A Trial of Calcium and Vitamin D for the Prevention of Colorectal Adenomas

Dietary vitamin D intake and risk of colorectal cancer according to vitamin D receptor expression in tumors and their surrounding stroma

BACKGROUND

Colorectal Cancer (CRC) has been molecularly classified into several subtypes according to tumor, stromal, and immune components. Here, we investigated whether the preventive effect of vitamin D on CRC varies with subtypes defined by Vitamin D receptor (VDR) expression in tumors and their surrounding stroma, along with the association of somatic mutations in CRC.

METHODS

In a population-based prospective study of 22,743 Japanese participants, VDR expression levels in tumors and their surrounding stroma were defined in 507 cases of newly diagnosed CRC using immunohistochemistry. Hazard ratios of CRC and its subtypes according to dietary vitamin D intake were estimated using multivariable Cox proportional hazards models.

RESULTS

Dietary vitamin D intake was not associated with CRC or its subtypes defined by VDR expression in tumors. However, an inverse association was observed for CRC with high VDR expression in the stroma (the highest tertile vs the lowest tertile: 0.46 [0.23-0.94], Ptrend = 0.03), but not for CRC with low VDR expression in the stroma (Pheterogeneity = 0.02). Furthermore, CRC with high VDR expression in the stroma had more somatic TP53 and BRAF mutations and fewer APC mutations than those with low VDR expression in the stroma.

CONCLUSIONS

This study provides the first evidence that the preventive effect of vitamin D on CRC depends on VDR expression in the stroma rather than in the tumors. CRC with high VDR expression in the stroma is likely to develop through a part of the serrated polyp pathway, which tends to occur with BRAF but not with APC mutations.

Vitamin D for the Prevention of Disease: An Endocrine Society Clinical Practice Guideline

BACKGROUND

Numerous studies demonstrate associations between serum concentrations of 25-hydroxyvitamin D (25[OH]D) and a variety of common disorders, including musculoskeletal, metabolic, cardiovascular, malignant, autoimmune, and infectious diseases. Although a causal link between serum 25(OH)D concentrations and many disorders has not been clearly established, these associations have led to widespread supplementation with vitamin D and increased laboratory testing for 25(OH)D in the general population. The benefit-risk ratio of this increase in vitamin D use is not clear, and the optimal vitamin D intake and the role of testing for 25(OH)D for disease prevention remain uncertain.

OBJECTIVE

To develop clinical guidelines for the use of vitamin D (cholecalciferol [vitamin D3] or ergocalciferol [vitamin D2]) to lower the risk of disease in individuals without established indications for vitamin D treatment or 25(OH)D testing.

METHODS

A multidisciplinary panel of clinical experts, along with experts in guideline methodology and systematic literature review, identified and prioritized 14 clinically relevant questions related to the use of vitamin D and 25(OH)D testing to lower the risk of disease. The panel prioritized randomized placebo-controlled trials in general populations (without an established indication for vitamin D treatment or 25[OH]D testing), evaluating the effects of empiric vitamin D administration throughout the lifespan, as well as in select conditions (pregnancy and prediabetes). The panel defined "empiric supplementation" as vitamin D intake that (a) exceeds the Dietary Reference Intakes (DRI) and (b) is implemented without testing for 25(OH)D. Systematic reviews queried electronic databases for publications related to these 14 clinical questions. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology was used to assess the certainty of evidence and guide recommendations. The approach incorporated perspectives from a patient representative and considered patient values, costs and resources required, acceptability and feasibility, and impact on health equity of the proposed recommendations. The process to develop this clinical guideline did not use a risk assessment framework and was not designed to replace current DRI for vitamin D.

RESULTS

The panel suggests empiric vitamin D supplementation for children and adolescents aged 1 to 18 years to prevent nutritional rickets and because of its potential to lower the risk of respiratory tract infections; for those aged 75 years and older because of its potential to lower the risk of mortality; for those who are pregnant because of its potential to lower the risk of preeclampsia, intra-uterine mortality, preterm birth, small-for-gestational-age birth, and neonatal mortality; and for those with high-risk prediabetes because of its potential to reduce progression to diabetes. Because the vitamin D doses in the included clinical trials varied considerably and many trial participants were allowed to continue their own vitamin D-containing supplements, the optimal doses for empiric vitamin D supplementation remain unclear for the populations considered. For nonpregnant people older than 50 years for whom vitamin D is indicated, the panel suggests supplementation via daily administration of vitamin D, rather than intermittent use of high doses. The panel suggests against empiric vitamin D supplementation above the current DRI to lower the risk of disease in healthy adults younger than 75 years. No clinical trial evidence was found to support routine screening for 25(OH)D in the general population, nor in those with obesity or dark complexion, and there was no clear evidence defining the optimal target level of 25(OH)D required for disease prevention in the populations considered; thus, the panel suggests against routine 25(OH)D testing in all populations considered. The panel judged that, in most situations, empiric vitamin D supplementation is inexpensive, feasible, acceptable to both healthy individuals and health care professionals, and has no negative effect on health equity.

CONCLUSION

The panel suggests empiric vitamin D for those aged 1 to 18 years and adults over 75 years of age, those who are pregnant, and those with high-risk prediabetes. Due to the scarcity of natural food sources rich in vitamin D, empiric supplementation can be achieved through a combination of fortified foods and supplements that contain vitamin D. Based on the absence of supportive clinical trial evidence, the panel suggests against routine 25(OH)D testing in the absence of established indications. These recommendations are not meant to replace the current DRIs for vitamin D, nor do they apply to people with established indications for vitamin D treatment or 25(OH)D testing. Further research is needed to determine optimal 25(OH)D levels for specific health benefits.

A Systematic Review Supporting the Endocrine Society Clinical Practice Guidelines on Vitamin D

CONTEXT

Low vitamin D status is common and is associated with various common medical conditions.

OBJECTIVE

To support the development of the Endocrine Society's Clinical Practice Guideline on Vitamin D for the Prevention of Disease.

METHODS

We searched multiple databases for studies that addressed 14 clinical questions prioritized by the guideline panel. Of the 14 questions, 10 clinical questions assessed the effect of vitamin D vs no vitamin D in the general population throughout the lifespan, during pregnancy, and in adults with prediabetes; 1 question assessed dosing; and 3 questions addressed screening with serum 25-hydroxyvitamin D (25[OH]D). The Grading of Recommendations Assessment, Development and Evaluation approach was used to assess certainty of evidence.

RESULTS

Electronic searches yielded 37 007 citations, from which we included 151 studies. In children and adolescents, low-certainty evidence suggested reduction in respiratory tract infections with empiric vitamin D. There was no significant effect on select outcomes in healthy adults aged 19 to 74 years with variable certainty of evidence. There was a very small reduction in mortality among adults older than 75 years with high certainty of evidence. In pregnant women, low-certainty evidence suggested possible benefit on various maternal, fetal, and neonatal outcomes. In adults with prediabetes, moderate certainty of evidence suggested reduction in the rate of progression to diabetes. Administration of high-dose intermittent vitamin D may increase falls, compared to lower-dose daily dosing. We did not identify trials on the benefits and harms of screening with serum 25(OH)D.

CONCLUSION

The evidence summarized in this systematic review addresses the benefits and harms of vitamin D for the prevention of disease. The guideline panel considered additional information about individuals' and providers' values and preferences and other important decisional and contextual factors to develop clinical recommendations.

The Role of Dietary Vitamins and Antioxidants in Preventing Colorectal Cancer: A Systematic Review

The role of dietary vitamins and antioxidants in preventing colorectal cancer (CRC) is a significant area of research within nutritional oncology. However, the relationship between these nutrients and CRC prevention is complex and influenced by factors such as dosage, timing, and individual health status. This review aims to comprehensively analyze and synthesize the existing scientific literature on the potential role of dietary vitamins and antioxidants in preventing CRC. A comprehensive literature review was conducted by searching electronic databases to identify studies examining the prospected impacts of dietary vitamins and antioxidants on the prevention of CRC. According to the outcomes of this review, this research review shows a complex link between vitamins and CRC. While some vitamins such as B2, B6, and D seemed helpful, others such as A and E had mixed results. Vitamin C deficiency was even linked to worse outcomes in cancer patients. Overall, the studies suggest focusing on a balanced diet rich in various vitamins rather than relying solely on individual supplements to prevent CRC. On the other hand, the results of our review suggest that the relationship between antioxidant intake and CRC is more intricate than previously thought. Data from this review indicates that taking specific antioxidant supplements such as selenium and vitamin E does not seem to offer the same protection. This suggests that a balanced diet with a variety of antioxidants is more helpful than focusing on single supplements. While we did not observe a direct association, future studies could investigate how different types and combinations of antioxidants might influence CRC development. In conclusion, the present systematic review highlights the need for more research on the relationship between vitamins, antioxidants, and CRC. We need to understand how these nutrients affect both the survival of people with CRC and the prevention of the disease. This will help us determine the best ways to use vitamins and antioxidants in CRC management and prevention.

