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Nutrition Journal Jun 2024This meta-analysis aims to analyze the relationship between serum vitamin D (VD) levels and Graves' disease (GD). (Meta-Analysis)
Meta-Analysis
OBJECTIVE
This meta-analysis aims to analyze the relationship between serum vitamin D (VD) levels and Graves' disease (GD).
METHODS
We conducted a search for publications on VD and GD in the English language. Our search encompassed databases such as PubMed, Embase, Web of Science, and the Cochrane Library, covering publications available through August 2023. A meta-analysis was performed using Cochrane RevMan 5.4 software. The standardized mean difference (SMD) and 95% confidence interval (CI) were used for outcome calculation. We used R software to test for publication bias.
RESULTS
Twelve studies were selected, comprising 937 (22.4%) cases with GD and 3254 (77.6%) controls. The overall meta-analysis revealed that patients with GD are significantly more likely to have low VD levels (SMD = - 0.66; 95% CI: -1.05, - 0.27; p = 0.001) than those in the control group. Egger's test results indicated no publication bias (p = 0.0791). These studies exhibited a high degree of heterogeneity (chi-square = 205.86, p < 0.00001; I = 95%). Subgroup analysis was conducted based on assay method, geographic location, and mean age of the case group to explore the heterogeneity sources. Assay methods and geographic locations were identified as potential heterogeneity sources. Based on the mean age, there were no statistically significant differences found in the subgroup analysis of the included studies.
CONCLUSION
There is promising evidence that low serum VD levels may increase the risk of GD. Further rigorous and long-term trials are needed to explore the role of VD in the onset and treatment of GD.
Topics: Humans; Graves Disease; Vitamin D; Vitamin D Deficiency
PubMed: 38849834
DOI: 10.1186/s12937-024-00960-2 -
International Journal For Vitamin and... Dec 2023It is now becoming increasingly recognized that the effects of vitamin D supplementation may vary by several factors including vitamin D deficiency status, ethnicity,... (Meta-Analysis)
Meta-Analysis Review
Genetic variations of vitamin D receptor and vitamin D supplementation interaction in relation to serum vitamin D and metabolic traits: a systematic review and meta-analysis.
It is now becoming increasingly recognized that the effects of vitamin D supplementation may vary by several factors including vitamin D deficiency status, ethnicity, and/or the presence of genetic variants, which affect individual responses to supplementation. This study investigates the interaction between metabolic traits and circulating 25-hydroxyvitamin-D (25OHD) concentration with 4 polymorphisms of vitamin D receptor (VDR) including BsmI, ApaI, TaqI, FokI, and vitamin D supplementation. A systematic review and meta-analysis of papers until August 2021 on PubMed, The Cochrane Library, Scopus, Web of Science, Google Scholar, ProQuest, Science Direct, and Embase about the association between functionally relevant VDR variants and vitamin D supplementation on circulating 25OHD and metabolic traits. A total of 2994 cases from 16 randomized controlled trial (RCT) studies were included in meta-analyses. There were no significant changes in the serum concentrations of 25OHD and metabolic traits after vitamin D supplementation in different variants of BsmI, ApaI, TaqI, and FokI polymorphism in the VDR gene in the overall analysis (p>0.05). However, the results showed there is significant interaction between these above VDR polymorphisms and vitamin D supplement on serum 25OHD level after subgroup analyses based on the study duration, gender, age, BMI, health status, Hardy-Weinberg Equilibrium, PCR, and race (p<0.05). The present meta-analysis demonstrates that the effect of vitamin D supplementation on serum 25OHD and metabolic traits is independent of genetic variants of the VDR gene (BsmI, ApaI, TaqI, and FokI). However, future trials should consider inter-individual differences and, in particular, should aim to clarify whether certain subgroups of individuals may benefit from vitamin D supplementation in the context of metabolic health.
