 90 and 120 mg/kg b.w. ASEDS, respectively). HPLC was used to determine major compounds in ASEDS. The effects of ASEDS on immune cells, immunoglobulins A, G and M levels, lipoproteins, and antioxidant status of rats were evaluated.

RESULTS

ASEDS indicated high content of Acutumine, Quinine, Catechin, Chlorogenic acid, Gallic acid, Quercetin, Vanillic acid, Luteolin, Formosanin C, Saponin, Cyanidin, Tannic acid, 3-Carene, Limonene and α-terpineol. Cyclophosphamide triggered significant (p < 0.05) reduction in total leucocyte count and differentials, IgA, IgG, high-density lipoproteins (HDL), catalase, superoxide dismutase, glutathione peroxidase, vitamins A, C and E levels of untreated rats. Administration of ASEDS led to significant (p < 0.05) improvement in immune cell counts, immunoglobulin synthesis, high-density lipoprotein concentration, and antioxidant status of rats in the treated groups.

CONCLUSIONS

The results obtained from the study showed the immunomodulatory activity of ASEDS, thereby indicating its potential in immunostimulatory drug discovery.

Immunoceuticals: Harnessing Their Immunomodulatory Potential to Promote Health and Wellness

Knowledge that certain nutraceuticals can modulate the immune system is not new. These naturally occurring compounds are known as immunoceuticals, which is a novel term that refers to products and systems that naturally improve an individual's immuno-competence. Examples of immunoceuticals include vitamin D3, mushroom glycans, flavonols, quercetin, omega-3 fatty acids, carotenoids, and micronutrients (e.g., zinc and selenium), to name a few. The immune system is a complex and highly intricate system comprising molecules, cells, tissues, and organs that are regulated by many different genetic and environmental factors. There are instances, such as pathological conditions, in which a normal immune response is suboptimal or inappropriate and thus augmentation or tuning of the immune response by immunoceuticals may be desired. With infectious diseases, cancers, autoimmune disorders, inflammatory conditions, and allergies on the rise in both humans and animals, the importance of the use of immunoceuticals to prevent, treat, or augment the treatment of these conditions is becoming more evident as a natural and often economical approach to support wellness. The global nutraceuticals market, which includes immunoceuticals, is a multi-billion-dollar industry, with a market size value of USD 454.55 billion in 2021, which is expected to reach USD 991.09 billion by 2030. This review will provide an overview of the immune system, the importance of immunomodulation, and defining and testing for immunocompetence, followed by a discussion of several key immunoceuticals with clinically proven and evidence-based immunomodulatory properties.

Determinants of Dietary Vitamin D Intake in Population-Based Cohort Sample of Polish Female Adolescents

Vitamin D has a pleiotropic effect and its deficiency is a risk factor for many diseases. The purpose of this study was to analyze the dietary intake of vitamin D and the factors determining this intake by female post-primary school students in Poland. The study was conducted on a nationwide sample of 4469 female Polish adolescents (aged 14-20) recruited from all regions across Poland. The vitamin D intake was assessed using VIDEO-FFQ (Vitamin D Estimation Only-Food Frequency Questionnaire). The median dietary vitamin D intake was 2.33 μg per day and it was lower than the 15 μg recommended in Poland for more than 98% of the group. The highest vitamin D intake per day was noted for fish (0.52 μg), whereas the lowest was noted for fats (0.04 μg). Factors that influenced the dietary vitamin D intake were the amount and species of fish consumed, region of residence, use of vitamin D supplements, and vegetarian or vegan diets. In contrast, vitamin D intake did not depend on body mass index and age. Based on the results of the survey, it can be concluded that the alarmingly low intake of vitamin D by Polish female adolescents is a result of the limited supply of vitamin D primarily from fish and fish products. This may be due to insufficient nutritional knowledge, indicating an urgent need to educate the surveyed population in this area.

