Vitamin D3 Metabolism Research Articles

ODP594 Vitamin D Levels At Hospital Admission Predict Severity Of Covid-19: A Controlled Prospective Study

Abstract Low Vitamin D (VD) levels in COVID-19 patients have been related to increased disease severity and worse outcomes. However, most of these trials designs were not-controlled and retrospective, including patients with demographic differences and biases potentially influencing the reported associations between lower VD levels and severe COVID-19. Aim of this study was to prospectively evaluate VD levels influence on disease severity in a COVID-19 patients cohort matched for age, sex and comorbidities with control subjects. Patients admitted to San Raffaele University Hospital for COVID-19 from March to June 2021 were consecutively enrolled in this study, which was approved by the local IRB, after giving their informed consent. Severe (i. e. those needing high flow oxygen therapy) and non-severe COVID-19 patients matched for age, sex and comorbidities were recruited at admission in Emergency Department (ED). Control subjects from the outpatient Endocrinology Unit of the same Hospital were enrolled in the same period. We excluded patients with comorbidities and therapies influencing VD metabolism. 25OH-VD levels were evaluated at admission in ED and VD deficiency was defined by serum 25OH-VD below 20 ng/mL. A total of 73 COVID-19 patients and 30 control subjects were included in the study. No differences regarding age, sex and comorbidities were found between patients and control groups, but 25OH-VD levels were statistically lower in COVID-19 patients (13.3 vs 23.6 ng/mL, p<0. 001) with a higher prevalence of VD deficiency (75% vs 43%, p=0. 002). After the ED admission, during the hospitalization, a severe disease occurred in a total of 46 COVID-19 patients, and 27 were affected by a non-severe one. No differences regarding age, sex and comorbidities were found between severe vs non-severe groups, but 25OH-VD was significantly lower in the severe one (11.7 vs 16.7 ng/mL, p=0. 007) with a higher prevalence of VD deficiency (85% vs 59%, p=0. 015). We observed lower 25OH-VD levels at admission in patients with non-invasive mechanical ventilation requirement (n.18) and in those admitted in intensive care unit (n.8) during hospitalization, compared to the other patients (p=0. 003 and p=0. 01), although no differences regarding age and comorbidities were found. Moreover, in patients with VD deficiency we found higher levels of inflammatory markers C-reactive protein and ferritin (69 vs 42 mg/L, p=0. 036; 723 vs 414 ng/mL, p=0. 028), and lower SaO2/FiO2 and PaO2/FiO2 ratios (433 vs 447, p=0. 005; 261 vs 311; p<0. 001) at hospital admission. In conclusion, our prospective data confirm that low VD levels are widely found in hospitalized COVID-19 patients compared to control subjects and predict increased disease severity independently from age, sex and comorbidities of patients affected. We suggest that tackling VD deficiency may be an effective preventive measure to prevent severe COVID-19. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

Using follicular fluid metabolomics to investigate the association between air pollution and oocyte quality

Background and aimOur objective was to use metabolomics in a toxicological-relevant target tissue to gain insight into the biological processes that may underlie the negative association between air pollution exposure and oocyte quality. MethodsOur study included 125 women undergoing in vitro fertilization at an academic fertility center in Massachusetts, US (2005–2015). A follicular fluid sample was collected during oocyte retrieval and untargeted metabolic profiling was conducted using liquid chromatography with ultra-high-resolution mass spectrometry and two chromatography columns (C18 and HILIC). Daily exposure to nitrogen dioxide (NO2), ozone, fine particulate matter, and black carbon was estimated at the women’s residence using spatiotemporal models and averaged over the period of ovarian stimulation (2-weeks). Multivariable linear regression models were used to evaluate the associations between the air pollutants, number of mature oocytes, and metabolic feature intensities. A meet-in-the-middle approach was used to identify overlapping features and metabolic pathways. ResultsOf the air pollutants, NO2 exposure had the largest number of overlapping metabolites (C18: 105; HILIC: 91) and biological pathways (C18: 3; HILIC: 6) with number of mature oocytes. Key pathways of overlap included vitamin D3 metabolism (both columns), bile acid biosynthesis (both columns), C21-steroid hormone metabolism (HILIC), androgen and estrogen metabolism (HILIC), vitamin A metabolism (HILIC), carnitine shuttle (HILIC), and prostaglandin formation (C18). Three overlapping metabolites were confirmed with level-1 or level-2 evidence. For example, hypoxanthine, a metabolite that protects against oxidant-induced cell injury, was positively associated with NO2 exposure and negatively associated with number of mature oocytes. Minimal overlap was observed between the other pollutants and the number of mature oocytes. ConclusionsHigher exposure to NO2 during ovarian stimulation was associated with many metabolites and biologic pathways involved in endogenous vitamin metabolism, hormone synthesis, and oxidative stress that may mediate the observed associations with lower oocyte quality.

