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Vitamin D deficiency and treatment versus risk of infection in end-stage renal disease patients under dialysis: a systematic review and meta-analysis.
Su, G, Liu, Z, Qin, X, Hong, X, Liu, X, Wen, Z, Lindholm, B, Carrero, JJ, Johnson, DW, Brusselaers, N, et al
Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association. 2019;(1):146-156
Abstract
BACKGROUND Infections are common and can be fatal in patients undergoing long-term dialysis. Recent studies have shown conflicting evidence associating infection with vitamin D status or use of vitamin D and have not been systematically reviewed in this population. METHODS We searched PubMed, Web of Science, Cochrane Library, Embase and three Chinese databases from inception until December 2017 for interventional [non-randomized or randomized controlled trials (RCTs)], cohort and case-control studies on levels of serum 25-hydroxyvitamin D [25(OH)D] or use of vitamin D [supplemental nutritional vitamin D or vitamin D receptor activator (VDRA)] and infection (any infection, infection-required hospitalization or infection-related death or composite) in long-term dialysis patients. We conducted a meta-analysis on the relative risk (RR) of infection and level of 25(OH)D or use of vitamin D. RESULTS Of 2440 reports identified, 17 studies met inclusion criteria, all with moderate quality, with 6 cohort studies evaluating 25(OH)D serum concentrations (n = 5714) and 11 (2 RCTs and 9 observational studies) evaluating the use of vitamin D (n = 92 309). The risk of composite infection was 39% lower {relative risk [RR] 0.61 [95% confidence interval (CI) 0.41-0.89]} in the subjects with high or normal levels of 25(OH)D than in those with low levels. When compared with those who did not use vitamin D, the pooled adjusted risk for composite infection was 41% lower in those who used vitamin D [RR 0.59 (95% CI 0.43-0.81)]. CONCLUSIONS High or normal serum levels of 25(OH)D and the use of vitamin D, particularly VDRA, were each associated with a lower risk of composite infection in long-term dialysis patients.
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A New Light on Vitamin D in Obesity: A Novel Association with Trimethylamine-N-Oxide (TMAO).
Barrea, L, Muscogiuri, G, Annunziata, G, Laudisio, D, de Alteriis, G, Tenore, GC, Colao, A, Savastano, S
Nutrients. 2019;(6)
Abstract
Abstract: Vitamin D deficiency and obesity are two public health problems extensively exacerbated over the last years. Among the several mechanisms proposed to account for the complex interplay between vitamin D and obesity, one that has gained particular attention is related to the emerging role of obesity-related changes in gut microbiota and gut-derived metabolites, such as Trimethylamine-N-oxide (TMAO). Vitamin D deficiency and high circulating TMAO levels are associated with body weight and the severity of non-alcoholic fatty liver disease (NAFLD). Considering the link of obesity with vitamin D on the one hand and obesity with TMAO on the other hand, and the central role of the liver in both the vitamin D and TMAO metabolism, the aim of this cross-sectional observational study was first, to confirm the possible inverse association between vitamin D and TMAO across different body mass index (BMI) classes and second, to investigate if this association could be influenced by the presence of NAFLD. One hundred and four adult subjects (50 males and 54 females; 35.38 ± 7.49 years) were enrolled. The fatty liver index (FLI) was used as a proxy for the diagnosis of NAFLD. Vitamin D deficiency was found in 65 participants (62.5%), while 33 subjects (31.7%) had insufficient levels, and the remaining subjects had sufficient levels of vitamin D. Subjects with both vitamin D deficiency and FLI-NAFLD had the highest TMAO levels (p < 0.001). By stratifying the sample population according to the BMI classes, vitamin D levels decreased significantly along with the increase of plasma TMAO concentrations, with the lowest vitamin D levels and highest TMAO, respectively, in class III obesity. Vitamin D levels showed significant opposite associations with circulating levels of TMAO (r = -0.588, p < 0.001), but this association was no longer significant after the adjustment for FLI values. The highest values of TMAO were significantly associated with the severity of obesity (OR 7.92; p < 0.001), deficiency of vitamin D (OR 1.62; p < 0.001), and FLI-NAFLD (OR 3.79; p < 0.001). The most sensitive and specific cut-off for vitamin D to predict the circulating levels of TMAO was ≤19.83 ng/mL (p < 0.001). In conclusion, our study suggests that high TMAO levels are associated with vitamin D deficiency and NAFLD. Further studies are required to investigate if there is a causality link or whether all of them are simply the consequence of obesity.