Oxidative Stress Induced by High Salt Diet—Possible Implications for Development and Clinical Manifestation of Cutaneous Inflammation and Endothelial Dysfunction in Psoriasis vulgaris

Although oxidative stress is recognized as an important effector mechanism of the immune system, uncontrolled formation of reactive oxygen and nitrogen species promotes excessive tissue damage and leads to disease development. In view of this, increased dietary salt intake has been found to damage redox systems in the vessel wall, resulting in endothelial dysfunction associated with NO uncoupling, inflammation, vascular wall remodeling and, eventually, atherosclerosis. Several studies have reported increased systemic oxidative stress accompanied by reduced antioxidant capacity following a high salt diet. In addition, vigorous ionic effects on the immune mechanisms, such as (trans)differentiation of T lymphocytes are emerging, which together with the evidence of NaCl accumulation in certain tissues warrants a re-examination of the data derived from in vitro research, in which the ionic influence was excluded. Psoriasis vulgaris (PV), as a primarily Th17-driven inflammatory skin disease with proven inflammation-induced accumulation of sodium chloride in the skin, merits our interest in the role of oxidative stress in the pathogenesis of PV, as well as in the possible beneficial effects that could be achieved through modulation of dietary salt intake and antioxidant supplementation.

Vitamin D supplementation for irritable bowel syndrome: A systematic review and meta-analysis

BACKGROUND AND AIM

Irritable bowel syndrome (IBS) is a prevalent and complex gastrointestinal disorder characterized by chronic abdominal pain and altered bowel habits. Observational studies have suggested a relationship between serum vitamin D levels and IBS symptoms. This systematic review and meta-analysis aimed to investigate the clinical effects of vitamin D supplementation on IBS symptom severity and quality of life (QoL) measures.

METHODS

Medline, Embase, Scopus, Web of Science, and The Cochrane Library databases were systematically searched. Data abstraction and quality assessment were conducted by four authors independently, and discrepancies were resolved through consensus from the senior author. Continuous data were pooled with standardized mean difference (SMD) using the DerSimonian and Laird's random-effects model. Sensitivity analysis by risk of bias and potentially "predatory" publication were performed as well.

RESULTS

A total of 685 patients across eight studies were included in the meta-analysis. Vitamin D supplementation significantly improved IBS symptom severity scale scores, with a SMD of -0.77 (95% confidence interval [CI] -1.47 to -0.07, P = 0.04, I2  = 91%). Improvements in IBS-QoL scores were also observed, albeit not statistically significant (SMD 0.54; 95% CI -0.34 to 1.41, P = 0.15, I2  = 87%). However, small sample sizes, a relatively young study population, limited ethnicities, and varied vitamin D dosing strategies across the studies were notable limitations.

CONCLUSIONS

Vitamin D supplementation could be part of our clinical armamentarium when managing IBS patients due to the potential efficacy and good safety profile. Further randomized, controlled trials are required to confirm the therapeutic effects.

Plasma Vitamin D (25-Hydroxyvitamin D) Levels in Hispaniolan Amazon Parrots (Amazona ventralis) Housed Indoors Over Time

Vitamin D is a hormone that can be ingested or synthesized in the body when skin is exposed to ultraviolet radiation (UV), typically from sunlight. In captivity, birds with no sunlight exposure may develop vitamin D deficiencies that may contribute to hypocalcemic conditions, even when fed a diet supplemented with vitamin D. An initial pilot study with Hispaniolan Amazon parrots (Amazona ventralis) conducted approximately 18 mo prior indicated there were significant differences in the 25-hydroxyvitamin D (vit D) plasma levels between the resident parrots (indoor-only housing) and a new group of historically outdoor-housed parrots (new parrots) 5 days after the arrival of the latter at our institution. The goals of this study were to determine if vit D, ionized calcium (Ca²⁺), and ionized magnesium (Mg²⁺) levels changed from baseline values (taken 18 mo prior) in the new birds as well as to compare those values to those of the resident birds over time. The treatment was a change in husbandry for the new parrots (no UV exposure and diet as provided for the resident parrots). To accomplish this, the authors compared vit D levels in the same two groups of birds that were fed the same vit D-fortified diet and given no access to natural or artificial UV light exposure for 18 mo. The resident parrots (N = 9) had been housed indoors for approximately 20 yr with no exposure to natural or supplemented UV light. The second group of birds (new parrots; N = 8) had been housed outdoors prior to the initiation of the pilot study in 2016 and were fed a similar-but not identical-diet prior to their arrival. Plasma samples were sent to the Michigan State University Diagnostic Center for Population and Animal Health for analysis. Test results demonstrated differences between the two groups of parrots, largely attributed to the decrease in vit D plasma levels in the new parrots over time to values equivalent to those measured in the resident birds. Differences were seen in plasma Ca²⁺, while no differences were demonstrated relative to Mg²⁺. We discuss these findings and suggest that plasma vit D levels decrease in the absence of UV light, even when animals are maintained on a vit D-fortified and balanced diet.

