Meta-analyses of vitamin D intake, 25-hydroxyvitamin D status, vitamin D receptor polymorphisms, and colorectal cancer risk

Sex Difference of Colon Adenoma Pathway and Colorectal Carcinogenesis

Colorectal cancer (CRC) is one of the most common causes of cancer morbidity in both sexes but shows sex differences. First, sex-specific differences in tumor recurrence and survival rates have been reported. For example, the development of CRC is found about 1.5 times higher and 4-8 years earlier in males compared to females, suggesting the protective role of estrogen in the disease. Furthermore, female patients have a higher risk of developing right-sided (proximal) colon cancer than male patients, which is known to have more aggressive clinical character compared to left-sided (distal) colon cancer. That is, left and right CRCs show differences in carcinogenic mechanism, that the chromosomal instability pathway is more common in left colon cancer while the microsatellite instability and serrated pathways are more common in right colon cancer. It is thought that there are sex-based differences on the background of carcinogenesis of CRC. Sex differences of CRC have two aspects, sexual dimorphism (biological differences in hormones and genes) and gender differences (non-biological differences in societal attitudes and behavior). Recently, sex difference of colon adenoma pathway and sexual dimorphism in the biology of gene and protein expression, and in endocrine cellular signaling in the CRC carcinogenesis have been accumulated. In addition, behavioral patterns can lead to differences in exposure to risk factors such as drinking or smoking, diet and physical activity. Therefore, understanding sex/gender-related biological and sociocultural differences in CRC risk will help in providing strategies for screening, treatment and prevention protocols to reduce the mortality and improve the quality of life. In this review, sex/gender differences in colon adenoma pathway and various aspects such as clinicopathological, biological, molecular, and socio-cultural aspects of CRC were described.

Determinants of cancer incidence and mortality among people with vitamin D deficiency: an epidemiology study using a real-world population database

Introduction

This study aimed to investigate the determinants of cancer incidence and mortality in patients with vitamin D deficiency using a real-world population database.

Methods

We utilized the International Diagnostic Classification Code (ICD9:268 / ICD10: E55) to define patients with vitamin D deficiency. Additionally, the Cox regression model was used to estimate overall mortality and identify potential factors contributing to mortality in cancer patients.

Results

In 5242 patients with vitamin D deficiency, the development of new-onset cancer was 229 (4.37%) patients. Colon cancer was the most prevalent cancer type. After considering confounding factors, patients aged 50-65 and more than 65 indicated a 3.10-fold (95% C.I.: 2.12-4.51) and 4.55-fold (95% C.I.: 3.03-6.82) cancer incidence, respectively compared with those aged <50. Moreover, patients with comorbidities of diabetes mellitus (DM) (HR: 1.56; 95% C.I.: 1.01-2.41) and liver disease (HR: 1.62; 95% C.I.: 1.03-2.54) presented a higher cancer incidence rate than those without DM/ liver disease. In addition, vitamin D deficiency patients with cancer and dementia histories indicated a significantly higher mortality risk (HR: 4.04; 95% C.I.: 1.05- 15.56) than those without dementia.

Conclusion

In conclusion, our study revealed that vitamin D deficiency patients with liver disease had an increased incidence of cancer, while those with dementia had an increased mortality rate among cancer patients.

Pre-diagnostic intake of vitamin D and incidence of colorectal cancer by anatomical subsites: the Norwegian Women and Cancer Cohort Study (NOWAC)

According to the World Cancer Research Fund International, vitamin D might decrease the risk of colorectal cancer (CRC). However, less is known about the association with cancers in different subsites of the colon and in the rectum. The aim of this study was to examine associations between pre-diagnostic intake of vitamin D and risk of CRC by anatomical subsites. Data from 95 416 participants in the Norwegian Women and Cancer Cohort Study was included, and vitamin D intake was estimated from two repeated FFQ. Associations between vitamin D intake and incidence of CRC were assessed using multivariable Cox regression. During follow-up, there were 1774 incident cases of CRC. A small but borderline significant inverse association was found for a 5-µg increase in vitamin D intake and risk of CRC (hazard ratio (HR) = 0·97; 95 % CI 0·93, 1·01) and colon cancer (HR = 0·96; 95 % CI 0·91, 1·01). High (≥ 20 µg) compared with low (< 10 µg) vitamin D intake was associated with 17 % borderline significant reduced risk of CRC (HR = 0·83; 95 % CI 0·68, 1·02). Medium (10-19 µg) v. low intake (< 10 µg) was associated with 27 % reduced risk of proximal colon cancer (HR = 0·73; 95 % CI 0·57, 0·94). No significant associations were observed between vitamin D intake and risk of distal colon or rectal cancer. Our study indicates that vitamin D may be differently associated with subsites of the colon. The association between vitamin D intake and proximal colon cancer is novel.

An overview of vitamins as epidrugs for colorectal cancer prevention

Gene expression altering epigenomic modifications such as DNA methylation, histone modification, and chromosome remodeling is crucial to regulating many biological processes. Several lifestyle factors, such as diet and natural, bioactive food compounds, such as vitamins, modify epigenetic patterns. However, epigenetic dysregulation can increase the risk of many diseases, including cancer. Various studies have provided supporting and contrasting evidence on the relationship between vitamins and cancer risk. Though there is a gap in knowledge about whether dietary vitamins can induce epigenetic modifications in the context of colorectal cancer (CRC), the possibility of using them as epidrugs for CRC treatment is being explored. This is promising because such studies might be informative about the most effective way to use vitamins in combination with DNA methyltransferase inhibitors and other approved therapies to prevent and treat CRC. This review summarizes the available epidemiological and observational studies involving dietary, circulating levels, and supplementation of vitamins and their relationship with CRC risk. Additionally, using available in vitro, in vivo, and human observational studies, the role of vitamins as potential epigenetic modifiers in CRC is discussed. This review is focused on the action of vitamins as modifiers of DNA methylation because aberrant DNA methylation, together with genetic alterations, can induce the initiation and progression of CRC. Although this review presents some studies with promising results, studies with better study designs are necessary. A thorough understanding of the underlying molecular mechanisms of vitamin-mediated epigenetic regulation of CRC genes can help identify effective therapeutic targets for CRC prevention and treatment.

Circulating vitamin D levels and colorectal cancer risk: A meta-analysis and systematic review of case-control and prospective cohort studies

The associations between circulating vitamin D concentrations and total and site-specific colorectal cancer (CRC) incidence have been examined in several epidemiological studies with overall inconclusive findings. The aim of this systematic review and meta-analysis of both case-control and prospective cohort studies was to evaluate the association between CRC and circulating levels of vitamin D. The main exposure and outcome were circulating total 25(OH)D and CRC, respectively, in the overall population (i.e., all subjects). Two reviewers, working independently, screened all the literature available to identify studies that met the inclusion criteria (e.g., case-control or prospective cohort studies, published in English, and excluding non-original papers). Data were pooled by the generic inverse variance method using a random or fixed effect model, as approriate. Heterogeneity was identified using the Cochran's Q-test and quantified by the I² statistic. Results were stratified by study design, sex, and metabolite of vitamin D. Sensitivity and subgroup analyses were also performed. A total of 28 original studies were included for the quantitative meta-analysis. Meta-analyses comparing the highest vs lowest categories, showed a 39% lower risk between levels of total 25(OH)D and CRC risk (OR (95% CI): 0.61 (0.52; 0.71); 11 studies) in case-control studies; whereas a 20% reduced CRC risk in prospective cohort studies (HR (95% CI): 0.80 (0.66; 0.97); 6 studies). Results in women mirrored main results, whereas results in men were non-significant in both analyses. Our findings support an inverse association between circulating vitamin D levels and CRC risk.

Epigenomic effects of vitamin D in colorectal cancer

Vitamin D regulates a plethora of physiological processes in the human body and has been proposed to exert several anticancer effects. Epigenetics plays an important role in regulating vitamin D actions. In this review, we highlight the recent advances in the understanding of different epigenetic factors such as lncRNAs, miRNAs, methylation and acetylation influenced by vitamin D and its downstream targets in colorectal cancer to find more potential therapeutic targets. We discuss how vitamin D exerts anticancer properties through interactions between the vitamin D receptor and genes (e.g., SLC30A10), the microenvironment, microbiota and other factors in colorectal cancer. Developing therapeutic approaches targeting the vitamin D signaling system will be aided by a better knowledge of the epigenetic impact of vitamin D.