Topics: Humans; Receptors, Calcitriol; Genetic Predisposition to Disease; Vitamin D; Polymorphism, Genetic; Dietary Supplements; Randomized Controlled Trials as Topic
PubMed: 35997204
DOI: 10.1024/0300-9831/a000762 -
The Cochrane Database of Systematic... Oct 2023Vitamin D possesses immunomodulatory properties and has been implicated in the pathogenesis and severity of inflammatory bowel disease (IBD). Animal studies and emerging... (Review)
Review
BACKGROUND
Vitamin D possesses immunomodulatory properties and has been implicated in the pathogenesis and severity of inflammatory bowel disease (IBD). Animal studies and emerging epidemiological evidence have demonstrated an association between vitamin D deficiency and worse disease activity. However, the role of vitamin D for the treatment of IBD is unclear.
OBJECTIVES
To evaluate the benefits and harms of vitamin D supplementation as a treatment for IBD.
SEARCH METHODS
We used standard, extensive Cochrane search methods. The latest search date was Jun 2023.
SELECTION CRITERIA
We included randomised controlled trials (RCTs) in people of all ages with active or inactive IBD comparing any dose of vitamin D with another dose of vitamin D, another intervention, placebo, or no intervention. We defined doses as: vitamin D (all doses), any-treatment-dose vitamin D (greater than 400 IU/day), high-treatment-dose vitamin D (greater than 1000 IU/day), low-treatment-dose vitamin D (400 IU/day to 1000 IU/day), and supplemental-dose vitamin D (less than 400 IU/day).
DATA COLLECTION AND ANALYSIS
We used standard Cochrane methods. Our primary outcomes were 1. clinical response for people with active disease, 2. clinical relapse for people in remission, 3. quality of life, and 4. withdrawals due to adverse events. Our secondary outcomes were 5. disease activity at end of study, 6. normalisation of vitamin D levels at end of study, and 7. total serious adverse events. We used GRADE to assess certainty of evidence for each outcome.
MAIN RESULTS
We included 22 RCTs with 1874 participants. Study duration ranged from four to 52 weeks. Ten studies enroled people with Crohn's disease (CD), five enroled people with ulcerative colitis (UC), and seven enroled people with CD and people with UC. Seventeen studies included adults, three included children, and two included both. Four studies enroled people with active disease, six enroled people in remission, and 12 enroled both. We assessed each study for risk of bias across seven individual domains. Five studies were at low risk of bias across all seven domains. Ten studies were at unclear risk of bias in at least one domain but with no areas of high risk of bias. Seven studies were at high risk of bias for blinding of participants and assessors. Vitamin D (all doses) versus placebo or no treatment Thirteen studies compared vitamin D against placebo or no treatment. We could not draw any conclusions on clinical response for UC as the certainty of the evidence was very low (risk ratio (RR) 4.00, 95% confidence interval (CI) 1.51 to 10.57; 1 study, 60 participants). There were no data on CD. There may be fewer clinical relapses for IBD when using vitamin D compared to placebo or no treatment (RR 0.57, 95% CI 0.34 to 0.96; 3 studies, 310 participants). The certainty of the evidence was low. We could not draw any conclusions on quality of life for IBD (standardised mean difference (SMD) -0.13, 95% CI -3.10 to 2.83 (the SMD value indicates a negligent decrease in quality of life, and the corresponding CIs indicate that the effect can range from a large decrease to a large increase in quality of life); 2 studies, 243 participants) or withdrawals due to adverse events for IBD (RR 1.97, 95% CI 0.18 to 21.27; 12 studies, 1251 participants; note 11 studies reported withdrawals but recorded 0 events in both groups. Thus, the RR and CIs were calculated from 1 study rather than 12). The certainty of the evidence was very low. High-treatment-dose vitamin D versus low-treatment-dose vitamin D Five studies compared high treatment vitamin D doses against low treatment vitamin D doses. There were no data on clinical response. There may be no difference in clinical relapse for CD (RR 0.48, 95% CI 0.23 to 1.01; 1 study, 34 participants). The certainty of the evidence was low. We could not draw any conclusions on withdrawals due to adverse events for IBD as the certainty of the evidence was very low (RR 0.89, 95% CI 0.06 to 13.08; 3 studies, 104 participants; note 2 studies reported withdrawals but recorded 0 events in both groups. Thus, the RR and CIs were calculated from 1 study rather than 3). The data on quality of life and disease activity could not be meta-analysed, were of very low certainty, and no conclusions could be drawn. Any-treatment-dose vitamin D versus supplemental-dose vitamin D Four studies compared treatment doses of vitamin D against supplemental doses. There were no data on clinical response and relapse. There were no data on quality of life that could be meta-analysed. We could not draw any conclusions on withdrawals due to adverse events for IBD as the certainty of the evidence was very low (RR 3.09, 95% CI 0.13 to 73.17; 4 studies, 233 participants; note 3 studies reported withdrawals but recorded 0 events in both groups. Thus, the RR and CIs were calculated from 1 study rather than 4).
