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Antioxidant vitamins supplementation reduce endometriosis related pelvic pain in humans: a systematic review and meta-analysis.
Zheng, SH, Chen, XX, Chen, Y, Wu, ZC, Chen, XQ, Li, XL
Reproductive biology and endocrinology : RB&E. 2023;21(1):79
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Endometriosis is a common gynaecological disorder in reproductive-age women which leads to infertility and pain symptoms. Current pain management approaches involve medications and surgical treatments, but their side effects and risk of recurrence have led to the exploration of alternative options. The aim of this study was to clarify the potential effects of antioxidant vitamins supplementation on endometriosis. This study was a systematic review and meta-analysis of eleven studies, comprising a total of 589 patients. Results showed that antioxidant vitamins supplementation can effectively alleviate endometriosis-related pain and reduce inflammatory markers. Authors conclude that antioxidant vitamins supplementation can be considered as an alternative treatment either on its own or in combination with other methods for managing endometriosis-related pain. However, further research would help to provide a clearer understanding of the role of antioxidant vitamins supplementation in women with endometriosis.
Abstract
OBJECTIVE This study aimed to clarify the effect of antioxidant vitamins supplementation on endometriosis-related pain. METHODS A systematic search of PubMed, Web of Science, Cochrane Library, Scopus, and China National Knowledge Infrastructure (CNK) databases was conducted to identify relevant studies published in English and Chinese up to 16 March 2023. The search terms used were "endometriosis" OR "endometrioma" OR "endometrium" AND "antioxidant" OR "Vitamin C" OR "Vitamin E" OR "Vitamin D" OR "25-OHD" OR "25(OH)D" OR "25-hydroxyvitamin D". Eligible studies were randomized controlled trials (RCTs) that assessed pain scores using the Visual Analogue Scale (VAS). Mean differences or odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to evaluate the effect of antioxidant vitamins supplementation on endometriosis. The quality of the included studies was assessed using the Cochrane Risk of Bias Tool. The study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. RESULTS A total of 13 RCTs involving 589 patients were included in this meta-analysis. We identified 11 studies that evaluated the effect of antioxidant vitamins supplementation on endometriosis-related pain. The results indicated that the supplementation of antioxidant vitamins can effectively alleviate endometriosis-related pain. Subgroup analysis showed that the supplementation of vitamin E (with or without vitamin C) had a positive effect on improving clinical pelvic pain in patients with chronic pelvic pain. Conversely, supplementation of vitamin D was associated with a reduction in pelvic pain in endometriosis patients, but the difference was not statistically significant compared to the placebo. Additionally, we observed changes in oxidative stress markers following vitamin supplementation. Plasma malondialdehyde (MDA) concentration decreased in patients with endometriosis after antioxidant vitamin supplementation, and the plasma MDA level was inversely correlated with the time and dose of vitamin E and C supplementation. Furthermore, the inflammatory markers in peritoneal fluid, including RANTES, interleukin-6, and monocyte chemoattractant protein-1, significantly decreased after antioxidant therapy. These findings suggest that antioxidant vitamins may alleviate pain in endometriosis patients by reducing inflammation. CONCLUSIONS The included studies support the potential role of antioxidant vitamins in the management of endometriosis. Supplementation with antioxidant vitamins effectively reduced the severity of dysmenorrhea, improved dyspareunia and pelvic pain, and enhanced quality of life in these patients. Therefore, antioxidant vitamin therapy could be considered as an alternative treatment method, either alone or in combination with other approaches, for endometriosis-related pain. TRIAL REGISTRATION PROSPERO registration number: CRD42023415198.
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Inverse Association Between Serum 25-Hydroxyvitamin D and Nonalcoholic Fatty Liver Disease.
Yuan, S, Larsson, SC
Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association. 2023;21(2):398-405.e4
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The prevalence of non-alcoholic fatty liver disease (NAFLD) is projected to increase due to the obesity epidemic, rise in diabetes prevalence, and other factors. An inverse association between serum 25-hydroxyvitamin D [S-25(OH)D], a clinical marker of vitamin D status, and NAFLD has been observed in several cross-sectional and case-control studies. The aim of this study was to determine the association between S-25(OH)D and NAFLD. This study is a 2-sample Mendelian randomisation study based on summary-level data of genome-wide association analyses on S-25(OH)D levels, NAFLD, and liver enzymes. Results show an inverse genetic correlation of S-25(OH)D with NAFLD and certain liver enzymes and an inverse association of genetically predicted S-25(OH)D with risk of NAFLD in European individuals. Authors conclude that vitamin D may play a role in NAFLD prevention. However, further studies are needed in order to confirm the causal effect of NAFLD on lowering S-25(OH)D levels.