Vitamin D and Risk of Obesity-Related Cancers: Results from the SUN (‘Seguimiento Universidad de Navarra’) Project

Obesity is associated with a higher risk of several types of cancer, grouped as obesity-related cancers (ORC). Vitamin D deficiency is more prevalent in obese subjects, and it has been suggested to play a role in the association between obesity and cancer risk. The aim of the study was to analyze the association between vitamin D intake and the subsequent risk of ORC in a prospective Spanish cohort of university graduates. The SUN Project, initiated in 1999, is a prospective dynamic multipurpose cohort. Participants answered a 556-item lifestyle baseline questionnaire that included a validated food-frequency questionnaire. We performed Cox regression models to estimate the hazard ratios (HRs) of ORC according to quartiles of energy-adjusted vitamin D intake (diet and supplements). We included 18,017 participants (mean age = 38 years, SD = 12 years), with a median follow-up of 12 years. Among 206,783 person-years of follow-up, we identified 225 cases of ORC. We found no significant associations between vitamin D intake and ORC risk after adjusting for potential confounders: HR_Q2vsQ1 = 1.19 (95% CI 0.81–1.75), HR_Q3vsQ1 = 1.20 (95% CI 0.81–1.78), and HR_Q4vsQ1 = 1.02 (95% CI 0.69–1.51). Dietary and supplemented vitamin D do not seem to be associated with ORC prevention in the middle-aged Spanish population.

The Multiple Effects of Vitamin D against Chronic Diseases: From Reduction of Lipid Peroxidation to Updated Evidence from Clinical Studies

Background: Vitamin D exerts multiple beneficial effects in humans, including neuronal, immune, and bone homeostasis and the regulation of cardiovascular functions. Recent studies correlate vitamin D with cancer cell growth and survival, but meta-analyses on this topic are often not consistent. Methods: A systematic search of the PubMed database and the Clinical Trial Register was performed to identify all potentially relevant English-language scientific papers containing original research articles on the effects of vitamin D on human health. Results: In this review, we analyzed the antioxidant and anti-inflammatory effects of vitamin D against acute and chronic diseases, focusing particularly on cancer, immune-related diseases, cardiomyophaties (including heart failure, cardiac arrhythmias, and atherosclerosis) and infectious diseases. Conclusions: Vitamin D significantly reduces the pro-oxidant systemic and tissue biomarkers involved in the development, progression, and recurrence of chronic cardiometabolic disease and cancer. The overall picture of this review provides the basis for new randomized controlled trials of oral vitamin D supplementation in patients with cancer and infectious, neurodegenerative, and cardiovascular diseases aimed at reducing risk factors for disease recurrence and improving quality of life.

Vitamin D deficiency: a potential risk factor for cancer in obesity?

Obesity is considered an abnormal or excessive accumulation of adipose tissue, due to a prolonged positive energy balance that arises when energy intake is greater than energy expenditure, leading to an increased risk for the individual health and for the development of metabolic chronic diseases including several different types of cancer. Vitamin D deficiency is a metabolic alteration, which is often associated with the obesity condition. Vitamin D is a liposoluble vitamin, which plays a pivotal role in calcium-phosphate metabolism but extraskeletal effects have also been described. Among these, it plays an important role also in adipocyte physiology and glucose metabolism, typically dysregulated in subjects affected by obesity. Moreover, it is now recognized that Vitamin D also influences the processes of cell proliferation, differentiation, adhesion potentially leading to carcinogenesis. Indeed, data indicate a potential link between vitamin D levels and cancer, and higher vitamin D concentrations have been associated with a lower risk of developing different kinds of tumors, including breast, colon, lymphoma, lung, and prostate cancers. Thus, this review will revise the literature regarding this issue investigating and highlighting the potential mechanism of action, which might lead to new therapeutical options.

THE CARDIOPROTECTIVE EFFECT OF VITAMIN D IN BREAST CANCER PATIENTS RECEIVING ADJUVANT DOXORUBICIN BASED CHEMOTHERAPY

PURPOSE

The primary objective of this study was to investigate the potential protective effect of Vitamin D (Vit D) on DOX induced cardio toxicity (DIC) in early breast cancer patients receiving adjuvant DOX based chemotherapy (AC). The secondary objective was to investigate the anti-inflammatory effect of Vit D by measuring serum IL-6 and its correlation with cardio toxicity.

METHODS

This study was carried out on 150 newly diagnosed women with breast cancer who were planned to receive four cycles of adjuvant AC chemotherapy regimen (60 mg/m² DOX and 600 mg/m² cyclophosphamide) every 21 days. Study patients were randomized 1:1 into a control group treated with AC and a Vit D group treated with AC plus 0.5 µg of Vit D (Bon One 0.5 µg) orally once daily during the whole treatment course. The cardio protective effect of Vit D was assessed by measuring serum levels of Lactate dehydrogenase (LDH), cardiac troponin T (cTnT), and anti-inflammatory Interleukin 6 (IL-6) at baseline, and after 4 cycles of AC in all study patients.

RESULTS

Vit D supplementation in Vit D group patients was associated with a significant decrease (P < 0.001) in serum levels of LDH, cTnT, and IL-6 compared to the control group .

CONCLUSION

The present work provides a promising clinical evidence to support the cardio protective effects of Vit D against DIC through attenuating the evoked pro-inflammatory cytokines induced by DOX.

High-dose vitamin D metabolite delivery inhibits breast cancer metastasis

Besides its well-known benefits on human health, calcitriol, the hormonally active form of vitamin D3, has been being evaluated in clinical trials as an anticancer agent. However, currently available results are contradictory and not fundamentally deciphered. To the best of our knowledge, hypercalcemia caused by high-dose calcitriol administration and its low bioavailability limit its anticancer investigations and translations. Here, we show that the one-step self-assembly of calcitriol and amphiphilic cholesterol-based conjugates leads to the formation of a stable minimalist micellar nanosystem. When administered to mice, this nanosystem demonstrates high calcitriol doses in breast tumor cells, significant tumor growth inhibition and antimetastasis capability, as well as good biocompatibility. We further reveal that the underlying molecular antimetastatic mechanisms involve downregulation of proteins facilitating metastasis and upregulation of paxillin, the key protein of focal adhesion, in primary tumors.

Vitamin D and Multiple Health Outcomes: An Umbrella Review of Observational Studies, Randomized Controlled Trials, and Mendelian Randomization Studies

Observational studies, randomized controlled trials (RCTs), and Mendelian randomization (MR) studies have yielded inconsistent results on the associations of vitamin D concentrations with multiple health outcomes. In the present umbrella review we aimed to evaluate the effects of low vitamin D concentrations and vitamin D supplementation on multiple health outcomes. We summarized current evidence obtained from meta-analyses of observational studies that examined associations between vitamin D concentrations and multiple health outcomes, meta-analyses of RCTs that investigated the effect of vitamin D supplementation on multiple health outcomes, and MR studies that explored the causal associations of vitamin D concentrations with various diseases (international prospective register of systematic reviews PROSPERO registration number CRD42018091434). A total of 296 meta-analyses of observational studies comprising 111 unique outcomes, 139 meta-analyses of RCTs comprising 46 unique outcomes, and 73 MR studies comprising 43 unique outcomes were included in the present umbrella review. Twenty-eight disease outcomes were identified by both meta-analyses of observational studies and MR studies. Seventeen of these reported disease outcomes had consistent results, demonstrating that lower concentrations of vitamin D were associated with a higher risk for all-cause mortality, Alzheimer's disease, hypertension, schizophrenia, and type 2 diabetes. The combinations of consistent evidence obtained by meta-analyses of observational studies and MR studies together with meta-analyses of RCTs showed that vitamin D supplementation was associated with a decreased risk for all-cause mortality but not associated with the risk for Alzheimer's disease, hypertension, schizophrenia, or type 2 diabetes. The results indicated that vitamin D supplementation is a promising strategy with long-term preventive effects on multiple chronic diseases and thus has the potential to decrease all-cause mortality. However, the current vitamin D supplementation strategy might not be an efficient intervention approach for these diseases, suggesting that new strategies are highly needed to improve the intervention outcomes.

The clinical significance of vitamin D levels and vitamin D receptor mRNA expression in colorectal neoplasms

BACKGROUND/AIM

This study aimed to investigate the clinical significance of changes in vitamin D [25(OH)D] levels and vitamin D receptor (VDR) mRNA expression in colorectal adenoma development.

METHODS

Plasma concentrations of 25(OH)D and mRNA expression of VDR in tissues were determined by enzyme-linked immunosorbent assay (ELISA) and real-time fluorescence quantitative polymerase chain reaction (RT-qPCR), respectively. In addition, the concentration of plasma 25(OH)D and levels of VDR mRNA in tissues were compared among healthy individuals and adenoma and adenocarcinoma patients.

RESULTS

Vitamin D receptor expression in colorectal adenocarcinoma tissues was significantly lower than that in para-cancerous tissues that were >5 cm away from malignant tumor sites (p < 0.01). The level of VDR expression in normal colorectal tissues from healthy individuals was significantly higher than that in colorectal adenomas (p < 0.01) and colorectal adenocarcinomas (p < 0.01); however, the VDR expression was not significantly different between colorectal adenomas and colorectal adenocarcinomas (p = 0.106). The concentration of 25(OH)D in healthy individuals was significantly higher than that in patients with colorectal adenomas (p < 0.01) and colorectal adenocarcinomas (p < 0.01); however, the concentration of 25(OH)D was not significantly different between colorectal adenomas and colorectal adenocarcinomas (p = 0.489). A low concentration of 25(OH)D was considered a risk factor for colorectal adenoma and colorectal adenocarcinoma, with odds ratios of 4.875 and 2.925, respectively.