AUTHORS' CONCLUSIONS
There may be fewer clinical relapses when comparing vitamin D with placebo, but we cannot draw any conclusions on differences in clinical response, quality of life, or withdrawals, due to very low-certainty evidence. When comparing high and low doses of vitamin D, there were no data for clinical response, but there may be no difference in relapse for CD. We cannot draw conclusions on the other outcomes due to very low certainty evidence. Finally, comparing vitamin D (all doses) to supplemental-dose vitamin D, there were no data on clinical relapse or response, and we could not draw conclusions on other outcomes due to very low certainty evidence or missing data. It is difficult to make any clear recommendations for future research on the basis of the findings of this review. Future studies must be clear on the baseline populations, the purpose of vitamin D treatment, and, therefore, study an appropriate dosing strategy. Stakeholders in the field may wish to reach consensus on such issues prior to new studies.
Topics: Adult; Animals; Child; Humans; Vitamin D; Remission Induction; Neoplasm Recurrence, Local; Colitis, Ulcerative; Crohn Disease; Recurrence
PubMed: 37781953
DOI: 10.1002/14651858.CD011806.pub2 -
Journal of Clinical Neuroscience :... Jan 2024Previous studies have linked vitamin D deficiency with autoimmune diseases, and recent research has found low vitamin D levels in neuromyelitis optica spectrum disorder... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Previous studies have linked vitamin D deficiency with autoimmune diseases, and recent research has found low vitamin D levels in neuromyelitis optica spectrum disorder (NMOSD) patients. We aimed to determine the variances in serum 25(OH)D levels between NMOSD patients and healthy controls.
METHODS
We searched English and Chinese databases (PubMed, Embase, Cochrane Library, Web of Science, CBM, CNKI, WanFang Med, VIP) for observational studies related to serum 25(OH)D levels in NMOSD patients published up to August 24, 2023. We included studies with healthy controls and compared serum 25(OH)D levels between NMOSD patients and controls. We computed the mean difference (MD) and 95% confidence interval (CI) for continuous variables to evaluate serum 25(OH)D levels and combined odds ratios (ORs) and 95% CIs for dichotomized 25(OH)D data.
RESULTS
Six papers were selected for meta-analysis, including 794 participants (347 in the NMOSD group and 447 in the healthy control group). Meta-analysis showed significantly lower serum 25(OH)D levels in the NMOSD group (MD: -7.83, 95 % CI: -10.99 to -4.68). The risk of 25(OH)D deficiency was 23.36 times higher in the NMOSD group (OR: 23.36, 95 % CI: 0.85 to 640.76, p = 0.06>0.05), with a 94 % occurrence rate. There was no significant difference in the risk of having sufficient 25(OH)D between the groups (p = 0.12>0.05).
CONCLUSION
NMOSD patients have lower serum 25(OH)D levels than healthy controls. However, the current research results do not provide evidence for a causal relationship between serum 25(OH)D levels and the onset of NMOSD. Routine vitamin D supplementation may be advantageous for patients with NMOSD.