From molecular basis to clinical insights: a challenging future for the vitamin D endocrine system in colorectal cancer

Colorectal cancer (CRC) is one of the most life-threatening neoplasias in terms of incidence and mortality worldwide. Vitamin D deficiency has been associated with an increased risk of CRC. 1α,25-Dihydroxyvitamin D3 [1,25(OH)2D3], the most active vitamin D metabolite, is a pleiotropic hormone that, through its binding to a transcription factor of the nuclear receptor superfamily, is a major regulator of the human genome. 1,25(OH)2D3 acts on colon carcinoma and stromal cells and displays tumor protective actions. Here, we review the variety of molecular mechanisms underlying the effects of 1,25(OH)2D3 in CRC, which affect multiple processes that are dysregulated during tumor initiation and progression. Additionally, we discuss the epidemiological data that associate vitamin D deficiency and CRC, and the most relevant randomized controlled trials of vitamin D3 supplementation conducted in both healthy individuals and CRC patients.

Claudins in Cancer: A Current and Future Therapeutic Target

Claudins are a family of 27 proteins that have an important role in the formation of tight junctions. They also have an important function in ion exchange, cell mobility, and the epithelial-to-mesenchymal transition, the latter being very important in cancer invasion and metastasis. Therapeutic targeting of claudins has been investigated to improve cancer outcomes. Recent evidence shows improved outcomes when combining monoclonal antibodies against claudin 18.2 with chemotherapy for patients with gastroesophageal junction cancer. Currently, chimeric antigen receptor T-cells targeting claudin 18 are under investigation. In this review, we will discuss the major functions of claudins, their distribution in the normal as well as cancerous tissues, and their effect in cancer metastasis, with a special focus on the therapeutic targeting of claudins to improve cancer outcomes.

Vitamin D and cancer

The role of vitamin D in the prevention of chronic diseases including cancer, has received a great deal of attention during the past few decades. The term "Cancer" represents multiple disease states with varying biological complexities. The strongest link between vitamin D and cancer is provided by ecological and studies like observational, in preclinical models. It is apparent that vitamin D exerts diverse biological responses in a tissue specific manner. Moreover, several human factors could affect bioactivity of vitamin D. The mechanism(s) underlying vitamin D initiated anti-carcinogenic effects are diverse and includes changes at the muti-system levels. The oncogenic environment could easily corrupt the traditional role of vitamin D or could ensure resistance to vitamin D mediated responses. Several researchers have identified gaps in our knowledge pertaining to the role of vitamin D in cancer. Further areas are identified to solidify the role of vitamin D in cancer control strategies.

Utilizing Human Genetics to Develop Chemoprevention for Cancer-Too Good an Opportunity to be Missed

Large-scale genetic studies are reliably identifying many risk factors for disease in the general population. Several of these genetic risk factors encode potential drug targets, and genetics has already helped to introduce targeted agents for some diseases, an example being lipid-lowering drugs to reduce the incidence of cardiovascular disease. Multiple drugs have been developed to treat cancers based on somatic mutations and genomics, but in stark contrast, there seems to be a reluctance to use germline genetic data to develop drugs to prevent malignancy, despite the large numbers of people who could benefit, the potential for lowering cancer rates, and the widespread current use of non-pharmaceutical measures to reduce cancer risk factors such as tobacco, alcohol, and infectious diseases. We argue that concerted efforts for cancer prevention based on genetics, including genes influenced by common polymorphisms that modulate cancer risk, are urgently needed. There are enormous, yet underutilized, opportunities to develop novel targeted agents for chemoprevention of cancer based on human germline genetics. Such efforts are likely to require the support of a dedicated funding program by national and international agencies. See related commentary by Winham and Sherman, p. 13.

Cardiovascular and Cerebrovascular Outcomes With Vitamin D Supplementation: A Systematic Review and Meta-Analysis

Vitamin D supplementation has seen a sharp increase in the primary healthcare setting but its efficacy in decreasing the risk of cardiovascular and cerebrovascular events is yet to be reliably established. We aim to determine whether vitamin D supplementation can significantly impact the risk of cardiovascular and cerebrovascular events. An extensive literature search of PubMed, Embase, and Cochrane CENTRAL was conducted from inception till August 2023 to include all the articles comparing vitamin D and placebo. Cardiovascular and cerebrovascular outcomes were presented as risk ratios (RR) with 95% confidence intervals (CIs) and pooled using a random effects model. Thirty-six trials consisting of 493,389 participants were included in our analysis. Our pooled analysis demonstrated no significant difference between vitamin D supplementation and placebo for the risk of cardiovascular mortality (RR 1.01, 95% CI 0.94-1.08; P = 0.80), stroke or cerebrovascular events (RR 1.03, 95% CI 0.95-1.11; P = 0.48), myocardial infarction (MI) (RR 0.98, 95% CI 0.91-1.06; P = 0.65), cerebrovascular mortality (RR 1.00, 95% CI 0.68-1.46; P = 0.99), arrhythmias (RR 0.98, 95% CI 0.66-1.44; P = 0.90) and hemorrhagic or ischemic stroke. There was no significant heterogeneity between the studies in any analysis. There was no significant difference in the risk of cardiovascular and cerebrovascular outcomes with vitamin D supplementation or placebo. Additional large high-powered studies focused on high-risk and vitamin D-deficient populations are required to resolve the current discrepancy in the literature and provide a definitive conclusion to this end.

Preventive effects of chemical drugs on recurrence of colorectal adenomas: systematic review and Bayesian network meta-analysis

BACKGROUND

The onset of colorectal adenomas (CRAs) is significantly associated with colorectal cancer. The preventive effects of chemical drugs on the recurrence of CRAs have been evaluated in a large number of randomized controlled trials (RCTs). However, there are still uncertainties about the relative effectiveness of such chemical drugs.

METHODS

We searched relevant RCTs published in six databases up to February 2023. The quality of the included studies was assessed by using the Cochrane risk of bias assessment tool and Review Manager 5.4. Pairwise comparison and network meta-analysis (NMA) were conducted using RStudio to compare the effects of chemical drugs on the recurrence of CRAs.

RESULTS

Forty-five high-quality RCTs were included. A total of 35 590 (test group: 20 822; control group: 14 768) subjects with a history of CRAs have been enrolled and randomized to receive placebo treatment or one of 24 interventions. Based on surface under the cumulative ranking values and NMA results, difluoromethylornithine (DFMO) + Sulindac significantly reduced the recurrence of CRAs, followed by berberine and nonsteroidal antiinflammatory drugs.

CONCLUSION

DFMO + Sulindac is more effective in reducing the recurrence of CRAs but has a high risk of adverse events. Considering drug safety, tolerance, and compliance, berberine has a brighter prospect of clinical development. However, further studies are needed to verify our findings.

Vitamin D Supplementation and Cardiovascular Disease Risks in More Than 134000 Individuals in 29 Randomized Clinical Trials and 157000 Individuals in 30 Prospective Cohort Studies: An Updated Systematic Review and Meta-analysis

BACKGROUND

According to the findings from observational studies and clinical trials assessing the effect of vitamin D supplements on cardiovascular diseases (CVDs), there are still contradictory results. This systematic review aimed to assess the effect of vitamin D supplements on CVDs considering cohort studies and clinical trials. Study Design: A systematic review.

METHODS

MEDLINE/PubMed, Science Direct, Embase, and Cochrane Library databases were reviewed by two reviewers independently until 2022. The study effect is risk ratio (RR) and 95% confidence interval (CI) according to Mantel Haenszel's random-effects model. Then, Stata version 14 was used for statistical analysis.

RESULTS

In clinical trial studies, the incidence of CVDs among the vitamin D-consuming group was not significantly different from that in the placebo group (RR: 0.99, 95% CI: 0.95-1.03; P=0.77; I 2=0%). CVD mortality was also not significantly different between the two groups (RR: 0.97, 95% CI: 0.90-1.05; P=0.72; I2=0%). In cohort studies, circulating 25 (OH) D increased the risk of CVD incidence by 31% (RR: 1.31, 95% CI: 1.19-1.45) and CVD mortality by 37% (RR: 1.37, 95% CI: 1.17-1.61).

CONCLUSION

According to current evidence from clinical trials, vitamin D supplementation should not be recommended for CVD prevention. However, there is a direct association between vitamin D deficiency and the incidence of CVDs as well as its mortality. According to the results of clinical trial studies carrying higher levels of scientific evidence, it can be concluded that vitamin D supplementation does not exert a significant effect on the incidence, mortality, and reduction of CVDs.

Vitamin A, D, E, and K as Matrix Metalloproteinase-2/9 Regulators That Affect Expression and Enzymatic Activity

Fat-soluble vitamins (vitamin A, D, E, and K) assume a pivotal role in maintaining human homeostasis by virtue of their enzymatic functions. The daily inclusion of these vitamins is imperative to the upkeep of various physiological processes including vision, bone health, immunity, and protection against oxidative stress. Current research highlights fat-soluble vitamins as potential therapeutics for human diseases, especially cancer. Fat-soluble vitamins exert their therapeutic effects through multiple pathways, including regulation of matrix metalloproteinases' (MMPs) expression and enzymatic activity. As MMPs have been reported to be involved in the pathology of various diseases, such as cancers, cardiovascular diseases, and neurological disorders, regulating the expression and/or activity of MMPs could be considered as a potent therapeutic strategy. Here, we summarize the properties of fat-soluble vitamins and their potential as promising candidates capable of effectively modulating MMPs through multiple pathways to treat human diseases.