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Vitamin D supplementation and musculoskeletal health.
Bouillon, R, Lips, P, Bilezikian, JP
The lancet. Diabetes & endocrinology. 2019;(2):85-86
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Vitamin D and Anti-Müllerian Hormone Levels in Infertility Treatment: The Change-Point Problem.
Bednarska-Czerwińska, A, Olszak-Wąsik, K, Olejek, A, Czerwiński, M, Tukiendorf, AA
Nutrients. 2019;(5)
Abstract
BACKGROUND Anti-Müllerian hormone (AMH) is considered to be one of the most significant indicators of women's fertility. Many studies have shown that vitamin D may modify human reproductive functions; however, the results are conflicting. The composition of follicular fluid (FF) creates the biochemical environment of the oocyte and affects its quality, which later determines the embryo quality. In this study, we aimed to revise with advanced statistical techniques the relationship between AMH and vitamin D in FF. METHODS The study was designed as a prospective single-center study in infertile patients with AMH ≥ 0.7 ng/mL who underwent controlled ovarian hyperstimulation for in vitro fertilization. AMH and vitamin D levels in FF were measured. Next, the standard and advanced statistical (including segmented regression) techniques were applied. RESULTS We observed a negative linear correlation between levels of AMH in serum and FF and total vitamin D concentrations up to approximately 30 ng/ml; with a statistically significant relationship in FF. Beyond that concentration, the trend was positive but statistically insignificant. CONCLUSIONS As an existing "change-point problem" was noticed, we suggest segmentation in the relationship between vitamin D and AMH during infertility treatment.
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[Research progress on the relevance between serum vitamin D and IL-33/ST2 levels and allergic rhinitis].
Zhu, DC, Feng, Y, Wang, BQ
Lin chuang er bi yan hou tou jing wai ke za zhi = Journal of clinical otorhinolaryngology, head, and neck surgery. 2019;(9):898-900
Abstract
Summary Allergic rhinitis(AR), a common and frequente disease, has attracted global attention in recent years. The imbalance between Th1 and Th2 cellular immune responses is the immunological basis of AR. Studies have found that vitamin D plays an important role in the occurrence of AR, and IL-33/ST2 is a newly discovered cytokine and signaling pathway in AR. There are certain specific associations between vitamin D and IL-33/ST2 in the pathogenesis of AR. This paper mainly analyzes the studies on the expression of vitamin D, IL-33/ST2 and Th1/Th2 cytokines in AR, so as to clarify the role of the above two factors in the pathogenesis of AR.
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Vitamin D: A Micronutrient Regulating Genes.
Carlberg, C
Current pharmaceutical design. 2019;(15):1740-1746
Abstract
BACKGROUND At sufficient sun exposure, humans can synthesize vitamin D3 endogenously in their skin, but today's lifestyle makes the secosteroid a true vitamin that needs to be taken up by diet or supplementation with pills. The vitamin D3 metabolite 1α,25-dihydroxyvitamin D3 acts as a nuclear hormone activating the transcription factor vitamin D receptor (VDR). METHODS This review discusses the biological effects of micronutrient vitamin D ranging from calcium homeostasis and bone formation to the modulation of innate and adaptive immunity. RESULTS Since normal human diet is sufficient in vitamin D, the need for efficient vitamin D3 synthesis in the skin acts as an evolutionary driver for its lightening during the migration out of Africa towards North. Via activating the VDR, vitamin D has direct effects on the epigenome and the expression of more than 1000 genes in most human tissues and cell types. CONCLUSIONS The pleiotropic action of vitamin D in health and disease prevention is explained through complex gene regulatory events of the transcription factor VDR.
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A narrative review on effects of vitamin D on main risk factors and severity of Non-Alcoholic Fatty Liver Disease.