Topics: Humans; Neuromyelitis Optica; Vitamin D; Vitamin D Deficiency
PubMed: 38113581
DOI: 10.1016/j.jocn.2023.12.010 -
Nutrition & Diabetes May 2024Vitamin D deficiency has been linked with several adverse maternal and fetal outcomes.
BACKGROUND
Vitamin D deficiency has been linked with several adverse maternal and fetal outcomes.
OBJECTIVE
To summarize systematic reviews and meta-analyses evaluating the effects of vitamin D deficiency and of vitamin D supplementation in pregnancy on maternal and offspring health-related outcomes.
METHODS
Prior to conducting this umbrella review, we registered the protocol in PROSPERO (CRD42022368003). We conducted searches in PubMed, Embase, and Cochrane Library for systematic reviews and meta-analyses on vitamin D in pregnancy, from database inception to October 2, 2023. All outcomes related to vitamin D in pregnancy obtained from the systematic reviews and meta-analyses were extracted.
DATA EXTRACTION
Two reviewers independently chose studies and collected information on health outcomes. The quality of the included articles' methodology was assessed using AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews-2).
RESULTS
We identified 16 eligible systematic reviews and meta-analyses, which included 250,569 women. Our results demonstrated that vitamin D deficiency in pregnancy is associated with increased risk of preterm birth, small-for gestational age/low birth weight infants, recurrent miscarriage, bacterial vaginosis and gestational diabetes mellitus. Vitamin D supplementation in pregnancy increases birth weight, and reduces the risk of maternal pre-eclampsia, miscarriage, and vitamin D deficiency, fetal or neonatal mortality, as well as attention-deficit hyperactivity disorder, and autism spectrum disorder in childhood. In women with gestational diabetes mellitus, vitamin D supplementation in pregnancy can reduce the risk of maternal hyperbilirubinemia, polyhydramnios, macrosomia, fetal distress, and neonatal hospitalization.
CONCLUSION
Due to the association with adverse maternal and offspring health outcomes, we recommend the vitamin D status in pregnancy should be monitored, particularly in women at high risk of vitamin D deficiency. It is suggested that pregnant women take a dose of >400 IU/day of vitamin D supplementation during pregnancy to prevent certain adverse outcomes.
Topics: Humans; Pregnancy; Female; Vitamin D Deficiency; Vitamin D; Pregnancy Complications; Dietary Supplements; Pregnancy Outcome; Systematic Reviews as Topic; Meta-Analysis as Topic; Infant, Newborn; Premature Birth
PubMed: 38816412
DOI: 10.1038/s41387-024-00296-0 -
Critical Reviews in Food Science and... 2024Micronutrients are clinically important in managing COVID-19, and numerous studies have been conducted, but inconsistent findings exist. (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
Micronutrients are clinically important in managing COVID-19, and numerous studies have been conducted, but inconsistent findings exist.
OBJECTIVE
To explore the association between micronutrients and COVID-19.
METHODS
PubMed, Web of Science, Embase, Cochrane Library and Scopus for study search on July 30, 2022 and October 15, 2022. Literature selection, data extraction and quality assessment were performed in a double-blinded, group discussion format. Meta-analysis with overlapping associations were reconsolidated using random effects models, and narrative evidence was performed in tabular presentations.
RESULTS
57 reviews and 57 latest original studies were included. 21 reviews and 53 original studies were of moderate to high quality. Vitamin D, vitamin B, zinc, selenium, and ferritin levels differed between patients and healthy people. Vitamin D and zinc deficiencies increased COVID-19 infection by 0.97-fold/0.39-fold and 1.53-fold. Vitamin D deficiency increased severity 0.86-fold, while low vitamin B and selenium levels reduced severity. Vitamin D and calcium deficiencies increased ICU admission by 1.09 and 4.09-fold. Vitamin D deficiency increased mechanical ventilation by 0.4-fold. Vitamin D, zinc, and calcium deficiencies increased COVID-19 mortality by 0.53-fold, 0.46-fold, and 5.99-fold, respectively.