CONCLUSIONS

The 25(OH)D levels and VDR mRNA expression might be associated with the development of colorectal adenoma and its progression to adenocarcinoma.

Evaluating Concordance of Bodies of Evidence from Randomized Controlled Trials, Dietary Intake, and Biomarkers of Intake in Cohort Studies: A Meta-Epidemiological Study

We aimed to identify and compare empirical data to determine the concordance of diet-disease effect estimates of bodies of evidence (BoE) from randomized controlled trials (RCTs), dietary intake, and biomarkers of dietary intake in cohort studies (CSs). The Cochrane Database of Systematic Reviews and MEDLINE were searched for systematic reviews (SRs) of RCTs and SRs of CSs that investigated both dietary intake and biomarkers of intake published between 1 January 2010 and 31 December 2019. For matched diet-disease associations, the concordance between results from the 3 different BoE was analyzed using 2 definitions: qualitative (e.g., 95% CI within a predefined range) and quantitative (test hypothesis on the z score). Moreover, the differences in the results coming from BoERCTs, BoECSs dietary intake, and BoECSs biomarkers were synthesized to get a pooled ratio of risk ratio (RRR) across all eligible diet-disease associations, so as to compare the 3 BoE. Overall, 49 diet-disease associations derived from 41 SRs were identified and included in the analysis. Twenty-four percent, 10%, and 39% of the diet-disease associations were qualitatively concordant comparing BoERCTs with BoECSs dietary intake, BoERCTs with BoECSs biomarkers, and comparing both BoE from CSs, respectively; 88%, 69%, and 90% of the diet-disease associations were quantitatively concordant comparing BoERCTs with BoECSs dietary intake, BoERCTs with BoECSs biomarkers, and comparing both BoE from CSs, respectively. The pooled RRRs comparing effects from BoERCTs with effects from BoECSs dietary intake were 1.09 (95% CI: 1.06, 1.13) and 1.18 (95% CI: 1.10, 1.25) compared with BoECSs biomarkers. Comparing both BoE from CSs, the difference in the results was also small (RRR: 0.92; 95% CI: 0.88, 0.96). Our findings suggest that BoE from RCTs and CSs are often quantitatively concordant. Prospective SRs in nutrition research should include, whenever possible, BoE from RCTs and CSs on dietary intake and biomarkers of intake to provide the whole picture for an investigated diet-disease association.

Vitamin D Receptor Gene Single Nucleotide Polymorphisms and Association With Vitamin D Levels and Endoscopic Disease Activity in Inflammatory Bowel Disease Patients: A Pilot Study

BACKGROUND

Inflammatory bowel diseases (IBDs) comprise a heterogenous group of chronic gastrointestinal disorders that are multifactorial in etiology. Experimental in vitro and in vivo studies suggest that intestinal vitamin D receptor (VDR) signaling plays a role in modulating the immune response in IBD as a cause and/or a consequence of chronic inflammation.

AIM

The aim of this study is to study the associations between vitamin D receptor gene single nucleotide polymorphisms(SNPs), vitamin D levels, and endoscopic disease activity in IBD.

METHODS

This is a cross-sectional analysis of IBD patients who underwent endoscopic evaluation at a tertiary care hospital. Demographic variables, IBD disease type and location, medical therapies, vitamin D levels, and endoscopic disease activity were collected. Colonic biopsies obtained were investigated for the presence of VDR SNPs: ApaI, TaqI, BsmI, FokI, and Tru9I.

RESULTS

Patients in endoscopic remission had higher vitamin D levels compared with those with inflammation found on endoscopy (P = <0.001). Patients with lower vitamin D levels were homozygous for Fok ancestral alleles (P = 0.0045). With regard to endoscopic disease activity, we found no differences in mutations of any of the VDR SNPs in our sample.

CONCLUSIONS

The association between the presence of the ancestral FokI and lower vitamin D levels suggests a multifactorial etiology for vitamin D deficiency in IBD. Higher vitamin D levels in those in endoscopic remission compared with lower levels in those with active inflammation suggests that the impact of VDR gene SNP on disease activity may be overcome with replacement therapy.

Vitamin D Intake and the Risk of Colorectal Cancer: An Updated Meta-Analysis and Systematic Review of Case-Control and Prospective Cohort Studies

Simple Summary

Colorectal cancer (CRC) is the third most diagnosed cancer in men and the second in women worldwide, being the second most deadly cancer worldwide. The evidence coming from experimental studies suggest a protective effect of vitamin D intake on the risk of CRC. Different studies have shown that vitamin D may play a chemopreventive role in colorectal adenoma incidence, malignant transformation and progression. Our objective was to conduct an updated systematic review and meta-analysis of both case-control and prospective cohort studies on vitamin D intake and CRC. This manuscript provides a complete and updated state-of-the-art about vitamin D intake and CRC risk.

Abstract

Obesity, a sedentary lifestyle, high red meat consumption and alcohol, and tobacco are considered the driving factors behind colorectal cancer (CRC) worldwide. Both diet and lifestyle are recognized to play an important role in the prevention of CRC. Forty years later, the vitamin D–cancer hypothesis is considered consistent. However, the relationship between low vitamin D intake and CRC is still controversial. The aim of this meta-analysis is to determine the associations between Vitamin D intake and CRC. MEDLINE-PubMed and Cochrane databases were searched up to May 2020 for studies evaluating the association between vitamin D intake (from foods and supplements) and CRC. Two reviewers, working independently, screened all titles and abstracts to identify the studies that met the inclusion criteria (case-control or prospective cohort (PC) studies published in English). Data were pooled by the generic inverse variance method using a random or fixed effect model. Heterogeneity was identified using the Cochran Q-test and quantified by the I² statistic. A total of 31 original studies were included for the quantitative meta-analysis, comprising a total 47.540 cases and 70.567 controls in case-control studies, and a total of 14.676 CRC-incident cases (out of 808.130 subjects in PC studies) from 17 countries. A significant 25% lower risk was reported comparing the highest vs. the lowest dietary vitamin D consumption and CRC risk (odds ratio (95% confidence interval): 0.75 (0.67; 0.85)) in case-control studies, whereas a non-significant association was reported in case of prospective studies (hazard ratio (95% confidence interval): 0.94 (0.79; 1.11). The present meta-analysis demonstrates that high dietary vitamin D is associated to CRC prevention. However, larger and high-quality prospective studies and clinical trials are warranted to confirm this association.

Dietary vitamin D intake and colorectal cancer risk: a longitudinal approach within the PREDIMED study

PURPOSE

We evaluated whether the intake of dietary vitamin D is associated with the incidence of both colorectal cancer (CRC) and colon cancer in the framework of the PREDIMED cohort of older adults at high cardiovascular risk.

METHODS

We analyzed data from 7216 men and women (55-80 years) without CRC at baseline from the PREvención con DIeta MEDiterránea study. Baseline consumption of vitamin D was assessed using a validated 137-item food frequency questionnaire. Cox proportional hazards ratios (HRs) of CRC and colon cancer incidence were estimated for quartiles and per 1-SD of baseline vitamin D intake.

RESULTS

During a median follow-up of 6 years, we documented 97 incident CRC cases after the exclusion of subjects with no baseline dietary data and/or outliers of energy intake. A non-significant HRs and 95% confidence intervals (CIs) of CRC for the comparison of extreme quartiles (4th vs 1st) of vitamin D intake were observed [0.55 (0.30-1.00), P for trend = 0.072], whereas it was significant for colon cancer incidence alone [0.44 (0.22-0.90), P for trend = 0.032]. However, this association became significant in CRC and colon cancer incidence, after excluding 391 subjects consuming baseline vitamin D and/or calcium medication or prescribed supplements [0.52 (0.28-0.96) and 0.41 (0.12-0.85), respectively].

CONCLUSION

A higher dietary intake of vitamin D was significantly associated with a reduced CRC risk in individuals at high cardiovascular risk.

Associations of vitamin D status with colorectal cancer risk and survival

Biological evidence suggests that vitamin D has numerous anticancer functions, but the associations between vitamin D status and colorectal cancer (CRC) risk and survival remain inconclusive. Based on UK Biobank, we prospectively evaluated the associations of season-standardized 25-hydroxyvitamin D (25(OH)D) concentrations with CRC risk among 360 061 participants, and with survival among 2509 CRC cases. We observed an inverse linear relationship between 25(OH)D concentrations and CRC risk (P for linearity = .01; HR per 1-SD increment, 0.95; 95% CI, 0.91-0.99). Compared to the lowest quartile of 25(OH)D, the highest quartile was associated with a 13% (HR, 0.87; 95% CI, 0.77-0.98) lower risk of CRC. For CRC survival, compared to those in the lowest quartile of 25(OH)D, cases in the highest quartile had a 20% (HR, 0.80; 95% CI, 0.65-0.99) lower risk for overall death. Our findings indicate that higher concentrations of serum 25(OH)D are associated with lower incidence and improved survival of CRC, suggesting a role of vitamin D in the pathogenesis of CRC.