Dietary regulation of intestinal stem cells in health and disease

Diet is a critical regulator for physiological metabolism and tissue homeostasis, with a close relation to health and disease. As an important organ for digestion and absorption, the intestine comes into direct contact with many dietary components. The rapid renewal of its mucosal epithelium depends on the continuous proliferation and differentiation of intestinal stem cells (ISCs). The function and metabolism of ISCs can be controlled by a variety of dietary patterns including calorie restriction, fasting, high-fat, ketogenic, and high-sugar diets, as well as different nutrients including vitamins, amino acids, dietary fibre, and probiotics. Therefore, dietary interventions targeting ISCs may make it possible to prevent and treat intestinal disorders such as colon cancer, inflammatory bowel disease, and radiation enteritis. This review summarised recent research on the role and mechanism of diet in regulating ISCs, and discussed the potential of dietary modulation for intestinal diseases.

Association Between Calcium Supplementation and the Risk of Cardiovascular Disease and Stroke: A Systematic Review and Meta-Analysis

BACKGROUND

Some observational studies and randomised controlled trials (RCTs) have reported an association between calcium supplementation and increased risk of cardiovascular disease. Previous meta-analyses on the topic, based on data from RCTs and observational studies, have contradictory findings. This meta-analysis was conducted to determine the difference in associated risks of calcium supplementation with cardiovascular disease and stroke in RCTs.

METHODS

Relevant studies published from database inception to 6 August 2021 were sourced from PubMed, Embase, Scopus, and the Cochrane Central Register of Controlled Trials. Any RCTs focusing on the relationship between calcium supplementation and incidence of cardiovascular disease or stroke were included. Articles were screened independently by two authors, according to the PICO criteria, with disagreements resolved by a third author.

RESULTS

Twelve RCTs were included in the meta-analysis. Calcium supplementation was not associated with myocardial infarction, total stroke, heart failure admission, and all-cause/cardiovascular mortality. Subgroup analysis focusing on calcium monotherapy/calcium co-therapy with vitamin D, female sex, follow-up duration, and geographical region did not affect the findings.

CONCLUSION

Calcium supplementation was not associated with myocardial infarction, total stroke, heart failure admission, and cardiovascular/all-cause mortality. Further studies are required to examine and understand these associations.

Serum 25-Hydroxyvitamin D Levels and Risk of Colorectal Cancer: An Age-Stratified Analysis

BACKGROUND & AIMS

The role of circulating 25-hydroxyvitamin D (25(OH)D) in the prevention of early-onset colorectal cancer (CRC) in young adults aged <50 years is uncertain. We evaluated the age-stratified associations (<50 vs ≥50 years) between circulating 25(OH)D levels and the risk of CRC in a large sample of Korean adults.

METHODS

Our cohort study included 236,382 participants (mean age, 38.0 [standard deviation, 9.0] years) who underwent a comprehensive health examination, including measurement of serum 25(OH)D levels. Serum 25(OH)D levels were categorized as <10, 10 to 20, and ≥20 ng/mL. CRC, along with the histologic subtype, site, and invasiveness, was ascertained through linkage with the national cancer registry. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident CRC according to the serum 25(OH)D status, with adjustment for potential confounders.

RESULTS

During the 1,393,741 person-years of follow-up (median, 6.5 years; interquartile range, 4.5-7.5 years), 341 participants developed CRC (incidence rate, 19.2 per 105 person-years). Among young individuals aged <50 years, serum 25(OH)D levels were inversely associated with the risk of incident CRC with HRs (95% CIs) of 0.61 (0.43-0.86) and 0.41 (0.27-0.63) for 25(OH)D 10 to 19 ng/mL and ≥20 ng/mL, respectively, with respect to the reference (<10 ng/mL) (P for trend <.001, time-dependent model). Significant associations were evident for adenocarcinoma, colon cancer, and invasive cancers. For those aged ≥50 years, associations were similar, although slightly attenuated compared with younger individuals.

CONCLUSIONS

Serum 25(OH)D levels may have beneficial associations with the risk of developing CRC for both early-onset and late-onset disease.

[Calcium, Vitamin D, and Colorectal Cancer]

Colorectal cancer has a high incidence and mortality worldwide, with Westernized lifestyles and diet being significant contributing factors. Vitamin D and calcium have been known to reduce the incidence of colorectal cancer by affecting cell differentiation, proliferation, and apoptosis. Despite observational studies which have suggested that a higher serum vitamin D level can lower the risk of colorectal cancer and improve survival rates, no large-scale randomized controlled trials to establish these benefits have been conducted to date. Calcium intake has also been found to have a beneficial role in reducing the incidence and improving survival rates of colorectal cancer in several observational studies. Moreover, intervention studies have proved its effect in preventing colorectal adenomas. However, there are few intervention studies that have identified the relationship of vitamin D and calcium with colon cancer. To elucidate the impact of vitamin D and calcium supplementation on colorectal cancer, well-designed and large-scale randomized controlled trials are necessary in the future.

Publication trends and hotspots of colorectal adenoma during 2002-2022: a bibliometric and visualized analysis

Background

Prevention and treatment of colorectal adenoma (CRA) are great significant to reduce morbidity and mortality of colorectal cancer. Although there have been numerous studies on CRA recently, few publications utilized the bibliometrics to evaluate this field. The objective of current study was to provide a comprehensive analysis of the current state and frontier progress of CRA over the past 20 years.

Methods

The Web of Science Core Collection was utilized to extracted all studies of CRA during 2002-2022. Bibliometric tools including CiteSpace, VOSviewer, and the Online Analysis Platform of Literature Metrology were used for statistical analysis. CiteSpace and the Online Analysis Platform were used to evaluate the contributions of various countries/regions, institutions, authors, and journals in this field. Research hotspots and trends were identified through keywords and references analysis by VOSviewer and CiteSpace.

Results

2,268 publications from 2002 to 2022 in total were identified. The number of global publications in this field has increased annually. The USA was the most productive country, contributing nearly 30% of global publications. But in recent years, China's publications grew rapidly and had the highest citation strength. The most productive institutions was the National Cancer Institute. Baron JA from the USA was the most productive and the one of most co-cited authors. Cancer Epidemiology Biomarkers & Prevention had the highest number of publications and Gastroenterology was the most co-cited journals. Analysis of keywords clusters showed that "mechanism/pathophysiology", "risk factors and prevention", "colonoscopy screening and treatment", "metabolism", and "microbiota" were the major frontier topics and the main research directions.

Conclusions

CRA publications have shown a gradual upward trend in recent years, most of which have been published by developed countries. Developing countries should further focus on CRA research and transnational cooperation with developed countries in the future, in order to better improve the situation of the increasing morbidity and mortality of CRC. Baron JA was the most outstanding researcher in this field. More attention should be devoted to "pathogenesis of CRA", "less invasive diagnostic methods", "chemoprevention", and "screening and risk prediction of CRA including gut microbiome and metabolism", which will be frontiers in the future.

Preventive effects of 13 different drugs on colorectal cancer: a network meta-analysis

Introduction

The aim of the study was to evaluate the preventive effect of 13 drugs on colorectal cancer (CRC) and guide the clinical application of these drugs.

Material and methods

PubMed, Web of Science, Embase, Cochrane Library, and China National Knowledge Infrastructure were searched for randomized controlled trials (RCTs) and cohort studies. The Cochrane bias risk assessment tool and the Newcastle-Ottawa Scale quality evaluation tool were used to evaluate the quality of the included RCTs and cohort studies. The funnel plot was used to analyze publication bias. A network meta-analysis of the extracted data was conducted using Stata16.0 software.

Results

A total of 57 studies (34 RCTs and 23 cohort studies) involving 82719 participants were included. The network meta-analysis revealed that the quality of the included studies was good; the funnel plot showed no obvious publication bias. The network meta-analysis showed that the preventive effect of 13 drugs on CRC was better than that of the placebo. Allopurinol (SUCRA: 97.2%) was found to have the best effect, followed by berberine (SUCRA: 89.9%), non-aspirin NSAIDs (SUCRA: 84.5%), statins (SUCRA: 66.5%), metformin (SUCRA: 66.3%), calcium (SUCRA: 48.9%), mesalazine (SUCRA: 44.5%), ursodeoxycholic acid (SUCRA: 42.6%), vitamin D (SUCRA: 41.4%), mercaptopurine (SUCRA: 39.4%), aspirin (SUCRA: 30.4%), folic acid (SUCRA: 24.9%), and eicosapentaenoic acid (SUCRA: 16.3%).

Conclusions

The preventive effect of allopurinol on CRC was better than that of the other 13 drugs. These results can help doctors and patients understand the preventative effects of these drugs more intuitively and provide an evidence-based basis for the clinical application of these drugs.

The mechanism of vitamin D3 in preventing colorectal cancer through network pharmacology

Objective: Colorectal cancer (CRC) is a common cancer that cannot be detected at an early stage and is a major challenge in oncology research. Studies have shown that vitamin D3 has some anti-cancer and preventive effects on colorectal cancer, but the exact anti-cancer mechanism is not clear. We applied the relevant research methods of network pharmacology to speculate and validate the possible potential pharmacological mechanisms of vitamin D3 for the prevention of colorectal cancer, and to provide more theoretical support for the clinical anticancer effects of vitamin D3. Methods: The relevant targets for vitamin D3 and CRC were obtained from the database of drug and disease targets, respectively. The target of vitamin D3 and the target of colorectal cancer were taken to intersect to obtain common targets. Then, the PPI network was constructed. In addition, the pathways of drug-disease interactions were predicted by GO and KEGG enrichment analysis. Finally, the obtained results were verified to ensure the reliability of the experiments. Results: 51 targets of vitamin D3 for the prevention of colorectal cancer were obtained. The 10 core targets were obtained from the PPI network. The 10 core targets include: ALB, SRC, MMP9, PPARG, HSP90AA1, IGF1, EGFR, MAPK1, MAP2K1 and IGF1R. The core targets were further validated by molecular docking and animal experiments. The results suggest that vitamin D3 plays a key role in the prevention of CRC through core targets, PI3K-Akt pathway, HIF-1 pathway, and FoxO pathway. Conclusion: This study will provide more theoretical support for vitamin D3 to reduce the incidence of CRC and is important to explore more pharmacological effects of vitamin D3.