Adenine-Induced Nephropathy Reduces Atherosclerosis in ApoE Knockout Mice.

Background: Cardiovascular events are the main cause of death in patients with chronic kidney disease. We hypothesize that the protective effects of renal cholesterol and vitamin D3 metabolism are lost under this condition. Nephropathy was induced by adenine in Apolipoprotein E knockout mice. The atherosclerotic phenotype was compared to mice with normal renal function. Methods: Mice were fed a western diet ±0.15% adenine. Urine and feces were collected to assess renal function and fecal output. Atherosclerosis, serum lipoprotein composition and functionality, hepatic lipids, and expression of genes involved in lipid metabolism, vitamin D3 and Na+ homeostasis, were assessed. Bones were analyzed by microCT. Results: Mice fed with adenine showed enhanced urinary Na+, Ca2+, and Pi excretion, reduced urinary pH, UreaUrine/UreaSerum, and CreatinineUrine/CreatinineSerum ratios. They developed less atherosclerosis. Lipoproteins in serum and hepatic lipids remained unchanged. Cholesterol efflux increased. Fecal output of cholesteryl ester and triglycerides increased. In the liver, mRNA levels of Cyp27a1, Cyp7a1, and Scarb1 increased; in the kidneys, Slc9a3, Slc12a3, Vdr, and Cyp24a1 decreased. Adenine increased cholesterol efflux in vitro. Tibias were shorter. Conclusion: Adenine induced tubular damage and was athero-protective because of enhanced cholesterol efflux and lipids elimination in feces. Bone growth was also affected.

The effect of iron dextran on vitamin D3 metabolism in SD rats

BackgroundIron and vitamin D (VD) is essential to health. Previous studies have shown that iron homeostasis has a potential effect on VD metabolism, but the mechanism is not fully understood.ObjectivesTo explore the relationship between VD metabolism and iron metabolism, as well as the regulatory mechanism of iron on VD metabolism.Methods40 male rats were fed adaptively for 7 days and randomly divided into control (C, n = 6 normal diet) group and model (M, n = 24 iron deficient diet) by simple randomization, the latter was used to establish iron deficiency anemia (IDA) model. After 6 weeks of feeding, the M group was randomly divided into: iron deficiency group (DFe), low iron group (LFe), medium iron group (MFe) and high iron group (HFe) by block randomization. Different doses of iron dextran (based on iron content (100 g·bw·d)): 0, 1.1, 3.3 and 9.9 mg) were given respectively. After 4 weeks, the rats were anesthetized with 8% chloral hydrate, Blood (collected from the abdominal aorta), liver and kidney tissues were collected. The serum and tissues were separately packed and frozen at -80℃ for testing.ResultsThe results showed that the levels of hemoglobin (Hb), red blood cell (RBC), serum iron (SI), liver iron, and kidney iron in DFe group were lower than those in the other four groups, while the levels of total iron-binding capacity (TIBC), transferrin (TF) and transferrin receptor (Tfr) in DFe group were higher than those in other groups; The serum levels of 25-(OH)D3 and 1,25-(OH)2D3 in DFe group were significantly lower than those in C group (P < 0.05). The correlation analysis showed that the levels of 25-(OH)D3 and 1,25-(OH)2D3 were negatively correlated with TIBC, TF and Tfr no correlation with SI. Western blotting, immunofluorescence, and q-PCR results showed that compared with C group, the protein and gene expressions of CYP2R1, CYP27A1, and CYP24A1 in DFe group were down-regulated, and the expression of CYP27B1 protein and gene was up-regulated in DFe group.ConclusionIron may be involved in the metabolism of VD3 by regulating the expression of VD3 hydroxylase, suggesting that appropriate iron supplementation might promote the activation of VD3.

