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1.
Effect of Vitamin D Deficiency on Liver Cancer Risk: A Systematic Review and Meta-Analysis.
Yi, Z, Wang, L, Tu, X
Asian Pacific journal of cancer prevention : APJCP. 2021;(4):991-997
Abstract
UNLABELLED Epidemiological studies have showed that vitamin D deficiency can increase the risk of liver cancers. Hence, we conducted a meta-analysis to explore the relationship between 25-hydroxyvitamin D [25(OH)D] levels and liver cancer risk. METHODS Cochrane Library, Medline, Web of Science, and Embase were searched up to Mar. 2020, and the references of those studies were also searched by hand. A meta-analysis of 11 studies was performed which met the inclusion criteria. Six case-control studies and five cohort studies were included. RESULTS A total of 11 studies (6 case-control and 5 cohort studies) with 12,895 incident cases were included in the meta-analysis. The meta-analysis showed that liver cancer risk was significantly increased for vitamin D deficiency, and the pooled RR and its 95% CIs was 2.16 (1.2, 3.88; P = 0.01). In comparative analyses between 25(OH)D levels in patients with hepatocellular carcinoma(HCC) and those in the control group individuals, the summary RR of liver cancer was -1.11 (95% CI=-1.96 to -0.25). The subgroup analysis of the different geographical region of the population showed that the risk of liver cancer in Asian subgroup, European subgroup and Egyptian subgroup increased for vitamin D deficiency (RR=1.34,95% CI 0.72 to 2.48, p <0.00001; RR=2.53,95% CI 1.62 to 3.93,p <0.0001;RR=29.5,95% CI 4.14 to 209.93, P=0.88). CONCLUSION The results of this meta-analysis indicate that vitamin D deficiency is associated with increased risk of liver cancer. The 25(OH)D3 levels are lower in HCC patients than those in health controls. Maintenance of sufficient serum vitamin D levels would be beneficial for prevention of liver cancer.
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2.
The association between vitamin D and acute rejection in human kidney transplantation: A systematic review and meta-analysis study.
Mirzakhani, M, Mohammadkhani, S, Hekmatirad, S, Aghapour, S, Gorjizadeh, N, Shahbazi, M, Mohammadnia-Afrouzi, M
Transplant immunology. 2021;:101410
Abstract
BACKGROUND Vitamin D (VitD) deficiency is associated with several diseases such as multiple sclerosis, rheumatoid arthritis, respiratory infection, and so forth. In the field of transplantation (kidney transplantation), some studies reported that patients with VitD deficiency are of increased chance of acute rejection, but other studies did not show such a chance. On the other hand, since VitD is a modulatory factor and can reduce the inflammatory response, understanding the exact role of it in transplantation may contribute to tolerance condition in these patients. METHODS The electronic databases, including PubMed, Scopus, Embase, ProQuest, Web of Science, and Google Scholar, were searched for eligible studies. In general, 14 studies with a total of 4770 patients were included in this meta-analysis. Regarding the methodological heterogeneity, we selected a random-effects combination model. Moreover, OR was chosen as an effect size for this study. RESULTS After the combination of 14 studies, we showed that patients in the VitD-deficient group had an 82% increased chance of acute rejection compared with patients in the VitD-sufficient group, and this effect was significant (OR 1.82; 95% confidence interval [CI] [1.29, 2.56]; I2 = 52.3%). This result was significant, and, regarding the narrow CI, it can be a conclusive result. Study quality and gender variables were the main sources of inconsistent results in the primary studies. Moreover, using meta-regression, we showed that VitD deficiency (independent from the estimated glomerular filtration rate (eGFR) of patients) increased the chance of acute rejection. CONCLUSION The normal VitD status of patients a few days before and after transplantation can reduce the chance of acute rejection.
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3.
Vitamin D and Type 1 Diabetes Risk: A Systematic Review and Meta-Analysis of Genetic Evidence.