Vitamin D Supplementation and Its Impact on Mortality and Cardiovascular Outcomes: Systematic Review and Meta-Analysis of 80 Randomized Clinical Trials

BACKGROUND

The impact of vitamin D supplementation on cardiovascular outcomes and mortality risk reduction remains unclear due to conflicting study findings.

METHODS

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs), published between 1983 and 2022, that reported the effect of vitamin D supplementation in adults versus placebo or no treatment on all-cause mortality (ACM), cardiovascular mortality (CVM), non-cardiovascular mortality (non-CVM), and cardiovascular morbidities. Only studies with a follow-up period longer than one year were included. The primary outcomes were ACM and CVM. Secondary outcomes were non-CVM, myocardial infarction, stroke, heart failure, and major or extended adverse cardiovascular events. Subgroup analyses were performed according to low-, fair- and good-quality RCTs.

RESULTS

Eighty RCTs were assessed, including 82,210 participants receiving vitamin D supplementation and 80,921 receiving placebo or no treatment. The participants' mean (SD) age was 66.1 (11.2) years, and 68.6% were female. Vitamin D supplementation was associated with a lower risk of ACM (OR: 0.95 [95%CI 0.91-0.99] p = 0.013), was close to statistical significance for a lower risk of non-CVM (OR: 0.94 [95%CI 0.87-1.00] p = 0.055), and was not statistically associated with a lower risk of any cardiovascular morbi-mortality outcome. Meta-analysis of low-quality RCTs showed no association with cardiovascular or non-cardiovascular morbi-mortality outcomes.

CONCLUSIONS

The emerging results of our meta-analysis present evidence that vitamin D supplementation appears to decrease the risk of ACM (especially convincing in the fair- and good-quality RCTs), while not showing a decrease in the specific cardiovascular morbidity and mortality risk. Thus, we conclude that further research is warranted in this area, with well-planned and executed studies as the basis for more robust recommendations.

Sijunzi decoction granules in the prevention and treatment of recurrence of colorectal adenoma: Study protocol for a multicenter, randomized, double-blind, placebo-controlled trial

Background: The recurrence of colorectal adenomas (CRAs) after endoscopy predisposes patients to a risk of colorectal cancer. Guided by the traditional Chinese medicine (TCM), patients with colorectal diseases usually manifest with spleen deficiency syndrome (SDS) and are treated with Sijunzi decoction (SJZD). Therefore, this trial aims to explore the efficacy and safety of SJZD in the prevention and treatment of CRAs recurrence.

Methods: SJZD on prevention and treatment of CRAs recurrence after resection: a multicenter, randomized, double-blind, placebo-controlled trial was designed. Patients who undergo polypectomy of CRAs will be recruited and randomized into a SJZD group and a placebo group in a 1:1 ratio. The intervention phase will be 12 months. The follow-up period will last 24 months. The primary outcome is the CRA recurrence rate after intervention. The secondary outcomes include the CRA recurrence rate at the second year post-polypectomy, the pathological type of adenoma and the alterations in SDS scores after intervention.

Discussion: Previous clinical practice has observed the sound effect of SJZD in the context of gastrointestinal diseases. A number of experiments have also validated the active components in SJZD. This trial aims to provide tangible evidence for the usage of SJZD, hoping to reduce the recurrence of CRAs.

Chemoprevention of colorectal cancer in general population and high-risk population: a systematic review and network meta-analysis

BACKGROUND

Many nutritional supplements and pharmacological agents have been reported to show preventive effects on colorectal adenoma and colorectal cancer (CRC). We performed a network meta-analysis to summarize such evidence and assess the efficacy and safety of these agents.

METHODS

We searched PubMed, Embase, and the Cochrane Library for studies published in English until October 31, 2021 that fit our inclusion criteria. We performed a systematic review and network meta-analysis to assess the comparative efficacy and safety of candidate agents (low-dose aspirin [Asp], high-dose Asp, cyclooxygenase-2 inhibitors [coxibs], calcium, vitamin D, folic acid, ursodeoxycholic acid [UDCA], estrogen, and progesterone, alone or in combination) for preventing colorectal adenoma and CRC. Cochrane risk-of-bias assessment tool was employed to evaluate the quality of each included study.

RESULTS

Thirty-two randomized controlled trials (278,694 participants) comparing 13 different interventions were included. Coxibs significantly reduced the risk of colorectal adenoma (risk ratio [RR]: 0.59, 95% confidence interval [CI]: 0.44-0.79, six trials involving 5486 participants), advanced adenoma (RR: 0.63, 95% CI: 0.43-0.92, four trials involving 4723 participants), and metachronous adenoma (RR: 0.58, 95% CI: 0.43-0.79, five trials involving 5258 participants) compared with placebo. Coxibs also significantly increased the risk of severe adverse events (RR: 1.29, 95% CI: 1.13-1.47, six trials involving 7109 participants). Other interventions, including Asp, folic acid, UDCA, vitamin D, and calcium, did not reduce the risk of colorectal adenoma in the general and high-risk populations compared with placebo.

CONCLUSIONS

Considering the balance between benefits and harms, regular use of coxibs for prevention of colorectal adenoma was not supported by the current evidence. Benefit of low-dose Asp for chemoprevention of colorectal adenoma still requires further evidence.

REGISTRATION

PROSPERO, No. CRD42022296376.

Impact of Common Vitamin D-Binding Protein Isoforms on Supplemental Vitamin D3 and/or Calcium Effects on Colorectal Adenoma Recurrence Risk: A Secondary Analysis of a Randomized Clinical Trial

Importance

Variants in the vitamin D-binding protein (DBP) gene (GC) encode DBP isoforms that may affect vitamin D metabolism. However, whether these isoforms modify the effects of vitamin D3 and/or calcium supplementation on colorectal adenoma recurrence is unclear. We hypothesized that supplementation effects may be stronger among those with the DBP2 isoform (encoded by the rs4588*A allele), which is associated with vitamin D deficiency and modified the associations of circulating vitamin D with risk for colorectal neoplasms in observational studies.

Objective

To estimate supplemental vitamin D3 and/or calcium effects on colorectal adenoma recurrence according to 3 common DBP isoforms (DBP1s, DBP1f, DBP2) encoded by 2 missense variants: rs7041 (NG_012837.3:g.57904T>G NP_001191235.1:p.Asp432Glu) and rs4588 (NG_012837.3:g.57915C>A NP_001191235.1:p.Thr436Lys).

Design, Setting, and Participants

Secondary analysis of a randomized, double-blind, placebo-controlled clinical trial of 2259 participants with a recently diagnosed adenoma and no remaining polyps after complete colonoscopy in the US from July 1, 2004, to August 31, 2013. The current analyses were performed from August 12, 2019, to July 16, 2022.

Interventions

Daily vitamin D3 (1000 IU), calcium (1200 mg), both, or placebo.

Main Outcomes and Measures

One or more adenomas diagnosed during 3 to 5 years of follow-up. Treatment effects were estimated according to DBP isoform as risk ratios (RRs) and 95% CIs using Poisson regression analysis.

Results

Of the 2259 participants randomized (mean [SD] age, 58 [6.8] years; 1033 [64%] men), 1604 non-Hispanic White participants (chosen to avoid population stratification bias) were included in the analysis. Among those with the DBP2 isoform (rs4588*AC or AA), the RRs (95% CI) for adenoma recurrence were 0.84 (0.72-1.00) with vitamin D3 relative to no vitamin D3, 0.83 (95% CI, 0.70-0.99) with calcium relative to no calcium, and 0.76 (95% CI, 0.59-0.98) with both agents relative to neither agent. Conversely, among those without DBP2 (rs4588*CC), the corresponding values were 1.08 (95% CI, 0.93-1.26; P = .03 for interaction) with vitamin D3 relative to no vitamin D3, 0.98 (95% CI, 0.84-1.14; P = .37 for interaction) with calcium relative to no calcium, and 1.09 (0.88-1.36; P = .03 for interaction) with both agents relative to neither agent. Among DBP2 homozygotes (rs4588*AA), the RR for adenoma recurrence was 0.57 (95% CI, 0.31-1.08) with both agents relative to neither agent.

Conclusions and Relevance

The findings of this secondary analysis of a randomized clinical trial suggest that individuals with the DBP2 isoform-encoding rs4588*A allele may particularly benefit from vitamin D3 and/or calcium supplementation for colorectal adenoma prevention.

Trial Registration

ClinicalTrials.gov Identifier: NCT00153816.