Measuring Vitamin D3 Metabolic Status, Comparison between Vitamin D Deficient and Sufficient Individuals

The main branch of vitamin D3 metabolism involves several hydroxylation reactions to obtain mono-, di- and trihydroxylated metabolites, including the circulating and active forms—25(OH)D3 and 1,25(OH)2D3, respectively. However, most clinical trials strictly target the determination of 25(OH)D3 to offer a view of the metabolic status of vitamin D3. Due to the growing interest in expanding this restricted view, we have developed a method for measuring vitamin D3 metabolism by determination of vitamin D3, 25(OH)D3, 24,25(OH)2D3, 1,25(OH)2D3 and 1,24,25(OH)3D3 in human plasma. The method was based on SPE–LC–MS/MS with a large volume injection of human plasma (240 µL). Detection of di- and trihydroxymetabolites, found at the picogram per milliliter level, was attained by the combined action of high preconcentration and clean-up effects. The method allows obtaining information about ratios such as the known vitamin D metabolite ratio (24,25(OH)2D3/25(OH)D3), which can provide complementary views of vitamin D3 metabolic status. The method was applied to a cohort of obese patients and a reference cohort of healthy volunteers to find metabolic correlations between target analytes as well as differences as a function of vitamin D levels within and between cohorts.

Vitamin D regulates insulin pathway and glucose metabolism in zebrafish (Danio rerio).

1,25-dihydroxyvitamin D3 [1,25(OH)2 D3 ], the most active vitamin D (VD) metabolite, is a steroid hormone playing an important role in many physiological functions in addition to maintaining mineral homeostasis. In this study, we explored the mechanism that the VD regulated insulin pathway and glucose metabolism in zebrafish in vitro and in vivo. Our results show that 1,25(OH)2 D3 significantly enhances the expression of insulin receptor a (insra), insulin receptor substrate 1 (irs1) and glucose transporter 2 (glut2), and promotes glycolysis and glycogenesis, while suppressing gluconeogenesis in zebrafish liver cell line (ZFL) under the condition of high glucose (20mM), instead of the normal glucose (10mM). Moreover, consistent results were obtained from the zebrafish fed with VD3 -deficient diet, as well as the cyp2r1-/- zebrafish, in which endogenous VD metabolism is blocked. Furthermore, results from dual-luciferase reporting system exhibited that 1,25(OH)2 D3 directly activated the transcription of insra, rather than insrb in zebrafish by binding to vitamin D response element (VDRE) located at -181 to -167bp in the promoter region of insra. Importantly, the 1,25(OH)2 D3 treatment significantly alleviated the symptoms of hyperglycemia in diabetic zebrafish. In conclusion, our study demonstrated that VD activates VDRE located in the promoter area of insra in zebrafish to promote insulin/insra signaling pathway, thereby contributing to the maintenance of glucose homeostasis.

Modern views on the metabolism and biological effects of vitaminD

VitaminD is a steroid hormone that plays a crucial role in maintaining normal bone condition and calcium homeostasis. In recent years, vitaminD has become a hot topic of endocrinological research, largelyDue to the COVID-19 pandemic and the likely correlation between hypovitaminosisD and a high risk of chronic lung disease and associated mortality. Recent studies have shown that vitaminD exhibits a complex multistage metabolism and acts as a hormone on many extracellular targets. This review examines some new intriguing and as yet unclear aspects of vitaminD metabolism, such as new concepts of enzyme regulation, new pleiotropic effects of vitaminD receptor activation (VDR), and epigenetic effects. The mechanisms of vitaminD synthesis in the skin, its metabolism in the hepatic cytochrome P450 system, catabolism, metabolites and transport, gene control and epigenetic modulation are considered inDetail. In addition to the well-known role of vitaminD in calcium and bone metabolism, it has many pleiotropic extraskeletal effects, including potent effects on the immune system, cardiovascular system, adipose tissue and glucose/lipid metabolism, muscle and more. Experimental studies have shown that VDRs are expressed by cancer cell lines. Recent studies have shown a link between low levels of vitaminD and almost all aspects of the metabolic syndrome, such as type 2 diabetes, fasting blood glucose, hypertension, dyslipidemia, obesity and insulin resistance. Several studies have focused on the role of vitaminD in adipose tissue biology. In particular, a negative correlation between vitaminD and leptin or resistin is shown, as well as an inverse correlation with adiponectin. Recent studies in vitaminD-deficient mice have shown impaired secretion of glucose-stimulated insulin by pancreatic islets. VitaminD is thought to play a role in the pathogenesis and progression of cancer, and vitaminD analogues can slow cancer progression and metastasis. It is concluded that vitaminD is a molecule with several endocrine, paracrine and autocrine effects on many tissues and organs, in addition to maintaining skeletal homeostasis. Research in this area, which aims to clarify the pleiotropy of many effects of vitaminD and its metabolites, continues.