Association Between Vitamin D Exposure and Head and Neck Cancer: A Systematic Review With Meta-Analysis

Background

Vitamin D deficiency is a well-described preventable cause of many cancers; the association of vitamin D use with the development of head and neck cancer (HNC) is not clear. We aim to conduct a systematic review of the studies assessing the relation between vitamin D exposure and the prevention and prognosis of the HNC using meta-analysis.

Methods

PubMed, EMBASE, Cochrane Library, Web of Science up to 1 January 2021, and reference lists of related studies were searched. We extracted observational studies reporting the association between vitamin D (vitamin D receptor gene polymorphisms, 25-hydroxyvitamin D concentrations, and vitamin D intake) and the outcomes of interest (HNC incidence and HNC mortality) in HNC patients aged 18 or older. Fixed effects models were used to calculate pooled effect sizes and 95% confidence intervals (CIs) by RevMan (version 5.3).

Results

Sixteen studies with a total of 81,908 participants were enrolled in our meta-analysis. Based on the pooled genomic analysis, comparing with participants with the genotypes of Ff + FF or FF, the pooled odds ratio (OR) of participants with the genotype of ff was 0.77 (95% CI: 0.61 to 0.97) and 0.75 (0.58 to 0.97), respectively. A similar trend was noted when comparing tt with Tt + TT or TT, in which OR (95% CI) was 0.70 (0.55 to 0.90) and 0.72 (0.55 to 0.95). No significant association was identified between BsmI polymorphism and HNC. Furthermore, the OR of HNC incidence was 0.77 (0.65 to 0.92) for participants with vitamin D intake over the ones with a regular diet. High concentrations of circulated 25-hydroxyvitamin D (25-OHD) significantly decreased by 32% of HNC incidence (OR (95% CI): 0.68 (0.59 to 0.78)) and increased HNC survival (pooled hazard ratio 1.13, 1.05 to 1.22) during a 4-5 years follow-up. High concentrations of circulating 25-OHD in patients with HNC led to a decreased risk of mortality to 0.75 (0.60 to 0.94) as the follow-up extends to 8-12 years.

Conclusions

Elevated activities of vitamin D by diet intake, genomic polymorphisms, or circulated 25-OHD may protect people from HNC and improve the prognosis of patients with HNC.

Systematic Review Registration

PROSPERO, identifier CRD42020176002 (https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=176002).

Vitamin D Receptor (VDR) Gene Polymorphism in Patients Diagnosed with Colorectal Cancer

Colorectal cancer (CRC) is one of the most commonly occurring neoplasias in humans. The prevalence of CRC rates is still rising. Although the exact background of the disease still remains unknown, it is believed that CRC may not only be a result of environmental factors, but also genetic ones. One of the mechanisms underlying CRC might be the vitamin D pathway, as CRC is the most closely linked neoplasia to vitamin D deficiency. This study shows a possible association of the vitamin D receptor (VDR) polymorphisms FokI, BsmI, ApaI, and TaqI with CRC susceptibility. A total of 103 patients diagnosed with CRC (61 men and 42 women, aged 57-82 years) and 109 healthy people (50 men and 59 women, aged 47-68 years) were genotyped using PCR-RFLP for FokI, BsmI, ApaI, and TaqI. None of the single nucleotide polymorphisms (SNPs) individually increased or decreased the risk of CRC. The evaluation of haplotypes revealed two that might enhance the likelihood of CRC development: taB (OR = 30.22; 95% CI 2.81-325.31; p = 0.01) and tAb (OR = 3.84; 95% CI 1.29-11.38; p = 0.01). In conclusion, genotyping is an easy and robust procedure that needs to be performed only once in a lifetime. A creation of a relevant SNP's panel might contribute to the identification of the groups that are at the greatest risk of CRC.

No Association Between Vitamin D Supplementation and Risk of Colorectal Adenomas or Serrated Polyps in a Randomized Trial

BACKGROUND & AIMS

The effects of vitamin D on risk of colorectal cancer precursors are not clear. We examined the influence of vitamin D supplementation on risk of colorectal adenomas and serrated polyps in a prespecified ancillary study of a large-scale prevention trial (the vitamin D and omegA-3 trial, VITAL) of individuals who were free of cancer and cardiovascular disease at enrollment.

METHODS

In VITAL trial, 25,871 adults with no history of cancer or cardiovascular disease (12,786 men 50 years or older and 13,085 women 55 years or older) were randomly assigned to groups given daily dietary supplements (2000 IU vitamin D₃ and 1 g marine n-3 fatty acid) or placebo. Patients were assigned to groups from November 2011 through March 2014 and the study ended on December 31, 2017. We confirmed conventional adenomas and serrated polyps by reviewing histopathology reports from participants who had reported a diagnosis of polyps and were asked by their doctors to return for a repeat colonoscopy or sigmoidoscopy in 5 years or less. We calculated the odds ratios (ORs) and 95% CIs by logistic regression, after adjusting for age, sex, n-3 treatment assignment, and history of endoscopy at time of randomization.

RESULTS

During a median follow-up of 5.3 years, we documented 308 cases of conventional adenomas in 12,927 participants in the vitamin D group and 287 cases in 12,944 participants in the placebo group (OR for the association of vitamin D supplementation with adenoma, 1.08; 95% CI, 0.92-1.27). There were 172 cases of serrated polyps in the vitamin D group and 169 cases in the placebo group (OR for the association of vitamin D supplementation with serrated polyp, 1.02; 95% CI, 0.82-1.26). Supplementation was not associated with polyp size, location, multiplicity, or histologic features. We found evidence for an interaction between vitamin D supplementation and serum level of 25-hydroxyvitamin D, measured in 15,787 participants at randomization. Among individuals with serum levels of 25-hydroxyvitamin D below 30 ng/mL, the OR associated with supplementation for conventional adenoma was 0.82 (95% CI, 0.60-1.13), whereas among individuals with serum levels of 25-hydroxyvitamin D above 30 ng/mL, the OR for conventional adenoma was 1.20 (95% CI, 0.92-1.55) (P for interaction = .07). There was a significant interaction between vitamin D supplementation and serum level of 25-hydroxyvitamin D in their association with advanced adenoma (P for interaction = .04).

CONCLUSIONS

Based on an ancillary study of data from the VITAL trial, daily vitamin D supplementation (2000 IU) was not associated with risk of colorectal cancer precursors in average-risk adults not selected for vitamin D insufficiency. A potential benefit for individuals with low baseline level of vitamin D requires further investigation. ClinicalTrials.gov number: NCT01169259.

Vitamin D and Clinical Cancer Outcomes: A Review of Meta-Analyses

The relationship between vitamin D status or supplementation and cancer outcomes has been examined in several meta‐analyses. To address remaining knowledge gaps, we conducted a systematic overview and critical appraisal of pertinent meta‐analyses. For meta‐analyses of trials, we assessed their quality using AMSTAR‐2 (A Measurement Tool to Assess Systematic Reviews), strength of associations using umbrella review methodology and credibility of evidence using GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) criteria. Meta‐analyses of observational studies reported inverse associations of 25OHD with risk of cancer incidence and cancer mortality and, particularly for colorectal cancer, fulfilled some of Bradford‐Hill's causation criteria. In meta‐analyses of trials, vitamin D supplementation did not affect cancer incidence. However, we found credible evidence that vitamin D supplementation reduced total cancer mortality risk, with five out of six meta‐analyses reporting a relative risk (RR) reduction of up to 16%: RR, 0.84 (95% CI, 0.74–0.95). The strength of the association, however, was classified as weak. This was true among meta‐analyses of high, moderate, and lower quality (AMSTAR‐2–rated). Trials did not include large numbers of vitamin D‐deficient participants; many tested relatively low doses and lacked sufficiently powered data on site‐specific cancers. In conclusion, meta‐analyses show that, although observational evidence indicates that low vitamin D status is associated with a higher risk of cancer outcomes, randomized trials show that vitamin D supplementation reduces total cancer mortality, but not cancer incidence. However, trials with larger proportions of vitamin D‐insufficient participants and longer durations of follow‐up, plus adequately powered data on site‐specific common cancers, would provide further insight into the evidence base. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

A prediction tool for vitamin D deficiency in New Zealand adults

PURPOSE

This study aims to develop a model for predicting vitamin D deficiency in New Zealand adults using easily accessible clinical characteristics.

METHODS

Data were derived from the Vitamin D Assessment (ViDA) study dataset. Included participants in the main analysis were aged 50-84 years and resided in Auckland, New Zealand. The dataset was split into a discovery dataset in which the prediction model was developed (n = 2036) and a validation dataset in which it was tested (n = 2037). The prediction model was developed using clinical characteristics in a logistic regression analysis with deseasonalised serum 25OHD (DS-25OHD) as the dependent variable.

RESULTS

DS-25OHD < 40 nmol/L was found in 8.2% of European participants, 18.8% of Māori participants, 23.1% of Pacific participants and 52.2% of South Asian participants. Predictors for DS-25OHD < 40 nmol/L in the European sub-cohort included increasing age, female sex, higher body mass index, current smoking, no alcohol intake, lower self-reported general health status, lower physical activity hours, lower outdoor hours and no use of vitamin D-containing supplementation. The area under the curve in the discovery dataset was 0.73, and in the validation dataset was 0.71. Of those with a prediction score ≥ 10 (total risk score range 0-21.5), the sensitivity and specificity for predicting vitamin D deficiency was 0.90 and 0.41, respectively.