Abstract
BACKGROUND & AIMS Serum 25-hydroxyvitamin D [S-25(OH)D] and nonalcoholic fatty liver disease (NAFLD) are correlated in many observational studies, whereas the causality of this association is uncertain, especially in European populations. We conducted a bidirectional Mendelian randomization study to determine the association between S-25(OH)D and NAFLD. METHODS Seven and 6 independent genetic variants associated with S-25(OH)D and NAFLD at the genome-wide-significance level, respectively, were selected as instrumental variables. Summary-level data for S-25(OH)D were obtained from the Study of Underlying Genetic Determinants of Vitamin D and Highly Related Traits consortium including 79,366 individuals. Summary-level data for NAFLD were available from a genome-wide association meta-analysis (1483 cases and 17,781 controls), the FinnGen consortium (894 cases and 217,898 controls), and the UK Biobank study (275 cases and 360,919 controls). Summary-level data for 4 liver enzymes were obtained from the UK Biobank. RESULTS There were genetic correlations of S-25(OH)D with NAFLD and certain liver enzymes. Genetically predicted higher levels of S-25(OH)D were consistently associated with a decreased risk of NAFLD in the 3 sources. For a 1-SD increase in genetically predicted S-25(OH)D levels, the combined odds ratio of NAFLD was 0.78 (95% confidence interval [CI], 0.69 to 0.89). Genetically predicted higher levels of S-25(OH)D showed a borderline association with aspartate aminotransferase levels (change -1.17; 95% CI, -1.36 to 0.01). Genetic predisposition to NAFLD was not associated with S-25(OH)D (change 0.13; 95% CI, -1.26 to 0.53). CONCLUSIONS Our findings have clinical implications as they suggest that increased vitamin D levels may play a role in NAFLD prevention in European populations.
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Effects of vitamin D treatment on thyroid function and autoimmunity markers in patients with Hashimoto's thyroiditis-A meta-analysis of randomized controlled trials.
Jiang, H, Chen, X, Qian, X, Shao, S
Journal of clinical pharmacy and therapeutics. 2022;47(6):767-775
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Hashimoto's thyroiditis (HT), also called chronic lymphocytic thyroiditis, is the most prevalent organ-specific autoimmune disorder as well as the most common cause of thyroid hypofunction. The main purpose of HT treatment is the control of hypothyroidism, including oral administration of a synthetic hormone to achieve normal circulating thyrotropin levels. The aim of this study was to review the association between vitamin D treatment in patients with HT by assessing patients’ serum circulating 25-hydroxyvitamin D - 25(OH)D - level to evaluate whether a change occurs in the course of disease. This study is a systematic review and meta-analysis of seven cohorts of patients from six studies (3 prospective cohort studies and 3 randomised controlled trials). Results show that vitamin D might significantly increase the serum 25(OH)D levels and produce changes in thyroid peroxidase antibodies titres. However, there wasn't a significant association between serum vitamin D supplementation and the levels of thyroid-stimulating hormone, thyroglobulin antibodies, free triiodothyronine and free thyroxine. Authors conclude that their findings suggest that vitamin D is not associated with the function of the thyroid in patients with HT. Thus, further well-designed randomised controlled trials with sufficient sample sizes investigating the effect of vitamin D on thyroid function are still warranted.
Abstract
INTRODUCTION Recent evidence suggested that vitamin D deficiency was associated with Hashimoto's thyroiditis (HT) pathogenesis and thyroid hypofunction. This study aimed to investigate whether vitamin D supplementation would be effective in the prevention and progression of hypothyroidism in patients with HT. METHODS PubMed, Embase and the Cochrane library were searched for randomized controlled trials (RCTs) and prospective cohort studies published from inception to August 2021. RESULTS A total of 7 cohorts of patients from six clinical trials with 258 patients with HT were included. Significant difference was found (WMD = 19.00, 95% CI: 12.43, 25.58, p < 0.001; I2 = 90.0%, pheterogeneity < 0.001) between the vitamin D group and control group in serum 25-hydroxyvitamin D level. And the combined results indicated vitamin D supplementation significantly reduced the level of thyroid peroxidase antibodies (TPO-Ab) compared to the control group (WMD = -158.18, 95% CI: -301.92, -14.45, p = 0.031; I2 = 68.8%, pheterogeneity = 0.007). Whereas no significant differences were found on the levels of thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4) compared to the control group (p > 0.05). WHAT IS NEW AND CONCLUSION Our study demonstrated that vitamin D treatment might significantly increase the serum 25(OH)D levels and produce changes in TPO-Ab titres. No significant association was found between serum vitamin D treatment and the levels of TG-Ab, TSH, FT3 and FT4, suggesting that vitamin D is not associated with the function of the thyroid in patients with HT.