Vitamin D3 Metabolic Enzymes in the Porcine Uterus: Expression, Localization and Autoregulation by 1,25(OH)2D3 In Vitro.

The role of vitamin D3 has been confirmed in female reproductive organs. This study aimed to examine vitamin D3 metabolic enzymes, i.e., CYP27B1 and CYP24A1, mRNA transcript and protein abundance, and protein localization in the uterus of pigs on days 2–5, 10–12, 15–16 and 18–20 of the estrous cycle. Additionally, we determined 1,25(OH)2D3 concentration in uterine flushings and the effect of 1,25(OH)2D3 (10, 50 and 100 ng/mL) in vitro on CYP27B1 and CYP24A1 mRNA transcript abundance in endometrial and myometrial slices. In the endometrium, a greater CYP27B1 mRNA transcript abundance was noted on days 10–12 and 18–20 than on days 15–16, whereas encoded protein abundance was greater on days 18–20 when compared to days 15–16. Endometrial CYP24A1 mRNA transcript abundance was greater on days 18–20 than on days 10–12 and 15–16. In the myometrium, CYP27B1 mRNA transcript abundance was greater on days 18–20 than on days 2–5 and 15–16, while protein abundance was larger in slices collected on days 18–20 than on days 15–16. Neither CYP24A1 mRNA transcript nor encoded protein abundance were detected in the myometrium. The highest 1,25(OH)2D3 concentration in uterine flushings was observed on days 18–20. Furthermore, the 1,25(OH)2D3 increased the abundance of the CYP24A1 mRNA transcript in endometrial slices. Overall, our results suggest that porcine uterus is an extra-renal site of vitamin D3 metabolism. Both the endometrium and the myometrium possess the ability to synthesize vitamin D3, while only the endometrium contributes to its catabolism.

Cholecalciferol as Bioactive Plasticizer of High Molecular Weight Poly(D,L-Lactic Acid) Scaffolds for Bone Regeneration.

Synthetic thermoplastic polymers are a widespread choice as material candidates for scaffolds for tissue engineering (TE), thanks to their ease of processing and tunable properties with respect to biological polymers. These features made them largely employed in melt-extrusion-based additive manufacturing, with particular application in hard-TE. In this field, high molecular weight (Mw) polymers ensuring entanglement network strength are often favorable candidates as scaffold materials because of their enhanced mechanical properties compared with lower Mw grades. However, this is accompanied by high viscosities once processed in molten conditions, which requires driving forces not always accessible technically or compatible with often chemically nonstabilized biomedical grades. When possible, this is circumvented by increasing the operating temperature, which often results in polymer chain scission and consequent degradation of properties. In addition, synthetic polymers are mostly considered bioinert compared with biological materials, and additional processing steps are often required to make them favorable for tissue regeneration. In this study, we report the plasticization of a common thermoplastic polymer with cholecalciferol, the metabolically inactive form of vitamin D3 (VD3). Plasticization of the polymer allowed us to reduce its melt viscosity, and therefore the energy requirements (mechanical [torque] and heat [temperature]) for extrusion, limiting ultimately polymer degradation. In addition, we evaluated the effect of cholecalciferol, which is more easily available than its active counterpart, on the osteogenic differentiation of human mesenchymal stromal cells (hMSCs). Results indicated that cholecalciferol supported osteogenic differentiation more than the osteogenic culture medium, suggesting that hMSCs possess the enzymatic toolbox for VD3 metabolism. Impact statement Limitations in mechanical and biological performances of scaffolds manufactured through melt deposition may result from material thermal degradation during processing and inherent bioinertness of synthetic polymers. Current approaches involve the incorporation of chemical additives to reduce the extent of thermal degradation, which are often nonbiocompatible or may lead to uncontrolled modifications to the polymer structure. Lack of polymer bioactivity is tackled by postfunctionalization methods that often involve extra processes extending scaffold production time. Therefore, new methods to improve scaffolds performances should consider preserving the integrity of the molecular structure and improving biological responsiveness of the material while keeping the process as straightforward as possible.