CONCLUSION

Non-European ethnicity is an important risk factor for vitamin D deficiency. Our vitamin D deficiency prediction model performed well and demonstrates its potential as a tool that can be integrated into clinical practice for the prediction of vitamin D deficiency.

Vitamin D Receptor Polymorphisms and Cancer

Increasing scientific evidence supports the link between vitamin D and cancer risk. The active metabolite 1,25(OH)2D exerts its activity by binding to the vitamin D receptor (VDR), an intracellular receptor that mediates transcriptional activation and repression of target genes. The binding of 1,25(OH)2D to VDR is able to regulate hundreds of different genes. VDR is active in virtually all tissues including the colon, breast, lung, ovary, bone, kidney, parathyroid gland, pancreatic b-cells, monocytes, T lymphocytes, melanocytes, keratinocytes, and also cancer cells.The relevance of VDR gene restriction fragment length polymorphisms for various types of cancer has been investigated by a great number of studies.We have carried out a systematic review of the literature to analyze the relevance of more VDR polymorphisms (Fok1, Bsm1, Taq1, Apa1, and Cdx2) for individual malignancies considering ethnicity as a key factor for heterogeneity.Up to December 2018, we identified 176 independent studies with data to assess the risk of breast, prostate, colorectal, skin (melanoma and non-melanoma skin cancer), lung, ovarian, kidney, bladder, gallbladder, esophageal, thyroid, head and neck, liver and pancreatic cancer, oral squamous cell carcinoma, non-Hodgkin lymphoma, multiple myeloma and sarcoma.Significant associations with VDR polymorphisms have been reported for prostate (Fok1, Bsm1, Taq1, Apa1, Cdx2), breast (Fok1, Bsm1, Taq1, Apa1, CdX2), colorectal (Fok1, Bsm1, Taq1, Apa1), and skin cancer (Fok1, Bsm1, Taq1). Very few studies reported risk estimates for the other cancer sites.Conflicting data have been reported for most malignancies, and at present, it is still not possible to make any definitive statements about the importance of the VDR genotype for cancer risk. It seems probable that other factors such as ethnicity, phenotype, 25(OH)D plasma levels, and UV radiation exposure play a role as confounding factors and introduce heterogeneity.To conclude, there is some indication that VDR polymorphisms may modulate the risk of some cancer sites and in future studies VDR genetic variation should be integrated also with assessment of vitamin D status and stratified by ethnicity.

Comparative Study of Organoids from Patient-Derived Normal and Tumor Colon and Rectal Tissue

Colon and rectal tumors, often referred to as colorectal cancer, show different gene expression patterns in studies that analyze whole tissue biopsies containing a mix of tumor and non-tumor cells. To better characterize colon and rectal tumors, we investigated the gene expression profile of organoids generated from endoscopic biopsies of rectal tumors and adjacent normal colon and rectum mucosa from therapy-naive rectal cancer patients. We also studied the effect of vitamin D on these organoid types. Gene profiling was performed by RNA-sequencing. Organoids from a normal colon and rectum had a shared gene expression profile that profoundly differed from that of rectal tumor organoids. We identified a group of genes of the biosynthetic machinery as rectal tumor organoid-specific, including those encoding the RNA polymerase II subunits POLR2H and POLR2J. The active vitamin D metabolite 1α,25-dihydroxyvitamin D3/calcitriol upregulated stemness-related genes (LGR5, LRIG1, SMOC2, and MSI1) in normal rectum organoids, while it downregulated differentiation marker genes (TFF2 and MUC2). Normal colon and rectum organoids share similar gene expression patterns and respond similarly to calcitriol. Rectal tumor organoids display distinct and heterogeneous gene expression profiles, with differences with respect to those of colon tumor organoids, and respond differently to calcitriol than normal rectum organoids.

25-Hydroxyvitamin D status, vitamin D intake, and skin cancer risk: a systematic review and dose-response meta-analysis of prospective studies

Sun exposure is a major environmental risk factor for skin cancers and is also an important source of vitamin D. However, while experimental evidence suggests that vitamin D may have a protective effect on skin cancer risk, epidemiologic studies investigating the influence of 25-hydroxyvitamin D (25(OH)D) level and/or vitamin D intake on skin cancer risk are conflicting. A systematic review and dose–response meta-analyses of prospective studies was conducted to clarify these associations. Relevant studies were identified by searching the PubMed database up to 30th August 2019. Random effects dose–response meta-analyses were used to estimate summary relative risks (SRRs) and 95% confidence intervals (CIs). Overall, thirteen prospective studies were included. Circulating level of 25(OH)D was associated with higher risks of melanoma (SRR (95% CI) per 30 nmol = 1.42 (1.17–1.72)) and keratinocyte cancer (KC) (SRR (95% CI) per 30 nmol/L = 1.30 (1.13–1.49)). The SRR (95% CI) per 30 nmol/L increase in 25(OH) D level was 1.41 (1.19–1.67), and 1.57 (0.64–3.86), for basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs), respectively. However, while we found that vitamin D intake (from diet, supplemental and total) was not associated with risks of melanoma and SCC, vitamin D intake was associated with slightly increased BCC risk, albeit with no heterogeneity across skin cancer type. This meta-analysis suggests positive associations between circulating 25(OH)D level and risk of melanoma and KC, however, this finding is most likely confounded by sun exposure. We found no associations between vitamin D intake skin cancers, except positive associations with BCC risk.

Association between Vitamin D Receptor Single-Nucleotide Polymorphisms and Colorectal Cancer in the Thai Population: A Case-Control Study

Vitamin D and its cognate intracellular nuclear receptor, namely, vitamin D receptor (VDR), are involved in the regulation of a variety of body metabolic processes, immune function, and oncogenesis. A large number of studies demonstrated the association of low vitamin D levels and variations in five common single nucleotide polymorphisms (SNPs), FokI, BsmI, Tru9I, ApaI, and TaqI, with the risk of several cancers, including colorectal cancers. However, these associations vary among different populations. This case-control study was aimed at analysing whether common single-nucleotide polymorphisms (SNPs) and haplotypes of the vitamin D receptor (VDR) gene contribute to colorectal carcinogenesis in the Thai population. We enrolled 364 Thai participants from King Chulalongkorn Memorial Hospital between 2014 and 2015. Half of the participants underwent colonoscopy and showed a normal colon without polyps (control group) and another half were newly diagnosed patients with colorectal cancer (CRC) by colonoscopy during the index period, were under treatment, or were followed up at the outpatient clinic (case group). Differences in allele and genotype frequencies of five common VDR SNPs, between the case and control groups, were the primary outcome measures. Differences in haplotype frequencies of the five SNPs between the case and control groups were the secondary outcome measures. Among the 364 participants, baseline characteristics were not significantly different between the case and control groups, except for the higher proportion of males in the CRC group. The mean vitamin D level was also not significantly different between the case and control groups (24.6 ± 9.1 vs. 25.3 ± 10.6 ng/mL, p = 0.52). None of the five VDR SNPs was associated with CRC development (p > 0.05). However, haplotype analysis of these polymorphisms demonstrated that the AGGT haplotype was associated with a decreased risk of CRC (odds ratio 0.24, 95% confidence interval 0.07-0.81, p = 0.01). The AGGT haplotype was associated with a lower risk of CRC in the Thai population. This genetic linkage might support the role of vitamin D in colorectal carcinogenesis. However, this finding requires further study within a larger population and a multivariate analysis of other established risk factors.

Association between blood circulating vitamin D and colorectal cancer risk in Asian countries: a systematic review and dose-response meta-analysis

OBJECTIVES

To assess the association between blood circulating vitamin D levels and colorectal cancer risk in the Asian population.

DESIGN

This is a systematic review and dose-response meta-analysis of observational studies that investigated the relationship between blood circulating vitamin D levels and colorectal cancer risk in the Asian population.

DATA SOURCES

Relevant studies were identified through a literature search in Medline, Embase and Web of Science from 1st January 1980 to 31st January 2019. Eligibility criteria: original studies published in peer-reviewed journals investigating the association between blood circulating vitamin D levels and the risk of colorectal cancer and/or adenoma in Asian countries.

DATA EXTRACTION AND SYNTHESIS

Two authors independently extracted data and assessed the quality of included studies. Study-specific ORs were pooled using a random-effects model. A dose-response meta-analysis was performed with generalised least squares regression. We applied the Newcastle-Ottawa Scale quality assessment to evaluate the quality of the selected studies.

RESULTS

The eight included studies encompassed a total of 2916 cases and 6678 controls. The pooled ORs of colorectal cancer for the highest versus lowest categories of blood circulating vitamin D levels was 0.75 (95% CI 0.58 to 0.97) up to 36.5 ng/mL in the Asian population. There was heterogeneity among the studies (I²=53.9%, P_{heterogeneity}=0.034). The dose-response meta-analysis indicated a significant linear relationship (P_{non-linearity}=0.11). An increment of 16 ng/mL in blood circulating vitamin D level corresponded to an OR of 0.79 (95% CI 0.64 to 0.97).