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Effects of Vitamin D Supplementation During Pregnancy on Birth Size: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
Maugeri, A, Barchitta, M, Blanco, I, Agodi, A
Nutrients. 2019;11(2)
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Vitamin D deficiency may affect mother and neonatal outcomes, increasing the risk of pregnancy complications, preterm birth, low birth weight (LBW), small for gestational age (SGA), and poor offspring health. This systematic review and meta-analysis evaluates the effects of oral vitamin D supplementation during pregnancy on foetal growth and incidence of LBW and SGA births. 13 randomised controlled trials (RCTs), published between 1980 and 2016, were included in the meta-analysis, including in total 2016 newborns (1184 from mothers in the intervention groups and 832 from controls). Dosages ranged from 200-4000 IU for daily intakes and 35000 IU to 600000 IU for single or intermittent administration. Whilst there was no evidence for publication bias (e.g. an over-reporting of positive outcomes), overall, the quality of the reviewed studies varied from very low (head circumference) to moderate (birth weight, birth length, LBW, and SGA). All studies evaluating the effect of vitamin D supplementation on blood 25-hydroxyvitamin D (OHD) levels showed that intervention significantly increased 25-OHD concentration in both mothers and infants. The meta-analysis showed that vitamin D supplementation significantly increased birth weight and length, independent of dosage and whether vitamin D was administered daily or in single/intermittent high dosages. Head circumference was increased in a non-dose dependent way with daily but not with single/intermittent vitamin D supplementation. Effects on all three parameters were seen when vitamin D was supplemented alone, but not in combination with other nutrients. Both, risk of LBW and SGA, were also significantly reduced with vitamin D supplementation.
Abstract
During pregnancy, vitamin D supplementation may be a feasible strategy to help prevent low birthweight (LBW) and small for gestational age (SGA) births. However, evidence from randomized controlled trials (RCTs) is inconclusive, probably due to heterogeneity in study design and type of intervention. A systematic literature search in the PubMed-Medline, EMBASE, and Cochrane Central Register of Controlled Trials databases was carried out to evaluate the effects of oral vitamin D supplementation during pregnancy on birthweight, birth length, head circumference, LBW, and SGA. The fixed-effects or random-effects models were used to calculate mean difference (MD), risk ratio (RR), and 95% Confidence Interval (CI). On a total of 13 RCTs, maternal vitamin D supplementation had a positive effect on birthweight (12 RCTs; MD = 103.17 g, 95% CI 62.29⁻144.04 g), length (6 RCTs; MD = 0.22 cm, 95% CI 0.11⁻0.33 cm), and head circumference (6 RCTs; MD:0.19 cm, 95% CI 0.13⁻0.24 cm). In line with these findings, we also demonstrated that maternal vitamin D supplementation reduced the risk of LBW (3 RCTs; RR = 0.40, 95% CI 0.22⁻0.74) and SGA (5 RCTS; RR = 0.69, 95% CI 0.51⁻0.92). The present systematic review and meta-analysis confirmed the well-established effect of maternal vitamin D supplementation on birth size. However, further research is required to better define risks and benefits associated with such interventions and the potential implications for public health.
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Vitamin D receptor gene FokI but not TaqI, ApaI, BsmI polymorphism is associated with Hashimoto's thyroiditis: a meta-analysis.
Wang, X, Cheng, W, Ma, Y, Zhu, J
Scientific reports. 2017;7:41540
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Vitamin D is a vitamin that is involved in several immune processes within the body. It acts on immune cells through binding to vitamin D receptors (VDR) and modulating their activity. However genetic variations in VDRs is apparent amongst individuals, with the four most common being TaqI, ApaI, FokI and BsmI. The presence of any of these variations has been associated with the development of several different diseases. This systematic review and meta-analysis aimed to determine whether any of these variations in the VDR was associated with the development of Hashimoto’s thyroiditis (HT), a disease whereby the immune system does not recognise and attacks the body’s own tissues. The results showed that only the FokI variation was associated with the development of HT and only in individuals with Asian heritage. It was concluded that the FokI variation of the VDR is associated with an increased risk of HT in Asians but not Caucasians, however how this occurs is not fully understood. This study could be used by healthcare professionals to understand that genetic variations on the VDR may be indicative of risk of developing HT in individuals from Asian descent.
Abstract
Four VD receptor (VDR) gene polymorphisms (TaqI, ApaI, FokI and BsmI) have been reported to influence Hashimoto's thyroiditis (HT) risk. However, individual studies have produced inconsistent results. We conducted a comprehensive meta-analysis of eleven case-control studies to better understand roles of the four polymorphisms in HT development. The results showed only FokI polymorphism was significantly associated with the risk of HT (F vs f: OR = 1.44, 95% CI = 1.09-1.91, P = 0.010; FF vs Ff + ff: OR = 1.72, 95% CI = 1.09-2.70, P = 0.019). Subgroup analyses demonstrated the significant effect was only present in Asian population (F vs f: OR = 1.45, 95% CI = 1.07-1.95, P = 0.016; FF vs ff: OR = 1.64, 95% CI = 1.03-2.59, P = 0.036; FF + Ff vs ff: OR = 1.34, 95% CI = 1.00-1.80, P = 0.047; FF vs Ff + ff: OR = 1.64, 95% CI = 1.03-2.64, P = 0.039), but not in Caucasian. For TaqI, ApaI and BsmI polymorphisms, no significant association was found in any model comparison. Based on the current literature, it appears that only VDR FokI polymorphism is associated with HT risk in Asian population, but not in Caucasians; and the TaqI, ApaI and BsmI polymorphisms have not positive association neither in the overall population, nor when stratified by ethnicity. Further well-designed studies with larger sample sizes and different ethnic population are needed to clarify the present findings.