Integration of omics data to generate and analyse COVID-19 specific genome-scale metabolic models

COVID-19 presents a complex disease that needs to be addressed using systems medicine approaches that include genome-scale metabolic models (GEMs). Previous studies have used a single model extraction method (MEM) and/or a single transcriptomic dataset to reconstruct context-specific models, which proved to be insufficient for the broader biological contexts. We have applied four MEMs in combination with five COVID-19 datasets. Models produced by GIMME were separated by infection, while tINIT preserved the biological variability in the data and enabled the best prediction of the enrichment of metabolic subsystems. Vitamin D3 metabolism was predicted to be down-regulated in one dataset by GIMME, and in all by tINIT. Models generated by tINIT and GIMME predicted downregulation of retinol metabolism in different datasets, while downregulated cholesterol metabolism was predicted only by tINIT-generated models. Predictions are in line with the observations in COVID-19 patients. Our data indicated that GIMME and tINIT models provided the most biologically relevant results and should have a larger emphasis in further analyses. Particularly tINIT models identified the metabolic pathways that are a part of the host response and are potential antiviral targets. The code and the results of the analyses are available to download from https://github.com/CompBioLj/COVID_GEMs_and_MEMs.

Nutritional Approaches as a Treatment for Impaired Bone Growth and Quality Following the Consumption of Ultra-Processed Food.

The severe impairment of bone development and quality was recently described as a new target for unbalanced ultra-processed food (UPF). Here, we describe nutritional approaches to repair this skeletal impairment in rats: supplementation with micro-nutrients and a rescue approach and switching the UPF to balanced nutrition during the growth period. The positive effect of supplementation with multi-vitamins and minerals on bone growth and quality was followed by the formation of mineral deposits on the rats’ kidneys and modifications in the expression of genes involved in inflammation and vitamin-D metabolism, demonstrating the cost of supplementation. Short and prolonged rescue improved trabecular parameters but incompletely improved the cortical parameters and the mechanical performance of the femur. Cortical porosity and cartilaginous lesions in the growth-plate were still detected one week after rescue and were reduced to normal levels 3 weeks after rescue. These findings highlight bone as a target for the effect of UPF and emphasize the importance of a balanced diet, especially during growth.

Characterization of a Cleavable Fusion of Human CYP24A1 with Adrenodoxin Reveals the Variable Role of Hydrophobics in Redox Partner Binding

The improper maintenance of the bioactivated form of vitamin-D (1α,25(OH)2D) may result in vitamin-D insufficiency and therefore compromise the absorption of dietary calcium. A significant regulator of vitamin-D metabolism is the inactivating function of the mitochondrial enzyme cytochrome P450 24A1 (CYP24A1). In humans, CYP24A1 carries out hydroxylation of carbon-23 (C23) or carbon-24 (C24) of the 1α,25(OH)2D side chain, eventually resulting in production of either an antagonist of the vitamin-D receptor (C23 pathway) or calcitroic acid (C24 pathway). Despite its importance to human health, the human isoform (hCYP24A1) remains largely uncharacterized due in part to the difficulty in producing the enzyme using recombinant means. In this study, we utilize a cleavable fusion with the cognate redox partner, human Adx (hAdx), to stabilize hCYP24A1 during production. The subsequent cleavage and isolation of active hCYP24A1 allowed for an investigation of substrate and analog binding, enzymatic activity, and redox partner recognition. We demonstrate involvement of a nonpolar contact involving Leu-80 of hAdx and a nonconserved proximal surface of hCYP24A1. Interestingly, shortening the length of this residue (L80V) results in enhanced binding between the CYP-Adx complex and 1α,25(OH)2D yet unexpectedly results in decreased catalysis. The same mutation has a negligible effect on rat CYP24A1 (a C24-hydroxylase), indicating the presence of a species-specific requirement that may correlate with differences in regioselectivity of the reaction. Taken together, this work presents an example of production of a challenging human CYP as well as providing details regarding hydrophobic modulation of a CYP-Adx complex that is critical to human vitamin-D metabolism.

Placental mRNA and Protein Expression of VDR, CYP27B1 and CYP2R1 Genes Related to Vitamin D Metabolism in Preeclamptic Women