CONCLUSIONS

The results of this meta-analysis indicate that blood circulating vitamin D level is associated with decreased risk of colorectal cancer in Asian countries. The dose-response meta-analysis shows that the strength of this association among the Asian population is similar to that among the Western population. Our study suggests that the Asian population should improve nutritional status and maintain a higher level of blood circulating vitamin D.

MicroRNA-binding site polymorphisms and risk of colorectal cancer: A systematic review and meta-analysis

Genetic variations in miRNAs binding site might participate in cancer risk. This study aimed to systematically review the association between miRNA‐binding site polymorphisms and colorectal cancer (CRC). Electronic literature search was carried out on PubMed, Web of Science (WOS), Scopus, and Embase. All types of observational studies till 30 November 2018 were included. Overall 85 studies (21 SNPs) from two systematic searches were included analysis. The results showed that in the Middle East population, the minor allele of rs731236 was associated with decreased risk of CRC (heterozygote model: 0.76 [0.61‐0.95]). The minor allele of rs3025039 was related to increased risk of CRC in East Asian population (allelic model: 1.25 [1.01‐1.54]). Results for rs3212986 were significant in overall and subgroup analysis (P < .05). For rs1801157 in subgroup analysis the association was significant in Asian populations (including allelic model: 2.28 [1.11‐4.69]). For rs712, subgroup analysis revealed a significant (allelic model: 1.41 [1.23‐1.61]) and borderline (allelic model: 0.92 [0.84‐1.00]) association in Chinese and Czech populations, respectively. The minor allele of rs17281995 increased risk of CRC in different genetic models (P < .05). Finally, rs5275, rs4648298, and rs61764370 did not show significant associations. In conclusion, minor allele of rs3025039, rs3212986, and rs712 polymorphisms increases the risk of CRC in the East Asian population, and heterozygote model of rs731236 polymorphism shows protective effect in the Middle East population. In Europeans, the minor allele of rs17281995 may increase the risk of CRC, while rs712 may have a protective effect. Further analysis based on population stratifications should be considered in future studies.

Acute Respiratory Tract Infection and 25-Hydroxyvitamin D Concentration: A Systematic Review and Meta-Analysis

Observational studies and randomised controlled studies suggest that vitamin D plays a role in the prevention of acute respiratory tract infection (ARTI); however, findings are inconsistent and the optimal serum 25-hydroxyvitamin D (25(OH)D) concentration remains unclear. To review the link between 25(OH)D concentration and ARTI, we searched PubMed and EMBASE databases to identify observational studies reporting the association between 25(OH)D concentration and risk or severity of ARTI. We used random-effects meta-analysis to pool findings across studies. Twenty-four studies were included in the review, 14 were included in the meta-analysis of ARTI risk and five in the meta-analysis of severity. Serum 25(OH)D concentration was inversely associated with risk and severity of ARTI; pooled odds ratios (95% confidence interval) were 1.83 (1.42-2.37) and 2.46 (1.65-3.66), respectively, comparing the lowest with the highest 25(OH)D category. For each 10 nmol/L decrease in 25(OH)D concentration, the odds of ARTI increased by 1.02 (0.97-1.07). This was a non-linear trend, with the sharpest increase in risk of ARTI occurring at 25(OH)D concentration < 37.5 nmol/L. In conclusion, there is an inverse non-linear association between 25(OH)D concentration and ARTI.

Vitamin D-Related Genes, Blood Vitamin D Levels and Colorectal Cancer Risk in Western European Populations

Higher circulating 25-hydroxyvitamin D levels (25(OH)D) have been found to be associated with lower risk for colorectal cancer (CRC) in prospective studies. Whether this association is modified by genetic variation in genes related to vitamin D metabolism and action has not been well studied in humans. We investigated 1307 functional and tagging single-nucleotide polymorphisms (SNPs; individually, and by gene/pathway) in 86 vitamin D-related genes in 1420 incident CRC cases matched to controls from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. We also evaluated the association between these SNPs and circulating 25(OH)D in a subset of controls. We confirmed previously reported CRC risk associations between SNPs in the VDR, GC, and CYP27B1 genes. We also identified additional associations with 25(OH)D, as well as CRC risk, and several potentially novel SNPs in genes related to vitamin D transport and action (LRP2, CUBN, NCOA7, and HDAC9). However, none of these SNPs were statistically significant after Benjamini-Hochberg (BH) multiple testing correction. When assessed by a priori defined functional pathways, tumor growth factor β (TGFβ) signaling was associated with CRC risk (P ≤ 0.001), with most statistically significant genes being SMAD7 (PBH = 0.008) and SMAD3 (PBH = 0.008), and 18 SNPs in the vitamin D receptor (VDR) binding sites (P = 0.036). The 25(OH)D-gene pathway analysis suggested that genetic variants in the genes related to VDR complex formation and transcriptional activity are associated with CRC depending on 25(OH)D levels (interaction P = 0.041). Additional studies in large populations and consortia, especially with measured circulating 25(OH)D, are needed to confirm our findings.

Vitamin D receptor gene polymorphisms in ocular surface squamous cell neoplasms

PURPOSE

To investigate vitamin D receptor polymorphisms in ocular surface squamous cell neoplasm and to evaluate the relationship between the identified polymorphisms and susceptibility to ocular surface squamous cell neoplasm and the clinical course.

MATERIALS AND METHODS

A totala of 70 patients with ocular surface squamous cell neoplasm (study group) and 75 healthy age and gender-matched individuals (control group) were included in the study. Vitamin D receptor FokI and BsmI polymorphisms were examined. The relationships between histopathological diagnosis, recurrence rates, tumor stage, and identified polymorphisms were investigated.

RESULTS

Histopathologically, 43 of the cases were squamous cell carcinoma and 27 of the cases were conjunctival intraepithelial neoplasia. The frequency of FokI (FF, Ff, ff) and BsmI (BB, Bb, bb) polymorphism genotype of vitamin D receptor gene were similar in the groups. The frequency of polymorphism (heterozygous or homozygous) for BsmI (Bb and bb) was significantly higher (p = 0.046) in the study group, while no difference was found between the groups in terms of polymorphic carriers (heterozygous or homozygous) for FokI. There was no correlation between tumor stage, recurrence-polymorphism frequency, and patient age-polymorphism frequency.

CONCLUSION

It is known that active vitamin D inhibits the growth of cancer cells by binding to vitamin D receptor with regulation of genes responsible for cell proliferation. The presence of BsmI polymorphism in vitamin D receptor, in particular bb genotype and b allele, appears to be associated with the susceptibility of ocular surface squamous cell neoplasm. BsmI gene polymorphisms of vitamin D receptor might play an effective role in the formation, progression, and in the course of ocular surface squamous cell neoplasm.

Vitamin D supplementation for prevention of cancer: The D2d cancer outcomes (D2dCA) study

Evidence on biological plausibility from mechanistic studies and data from observational studies suggest that vitamin D may be linked to risk of several types of cancer. However, evidence from clinical trials evaluating the effect of vitamin D supplementation on cancer risk is limited. The Vitamin D and Type 2 Diabetes (D2d) study is a multi-center, randomized, placebo-controlled clinical trial conducted to examine the causal relationship between oral vitamin D supplementation and development of diabetes among overweight adults with prediabetes. The D2d study provides a unique opportunity to assess the effect of vitamin D supplementation at a higher dose (4000 IU/day) than has been used in other clinical trials with cancer outcomes, in a population at higher than average risk for cancer. This paper provides: Krishnan and Feldman (2011) a) baseline characteristics of the D2d population included in the D2d cancer outcomes secondary study (D2dCA) and comparison to other large trials of vitamin D supplementation and cancer risk; Leyssens et al. (2013) b) description of data that are being collected during the trial and the planned statistical analyses to test whether vitamin D supplementation at a dose of 4000 IU/day has an effect on incident cancer overall, on incidence of certain types of cancer, and on incidence of precancerous lesions. Results of D2dCA will help guide future research and clinical recommendations related to vitamin D and cancer risk.

Milk and risk of colorectal, colon and rectal cancer in the Norwegian Women and Cancer (NOWAC) Cohort Study

According to World Cancer Research Fund International/American Institute for Cancer Research, it is 'probable' that dairy products decrease the risk of colorectal cancer (CRC). However, meta-analyses restricted to women have not shown associations between milk intake and risk of CRC. The aim of this study was to examine the association between milk intake and risk of CRC, colon cancer and rectal cancer among women. Data from 81 675 participants in the Norwegian Women and Cancer Cohort Study were included, and multivariable Cox proportional hazard regression models were used to investigate milk intake using two different analytical approaches: one that included repeated measurements and one that included baseline measurements only (872 and 1084 CRC cases, respectively). A weak inverse association between milk intake and risk of colon cancer may be indicated both in repeated measurements analyses and in baseline data analyses. Hazard ratios (HR) for colon cancer of 0·80 (95 % CI 0·62, 1·03, P trend 0·07) and 0·81 (95 % CI 0·64, 1·01, P trend 0·03) and HR for rectal cancer of 0·97 (95 % CI 0·67, 1·42, P trend 0·92) and 0·71 (95 % CI 0·50, 1·01, P trend 0·03) were found when comparing the high with the no/seldom milk intake group in energy-adjusted multivariable models. Our study indicates that there may be a weak inverse association between milk intake and risk of colon cancer among women. The two analytical approaches yielded different results for rectal cancer and hence CRC. Our study indicates that the use of single or repeated measurements in analyses may influence the results.