Sangouni, AA, Ghavamzadeh, S, Jamalzehi, A
Diabetes & metabolic syndrome. 2019;(3):2260-2265
Abstract
The global prevalence of Non-alcoholic fatty liver disease (NAFLD) is increasing rapidly. Many studies have been conducted on the treatment of NAFLD; nevertheless, there is still no approved drug treatment for this disease. Although the pathogenesis of NAFLD is not fully understood, but inflammation, insulin resistance, oxidative stress, obesity and dyslipidemia are among the main causes. Epidemiological studies have shown that hypovitaminosis D is associated with these factors causing NAFLD. In addition, rate of Vitamin D deficiency has been shown to be directly related to the severity of NAFLD. Accordingly, it is believed that vitamin D may help to treatment of NAFLD by improving the above-mentioned risk factors. The purpose of this review is to survey the recent advances in the field of Vitamin D efficacy on risk factors and the severity of NAFLD based on existing evidence, especially the clinical efficiency of vitamin D supplementation in patients with NAFLD.
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The effects of vitamin D supplementation on mental health, and biomarkers of inflammation and oxidative stress in patients with psychiatric disorders: A systematic review and meta-analysis of randomized controlled trials.
Jamilian, H, Amirani, E, Milajerdi, A, Kolahdooz, F, Mirzaei, H, Zaroudi, M, Ghaderi, A, Asemi, Z
Progress in neuro-psychopharmacology & biological psychiatry. 2019;:109651
Abstract
BACKGROUND In the current meta-analysis of randomized controlled trials (RCTs), the effects of vitamin D supplementation on mental health, and biomarkers of inflammation and oxidative stress in patients with psychiatric disorders are assessed. METHODS The following databases were search up to March 2019: MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials. The quality of the relevant extracted data was assessed according to the Cochrane risk of bias tool. Data were pooled by the use of the inverse variance method and expressed as mean difference with 95% Confidence Intervals (95% CI). RESULTS Eleven effect sizes from nine studies were included in the final analyses. A pooled analysis of 9 effect sizes showed a significant reduction in Beck Depression Inventory (BDI) score following supplementation with vitamin D [weighted mean difference (WMD): -3.91; 95% CI: -5.15 -2.66), I2= 85.9%]. Combining data from two available studies on the effects of vitamin D supplementation on Pittsburgh Sleep Quality Index (PSQI) also revealed a significant reduction in this score following the intervention (WMD: -1.78; 95% CI: -2.28, -1.28). In addition, there were significant increase in glutathione (GSH) through 3 studies (WMD: 180.70; 95% CI: 6.76, 354.64), and in total antioxidant capacity (TAC) through 3 studies (WMD: 90.09; 95% CI: 56.36, 123.82) after vitamin D supplementation. Combining data from five studies, we found a significant reduction in C-reactive protein (CRP) concentrations after vitamin D supplementation (WMD: -1.74; 95% CI: -2.82, -0.66). CONCLUSIONS Overall, the current meta-analysis demonstrated that taking vitamin D supplements among patients with psychiatric disorders had beneficial effects on BDI, PSQI, GSH, TAC and CRP levels, but did not affect other biomarkers of inflammation and oxidative stress.
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Effectiveness of vitamin D supplementation on the outcome of pulmonary tuberculosis treatment in adults: a meta-analysis of randomized controlled trials.