(1) Background: Considerable evidence indicates that the occurrence of preeclampsia (PE) is associated with a reduced vitamin D (VD) level. Several studies have found that VD deficiency is correlated with disturbed trophoblast invasion, reduced angiogenesis and increased vasoconstriction. Because the vitamin D receptor (VDR) and CYP27B1 and CYP2R1 hydrolases are strongly involved in VD metabolism, the goal of the present study was to evaluate their genes and proteins expression in the placentas from preeclamptic women. (2) Methods: Samples and clinical data were obtained from 100 Polish women (41 women with preeclampsia and 59 healthy pregnant controls). The whole PE group was divided into subgroups according to gestation week of pregnancy ending before and after 34 gestational weeks (early/late-onset preeclampsia (EOPE/LOPE)). However, finally, to reduce confounding by differences in gestational age, the EOPE group was excluded from the analysis of mRNA and protein placental expression, and we focus on the comparison between LOPE and control groups. The placental VDR, CYP27B1 and CYP2R1 mRNA expression was analyzed using RT-PCR, and placental protein levels were determined by ELISA assay. (3) Results. (3.1) Placental gene expression: Expression levels of both genes, CYP27B1 (1.17 vs. 1.05 in controls, p = 0.006) and CYP2R1 (2.01 vs. 1.89 in controls, p = 0.039), were significantly higher in preeclamptic placentas than in the control group. Interestingly, VDR expression was significantly lower in placentas from the PE group (1.15 vs. 1.20 in controls, p = 0.030). After dividing all preeclamptic women into subgroups only for the CYP27B1 gene, a significantly higher placental expression in the LOPE subgroup than the healthy controls was observed (padj = 0.038). (3.2) Placental protein expression: The results revealed that protein expression levels of CYP27B1 in the preeclamptic group were similar (5.32 vs. 5.23 in controls, p = 0.530). There was a significant difference in median VDR and CYP2R1 protein levels between studied groups (VDR: 2.56 vs. 3.32 in controls, p &lt; 0.001; CYP2R1: 1.32 vs. 1.43 in controls, p = 0.019). After stratification of preeclamptic women into subgroups, a significant difference was observed only in the VDR protein level. The medians in the LOPE subgroups were significantly lower compared to the healthy control group. In the whole study group, the placental VDR protein level was inversely correlated with systolic and diastolic blood pressure (all p &lt; 0.001), and positively correlated with gestational age (p &lt; 0.001) and infant birth weight (p = 0.014). (4) Conclusions: Lower mRNA and protein expression of VDR in preeclamptic placentas, and also VDR protein expression, could play a pivotal role in preeclampsia development. Additionally, the higher mRNA expression of both CYP27B1 and CYP2R1 hydrolase genes in placentas from preeclamptic women could indicate the compensatory role of these enzymes in preeclampsia etiology. Our results also indicate that placental VDR protein level could be one of the factors modulating blood pressure in pregnant women, as well as influencing gestational age and infant birth weight. Considering the importance of these findings, future studies are warranted.

Impact of Vitamin D Supplementation on Bone Mineral Density and All-Cause Mortality in Heart Transplant Patients.

Vitamin D (VD) deficiency is frequently reported in heart transplant (HT) recipients and routinely supplemented. However, the efficacy of VD supplementation on bone mineral density (BMD) and its association with all-cause mortality is underinvestigated. The VD levels and BMD were studied for two years, and the association of VD and BMD with all-cause mortality risk was investigated. Ninety-six HT patients (38.18 ± 12.10 years old; 74% men) were followed up during VD, Ca, and Mg supplementation. Anthropometric measurements, BMD by Dual-energy X-ray absorptiometry (DEXA) scan, VD concentrations, and related biochemical parameters were analyzed before, 1 year, and 2 years after HT. Despite significant improvement of VD3 and 25-hydroxy VD (25OHVD) levels especially in the men, BMD parameters were insignificantly changed. After 2 years, the all-cause mortality rate was 15.6%. High pretransplant levels of 25OHVD failed to improve the survival probability. Cox’s regression showed a 32.7% increased hazard ratio for each unit increase in body mass index (95% CI: 1.015–1.733, p = 0.038), in the VD-deficient group rather than in the VD-sufficient one. In conclusion, VD supplementation improves the biochemical status, especially in VD-deficient HT. However, its impact on the BMD and mortality was not as usually expected. Further investigation of the disturbed VD metabolism in HT is warranted.

Hypocalcemia in COVID-19 is associated with low vitamin D levels and impaired compensatory PTH response.