Calcium Supplements and Risk of CVD: A Meta-Analysis of Randomized Trials

Background

Vitamin D supplements may only be beneficial for the prevention of osteoporotic fractures when administered with calcium and in individuals with low blood levels of 25(OH)D, but possible hazards of calcium supplements on CVD cannot be excluded.

Objectives

We conducted a meta-analysis of all placebo-controlled randomized trials assessing the effects of calcium supplements alone or with vitamin D on CHD, stroke, and all-cause mortality.

Methods

A meta-analysis of 11 trials included 7 comparisons of calcium alone compared with control (n = 8634) and 6 comparisons of calcium plus vitamin D compared with control (n = 46,804). Aggregated study-level data were obtained from individual trials and combined using a fixed-effects meta-analysis. The main outcomes included MI, CHD death, any CHD, stroke, and all-cause mortality.

Results

Among trials of calcium alone (mean daily dose 1 g), calcium was not significantly associated with any excess risk of MI (RR, 1.15; 95% CI: 0.88, 1.51; n = 219 events), CHD death (RR, 1.24; 95% CI: 0.89, 1.73; n = 142), any CHD (RR, 1.01; 95% CI: 0.75, 1.37; n = 177), or stroke (RR, 1.15; 95% CI, 0.90, 1.46, n = 275). Among 6 trials of combined treatment, supplementation with calcium plus vitamin D was not significantly associated with any excess risk of MI (RR, 1.09; 95% CI: 0.95, 1.25; n = 854), CHD death (RR, 1.04; 95% CI: 0.85, 1.27; n = 391), any CHD (RR, 1.05; 95% CI: 0.93, 1.19; n = 1061), or stroke (RR, 1.02; 95% CI: 0.89, 1.17; n = 885). Likewise, calcium alone, or with vitamin D had no significant associations with all-cause mortality.

Conclusions

This meta-analysis demonstrated that calcium supplements were not associated with any significant hazard for CHD, stroke, or all-cause mortality and excluded excess risks above 0.3%-0.5% per year for CHD or stroke. Further trials of calcium and vitamin D are required in individuals with low blood levels of 25(OH)D for the prevention of fracture and other disease outcomes.

Efficacy of vitamin D3 supplementation on cancer mortality: systematic review and individual patient data meta-analysis of randomised controlled trials

To evaluate the effect of vitamin D₃ supplementation on cancer mortality in the general population and on prognosis in cancer patients, a systematic review and meta-analysis of randomised, placebo-controlled trials (RCTs) and individual patient data (IPD) was conducted. Overall, 14 RCTs with a total of 104,727 participants (2,015 cancer deaths) were identified and 7 RCTs, including 90% of all study participants (n=94,068), could be included in the IPD meta-analyses. The main meta-analysis of the 14 RCTs yielded a statistically non-significant reduction in cancer mortality by 6% (risk ratio (RR) [95%-confidence interval (95%CI)]: 0.94 [0.86-1.02]). Subgroup analyses revealed a 12% lower cancer mortality in the vitamin D₃ group compared with the placebo group in 10 trials with a daily dosing regimen (RR [95%CI]: 0.88 [0.78-0.98]), whereas no mortality reduction was seen in 4 trials using a bolus regimen (RR [95%CI]: 1.07 [0.91-1.24]; p-value for interaction: 0.042). The IPD meta-analysis (RR [95%CI]: 0.93 [0.84; 1.02]) confirmed the finding of all trials. The IPD were used to test effect modification by age, sex, body mass index, ethnicity, baseline serum 25-hydroxyvitamin D concentration, adherence and cancer-related factors but no statistically significant findings were obtained in meta-analyses of all trials. When restricted to trials with daily dosing in a post-hoc analysis, adults aged ≥70 years (RR [95%CI]: 0.83 [0.77; 0.98]) and subjects with vitamin D₃ therapy initiation before cancer diagnosis (RR [95%CI]: 0.87 [0.69; 0.99]) appeared to benefit most from daily vitamin D₃ supplementation. Measurements of baseline 25-hydroxyvitamin D levels and inclusion of other than non-Hispanic White adults were too sparse in the trials to draw conclusions. Results for all-cause and cancer-specific survival of participants with cancer were comparable to those obtained in the general population for cancer mortality. In conclusion, vitamin D₃ did not reduce cancer mortality in the main meta-analysis of all RCTs because the observed risk reduction by 6% was not statistically significant. However, a subgroup analysis revealed that vitamin D₃ administered daily, in contrast to bolus supplementation, reduced cancer mortality by 12%.

Vitamin D: review of physiology and clinical uses

Interest in vitamin D has increased within the scientific community due to the impact of osteoporosis in the aging population. Vitamin D receptors are present in many tissues and low vitamin D status has been associated with many diseases in observational studies. There was hope that enhanced vitamin D provision might help prevent and treat some widespread disorders. Some of these hopes have been refuted by the results of recent large and well-conducted randomized trials. This review provides an overview of the basic physiology of vitamin D and an update on the evidence base for its clinical applications.

Changes in Bone Turnover Markers after Osteoporotic Vertebral Compression Fractures in Males and Females

Background. To explore the normal changes in bone turnover markers (BTMs) and the correlations between the different BTMs after osteoporotic vertebral compression fracture (OVCF). Meanwhile, we explored the related differences that exist between sexes. Methods. A total of 130 OVCF patients were retrospectively reviewed. Using IBM SPSS 19.0 statistical software, the differences in the levels of BTMs and clinical parameters between sexes were assessed using Student’s unpaired $t$ test, and one-way ANOVA was used for the comparison of the three groups of samples. The correlations between P1NP, CTX, and clinical factors were assessed using Pearson’s correlation coefficient. Results. P1NP was 52.15 ng/ml within two weeks in male patients, and the level increased to 96.33 ng/ml after 12 weeks; in female patients, the increase was not as obvious as in male patients. CTX in male patients reached as much as approximately twice the initial value after 12 weeks. However, the situation in female patients was diverse. CTX was 0.58 ng/ml within two weeks and increased to 0.61 ng/ml within 2-12 weeks after the onset of OVCF. Subsequently, CTX decreased suddenly after 12 weeks. The increase in P1NP levels within 2 weeks after OVCF was significantly correlated with the levels of osteocalcin (OC) and bone-specific alkaline phosphatase (BAP). Changes in CTX within 2 weeks after OVCF were considerably related to phosphorus, 25 hydroxyvitamin D (25-OHD), OC, and BAP. Conclusion. The levels of P1NP and CTX increased differently in males and females after OVCF. The levels of OC and BAP were correlated with the levels of P1NP and CTX within 2 weeks of OVCF.

Vitamin D and Calcium as Key Potential Factors Related to Colorectal Cancer Prevention and Treatment: A Systematic Review

Colorectal cancer (CRC) is currently considered one of the most common and lethal types of tumors. Nutrition is of notorious relevance, given its influence in CRC prevention and treatment. This systematic review aimed to revise and update the state of knowledge regarding the potential role of vitamin D and calcium as key factors involved in the prevention and treatment of CRC. A literature search was performed in PubMed and Web of Science. A total of eight studies were finally included in the present review. Vitamin D showed a protective role by promoting transcriptomic changes associated with antitumor effects. However, no significant effects of vitamin D were noted in the relapse-free survival of patients at 5 years. On the other hand, previous scientific evidence demonstrated that calcium regulates the expression of colonic proteins that decrease cell proliferation and increase cell differentiation. Nevertheless, an increased risk of associated serrated adenomas was found in response to calcium and calcium + vitamin D supplementation. Moreover, supplementation with both nutrients showed positive changes on relevant CRC biomarkers including TGFα, TGFβ1, APC, β-catenin and E-cadherin. In conclusion, vitamin D supplementation seems to have a protective effect in the prevention and treatment of CRC, while calcium intake showed contradictory effects as a prevention or treatment tool; therefore, further studies are necessary to well understand its relevance in patients with CRC.

Cow’s milk-induced gastrointestinal disorders: From infancy to adulthood

Milk is related to many gastrointestinal disorders from the cradle to the grave due to the many milk ingredients that can trigger gastrointestinal discomfort and disorders. Cow’s milk protein allergy (CMPA) is the most common food allergy, especially in infancy and childhood, which may persist into adulthood. There are three main types of CMPA; immunoglobulin E (IgE)-mediated CMPA, non-IgE-mediated CMPA, and mixed type. CMPA appears before the first birthday in almost all cases. Symptoms may start even during the neonatal period and can be severe enough to simulate neonatal sepsis. CMPA (often non-IgE mediated) can present with symptoms of gastroesophageal reflux, eosinophilic esophagitis, hemorrhagic gastritis, food protein-induced protein-losing enteropathy, and food protein-induced enterocolitis syndrome. Most CMPAs are benign and outgrown during childhood. CMPA is not as common in adults as in children, but when present, it is usually severe with a protracted course. Lactose intolerance is a prevalent condition characterized by the development of many symptoms related to the consumption of foods containing lactose. Lactose intolerance has four typical types: Developmental, congenital, primary, and secondary. Lactose intolerance and CMPA may be the underlying pathophysiologic mechanisms for many functional gastrointestinal disorders in children and adults. They are also common in inflammatory bowel diseases. Milk consumption may have preventive or promoter effects on cancer development. Milk may also become a source of microbial infection in humans, causing a wide array of diseases, and may help increase the prevalence of antimicrobial resistance. This editorial summarizes the common milk-related disorders and their symptoms from childhood to adulthood.