Najjar, L, Sutherland, J, Zhou, A, Hyppönen, E
Nutrients. 2021;(12)
Abstract
Several observational studies have examined vitamin D pathway polymorphisms and their association with type 1 diabetes (T1D) susceptibility, with inconclusive results. We aimed to perform a systematic review and meta-analysis assessing associations between selected variants affecting 25-hydroxyvitamin D [25(OH)D] and T1D risk. We conducted a systematic search of Medline, Embase, Web of Science and OpenGWAS updated in April 2021. The following keywords "vitamin D" and/or "single nucleotide polymorphisms (SNPs)" and "T1D" were selected to identify relevant articles. Seven SNPs (or their proxies) in six genes were analysed: CYP2R1 rs10741657, CYP2R1 (low frequency) rs117913124, DHCR7/NADSYN1 rs12785878, GC rs3755967, CYP24A1 rs17216707, AMDHD1 rs10745742 and SEC23A rs8018720. Seven case-control and three cohort studies were eligible for quantitative synthesis (n = 10). Meta-analysis results suggested no association with T1D (range of pooled ORs for all SNPs: 0.97-1.02; p > 0.01). Heterogeneity was found in DHCR7/NADSYN1 rs12785878 (I2: 64.8%, p = 0.02). Sensitivity analysis showed exclusion of any single study did not alter the overall pooled effect. No association with T1D was observed among a Caucasian subgroup. In conclusion, the evidence from the meta-analysis indicates a null association between selected variants affecting serum 25(OH)D concentrations and T1D.
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4.
Maternal vitamin D status and risk of gestational diabetes mellitus: A systematic review and meta-analysis of prospective cohort studies.
Milajerdi, A, Abbasi, F, Mousavi, SM, Esmaillzadeh, A
Clinical nutrition (Edinburgh, Scotland). 2021;(5):2576-2586
Abstract
BACKGROUND No earlier systematic review and meta-analysis have been done on the association between maternal serum vitamin D status and risk of GDM among prospective studies. The current study was done to systematically review prospective cohort studies (with several years of follow-up) on the association between maternal serum vitamin D deficiency or insufficiency and risk of GDM. METHODS Relevant papers published up to January 2020 were searched through PubMed, MEDLINE, SCOPUS, EMBASE, and Google Scholar using suitable keywords. All prospective cohort studies reporting Hazard Ratios (HRs) or Relative Risks (RRs) and 95% Confidence Intervals (CI) for GDM across categories of maternal serum vitamin D status were included. RESULTS A total of 29 prospective and nested case-control studies were included in the current systematic review, of which 27 studies had sufficient data for the meta-analysis. Individuals with vitamin D deficiency had a 26% greater risk of developing GDM than those with normal serum vitamin D concentrations (OR: 1.26; 95% CI: 1.13, 1.41). In addition, a significant positive association was seen between combined vitamin D insufficiency and deficiency and risk of developing GDM (OR: 1.23; 95% CI: 1.11, 1.35). Dose-response analysis showed a significant U-shaped non-linear association between serum vitamin D concentrations and risk of developing GDM (P < 0.001), such that those with serum vitamin D concentrations between 40 and 90 nmol/L had significantly reduced risk of GDM. CONCLUSIONS We found a significant association between vitamin D deficiency and an increased risk of GDM. The lowest risk of GDM was found among those with a serum vitamin D levels of 40-90 nmol/L. Further studies, including randomized clinical trials, are needed to confirm our findings. REGISTRATION PROSPERO (ID: 180722), https://www.crd.york.ac.uk/prospero/.
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5.
Low vitamin D status is associated with coronavirus disease 2019 outcomes: a systematic review and meta-analysis.
Liu, N, Sun, J, Wang, X, Zhang, T, Zhao, M, Li, H
International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases. 2021;:58-64
Abstract
BACKGROUND Observational studies suggest that the risk and clinical prognosis of coronavirus disease 2019 (COVID-19) are related to low vitamin D status; however, the data are inconsistent. OBJECTIVES We conducted a systematic review and meta-analysis to assess the association between low vitamin D status and COVID-19. METHODS A systematic search was conducted with PubMed, Embase, and the Cochrane Library from database inception to September 25, 2020. The standardized mean difference (SMD) or odds ratio (OR) and corresponding 95% confidence interval (CI) was applied to estimate pooled results. Random - or fixed-effect models based on heterogeneity were used for the meta-analysis. Funnel plots and Egger regression tests were used to assess publication bias. RESULTS A total of ten articles with 361,934 participants were selected for meta-analysis. Overall, the pooled OR in the fixed-effect model showed that vitamin D deficiency or insufficiency was associated with an increased risk of COVID-19 (OR = 1.43, 95% CI 1.00-2.05). In addition, COVID-19-positive individuals had lower vitamin D levels than COVID-19-negative individuals (SMD = -0.37, 95% CI = -0.52 to -0.21). Significant heterogeneity existed in both endpoints. Funnel plots and Egger regression tests revealed significant publication bias. CONCLUSIONS This systematic review and meta-analysis indicated that low vitamin D status might be associated with an increased risk of COVID-19 infection. Further studies are needed to evaluate the impact of vitamin D supplementation on the clinical severity and prognosis in patients with COVID-19. SYSTEMATIC REVIEW REGISTRATION PROSPERO registration no: CRD42020216740.
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6.