Vitamin D Supplementation in Patients with Juvenile Idiopathic Arthritis

Vitamin D has been implicated in the pathogenesis of skeletal disorders and various autoimmune disorders. Vitamin D can be consumed from the diet or synthesized in the skin upon ultraviolet exposure and hydroxylation in the liver and kidneys. In its bioactive form, vitamin D exerts a potent immunomodulatory effect and is important for bone health. Juvenile idiopathic arthritis (JIA) is a collection of inflammatory joint diseases in children that share the manifestation of inflamed synovium, which can result in growth arrest, articular deformity, bone density loss, and disability. To evaluate the potential effect of vitamin D on JIA disease manifestations and outcomes, we review the role of vitamin D in bone metabolism, discuss the mechanism of vitamin D in modulating the innate and adaptive immune systems, evaluate the clinical significance of vitamin D in patients with JIA, and summarize the supplementation studies.

COVID-19 and Micronutrient Deficiency symptoms – is there some overlap?

Background & aims

COVID-19 is highly inflammatory and when it affects the elderly who have multiple comorbidities, the risk of malnutrition is high. The aim of this review is to highlight the evidence for COVID-19 and risk for malnutrition (macro- and micro-nutrient deficiency) sharing two case reports.

Methods

We report two cases of patients with COVID-19. The first case includes a 75-year-old male with increasing confusion, delirium and malnutrition once he had clinically resolved from his COVID-19 diagnosis. The patient had a number of comorbidities and was treated with diuretics before and after his hospital admission. He was treated with intravenous thiamine and enteral nutrition. The second case includes a 77-year-old male with diabetes who presented with suspected vitamin C deficiency likely due to chronic aspirin use nearly two weeks prior to being diagnosed with pneumonia and COVID-19. The patient recovered from his COVID-19 diagnosis but continued to decline nutritionally and was readmitted sixty days later with failure to thrive.

Results

The first case had significant improvements in his appetite and neurological conditions following thiamine infusion and enteral nutrition and was discharged to home after a 19-day hospital stay. The second case presented with a vitamin C deficiency before testing positive for COVID-19. Although he did recover from COVID-19 he struggled to meet nutritional needs post-COVID and passed away 60 days after his COVID-19 diagnosis with pneumonia and failure to thrive.

Conclusion

Elderly patients with chronic diseases who use nutrient depleting medications are particularly high risk for micronutrient deficiency when they also experience the inflammatory insult of COVID-19. Patients who continue to have poor nutrition intake even after they appear to be clinically resolved from the virus should be closely monitored.

Are Low Serum Vitamin D Levels a Risk Factor for Advent of COVID-19 Associated Rhinocerebral Mucormycosis: A Preliminary Case Control Study

To determine whether low serum vitamin D level is a risk factor for development of Rhinocerebral mucormycosis in COVID-19 afflicted patients. A case control study was conducted in a tertiary care hospital utilizing the archived records of COVID-19 afflicted Rhinocerebral mucormycosis cases and age and gender matched controls. The mean value (± standard deviation) of vitamin D level in patients with Mucormycosis was 19.65 ± 13.07 ng/ml and in control subjects it was 27.88 ± 18.04 ng/ml.There was a significant difference between groups (p = 0.02). Thus, low Vitamin D level may be implicated as a risk factor for the advent of mucormycosis in a COVID-19 afflicted patient and therefore Vitamin D supplements may be provided to such patients to achieve normal serum levels.