CONCLUSION
The associations between vitamin D, zinc, and calcium deficiencies and adverse evolution of COVID-19 were positive, while the association between vitamin C and COVID-19 was insignificant. PROSPERO CRD42022353953.
Topics: Humans; COVID-19; Ferritins; Micronutrients; SARS-CoV-2; Selenium; Vitamin D; Vitamin D Deficiency; Zinc; Meta-Analysis as Topic
PubMed: 36794398
DOI: 10.1080/10408398.2023.2174948 -
BMC Pediatrics Mar 2024The impact of vitamin D on type 1 diabetes has been a controversial topic in public health. Furthermore, significant differences in the proportion of vitamin D have been... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The impact of vitamin D on type 1 diabetes has been a controversial topic in public health. Furthermore, significant differences in the proportion of vitamin D have been noted. The purpose of this systematic review was to determine the overall proportion of vitamin D deficiency in children/adolescents with type 1 diabetes (T1D).
METHODS
Based on six electronic databases (PubMed, Web of Science, Embase, Ovid Medline, ProQuest, and Cochrane Library), eligible studies since the databases' inception up to April 2022 were searched. Reference lists were also manually searched to identify additional studies. Overall, studies with statistical information on vitamin D deficiency in children and adolescents with T1D were included, and a random effects model was applied for the meta-analysis. In addition, subgroup and sensitivity analyses were carried out to evaluate heterogeneity, and publication bias was evaluated by using Egger's test.
RESULTS
A total of 45 studies involving 6,995 participants met the inclusion criteria; these included 25 countries covering Africa, Oceania, Europe, North America and Asia. The proportion of vitamin D deficiency in children/adolescents with T1D was 45% (95% confidence interval [CI] 37-54%, I = 97.94%). Subgroup analysis further revealed that the publication year, study design, vitamin D classification, season and geographical region significantly contributed to the variation in the reported incidence of vitamin D deficiency.
CONCLUSIONS
The results of the meta-analysis showed that the proportion of vitamin D deficiency among T1D children/adolescents was 45%. In addition, the proportion remains higher, which has important implications for adapting health and social care systems.
Topics: Child; Humans; Adolescent; Diabetes Mellitus, Type 1; Vitamins; Vitamin D; Vitamin D Deficiency; Research Design
PubMed: 38493103
DOI: 10.1186/s12887-024-04683-5 -
Cureus May 2024There have been suggestions that vitamin D has anti-inflammatory effects; however, the variabilities of vitamin D levels among specific groups of patients and its... (Review)
Review
There have been suggestions that vitamin D has anti-inflammatory effects; however, the variabilities of vitamin D levels among specific groups of patients and its association with these inflammatory events have not been demonstrated. This study aims to study the association between vitamin D levels and vitamin D deficiency and inflammatory events among the elderly population. PubMed, Web of Science, Scopus, Science Direct, and ClinicalKey were systematically searched in December 2023 to include the relevant data. Comprehensive Meta-Analysis (version 3.0, Biostat, Inc., Englewood, NJ) was the software used for data analyses. A total of 12 studies were included in this analysis with 14,717 elderly patients. There was an overall significant decrease in vitamin D levels in elderly patients with high inflammatory markers compared to controls (Hedges' g = -0.221, 95% CI: -0.268, -0.173, P < 0.001), and event of vitamin D deficiency was found to be 0.321 (95% CI: 0.305, 0.337, P < 0.001). There is a significant decrease in vitamin D levels among the elderly with different inflammatory conditions. Future longitudinal studies and well-designed, large, randomized controlled trials are required to study the association between vitamin D deficiency and the incidence of inflammatory events in this specific group of patients.