Vitamin D supplementation for the prevention of total cancer incidence and mortality: An updated systematic review and meta-analysis

Introduction

Previous randomized controlled trials (RCTs) and meta-analyses of RCTs evaluating vitamin D supplementation for the prevention of cancer incidence and mortality have found inconsistent results and no meta-analysis has assessed the quality of the evidence available. We, therefore, aimed to perform an updated meta-analysis by including recent large-scale RCTs and assessing the quality of the pooled evidence.

Methods

We searched several databases and trial registers from inception to April 2022. We used a random-effects model to estimate pooled risk ratios (RRs) and 95% confidence intervals (CIs). We used the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) considerations to evaluate the certainty of evidence.

Results

We included 13 RCTs in our study. Vitamin D supplementation had no effect on the risk of total cancer incidence (RR 0.99, 95% CI: 0.94-1.04; I 2 = 0%), total cancer mortality (RR 0.93, 95% CI: 0.84-1.03; I 2 = 24%) and total mortality (RR 0.92, 95% CI: 0.82-1.04; I 2 = 36%). The overall quality of evidence was high for all outcomes.

Discussion

Vitamin D supplementation is ineffective in reducing total cancer incidence and mortality in largely vitamin D-replete older adult populations. Future research should be based on populations with a higher prevalence of vitamin D deficiency and should involve more extended follow-up periods.

Study protocol

PROSPERO database, CRD42021285401.

Vitamin D in Cancer Prevention: Gaps in Current Knowledge and Room for Hope

Intensive epigenome and transcriptome analyses have unveiled numerous biological mechanisms, including the regulation of cell differentiation, proliferation, and induced apoptosis in neoplastic cells, as well as the modulation of the antineoplastic action of the immune system, which plausibly explains the observed population-based relationship between low vitamin D status and increased cancer risk. However, large randomized clinical trials involving cholecalciferol supplementation have so far failed to show the potential of such interventions in cancer prevention. In this article, we attempt to reconcile the supposed contradiction of these findings by undertaking a thorough review of the literature, including an assessment of the limitations in the design, conduct, and analysis of the studies conducted thus far. We examine the long-standing dilemma of whether the beneficial effects of vitamin D levels increase significantly above a critical threshold or if the conjecture is valid that an increase in available cholecalciferol translates directly into an increase in calcitriol activity. In addition, we try to shed light on the high interindividual epigenetic and transcriptomic variability in response to cholecalciferol supplementation. Moreover, we critically review the standards of interpretation of the available study results and propose criteria that could allow us to reach sound conclusions in this field. Finally, we advocate for options tailored to individual vitamin D needs, combined with a comprehensive intervention that favors prevention through a healthy environment and responsible health behaviors.

Metformin Use Is Inversely Associated with Prevalent, but Not Incident Colorectal Adenomas

BACKGROUND

Chemoprevention for colorectal neoplasia has attracted growing interest, with multiple medications investigated. Metformin may decrease the overall incidence of cancer in patients with diabetes and may decrease the incidence of colorectal cancer.

AIMS

We aimed to determine the impact of metformin use on the behavior of colorectal adenomas in a US veteran population.

METHODS

All patients with at least two high-quality colonoscopies between January 1997 and December 2013 at Veterans Affairs New York Harbor Healthcare System were identified. Outpatient prescription records were used to determine metformin exposure, and colonoscopy findings were recorded. Multivariable logistic regression was used to determine factors associated with adenoma detection on baseline and interval colonoscopy.

RESULTS

In total, 1869 patients with two successive colonoscopies (median 4.5 years) were included. Four hundred and sixty patients had metformin exposure prior to baseline and/or interval colonoscopy. Overall adenoma detection rate was 59.7% at baseline and 45.9% at interval colonoscopy. On multivariable analysis, metformin use was associated with decreased adenoma prevalence at baseline (OR 0.68; 95% CI 0.51-0.92; p = 0.015). Metformin did not impact adenoma incidence at interval colonoscopy whether prescribed before baseline (OR 1.26; 95% CI 0.60-2.67), after baseline (OR 1.25; 95% CI 0.91-1.72), or before and after baseline (OR 1.14; 95% CI 0.82-1.58).

CONCLUSIONS

In this retrospective analysis of an average-risk cohort, metformin use was associated with a decreased prevalence of colorectal adenomas at baseline colonoscopy. This inverse association did not persist on interval colonoscopy. Prospective studies are needed to evaluate potential chemoprotective effects of metformin over time.

Vitamin D and Colorectal Cancer: Current Perspectives and Future Directions

Vitamin D is considered to be the main mediator of the beneficial effects of sun exposure. In humans, highest expression of Vitamin D receptors is found in the intestinal tract. In addition, 1α,25-dihydroxyvitamin D3 (or calcitriol), the most active Vitamin D metabolite, plays important homeostatic roles in the intestine, particularly calcium absorption. Vitamin D deficiency is defined as a serum 25-hydroxyvitamin D [25(OH)D] level of < 20 ng/mL. Previous studies show that higher circulating 25(OH)D levels are associated with reduced risk of colorectal cancer (CRC) and improved survival. Most research to date has been conducted in animals, specifically mice. Although human studies have a limited number of participants, one study recruiting a large cohort of patients with advanced or metastatic CRC revealed that higher plasma 25(OH)D levels are associated with improved overall and progression-free survival. However, the effects of Vitamin D supplementation on incidence and mortality of CRC remain inconclusive. Although Vitamin D may help to prevent cancer, there is a paucity of research demonstrating conclusively that Vitamin D alters prognosis after chemotherapy. Here, we review the mechanisms by which Vitamin D affects CRC, as well as the results of clinical, epidemiological, and human intervention studies. We also discuss current perspectives and future directions regarding Vitamin D and CRC.

The Cytotoxic Effect of Isolated Cannabinoid Extracts on Polypoid Colorectal Tissue

Purified cannabinoids have been shown to prevent proliferation and induce apoptosis in colorectal carcinoma cell lines. To assess the cytotoxic effect of cannabinoid extracts and purified cannabinoids on both colorectal polyps and normal colonic cells, as well as their synergistic interaction. Various blends were tested to identify the optimal synergistic effect. Methods: Biopsies from polyps and healthy colonic tissue were obtained from 22 patients undergoing colonic polypectomies. The toxicity of a variety of cannabinoid extracts and purified cannabinoids at different concentrations was evaluated. The synergistic effect of cannabinoids was calculated based on the cells’ survival. Isolated cannabinoids illustrated different toxic effects on the viability of cells derived from colorectal polyps. THC-d8 and THC-d9 were the most toxic and exhibited persistent toxicity in all the polyps tested. CBD was more toxic to polypoid cells in comparison to normal colonic cells at a concentration of 15 µM. The combinations of the cannabinoids CBDV, THCV, CBDVA, CBCA, and CBGA exhibited a synergistic inhibitory effect on the viability of cells derived from colon polyps of patients. Isolated cannabinoid compounds interacted synergistically against colonic polyps, and some also possessed a differential toxic effect on polyp and adjacent colonic tissue, suggesting possible future therapeutic value.

The efficacy of chemopreventive agents on the incidence of colorectal adenomas: A systematic review and network meta-analysis

Colorectal cancer (CRC) is the fourth most common cancer and third leading cause of cancer-related death worldwide. Use of chemopreventive agents (CPAs) to reduce the incidence of precursor colorectal adenomas could lower the future burden of CRC. Many classes of potential CPAs have been investigated. To identify the most effective CPAs, we conducted a systematic review and a network meta-analysis (NMA). An electronic search was performed through August 2020 to identify all randomized controlled trials (RCTs) assessing the efficacy of CPAs in reducing the incidence of colorectal adenomas at the time of surveillance colonoscopy among patients who had previously undergone polypectomy during an index colonoscopy. In total, 33 RCTs were included in the NMA, which was conducted under a Bayesian inference framework. Random effects models were used with adjustment for follow-up length and control group event rates to yield relative risks (RRs) and 95% credible intervals (CrIs). Our full network consisted of 13 interventions in addition to a placebo arm. Of 20,925 included patients, 7766 had an adenoma. Compared to placebo, the combination of difluoromethylornithine (DFMO) + Sulindac (RR 0.24, CrI 0.10-0.55) demonstrated a protective effect, while aspirin had a RR of 0.77 (CrI 0.60-1.00), celecoxib 800 mg had a RR of 0.56 (CrI 0.31-1.01) and metformin had a RR of 0.56 (CrI 0.22-1.39). Our results suggest that select CPAs may be efficacious in preventing the development of adenomas. Further studies are needed to identify those patients most likely to benefit and the minimum effective dosages of CPAs.

Vitamin D intake as well as circulating 25-hydroxyvitamin D level and risk for the incidence and recurrence of colorectal cancer precursors: A meta-analysis

Objective

Vitamin D consumption and circulating 25(OH)D level are associated with decreased risk of colorectal cancer (CRC) and colorectal adenoma (CRA), but few studies have assessed their relationship with the incidence and recurrence of CRC precursors. Therefore, we performed this meta-analysis to further evaluate the association.

Methods

We searched PubMed, Web of Science, Scopus and Embase databases in English until August 2021. Studies evaluating the association of vitamin D intake and circulating 25(OH)D level with risk of CRC precursors were included. A random-effects model was used to pool the risk estimates.