Essential metals, vitamins and antioxidant enzyme activities in COVID-19 patients and their potential associations with the disease severity

The role of micronutrient deficiency in the pathogenesis of COVID-19 has been reviewed in the literature; however, the data are limited and conflicting. This study investigated the association between the status of essential metals, vitamins, and antioxidant enzyme activities in COVID-19 patients and disease severity. We recruited 155 patients, who were grouped into four classes based on the Adults guideline for the Management of Coronavirus Disease 2019 at King Faisal Specialist & Research Centre (KFSH&RC): asymptomatic (N = 16), mild (N = 49), moderate (N = 68), and severe (N = 22). We measured serum levels of copper (Cu), zinc (Zn), selenium (Se), vitamin D₃, vitamin A, vitamin E, total antioxidant capacity, and superoxide dismutase (SOD). Among the patients, 30%, 25%, 37%, and 68% were deficient in Se (< 70.08 µg/L), Zn (< 0.693 µg/mL), vitamin A (< 0.343 µg/mL), and vitamin D₃ (< 20.05 µg/L), respectively, and SOD activity was low. Among the patients, 28% had elevated Cu levels (> 1.401 µg/mL, KFSH&RC upper reference limit). Multiple regression analysis revealed an 18% decrease in Se levels in patients with severe symptoms, which increased to 30% after adjusting the model for inflammatory markers. Regardless of inflammation, Se was independently associated with COVID-19 severity. In contrast, a 50% increase in Cu levels was associated with disease severity only after adjusting for C-reactive protein, reflecting its possible inflammatory and pro-oxidant role in COVID-19 pathogenesis. We noted an imbalance in the ratio between Cu and Zn, with ~ 83% of patients having a Cu/Zn ratio > 1, which is an indicator of inflammation. Cu-to-Zn ratio increased to 45% in patients with mild symptoms and 34%–36% in patients with moderate symptoms compared to asymptomatic patients. These relationships were only obtained when one of the laboratory parameters (lymphocyte or monocyte) or inflammatory markers (neutrophil-to-lymphocyte ratio) was included in the regression model. These findings suggest that Cu/Zn might further exacerbate inflammation in COVID-19 patients and might be synergistically associated with disease severity. A 23% decrease in vitamin A was seen in patients with severe symptoms, which disappeared after adjusting for inflammatory markers. This finding may highlight the potential role of inflammation in mediating the relationship between COVID-19 severity and vitamin A levels. Despite our patients’ low status of Zn, vitamin D₃, and antioxidant enzyme (SOD), there is no evidence of their role in COVID-19 progression. Our findings reinforce that deficiency or excess of certain micronutrients plays a role in the pathogenesis of COVID-19. More studies are required to support our results.

Vitamin D deficiency: concern for rheumatoid arthritis and COVID-19?

Vitamin D is an immunomodulatory hormone with an established role in calcium and phosphate metabolism and skeletal mineralization. Evidence showing its immunological benefits by regulating essential components of the innate and adaptive immune system is prevalent. Vitamin D deficiency is reported worldwide and is thereby found to be associated with various immune-related diseases. Rheumatoid Arthritis and COVID-19 are two such diseases, sharing a similar hyperinflammatory response. Various studies have found an association of lower Vitamin D levels to be associated with both these diseases. However, contrasting data is also reported. We review here the available scientific data on risk factor association and supplementation benefits of Vitamin D in Rheumatoid Arthritis and COVID-19, intending to critically evaluate the literature.

Vitamin D Actions: The Lung Is a Major Target for Vitamin D, FGF23, and Klotho

Vitamin D is well known for its role as a calcium regulator and in maintenance of phosphate homeostasis in musculoskeletal health, and fibroblast growth factor 23 (FGF23) and its coreceptor α-klotho are known for their roles as regulators of serum phosphate levels. However, apart from these classical actions, recent data point out a relevant role of vitamin D and FGF23/klotho in lung health. The expression of the vitamin D receptor by different cell types in the lung and the fact that those cells respond to vitamin D or can locally produce vitamin D indicate that the lung represents a target for vitamin D actions. Similarly, the presence of the four FGF receptor isoforms in the lung and the ability of FGF23 to stimulate pulmonary cells support the concept that the lung is a target for FGF23 actions, whereas the contribution of klotho is still undetermined. This review will give an overview on how vitamin D or FGF23/klotho may act on the lung and interfere positively or negatively with lung health. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

The Effects of Vitamin D on the Expression of IL-33 and Its Receptor ST2 in Skin Cells; Potential Implication for Psoriasis