PubMed: 38910627
DOI: 10.7759/cureus.60892 -
Heliyon Nov 2023Various pathophysiologic mechanisms were proposed to underlie the effect of vitamin D on MetS components. In this systematic review, we reviewed randomized control...
Effects of vitamin D supplementation on cardiometabolic parameters among patients with metabolic syndrome: A systematic review and GRADE evidence synthesis of randomized controlled trials.
Various pathophysiologic mechanisms were proposed to underlie the effect of vitamin D on MetS components. In this systematic review, we reviewed randomized control clinical trials to verify whether vitamin D supplementation (VDS) at different doses is effective concomitantly in controlling high-density lipoprotein cholesterol (HDL-c), triglycerides (TG), fasting glucose level, blood pressure, and central obesity in adults diagnosed with MetS. The following scientific databases were searched from 1998 until April 2023: EMBASE, MEDLINE (PubMed), Web of Science, Latin American and Caribbean Health Sciences Literature (Lilacs), the Cochrane Central Register of Controlled Trials, clinicaltrial.gov, and Google Scholar. No language restrictions were applied. Seven studies were included, and they showed a high level of heterogeneity. All studies reported a significant increase in serum 25(OH)D levels in the intervention groups. Of these, only two noted a significant decrease in triglyceride (TG) level and waist circumference. However, the certainty levels of the evidence rating were very low and low for triglyceride (TG) level and waist circumference, respectively, and moderate for fasting glucose level, blood pressure, and HDL-c. In conclusion, despite these benefits, considering the low certainty, the evidence does not support that VDS decreases triglyceride (TG) level and waist circumference in adults with MetS.
PubMed: 37885733
DOI: 10.1016/j.heliyon.2023.e20845 -
PloS One 2024Maternal vitamin D deficiency is a prevalent public health issue worldwide. While isolated reports from certain cities in China have highlighted the existence of... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
Maternal vitamin D deficiency is a prevalent public health issue worldwide. While isolated reports from certain cities in China have highlighted the existence of maternal vitamin D deficiency, no nationwide investigation has been conducted on this topic. Therefore, we conducted a meta-analysis and systematic review to examine the prevalence and associated influencing factors of maternal vitamin D deficiency in mainland China. This study aims to provide a theoretical foundation for future prevention and supplementation strategies for maternal vitamin D.
METHODS
We retrieved relevant Chinese and English literature on the status of maternal vitamin D deficiency in mainland China from databases such as CNKI, Wanfang Data, VIP, CBM, Web of Science, Google Scholar, and PubMed. The literature search and database construction were conducted until September 8, 2023. Data were extracted and synthesized following PRISMA guidelines.After literature screening and quality assessment, we performed meta-analysis, sensitivity analysis, and identified publication bias using RevMan 5.3 software.
RESULTS
A total of 26 articles were reviewed, involving 128,820 pregnant women. Among them, 108,768 had vitamin D insufficiency or deficiency, resulting in a prevalence of 84% (95% CI: 81%~88%). Subgroup analysis revealed the highest prevalence of vitamin D deficiency or insufficiency among pregnant women in mainland China to be in the northwest region (94%, 95% CI: 94%~95%). Furthermore, the highest prevalence was observed during the winter and spring seasons (80%, 95% CI: 77%~83%) and in the early stages of pregnancy (93%, 95% CI: 90%~95%). Significant statistical differences (P<0.05) were found among these three subgroups. No publication bias was detected, and sensitivity analysis indicated the stability of the meta-analysis outcome.
CONCLUSION
This study provides evidence of the prevalence of vitamin D deficiency or insufficiency among pregnant women in mainland China. To improve the overall health and well-being of the population, relevant health authorities should develop policies aimed at alleviating this phenomenon.
Topics: Humans; Female; Pregnancy; China; Vitamin D Deficiency; Vitamin D; Pregnancy Complications; Prevalence; Seasons
PubMed: 38723005
DOI: 10.1371/journal.pone.0297613