BackgroundHypocalcemia has been identified as a major distinctive feature of COVID-19, predicting poor clinical outcomes. Among the mechanisms underlying this biochemical finding, high prevalence of vitamin D (VD) deficiency in COVID-19 patients reported so far in several studies was advocated. However, robust data in favor of this hypothesis are still lacking. Therefore, aim of our study was to investigate the role of hypovitaminosis D and parathyroid hormone (PTH) levels in the development of hypocalcemia in COVID-19 patients.MethodsPatients admitted to IRCCS Ospedale San Raffaele for COVID-19 were enrolled in this study, excluding those with comorbidities and therapies influencing calcium and VD metabolism. Serum levels of total calcium (tCa), ionized calcium (Ca2+), 25-OH-VD, and PTH were evaluated at admission. We defined VD deficiency as VD below 20 ng/mL, hypocalcemia as tCa below 2.2 mmol/L or as Ca2+ below 1.18 mmol/L, and hyperparathyroidism as PTH above 65 pg/mL.ResultsA total of 78 patients were included in the study. Median tCa and Ca2+ levels were 2.15 and 1.15 mmol/L, respectively. Total and ionized hypocalcemia were observed in 53 (67.9%) and 55 (70.5%) patients, respectively. VD deficiency was found in 67.9% of patients, but secondary hyperparathyroidism was detected in 20.5% of them, only. tCa levels were significantly lower in patients with VD deficiency and regression analyses showed a positive correlation between VD and tCa.ConclusionsIn conclusion, we confirmed a high prevalence of hypocalcemia in COVID-19 patients and we showed for the first time that it occurred largely in the context of marked hypovitaminosis D not adequately compensated by secondary hyperparathyroidism.

Effects of vitamin D in thyroid autoimmune pathologies: literature review and own data

Background. Vitamin D (VD) is a versatile steroid hormone that regulates the activity of several thousand genes. Over the past decades, numerous diseases associated with VD deficiency have been reported, including cancer and autoimmune thyroid disorders. Researches revealed that VD can influence the development and course of these diseases. The VD participation in modulation of the hypothalamus-pituitary-thyroid gland axis, both at the level of the pituitary gland and at that of the thyroid, has been shown. The effect of VD on autoimmune diseases, including thyroid autoimmune diseases, is widely studied. Most of the existing data support the relationship between VD deficiency and a greater tendency to develop and higher antibody titers associated with Hashimoto’s thyroiditis, Graves’ disease (GD) and postpartum thyroiditis. An important fact is that epidemiological studies have demonstrated a high prevalence of VD deficiency or insufficiency throughout the world. VD insufficiency is a potent dietary trigger that results in severe, chronic diseases. The question arises how reliable is the relationship between VD and autoimmune thyroid diseases (AITD). Although the results of the studies performed are somewhat contradictory, the vast majority of data indicates a link between VD deficiency and an increased risk of developing the disease, high antibody titers, and difficulties in treatment. Genetic polymorphisms associated with VD function and metabolism also have some influence on the risk of ATD. With regard to the precise nature of the relationship between VD and AITD, it is believed that VD plays a small but significant role in the AITD pathogenesis. After the AITD development, its consequence may be an increase in VD deficiency. It is the need to determine the effect of VD supplementation in the prevention and treatment of AITD and its optimal level directly for clinical practice. It is necessary for clinical practice to determine the effect of VD supplements in the prevention and treatment of AITD and its optimal level. A study, the purpose of which was to study the content of VD, namely 25(OH)D in 176 patients with GD complicated by autoimmune ophthalmopathy (AO) and to identify a correlation relationship with antithyroid antibodies (TPO, TSHR-Ab) was carried out at the State Institution “V.P. Komissarenko Institute of Endocrinology and Metabolism of the National Academy of Medical Sciences of Ukraine”. Materials and methods. The levels of 25(OH)D, TSH, TSHR-Ab, TPO were determined by enzyme immunoassay using standard kits from Siemens firm. During the study, 176 patients were divided into two groups, depending on the presence of AO: the first group consisted of patients with GD without AO (62 people), the second group included patients with GD and AO (114 people). Results. In GD, 91.78 % of patients (161 people) have an insufficient level of 25(OH)D content: a suboptimal level was recorded in 42 patients (23.86 %), and a deficit — in 119 patients (67.61 %). A significant negative correlation relationship was revealed between TSHR-Ab and 25(OH)D in the group of patients with GD and AO — with a lower level of 25(OH)D, the higher values of TSHR-Ab correlate. Compensation of the 25(OH)D deficiency leads to a significant (P&lt; 0.05) decrease in the levels of TSHR-Ab and TPO in patients with GD. Besides, there is a large body of literature available lin-king vitamin D to thyroid autoimmunity as a result of cross-sectional studies and observations. Conclusions. Thus, there is still an urgent need for large multicenter studies to evaluate the effect of vitamin D supplementation on meaningful long-term clinical endpoints in AITD.