Interleukin 33 (IL-33) belongs to the IL-1 family and is produced constitutively by epithelial and endothelial cells of various organs, such as the skin. It takes part in the maintenance of tissue homeostasis, repair, and immune response, including activation of Th2 lymphocytes. Its involvement in pathogenesis of several inflammatory diseases including psoriasis was also suggested, but this is not fully understood. The aim of the study was to investigate expression of IL-33 and its receptor, ST2, in psoriasis, and the effects of the active form of vitamin D (1,25(OH)2D3) on their expression in skin cells. Here we examined mRNA and protein profiles of IL-33 and ST2 in 18 psoriatic patients and healthy volunteers by qPCR and immunostaining techniques. Potential effects of 1,25(OH)2D3 and its receptor (VDR) on the expression of IL-33 and ST2 were tested in cultured keratinocytes, melanocytes, fibroblasts, and basal cell carcinoma cells. It was shown that 1,25(OH)2D3 effectively stimulated expression of IL-33 and its receptor ST2's mRNAs in a time-dependent manner, in keratinocytes and to the lesser extends in melanocytes, but not in fibroblasts. Furthermore, the effect of vitamin D on expression of IL-33 and ST2 was VDR-dependent. Finally, we demonstrated that the expression of mRNA for IL-33 was mainly elevated in the psoriatic skin but not in its margin. Interestingly, ST2 mRNA was downregulated in psoriatic lesion compared to both marginal tissue as well as healthy skin. Our data indicated that vitamin D can modulate IL-33 signaling, opening up new perspectives for our understanding of the mechanism of vitamin D action in psoriasis therapy.

Impact of Vitamin D Supplementation on Multiple Sclerosis

Multiple sclerosis (MS) is an autoimmune disease affecting a large number of people every year. The exact causal factor for this disease is unclear, but it commonly affects middle-aged women, with known triggers like stress, childbirth, infections, poor diet, lack of sleep, etc.

Many epidemiological studies have indicated that various genetic abnormalities are also critical drivers of the onset of MS. The major risk factors of MS identified include hypovitaminosis D while environmental protective factors include allele HLA DRB1 1501, obesity, Epstein-Barr virus infection, sexual hormones, and smoking.

Our article explores the correlation between the deficiency of vitamin D and the onset and progression of MS. The study uses a systematic review methodology by researching and reviewing scholarly articles exploring the topic. We conducted online searches of literature on Google Scholar and PubMed using the keywords "vitamin D deficiency" and "multiple sclerosis" and accessed the relevant secondary literature sources for review. The variables under study included vitamin D insufficiency as the dependent variable while MS was the independent variable. Causal variables included environmental, genetic, and protective factors.

We hypothesized that there is indeed a correlation between vitamin D deficiency and MS. The findings from our review indicate a strong correlation between the insufficiency of vitamin D and the onset and progression of MS. These results are essential in devising interventions to accomplish primary and secondary prevention of MS, as well as integrating vitamin D supplementation in current treatment protocols for MS.

Hypovitaminosis D Is Associated with Higher Levels of Inflammatory Cytokines and with HAM/TSP in HTLV-Infected Patients

Recent studies have shown the effects of vitamin D on host response to infectious diseases. Some studies detected a high prevalence of hypovitaminosis D in HIV-infected patients, but scarce information exists for HTLV-1 infection. We conducted a cross-sectional study to evaluate the frequency of hypovitaminosis D in HTLV-1 patients and its relationship with their immune response in HTLV-infected patients and in age- and gender-matched controls at a Brazilian rehabilitation hospital. We compared vitamin D, interleukin-6 (IL-6), tumoral necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) levels across groups. Logistic regression was utilized to assess the association between hypovitaminosis D and cytokine levels. We enrolled 161 HTLV-infected subjects (129 HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients, 32 asymptomatic HTLV carriers) and equal number of HTLV-negative controls. We observed a significantly higher prevalence of hypovitaminosis D in patients with HAM/TSP than in HTLV asymptomatic carriers (p < 0.001), or controls (p < 0.001). HAM/TSP patients also had higher levels of IL-6 and IFN-γ than asymptomatic carriers. Patients with HAM/TSP and hypovitaminosis D had higher levels of TNF-α than asymptomatic HTLV carriers. These findings suggest hypovitaminosis D plays a role in HAM/TSP pathogenesis, and it needs to be evaluated in further studies.