Zhang, J, Chen, C, Yang, J
Chinese medical journal. 2019;(24):2950-2959
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Abstract
BACKGROUND Tuberculosis (TB) is one of the most debilitating diseases worldwide. Current studies have shown that vitamin D plays a significant role in host immune defense against Mycobacterium tuberculosis, but clinical trials reported inconsistent results. Therefore, we systematically reviewed the literature to investigate whether vitamin D supplementation could improve the effect of anti-TB therapy. METHODS We systematically searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials from their inception to February 8th, 2019 for randomized controlled trials on vitamin D supplementation in patients with pulmonary TB receiving anti-TB therapy. The primary outcomes were time to sputum culture and smear conversion and proportion of participants with negative sputum culture. The secondary outcomes were clinical response to treatment and adverse events. A random-effects model was used to pool studies. Data were analyzed using RevMan 5.3 software. RESULTS Five studies with a total of 1126 participants were included in our meta-analysis. Vitamin D supplementation did not shorten the time to sputum culture and smear conversion (hazard ratio [HR] 1.04, 95% confidence interval [CI] 0.89-1.23, P = 0.60; HR 1.15, 95% CI 0.93-1.41, P = 0.20, respectively) and did not lead to an increase in the proportion of participants with negative sputum culture (relative risk [RR] 1.04, 95% CI 0.97-1.11, P = 0.32). However, it reduced the time to sputum culture conversion in the sub-group of participants with TaqI tt genotype (HR 8.09, 95% CI 1.39-47.09, P = 0.02) and improved the multidrug-resistant (MDR) TB sputum culture conversion rate (RR 2.40, 95% CI 1.11-5.18, P = 0.03). There was no influence on secondary outcomes. CONCLUSIONS Vitamin D supplementation had no beneficial effect on anti-TB treatment, but it reduced the time to sputum culture conversion in participants with tt genotype of the TaqI vitamin D receptor gene polymorphism and improved the MDR TB sputum culture conversion rate.
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Vitamin D Supplementation and Cardiovascular Disease Risks in More Than 83 000 Individuals in 21 Randomized Clinical Trials: A Meta-analysis.
Barbarawi, M, Kheiri, B, Zayed, Y, Barbarawi, O, Dhillon, H, Swaid, B, Yelangi, A, Sundus, S, Bachuwa, G, Alkotob, ML, et al
JAMA cardiology. 2019;(8):765-776
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Abstract
IMPORTANCE Observational studies have reported an association between low serum vitamin D levels and elevated risk of cardiovascular disease (CVD) events, but such studies cannot prove causation because of possible unmeasured confounding. OBJECTIVE We conducted a meta-analysis of randomized clinical trials that tested the association of vitamin D supplementation with reduced CVD events and all-cause mortality. DATA SOURCES Literature search through PubMed, the Cochrane Library, and Embase was completed by 2 reviewers from each database's inception to December 15, 2018. STUDY SELECTION Inclusion criteria were randomized clinical trials that reported the effect of long-term (≥1 year) vitamin D supplementation on CVD events and all-cause mortality. Studies that did not include cardiovascular outcomes were excluded. DATA EXTRACTION AND SYNTHESIS Data were abstracted independently by 2 authors. Random-effects models were used to report the risk ratios (RRs) and 95% CIs. MAIN OUTCOMES AND MEASURES Major adverse cardiovascular events was the primary outcome, and rates of myocardial infarction, stroke or cerebrovascular accident, CVD mortality, and all-cause mortality were the secondary end points. RESULTS Twenty-one randomized clinical trials were included (including 83 291 patients, of whom 41 669 received vitamin D and 41 622 received placebos). The mean (SD) age of trial participants was 65.8 (8.4) years; 61 943 (74.4%) were female. Only 4 trials had prespecified CVD as a primary end point. Vitamin D supplementation compared with placebo was not associated with reduced major adverse cardiovascular events (RR, 1.00 [95% CI, 0.95-1.06]; P = .85) nor the secondary end points of myocardial infarction (RR, 1.00 [95% CI, 0.93-1.08]; P = .92), stroke (RR, 1.06 [95% CI, 0.98-1.15]; P = .16), CVD mortality (RR, 0.98 [95% CI, 0.90-1.07]; P = .68), or all-cause mortality (RR, 0.97 [95% CI, 0.93-1.02]; P = .23). Results were generally consistent by sex, baseline 25-hydroxyvitamin D level, vitamin D dosage, formulation (daily vs bolus dosing), and presence or absence of concurrent calcium administration. CONCLUSIONS AND RELEVANCE In this updated meta-analysis, vitamin D supplementation was not associated with reduced major adverse cardiovascular events, individual CVD end points (myocardial infarction, stroke, CVD mortality), or all-cause mortality. The findings suggest that vitamin D supplementation does not confer cardiovascular protection and is not indicated for this purpose.