No Evidence for Posttreatment Effects of Vitamin D and Calcium Supplementation on Risk of Colorectal Adenomas in a Randomized Trial

Vitamin D and calcium supplementation are postulated to have chemopreventive effects against colorectal neoplasia, yet in our previously reported randomized trial, there was no overall efficacy of calcium and/or vitamin D₃ against colorectal adenoma recurrence. It is possible vitamin D₃ and calcium chemopreventive effects are not detectable until beyond the 3- to 5-year follow-up captured in that trial. Accordingly, we explored possible vitamin D and calcium effects on posttreatment (observational) adenoma occurrence. In this secondary analysis of the observational follow-up phase of the Vitamin D/Calcium Polyp Prevention Study, participants who completed the treatment phase were invited to be followed for one additional surveillance colonoscopy cycle. We evaluated adenoma occurrence risk at surveillance colonoscopy, with a mean of 55 ± 15 months after treatment follow-up, according to randomized treatment with vitamin D versus no vitamin D, calcium versus no calcium, and calcium plus vitamin D versus calcium alone. Secondary outcomes included advanced and multiple adenomas. Among the 1,121 participants with observational follow-up, the relative risk (95% confidence interval, CI) of any adenoma was 1.04 (0.93-1.17) for vitamin D versus no vitamin D; 0.95 (0.84-1.08) for calcium versus no calcium; 1.07 (0.91-1.25) for calcium plus vitamin D versus calcium; and 0.96 (0.81-1.15) for calcium plus vitamin D versus neither. Risks of advanced or multiple adenomas also did not differ by treatment. Our results do not support an association between supplemental calcium and/or vitamin D₃ for 3 to 5 years and risk of recurrent colorectal adenoma at an average of 4.6 years after treatment.

Vitamin D and breast cancer: A systematic review and meta-analysis of observational studies

CONTEXT

Breast cancer (BC) is the most common malignancy among women in the US. Vitamin D status and intakes are thought to be inversely associated with BC occurrence.

OBJECTIVES

In our systematic review and meta-analysis, we evaluated evidence linking serum 25(OH)D (both in serum and diet) with breast cancer (BC) occurrence.

DATA SOURCES AND EXTRACTION

Only observational studies from databases such as PubMed and Cochrane (January 1st 2000 through March 15th, 2018) were included using PRISMA guidelines. Publication bias and consistency upon replication were assessed, while harmonizing risk ratios (RR, 95% CI) of BC, per fixed increment of 5 exposures [10 ng/mL of 25(OH)D; 100 IU/d for total/dietary vitamin D intakes; vitamin D deficiency; supplement use). RRs were pooled using random effect models.

DATA ANALYSIS

Pooled findings from 22 studies suggested a net direct association between 25(OH)D deficiency and BC, with RR_pooled = 1.91, 95% CI: 1.51-2.41, P < 0.001). Total vitamin D intake (RR_pooled = 0.99, 95% CI: 0.97-1.00, P = 0.022, per 100 IU/d) and supplemental vitamin D (RR_pooled = 0.97, 95% CI:0.95-1.00, P = 0.026) were inversely associated with BC. No evidence of publication bias was found; all 5 exposures of interest were consistent upon replication.

CONCLUSIONS

25(OH)D deficiency was directly related to BC while total vitamin D and supplemental vitamin D intakes had an inverse relationship with this outcome. Randomized clinical trials are warranted pending further evidence from primary meta-analyses of observational studies.

Effects of vitamin D and calcium on expression of MSH2 and transforming growth factors in normal-appearing colorectal mucosa of sporadic colorectal adenoma patients: A randomized clinical trial

Abnormal expression of the DNA mismatch repair protein MSH2 and autocrine/paracrine transforming growth factors TGFα (growth promoter) and TGFβ₁ (growth inhibitor) is common during colorectal carcinogenesis. To estimate vitamin D and calcium effects on these biomarkers in the normal-appearing colorectal mucosa of sporadic colorectal adenoma patients, we conducted a pilot, randomized, double-blinded, placebo-controlled, modified 2 × 2 factorial chemoprevention clinical trial (N = 104) of supplemental vitamin D₃ (1000 IU daily) and calcium (1200 mg daily), alone and in combination, versus placebo over 1 year. The expression of the three biomarkers and Ki-67/mib-1 in colorectal crypts in biopsies of normal-appearing rectal mucosa were detected using automated immunohistochemistry and quantified using image analysis. In the vitamin D₃ and vitamin D₃ plus calcium groups, relative to their reference groups, in the upper 40% (differentiation zone) of crypts, it was estimated that, respectively, the MSH2/mib-1 ratio increased by 47% (P = 0.14) and 62% (P = 0.08), TGFβ₁ expression increased by 41% (P = 0.25) and 78% (P = 0.14), and the TGFα/TGFβ₁ ratio decreased by 25% (P = 0.31) and 44% (P = 0.13). Although not statistically significant, these results support further research into (i) whether supplemental vitamin D₃ , alone or in combination with calcium, may increase DNA mismatch repair relative to proliferation, increase TGFβ₁ expression, and decrease autocrine/paracrine growth promotion relative to growth inhibition in the colorectal epithelium, all hypothesized to reduce risk for colorectal carcinogenesis; and (ii) the expression of MSH2 relative to mib-1, TGFβ₁ alone, and TGFα relative to TGFβ₁ in the normal-appearing rectal mucosa as potential modifiable, pre-neoplastic markers of risk for colorectal neoplasms.

Dietary vitamin D intake and vitamin D related genetic polymorphisms are not associated with gastric cancer in a hospital-based case-control study in Korea

There have been few studies on the association between vitamin D levels and gastric cancer in Asian populations, but no studies have been performed on the interactions between vitamin D intake and polymorphisms in the vitamin D pathway. The effects of vitamin D intake, vitamin D related genetic polymorphisms, and their association with the incidence of gastric cancer were investigated in a hospital case-control study, including 715 pairs of newly diagnosed gastric cancer patients and controls matched for age and sex. Correlations between vitamin D intake and plasma vitamin D concentrations were also assessed in a subset of subjects. No statistically significant difference was observed in the dietary intake of vitamin D between the patients and controls, nor were there any evident associations between vitamin D intake and risk of gastric cancer in multivariate analyses. Vitamin D intake significantly correlated with the circulating 25-hydroxyvitamin D levels, but not with the active form of the vitamin, 1,25-dihydroxyvitamin D. There were no statistically significant interactions between vitamin D intake, and VDR or TXNIP polymorphisms. This study suggests that dietary vitamin D intake is not associated with gastric cancer risk, and the genetic polymorphisms of vitamin D-related genes do not modulate the effect of vitamin D with respect to gastric carcinogenesis.

Ancient Nuclear Receptor VDR With New Functions: Microbiome and Inflammation

The biological functions of 1α,25-dihydroxyvitamin D3 are regulated by nuclear receptor vitamin D receptor (VDR). The expression level of VDR is high in intestine. VDR is an essential regulator of intestinal cell proliferation, barrier function, and immunity. Vitamin D/VDR plays a protective role in inflammatory bowel diseases (IBDs), both ulcerative colitis and Crohn's disease. Emerging evidence demonstrates low VDR expression and dysfunction of vitamin D/VDR signaling in patients with IBD. Here, we summarize the progress made in vitamin D/VDR signaling in genetic regulation, immunity, and the microbiome in IBD. We cover the mechanisms of intestinal VDR in regulating inflammation through inhibiting the NF-ĸB pathway and activating autophagy. Recent studies suggest that the association of VDR single nucleotide polymorphisms with immune and intestinal pathology may be sex dependent. We emphasize the tissue specificity of VDR and its sex- and time-dependent effects. Furthermore, we discuss potential clinical application and future direction of vitamin D/VDR in preventing and treating IBD.