Vitamin D deficiency is not associated with graft versus host disease after hematopoietic stem cell transplantation: A meta-analysis.
Chiengthong, K, Cheungpasitporn, W, Thongprayoon, C, Lertjitbanjong, P, Cato, LD, Bathini, T, Ungprasert, P, Mao, MA, Chokesuwattanaskul, R
Journal of evidence-based medicine. 2020;(3):183-191
Abstract
OBJECTIVE Vitamin D status plays an important role in immunoregulation, and a deficiency is believed to be related to Graft Versus Host Disease (GVHD) in patients after hematopoietic stem cell transplantation (HSCT). We aim to study the association between vitamin D deficiency and GVHD after HSCT. METHODS A literature search was conducted utilizing MEDLINE, EMBASE, and The Cochrane Library Database from inception to July 2019. Eligible studies were required to1 be clinical trials or observational studies (cohort, case-control, or cross-sectional studies);2 provide data to calculate the odds ratios (OR) of GVHD in HSCT patients with vitamin D deficiency. Two reviewers independently extracted the data and assessed the risk of bias. Pooled odds ratios (OR) with 95% confidence interval (CI) were estimated using random-effects meta-analysis through the Comprehensive Meta-Analysis 3.3 software. RESULTS In total, 8 observational studies consisting of 1335 HSCT patients were enrolled in this systematic review. Overall, there was no significant association between vitamin D deficiency and acute GVHD (OR = 1.06, 95% CI 0.74-1.53, P > 0.05). There was no significant association between vitamin D deficiency and chronic GVHD (OR = 1.75, 95% CI 0.72-4.26, P > 0.05). Funnel plots and Egger regression asymmetry test were performed and showed no publication bias. CONCLUSION There is not a statistically significant association between vitamin D deficiency and neither acute nor chronic GVHD.
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7.
The effects of correction of vitamin D deficiency on arterial stiffness: A systematic review and updated meta-analysis of randomized controlled trials.
Chen, NC, Hsu, CY, Mao, PC, Dreyer, G, Wu, FZ, Chen, CL
The Journal of steroid biochemistry and molecular biology. 2020;:105561
Abstract
It is unclear whether nutritional vitamin D supplementation in vitamin d-deficient persons improves arterial stiffness. To conduct a meta-analysis of the effects of the nutritional vitamin D therapy on arterial stiffness in adults with vitamin D deficiency, the Scopus, PUBMED, EMBASE, and Cochrane databases were searched for systematic reviews conducted up to October 5, 2018. Randomized clinical trials that compared nutritional vitamin D therapy with placebo in adults with vitamin D deficiency were eligible. Two reviewers independently evaluated eligibility of all retrieved studies based on titles and abstracts. Meta-analysis was performed using random effect or fixed effects model and inverse variance method was used to calculate the effect using standardized mean difference (SMD) and weighted mean difference. A leave-one-out method was used for sensitivity analysis. The main outcome was arterial stiffness, indicated by the carotid-femoral pulse wave velocity (PWV). We identified 237 records, of which 9 satisfied the inclusion criteria of the study. Our meta-analysis included relatively high-quality placebo-controlled randomized trials. In a random-effects model, nutritional vitamin D was associated with significant reductions in the pooled difference of PWV [(SMD: -0.29; 95 % CI: -0.51 to -0.06), p = 0.01; Cochran's Q test: chi2 = 21.85; df = 9; p = 0.009; I2 = 59 %; n = 909 from 9 studies]. All sensitivity analyses yielded similar results. Nutritional vitamin D supplementation significantly improved arterial stiffness (PWV) in several subgroups by correcting vitamin D deficiency, for a study duration of ≥4 months and a daily dose of vitamin D3 ≥ 2000 IU. The study indicated that the correction of vitamin D deficiency by nutritional vitamin D supplementation may improve arterial stiffness in vitamin d-deficient persons, especially by the correction of vitamin D deficiency with a daily dose of vitamin D3 ≥ 2000 IU. However, further studies are required to confirm this.
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8.
Association between serum vitamin D levels and venous thromboembolism (VTE): A systematic review and meta-analysis of observational studies.