Results

A total of 48 studies were selected for inclusion. The CRC precursors incidence was negatively correlated with total vitamin D intake (RR = 0.84 95%CI: 0.80–0.88) and circulating 25(OH)D level (RR = 0.79 95%CI: 0.67–0.92). However, vitamin D intake and circulating 25(OH)D level did not show significant effects on the risk of CRC precursors recurrence. For dose-response analysis, evidence of a linear association was found between CRC precursors incidence and circulating 25(OH)D level, and the risk decreased by 14% per 10 ng/ml increment of circulating 25(OH)D level (RR = 0.86 95% CI: 0.75–0.99).

Conclusion

Vitamin D intake and circulating 25(OH)D level can play an effective role in reducing the risk of incidence of CRC precursors. However, they have not prevented the recurrence of CRC precursors.

Vitamin D supplementation and risk of stroke: A meta-analysis of randomized controlled trials

Background

Previous observational studies have supported the hypothesis that vitamin D supplementation protects against stroke. However, several current intervention studies contradict this observation. Therefore, we conducted a meta-analysis to investigate further the association between vitamin D supplementation and the risk of stroke.

Methods

This meta-analysis was conducted in accordance with the PRISMA statement and included all the randomized controlled trials (RCTs) that analyzed the relationship between vitamin D supplementation and the risk of stroke. A literature search strategy was established, and the following Medical Search Terms (MeSH) were used: “vitamin D,” “Calcitriol,” “Calcifediol,” “Cholecalciferol,” “25-Hydroxyvitamin D 2,” “ergocalciferols,” “stroke,” and stroke-derived terms. We searched for articles published before January 2022 in several databases, namely, PubMed, Web of Science, EMBASE, and The Cochrane Library. We also reviewed references included in relevant published meta-analyses and searched the http://www.ClinicalTrials.gov website for additional RCTs. The Q test and I2 were utilized to assess the degree of heterogeneity among the studies. Review Manager 5.3 and STATA16.0 software programs were used to assess the literature quality and perform statistical analyses.

Results

In total, twenty-four RCTs (86,202 participants) were included. There was no statistical heterogeneity among the RCTs (I2 = 0.0%, P = 0.94) included in this meta-analysis. We determined that vitamin D supplementation was not associated with a reduced risk of stroke compared with the placebo (RR = 1.02, 95% CI: 0.93–1.13, P = 0.65). In total, 10 studies only included women, and 14 studies included women and men among the 24 RCTs. Therefore, we performed a subgroup analysis based on sex. After the subgroup analysis, the effect remained statistically insignificant (mixed-sex group: RR = 1.06, 95% CI: 0.93–1.22, P = 0.37, women group: RR = 0.98, 95% CI: 0.86–1.13, P = 0.80). The results were generally comparable, based on age, body mass index (BMI), follow-up period, baseline 25-hydroxyvitamin D (25(OH)D) levels, the designated endpoint, latitude, vitamin D dosage, type of vitamin D administered, and an absence or presence of concurrent calcium supplementation (P &gt; 0.05).

Conclusion

Our study revealed that additional vitamin D supplementation did not reduce the risk of stroke. Therefore, additional RCTs of similar design should not be encouraged to assess any association between vitamin D supplementation and reduced stroke risk.

Association between Vitamin D Supplementation and Cancer Mortality: A Systematic Review and Meta-Analysis

Simple Summary

It has been questioned whether vitamin D supplements can reduce the mortality and incidence of tumors. In this systematic review and meta-analysis of 12 randomized controlled trials with a total of 72,669 participants, vitamin D supplementation could not reduce the cancer mortality or cancer incidence. Our results suggest a reconsideration of the previous view that vitamin D supplementation could reduce overall cancer mortality is needed.

Abstract

Background: Vitamin D deficiency is related to increased cancer risk and deaths. However, whether vitamin D supplementation reduces cancer mortality remains unclear, and several randomized controlled trials yield inconsistent results. Methods: Medline, Embase, and the Cochrane Central Register of Controlled Trials were searched from their inception until 28 June 2022, for randomized controlled trials investigating vitamin D supplementation. Pooled relative risks (RRs) and their 95% confidence intervals (CIs) were estimated. Trials with vitamin D supplementation combined with calcium supplementation versus placebo alone and recruiting participants with cancer at baseline were excluded in the present study. Results: This study included 12 trials with a total of 72,669 participants. Vitamin D supplementation did not reduce overall cancer mortality (RR 0.96, 95% CI 0.80–1.16). However, vitamin D supplementation was associated with a reduction in lung cancer mortality (RR 0.63, 95% CI 0.45–0.90). Conclusions: Vitamin D supplementation could not reduce cancer mortality in this highly purified meta-analysis. Further RCTs that evaluate the association between vitamin D supplementation and total cancer mortality are still needed.

Association of Vitamin D Supplementation with Cardiovascular Events: A Systematic Review and Meta-Analysis

BACKGROUND

low vitamin D status has been associated with an increased incidence of cardiovascular events. However, whether vitamin D supplementation would reduce the incidence of cardiovascular events remains unclear.

PURPOSE

To perform a systematic review and meta-analysis of the effect of vitamin D supplementation on the mortality and incidence of cardiovascular events.

DATA SOURCES

We searched Medline, Embase, and the Cochrane Central Register of Controlled Trials from their inception until 3 May 2022.

STUDY SELECTION

Two authors searched for randomized clinical trials that reported vitamin D supplementation's effect on cardiovascular events outcomes.

DATA EXTRACTION

Two authors conducted independent data extraction.

DATA SYNTHESIS

We identified 41,809 reports; after exclusions, 18 trials with a total of 70,278 participants were eligible for analysis. Vitamin D supplementation was not associated with the mortality of cardiovascular events (RR 0.96, 95% CI 0.88-1.06, I2 = 0%), the incidence of stroke (RR 1.05, 95% CI 0.92-1.20, I2 = 0%), myocardial infarction (RR 0.97, 95% CI 0.87-1.09, I2 = 0%), total cardiovascular events (RR 0.97, 95% CI 0.91-1.04, I2 = 27%), or cerebrovascular events (RR 1.01, 95% CI 0.87-1.18, I2 = 0%).

LIMITATION

Cardiovascular events were the secondary outcome in most trials and thus, might be selectively reported.

CONCLUSION

In this meta-analysis of randomized clinical trials, vitamin D supplementation was not associated with a lower risk of cardiovascular events than no supplementation. These findings do not support the routine use of vitamin D supplementation in general.

Vitamin and Mineral Supplements for the Primary Prevention of Cardiovascular Disease and Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Cardiovascular disease and cancer are the 2 leading causes of death in the US, and vitamin and mineral supplementation has been proposed to help prevent these conditions.

OBJECTIVE

To review the benefits and harms of vitamin and mineral supplementation in healthy adults to prevent cardiovascular disease and cancer to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMed (publisher-supplied records only), Cochrane Library, and Embase (January 2013 to February 1, 2022); prior reviews.

STUDY SELECTION

English-language randomized clinical trials (RCTs) of vitamin or mineral use among adults without cardiovascular disease or cancer and with no known vitamin or mineral deficiencies; observational cohort studies examining serious harms.

DATA EXTRACTION AND SYNTHESIS

Single extraction, verified by a second reviewer. Quantitative pooling methods appropriate for rare events were used for most analyses.

MAIN OUTCOMES AND MEASURES

Mortality, cardiovascular disease events, cancer incidence, serious harms.

RESULTS

Eighty-four studies (N=739 803) were included. In pooled analyses, multivitamin use was significantly associated with a lower incidence of any cancer (odds ratio [OR], 0.93 [95% CI, 0.87-0.99]; 4 RCTs [n=48 859]; absolute risk difference [ARD] range among adequately powered trials, -0.2% to -1.2%) and lung cancer (OR, 0.75 [95% CI, 0.58-0.95]; 2 RCTs [n=36 052]; ARD, 0.2%). However, the evidence for multivitamins had important limitations. Beta carotene (with or without vitamin A) was significantly associated with an increased risk of lung cancer (OR, 1.20 [95% CI, 1.01-1.42]; 4 RCTs [n=94 830]; ARD range, -0.1% to 0.6%) and cardiovascular mortality (OR, 1.10 [95% CI, 1.02-1.19]; 5 RCTs [n=94 506] ARD range, -0.8% to 0.8%). Vitamin D use was not significantly associated with all-cause mortality (OR, 0.96 [95% CI, 0.91-1.02]; 27 RCTs [n=117 082]), cardiovascular disease (eg, composite cardiovascular disease event outcome: OR, 1.00 [95% CI, 0.95-1.05]; 7 RCTs [n=74 925]), or cancer outcomes (eg, any cancer incidence: OR, 0.98 [95% CI, 0.92-1.03]; 19 RCTs [n=86 899]). Vitamin E was not significantly associated with all-cause mortality (OR, 1.02 [95% CI, 0.97-1.07]; 9 RCTs [n=107 772]), cardiovascular disease events (OR, 0.96 [95% CI, 0.90-1.04]; 4 RCTs [n=62 136]), or cancer incidence (OR, 1.02 [95% CI, 0.98-1.08]; 5 RCTs [n=76 777]). Evidence for benefit of other supplements was equivocal, minimal, or absent. Limited evidence suggested some supplements may be associated with higher risk of serious harms (hip fracture [vitamin A], hemorrhagic stroke [vitamin E], and kidney stones [vitamin C, calcium]).