The Effects of Vitamin D on Immune System and Inflammatory Diseases

Immune cells, including dendritic cells, macrophages, and T and B cells, express the vitamin D receptor and 1α-hydroxylase. In vitro studies have shown that 1,25-dihydroxyvitamin D, the active form of vitamin D, has an anti-inflammatory effect. Recent epidemiological evidence has indicated a significant association between vitamin D deficiency and an increased incidence, or aggravation, of infectious diseases and inflammatory autoimmune diseases, such as rheumatoid arthritis, systemic lupus erythematosus, and multiple sclerosis. However, the impact of vitamin D on treatment and prevention, particularly in infectious diseases such as the 2019 coronavirus disease (COVID-19), remains controversial. Here, we review recent evidence associated with the relationship between vitamin D and inflammatory diseases and describe the underlying immunomodulatory effect of vitamin D.

Vitamin D and COVID-19: An Overview of Recent Evidence

The novel coronavirus severe acute respiratory syndrome (SARS-CoV-2) has progressed rapidly from an outbreak to a global pandemic, with new variants rapidly emerging. Coronavirus disease 2019 (COVID-19), the disease resulting from SARS-CoV-2 infection, can lead to multiorgan damage. Due to the extremely contagious and fatal nature of the virus, it has been a priority of medical research to find effective means of treatment. Amid this search, the role of vitamin D in modulating various aspects of the innate and adaptive immune system has been discussed. This review aims to consolidate the research surrounding the role of vitamin D in the treatment and prevention of COVID-19. While there are some conflicting results reported, the consensus is that vitamin D has a host of immunomodulatory effects which may be beneficial in the context of COVID-19 and that low levels of vitamin D can result in dysfunction of crucial antimicrobial effects, potentially contributing to poor prognosis. Studies also show that the effects of low vitamin D can be mitigated via supplementation, although the benefits of vitamin D supplementation in the treatment of COVID-19 remain controversial.

Regulation of T Cell Responses by Ionic Salt Signals

T helper cell responses are tailored to their respective antigens and adapted to their specific tissue microenvironment. While a great proportion of T cells acquire a resident identity, a significant proportion of T cells continue circulating, thus encountering changing microenvironmental signals during immune surveillance. One signal, which has previously been largely overlooked, is sodium chloride. It has been proposed to have potent effects on T cell responses in the context of autoimmune, allergic and infectious tissue inflammation in mouse models and humans. Sodium chloride is stringently regulated in the blood by the kidneys but displays differential deposition patterns in peripheral tissues. Sodium chloride accumulation might furthermore be regulated by dietary intake and thus by intentional behavior. Together, these results make sodium chloride an interesting but still controversial signal for immune modulation. Its downstream cellular activities represent a potential therapeutic target given its effects on T cell cytokine production. In this review article, we provide an overview and critical evaluation of the impact of this ionic signal on T helper cell polarization and T helper cell effector functions. In addition, the impact of sodium chloride from the tissue microenvironment is assessed for human health and disease and for its therapeutic potential.

The Impact of Vitamin D on Skin Aging

The active metabolites of vitamin D₃ (D₃) and lumisterol (L₃) exert a variety of antiaging and photoprotective effects on the skin. These are achieved through immunomodulation and include anti-inflammatory actions, regulation of keratinocytes proliferation, and differentiation programs to build the epidermal barrier necessary for maintaining skin homeostasis. In addition, they induce antioxidative responses, inhibit DNA damage and induce DNA repair mechanisms to attenuate premature skin aging and cancerogenesis. The mechanism of action would involve interaction with multiple nuclear receptors including VDR, AhR, LXR, reverse agonism on RORα and -γ, and nongenomic actions through 1,25D₃-MARRS receptor and interaction with the nongenomic binding site of the VDR. Therefore, active forms of vitamin D₃ including its canonical (1,25(OH)₂D₃) and noncanonical (CYP11A1-intitated) D₃ derivatives as well as L₃ derivatives are promising agents for the prevention, attenuation, or treatment of premature skin aging. They could be administrated orally and/or topically. Other forms of parenteral application of vitamin D₃ precursor should be considered to avoid its predominant metabolism to 25(OH)D₃ that is not recognized by CYP11A1 enzyme. The efficacy of topically applied vitamin D₃ and L₃ derivatives needs further clinical evaluation in future trials.