Дефіцит вітаміну D3 та його роль у розвитку метаболічних порушень

Подано дані про вплив вітаміну D3 на кальцій-фосфорний і вуглеводний обміни, а також на функціональну активність β-клітин підшлункової залози на тлі D-гіповітамінозу та при експериментальному діабеті в мишей. Описано деякі механізми порушення обміну вітаміну D3 і результати його клінічного застосування в пацієнтів із цукровим діабетом 1-го і 2-го типу.

Pollutants enhance IgE sensitization in the gut via local alteration of vitamin D-metabolizing enzymes.

Mechanisms linking ingested pollutants to increased incidence of allergy are poorly understood. We report that mice exposed to low doses of cadmium develop higher IgE responses following oral allergen sensitization and more severe allergic symptoms upon allergen challenge. The environmentally relevant doses of this pollutant also induced oxidative/inflammatory responses in the gut of SPF, but not germ-free mice. Interestingly, the increased IgE responses correlated with stimulation of the vitamin D3-metabolizing enzymes CYP27B1 and CYP24A1 in the gut and increased luminal levels of oxidized vitamin D3 metabolites that are not ligands of the vitamin D receptor. Inhibition of CYP27B1 and CYP24A1 via oral administration of pharmacological inhibitors reduced IgE responses induced in mice orally exposed to cadmium. Our findings identify local alteration of vitamin D signaling as a new mechanism for induction of IgE responses by environmental pollutants. They also identify vitamin D3-metabolizing enzymes as therapeutic targets for the treatment of allergy.

Vitamin D Levels Are Associated With Blood Glucose and BMI in COVID-19 Patients, Predicting Disease Severity.

ContextHigh prevalence of Vitamin-D (VD) deficiency in COVID-19 patients was reported and hypothesized to increase COVID-19 severity likely due to its negative impact on immune and inflammatory responses. Furthermore, clear associations between hypovitaminosis-D and fat body-mass excess and diabetes, factors associated with COVID-19 severity, have been widely recognized.ObjectiveThe aim of this study was to evaluate in COVID-19 patients the relationship between VD levels and inflammatory response, BMI, blood glucose and disease severity.DesignPatients admitted to San Raffaele-Hospital for COVID-19 were enrolled in this study, excluding those with comorbidities and therapies influencing VD-metabolism. 25(OH)VD levels, plasma glucose levels, BMI and inflammatory parameters were evaluated at admission.ResultsA total of 88 patients were included. Median VD level was 16.3 ng/mL and VD-deficiency was found in 68.2% of patients. VD-deficiency was found more frequently in male patients and in those affected by severe COVID-19. Regression analyses showed a positive correlation between VD and PaO2/FiO2 ratio, and negative correlations between VD and plasma glucose, BMI, Neutrophil/Lymphocyte ratio, CRP and IL-6.Patients with both hypovitaminosis-D and diabetes mellitus, as well those with hypovitaminosis-D and overweight, were more frequently affected by a severe disease with worse inflammatory response and respiratory parameters, compared to those without or just one of these conditions.ConclusionsWe showed, for the first-time, a strict association of VD levels with blood glucose and BMI in COVID-19 patients. VD-deficiency might be a novel common pathophysiological mechanism involved in the detrimental effect of hyperglycemia and adiposity on disease severity.

26634 Insights into the mechanisms of EGFRi-induced cutaneous adverse drug reactions from functional phospho-proteomic and transcriptomic data

Cutaneous adverse drug reactions (CADR) are frequent during oncology therapy with epidermal growth factor inhibitors (EGFRi). These molecules modify the keratinocyte differentiation programming, impairing proper skin barrier formation. However, the molecular signatures associated with CADR remain unknown. To investigate this mechanisms we employed phospo-proteomic and transcriptomic assays on reconstructed human epidermis (RHE) tissues exposed to a therapeutically relevant concentration of afatinib, a second generation EGFRi. Upon exposure of the RHEs to the drug we observed activation of the PI3K/AKT pathway, associated with an increased expression of gene families involved in keratinocyte differentiation, senescence, oxidative stress and alterations in the epidermal immune-related markers. Moreover, our results showed that afatinib may interfere with vitamin D3 (VD3) metabolism, acting via CYP27A1 and CYP24A1 to regulate calcium concentration through the PI3K/AKT pathway. As a result, keratinocytes switch from a pro-proliferating to a pro-differentiative program, characterized by upregulation of biomarkers associated with increased keratinization, cornification, Th2 response and decreased innate immunity. Such effects may increase the skin susceptibility to cutaneous penetration of irritants and pathogens. Taken together these findings shed new light on the molecular mechanisms of EGFRi induced CADRs.