CONCLUSIONS AND RELEVANCE

Vitamin and mineral supplementation was associated with little or no benefit in preventing cancer, cardiovascular disease, and death, with the exception of a small benefit for cancer incidence with multivitamin use. Beta carotene was associated with an increased risk of lung cancer and other harmful outcomes in persons at high risk of lung cancer.

Predictors of Incident Serrated Polyps: Results from a Large Multicenter Clinical Trial

BACKGROUND

Serrated polyps (SP) are important colorectal cancer precursors, yet their epidemiology is incompletely understood. We measured risk factors for incident sessile-serrated lesions (SSL) and microvesicular (MVHP) and goblet-cell rich (GCHP) hyperplastic polyp subtypes.

METHODS

We conducted a cohort study of patients undergoing colonoscopic surveillance nested within a chemoprevention trial. Outcomes of interest were ≥1 SPs, including SSLs, MVHPs, and GCHPs specifically. Multivariable generalized estimating equation models were used to estimate adjusted risk ratios (RR) and 95% confidence intervals (CI) for different polyp types.

RESULTS

Among 2,102 participants, a total of 1,615 SPs (including 212 SSLs) were found among 758 participants during follow-up. Prior history of SPs was strongly associated with subsequent occurrence of SPs. There was no apparent association between age, sex, or education and risk of SPs. Black participants were at lower risk of SSLs and MVHPs, but higher risk of GCHPs compared with white participants [RR, 0.40; 95% CI, 0.16-0.99); RR, 0.63 (95% CI, 0.42-0.96); and RR, 1.83 (95% CI, 1.23-2.72) respectively]. Alcohol and smoking exposure were also associated with SPs, including hyperplastic polyp subtypes in particular.

CONCLUSIONS

In this prospective study, the risk of SP subtypes differed by race, alcohol, and smoking status, and prior history of SPs. Risk factor associations for SPs differ from risk factors for conventional adenomas, supporting the concept of etiologic heterogeneity of colorectal cancer.

IMPACT

These findings allow for better risk stratification of patients undergoing colorectal cancer screening and could inform screening test selection.

Association of demographic and health characteristics with circulating oxysterol concentrations

BACKGOUND

Circulating oxysterols, cholesterol metabolites with important signaling functions, are increasingly being recognized as candidate biomarkers for several diseases, but associations with demographic and health characteristics remain poorly described.

OBJECTIVE

This study aims to characterize associations of major circulating oxysterols with sex, age, race/ethnicity, body mass index (BMI), lifestyle factors, and use of common medications.

METHODS

We measured plasma concentrations of 27-hydroxycholesterol (27-OHC), 25-hydroxycholesterol (25-OHC), 24(S)-hydroxycholesterol (24(S)-OHC), 7ɑ-hydroxycholesterol (7ɑ-OHC), and 4β-hydroxycholesterol (4β-OHC) from 1,440 participants of a completed clinical trial for the chemoprevention of colorectal adenomas. Adjusted percent difference in means were calculated using linear regression.

RESULTS

Women had 18% (95% CI, 14%, 22%) lower 27-OHC and 21% (15%, 27%) higher 4β-OHC than men. Blacks had 15% (7%, 23%) higher 4β-OHC than Non-Hispanic Whites, and Asian or Pacific Islanders had 19% (2%, 35%) higher 7ɑ-OHC than Non-Hispanic Whites. Individuals of BMI ≥35 kg/m2 had 33% (25%, 41%) lower 4β-OHC than those <25 kg/m2. Current smokers had 15% (5%, 24%) higher 7ɑ-OHC than never smokers, and daily alcohol drinkers had 17% (10%, 24%) higher 7ɑ-OHC than never drinkers. Statin use was associated with lower concentrations of all 5 oxysterols. Differences in mean <15% were found for characteristics such as age, total dietary energy intake, physical activity, diabetes, and anti-inflammatory drug use.

CONCLUSION

Circulating oxysterols are uniquely associated with multiple demographic and health characteristics.

Future challenges in gastroenterology and hepatology, between innovations and unmet needs: A SIGE Young Editorial Board's perspective

Gastroenterology, Digestive Endoscopy and Hepatology have faced significant improvements in terms of diagnosis and therapy in the last decades. However, many fields still remain poorly explored, and many questions unanswered. Moreover, basic-science, as well as translational and clinical discoveries, together with technology advancement will determine further steps toward a better, refined care for many gastroenterological disorders in the future. Therefore, the Young Investigators of the Italian Society of Gastroenterology (SIGE) joined together, offering a perspective on major future innovations in some hot clinical topics in Gastroenterology, Endoscopy, and Hepatology, as well as the current pitfalls and the grey zones.

Effect of Vitamin D Supplementation on Risk of Fractures and Falls According to Dosage and Interval: A Meta-Analysis

BACKGROUND

Although recent studies comparing various dosages and intervals of vitamin D supplementation have been published, it is yet to be elucidated whether there is an appropriate dose or interval to provide benefit regarding fracture risk. We aimed to assess the published evidence available to date regarding the putative beneficial effects of vitamin D supplements on fractures and falls according to various dosages and intervals.

METHODS

We performed a meta-analysis of randomized controlled studies reporting associations between vitamin D supplementation and the risks of fractures and falls in PubMed, EMBASE, and Cochrane library. Studies with supplements of ergocalciferol or calcitriol, those with a number of event ≤10, or those with a follow-up duration of less than 6 months were also excluded.

RESULTS

Thirty-two studies were included in the final analysis. Vitamin D supplementation with daily dose of 800 to 1,000 mg was associated with lower risks of osteoporotic fracture and fall (pooled relative risk [RR], 0.87; 95% confidence interval [CI], 0.78 to 0.97 and RR, 0.91; 95% CI, 0.85 to 0.98), while studies with <800 or >1,000 mg/day did not. Also, among intervals, daily administration of vitamin D was associated with the reduced risk of falls, while intermittent dose was not. Also, patients with vitamin D deficiency showed a significant risk reduction of falls after vitamin D supplementation.

CONCLUSION

Daily vitamin D dose of 800 to 1,000 IU was the most probable way to reduce the fracture and fall risk. Further studies designed with various regimens and targeted vitamin D levels are required to elucidate the benefits of vitamin D supplements.

Association between vitamin D supplementation and cancer incidence and mortality: A trial sequential meta-analysis of randomized controlled trials

Observational studies and clinical trials have evaluated the associations between vitamin D supplementation and cancer incidence/mortality and obtained mixed results. Previous meta-analyses have also yielded inconsistent conclusions. In this paper, we conduct an updated meta-analysis by including current randomized clinical trials (RCTs) to assess the association between vitamin D supplementation and cancer incidence and mortality. The PubMed, Scopus and Embase databases were systematically searched from their inception to 6 February 2022. Fixed-effects meta-analyses were conducted. Trial sequential analyses were performed using a risk ratio reduction threshold of 10% for cancer incidence and mortality. Twenty-six RCTs were eligible, and pooled results indicated that vitamin D supplementation, compared to placebo with/without calcium, was not associated with a reduction in total cancer incidence (risk ratio: 0.98, 95% CI: 0.94, 1.02; I2 = 0%). In contrast, vitamin D supplementation significantly reduced total cancer mortality (risk ratio: 0.88, 95% CI: 0.8, 0.96; I2 = 0%). Moreover, trial sequential analysis provided reliable evidence that supplementation with vitamin D lowered the relative risk of total cancer mortality by 10%. Our updated meta-analysis suggested that vitamin D supplementation did not reduce total cancer incidence but significantly lowered total cancer mortality.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2022.2056574 .

Osteoporosis Is Associated with an Increased Risk of Colorectal Adenoma and High-Risk Adenoma: A Retrospective, Multicenter, Cross-Sectional, Case-Control Study

Background/Aims

The protective effects of vitamin D and calcium on colorectal neoplasms are known. Bone mineral density (BMD) may be a reliable biomarker that reflects the long-term anticancer effect of vitamin D and calcium. This study aimed to evaluate the association between BMD and colorectal adenomas including high-risk adenoma.

Methods

A multicenter, cross-sectional, case-control study was conducted among participants with average risk of colorectal cancer who underwent BMD and screening colonoscopy between 2015 and 2019. The main outcome was the detection of colorectal neoplasms. The variable under consideration was low BMD (osteopenia/osteoporosis). The logistic regression model included baseline demographics, components of metabolic syndrome, fatty liver disease status, and aspirin and multivitamin use.

Results

A total of 2,109 subjects were enrolled. The mean age was 52.1±10.8 years and 42.6% were male. The adenoma detection rate was 43%. Colorectal adenoma and high-risk adenoma were both more prevalent in subjects with low BMD than those with normal BMD (48.2% vs 38.8% and 12.1% vs 9.1%). In the univariate analysis, old age, male sex, smoking, metabolic components, fatty liver, and osteoporosis were significantly associated with the risk of adenoma and high-risk adenoma. In the multivariate analysis, osteoporosis was independently associated with risk of colorectal adenoma (odds ratio [OR], 1.65; 95% confidence interval [CI], 1.11 to 2.46; p=0.014) and high-risk adenoma (OR, 1.94; 95% CI, 1.14 to 3.29; p=0.014).

Conclusions

Osteoporosis is an independent risk factor of colorectal adenoma and high-risk adenoma.