Vitamin D and coronavirus disease 2019 (COVID-19): rapid evidence review

BACKGROUND

The rapid global spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19), has re-ignited interest in the possible role of vitamin D in modulation of host responses to respiratory pathogens. Indeed, vitamin D supplementation has been proposed as a potential preventative or therapeutic strategy. Recommendations for any intervention, particularly in the context of a potentially fatal pandemic infection, should be strictly based on clinically informed appraisal of the evidence base. In this narrative review, we examine current evidence relating to vitamin D and COVID-19 and consider the most appropriate practical recommendations.

OBSERVATIONS

Although there are a growing number of studies investigating the links between vitamin D and COVID-19, they are mostly small and observational with high risk of bias, residual confounding, and reverse causality. Extrapolation of molecular actions of 1,25(OH)₂-vitamin D to an effect of increased 25(OH)-vitamin D as a result of vitamin D supplementation is generally unfounded, as is the automatic conclusion of causal mechanisms from observational studies linking low 25(OH)-vitamin D to incident disease. Efficacy is ideally demonstrated in the context of adequately powered randomised intervention studies, although such approaches may not always be feasible.

CONCLUSIONS

At present, evidence to support vitamin D supplementation for the prevention or treatment of COVID-19 is inconclusive. In the absence of any further compelling data, adherence to existing national guidance on vitamin D supplementation to prevent vitamin D deficiency, predicated principally on maintaining musculoskeletal health, appears appropriate.

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

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

Vitamin D and COVID-19 susceptibility and severity in the COVID-19 Host Genetics Initiative: A Mendelian randomization study

BACKGROUND

Increased vitamin D levels, as reflected by 25-hydroxy vitamin D (25OHD) measurements, have been proposed to protect against COVID-19 based on in vitro, observational, and ecological studies. However, vitamin D levels are associated with many confounding variables, and thus associations described to date may not be causal. Vitamin D Mendelian randomization (MR) studies have provided results that are concordant with large-scale vitamin D randomized trials. Here, we used 2-sample MR to assess evidence supporting a causal effect of circulating 25OHD levels on COVID-19 susceptibility and severity.

METHODS AND FINDINGS

Genetic variants strongly associated with 25OHD levels in a genome-wide association study (GWAS) of 443,734 participants of European ancestry (including 401,460 from the UK Biobank) were used as instrumental variables. GWASs of COVID-19 susceptibility, hospitalization, and severe disease from the COVID-19 Host Genetics Initiative were used as outcome GWASs. These included up to 14,134 individuals with COVID-19, and up to 1,284,876 without COVID-19, from up to 11 countries. SARS-CoV-2 positivity was determined by laboratory testing or medical chart review. Population controls without COVID-19 were also included in the control groups for all outcomes, including hospitalization and severe disease. Analyses were restricted to individuals of European descent when possible. Using inverse-weighted MR, genetically increased 25OHD levels by 1 standard deviation on the logarithmic scale had no significant association with COVID-19 susceptibility (odds ratio [OR] = 0.95; 95% CI 0.84, 1.08; p = 0.44), hospitalization (OR = 1.09; 95% CI: 0.89, 1.33; p = 0.41), and severe disease (OR = 0.97; 95% CI: 0.77, 1.22; p = 0.77). We used an additional 6 meta-analytic methods, as well as conducting sensitivity analyses after removal of variants at risk of horizontal pleiotropy, and obtained similar results. These results may be limited by weak instrument bias in some analyses. Further, our results do not apply to individuals with vitamin D deficiency.

CONCLUSIONS

In this 2-sample MR study, we did not observe evidence to support an association between 25OHD levels and COVID-19 susceptibility, severity, or hospitalization. Hence, vitamin D supplementation as a means of protecting against worsened COVID-19 outcomes is not supported by genetic evidence. Other therapeutic or preventative avenues should be given higher priority for COVID-19 randomized controlled trials.