Wan, J, Yuan, J, Li, X, Bao, Y, Hou, Y, Li, Z, Tan, SC, Low, TY, Chu, Y
Complementary therapies in medicine. 2020;:102579
Abstract
OBJECTIVE Although many studies have attempted to unravel the relationship between vitamin D deficiency and the incidence of VTE, the results remained inconsistent. To address this discrepancy, we performed a systematic review and meta-analysis to precisely disentangle the relationship between serum vitamin D levels and VTE risk. METHODS The Web of Science, Scopus, PubMed/Medline, Embase, and Google Scholar databases were searched for all available observational studies that reported the risk of venous thromboembolism (VTE) based on serum vitamin D levels categories. The search was performed up to March 2020. RESULTS Seven studies were included. The overall analysis showed a significantly increased risk of VTE in subjects with low levels of serum vitamin D compared with those with normal vitamin D levels (RR = 1.34; 95% CI: 1.07-1.69; P = 0.011). In a sensitivity analysis, we did not observe a significant effect of any individual study on the combined effect sizes. Nevertheless, significant heterogeneity was present among the studies (Cochrane Q test, p = 0.018, I2 = 61%). In the stratified analysis, low vitamin D levels were positively associated with an increased risk of VTE in prospective population-based studies (RR = 1.31; 95% CI: 1.06-1.61; P = 0.010) and in subjects below 60 years old (RR = 1.28; 95% CI: 1.07-1.54; P = 0.060). CONCLUSION our systematic review and meta-analysis showed that a low serum vitamin D level was indeed associated with an increased risk of VTE.
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9.
Association of Vitamin D Levels with Incident All-Cause Dementia in Longitudinal Observational Studies: A Systematic Review and Meta-analysis.
Kalra, A, Teixeira, AL, Diniz, BS
The journal of prevention of Alzheimer's disease. 2020;(1):14-20
Abstract
BACKGROUND The role of vitamin D is not only limited to bone health and pathogenesis of chronic diseases. Evidence now suggests that it is also involved in the development of various dementias and Alzheimer's disease (AD). OBJECTIVE To carry out a systematic review and meta-analysis to evaluate the association between vitamin D levels and increased risk of incident all-cause dementia in longitudinal studies. DESIGN We conducted a systematic review and meta-analysis using the electronic bibliographic databases PubMed and Scopus. SETTING Prospective cohort studies. PARTICIPANTS Community-dwelling older adults. MEASUREMENTS Vitamin D serum concentrations were categorized in three groups: normal levels (>50 nmol/L), insufficient levels (25 - 49.9 nmol/L), and deficient levels (<25 nmol/L). We performed a meta-analysis using the general inverse variance method to calculate the pooled risk of AD and all-cause dementia according to vitamin D levels. Random-effects or fixed-effect model were used to calculate the pooled risk based on the heterogeneity analysis. RESULTS Five studies were included in the meta-analysis. The pooled risk of all-cause dementia and AD was significantly higher in those with deficient serum vitamin D level compared to those with normal level (1.33, CI95% [1.15, 1.54], and 1.87, CI95% [1.03, 3.41], respectively). Those with insufficient level also had a higher pooled risk of all-cause dementia and AD, but the strength of association was less robust (1.14 CI95% [1.02, 1.27] and 1.25, CI95% [1.04 - 1.51], respectively). CONCLUSION We found a gradient effect for the risk of all-cause dementia and AD according to the vitamin D level, with higher risk in those in the deficient levels group and intermediate risk in those with insufficient levels. Our findings were limited by the relatively small number of studies included in the meta-analysis and their geographic restriction.
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10.
Is there an association between vitamin D and diabetic foot disease? A meta-analysis.
Yammine, K, Hayek, F, Assi, C
Wound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society. 2020;(1):90-96
Abstract
It has been demonstrated that Vitamin D (25(OH)D) deficiency is associated with diabetes and with diabetic neuropathy. Some reports stated that vitamin D deficiency is also associated with diabetic foot ulcer and/or infection. Knowing the beneficial effect of vitamin D on wound healing, a quantitative evidence synthesis is needed to look for such association. Medline, Embase, Scopus, CINAHL, Cochrane Library, and Google Scholar were searched for from inception. The outcomes were set to be either the serum 25(OH)D level or the prevalence of patients with 25(OH)D with severe deficiency. Ten studies met the inclusion criteria with 1,644 patients; 817 diabetic patients with foot ulcers and 827 patients having diabetes without foot complications. The weighted mean differences was -0.93 (95% CI = -1.684 to -0.174, I2 = 97.8%, p = 0.01). The odds ratio of having severe vitamin D deficiency was 3.6 (95% CI = 2.940 to 4.415, I2 = 40.9%, p < 0.0001), in favor of the foot group. The quality of the included studies was found to be good to excellent. Diabetic foot complications are associated with significantly lower levels of vitamin D. Patients with diabetic ulcers or diabetic infection are at higher risk of bearing severe vitamin D deficiency. Knowing the beneficial effect of vitamin D on wound healing, it is likely that recognizing and supplementing with vitamin D could prevent or improve the outcomes of diabetic foot complications.