The burgeoning role of cytochrome P450-mediated vitamin D metabolites against colorectal cancer

The metabolites of vitamin D₃ (VD3) mediated by different cytochrome P450 (CYP) enzymes, play fundamental roles in many physiological processes in relation to human health. These metabolites regulate a variety of cellular signal pathways through the direct binding of activated vitamin D receptor/retinoic X receptor (VDR/RXR) heterodimeric complex to specific DNA sequences. Thus, the polymorphisms of VDR and VD3 metabolizing enzymes lead to differentiated efficiency of VD3 and further affect serum VD3 levels. Moreover, VDR activation is demonstrated to inhibit the growth of various cancers, including colorectal cancer. However, excessive intake of vitamin D may lead to hypercalcemia, which limits the application of vitamin D tremendously. In this review, we have summarized the advances in VD3 research, especially the metabolism map of VD3 and the molecular mechanisms of inhibiting growth and inducing differentiation in colorectal cancer mediated by VDR-associated cellular signal pathways. The relationship between VDR polymorphism and the risk of colorectal cancer is also illustrated. In particular, novel pathways of the activation of VD3 started by CYP11A1 and CYP3A4 are highlighted, which produce several noncalcemic and antiproliferative metabolites. At last, the hypothesis is put forward that further research of CYP-mediated VD3 metabolites may develop therapeutic agents for colorectal cancer without resulting in hypercalcemia.

Vitamin D and Cancer Risk and Mortality: State of the Science, Gaps, and Challenges

There has been substantial enthusiasm recently regarding the potential role of vitamin D in the primary and secondary prevention of cancer. Laboratory studies demonstrate a range of anticarcinogenic effects for vitamin D compounds, but human studies have yielded little consistent evidence supporting a protective association. Higher circulating levels of vitamin D (i.e., 25-hydroxyvitamin D or 25(OH)D) appear to be associated with reduced risk of colorectal and bladder malignancies, but higher risk of prostate and possibly pancreatic cancers, with no clear association for most other organ sites examined. Despite there being no official institutional recommendations regarding the use of vitamin D supplements for cancer prevention, screenings for vitamin D deficiency and vitamin D supplement use have increased substantially over the past decade. These widespread practices demonstrate that population sociobehavioral changes are often adopted before scientifically well-informed policies and recommendations are available. This review critically examines the currently available epidemiologic literature regarding the associations between circulating 25(OH)D, vitamin D supplementation, and vitamin D-related genetic variation and cancer risk and mortality, with a particular emphasis on prospective studies. We identify several important gaps in our scientific knowledge that should be addressed in order to provide sufficient reproducible data to inform evidence-based recommendations related to optimal 25(OH)D concentrations (and any role for vitamin D supplementation) for the primary and secondary prevention of cancer. With few exceptions, such recommendations cannot be made at this time.

Plasma 25-hydroxyvitamin D concentration and subsequent risk of total and site specific cancers in Japanese population: large case-cohort study within Japan Public Health Center-based Prospective Study cohort

OBJECTIVE

To evaluate the association between pre-diagnostic circulating vitamin D concentration and the subsequent risk of overall and site specific cancer in a large cohort study.

DESIGN

Nested case-cohort study within the Japan Public Health Center-based Prospective Study cohort.

SETTING

Nine public health centre areas across Japan.

PARTICIPANTS

3301 incident cases of cancer and 4044 randomly selected subcohort participants.

EXPOSURE

Plasma concentration of 25-hydroxyvitamin D measured by enzyme immunoassay. Participants were divided into quarters based on the sex and season specific distribution of 25-hydroxyvitamin D among subcohorts. Weighted Cox proportional hazard models were used to calculate the multivariable adjusted hazard ratios for overall and site specific cancer across categories of 25-hydroxyvitamin D concentration, with the lowest quarter as the reference.

MAIN OUTCOME MEASURE

Incidence of overall or site specific cancer.

RESULTS

Plasma 25-hydroxyvitamin D concentration was inversely associated with the risk of total cancer, with multivariable adjusted hazard ratios for the second to fourth quarters compared with the lowest quarter of 0.81 (95% confidence interval 0.70 to 0.94), 0.75 (0.65 to 0.87), and 0.78 (0.67 to 0.91), respectively (P for trend=0.001). Among the findings for cancers at specific sites, an inverse association was found for liver cancer, with corresponding hazard ratios of 0.70 (0.44 to 1.13), 0.65 (0.40 to 1.06), and 0.45 (0.26 to 0.79) (P for trend=0.006). A sensitivity analysis showed that alternately removing cases of cancer at one specific site from total cancer cases did not substantially change the overall hazard ratios.

CONCLUSIONS

In this large prospective study, higher vitamin D concentration was associated with lower risk of total cancer. These findings support the hypothesis that vitamin D has protective effects against cancers at many sites.

Associations between VDR gene polymorphisms and colorectal cancer susceptibility: an updated meta-analysis based on 39 case-control studies

BACKGROUND

Recent studies have reported the associations between vitamin D receptor (VDR) polymorphisms and colorectal cancer (CRC), but the results were not always consistent. This meta-analysis aims to evaluate whether VDR polymorphisms are associated with CRC susceptibility.

MATERIALS AND METHODS

Studies on the associations between VDR polymorphisms and CRC were retrieved from the Web of Science, PubMed, the Chinese Biomedical Database (CBM), Chinese National Knowledge Infrastructure (CNKI) and Wanfang (Chinese) databases. The odds ratio (OR) with 95% confidence intervals (CIs) was obtained.

RESULTS

Thirty-nine articles met all inclusion criteria and were included in the meta-analysis including 22101 CRC cases and 23696 healthy controls. The 39 articles consisted of five VDR gene polymorphisms including ApaI, FokI, BsmI, TaqI and Cdx2. The results of meta-analysis showed that the FokI polymorphism was on the fringe of statistically significant in the comparisons of F allele vs. f allele in fixed model (OR = 1.029, 95% CI = 0.999-1.059, Praw = 0.057, PFDR = 0.057). Moreover, for the associations between BsmI polymorphism with CRC, We observed significant differences in allele frequencies, the homozygous model and the dominant model between CRC patients and healthy controls (B vs. b: OR = 0.862, 95% CI = 0.761-0.976, Praw = 0.019, PFDR = 0.019; BB vs. bb: OR = 0.786, 95% CI = 0.636-0.972, Praw = 0.026, PFDR = 0.039; BB + Bb vs. bb: OR = 0.934, 95% CI = 0.888-0.982, Praw = 0.008, PFDR = 0.024, respectively).

CONCLUSIONS

This meta-analysis suggests that BsmI is associated with CRC risk and FokI might be a risk factor for CRC. However, these associations with CRC need further studied.

Obesity is associated with vitamin D deficiency in Danish children and adolescents

BACKGROUND

Sufficient serum concentrations of vitamin D are required to maintain bone health during growth. The aims of this study were to determine whether vitamin D deficiency is more prevalent among children and adolescents with obesity compared to their normal weight peers and to identify clinical and biochemical variables associated with vitamin D deficiency.

METHODS

One thousand four hundred and eighty-four children and adolescents with overweight/obesity and 2143 population-based controls were recruited from the Danish Childhood Obesity Biobank. Anthropometric variables and fasting concentrations of serum 25-hydroxy vitamin D (25-OH-D), plasma parathyroid hormone (PTH), calcium and phosphate were assessed at baseline. Vitamin D deficiency was defined as serum 25-OH-D concentrations <30 nmol/L. Linear and logistic regressions were used to identify variables associated with vitamin D deficiency.

RESULTS

A total of 16.5% of the children and adolescents with obesity (body mass index [BMI] standard deviation score [SDS]>2.33) exhibited vitamin D deficiency, with an odds ratio (OR) 3.41 (confidence interval [CI]: 2.27-5.71; p<0.0001) for being vitamin D deficient compared to their normal weight peers. BMI-SDS was independently and inversely associated with serum 25-OH-D concentrations. Other independent risk factors for vitamin D deficiency were being older than 14 years (OR: 2.39; CI: 1.28-4.48; p=0.006), more than 4 daily hours of screen time (OR: 4.56; CI: 2.59-8.05; p<0.0001) and blood sample assessment during winter-spring (OR: 6.44; CI: 4.47-9.26; p<0.0001).

CONCLUSIONS

Vitamin D deficiency was common among Danish children and adolescents with obesity. The degree of obesity was independently associated with lower serum 25-OH-D concentrations.

Vitamin D status in irritable bowel syndrome and the impact of supplementation on symptoms: what do we know and what do we need to know?

BACKGROUND

Low vitamin D status is associated with risk of colorectal cancer and has been implicated in inflammatory bowel disease. Irritable bowel syndrome (IBS) is a chronic, relapsing, functional bowel disorder. A nascent literature suggests a role for vitamin D in IBS, but this has not been collated or critiqued. To date, seven studies have been published: four observational studies and three randomised controlled trials (RCTs). All observational studies reported that a substantial proportion of the IBS population was vitamin D deficient. Two intervention studies reported improvement in IBS symptom severity scores and quality of life (QoL) with vitamin D supplementation. There are limited data around the role of vitamin D in IBS.

CONCLUSIONS

The available evidence suggests that low vitamin D status is common among the IBS population and merits assessment and rectification for general health reasons alone. An inverse correlation between serum vitamin D and IBS symptom severity is suggested and vitamin D interventions may benefit symptoms. However, the available RCTs do not provide strong, generalisable evidence; larger and adequately powered interventions are needed to establish a case for therapeutic application of vitamin D in IBS.

Association Between Low Relative Muscle Mass and the Risk of Colorectal Neoplasms

GOALS

We aimed to ascertain whether low relative muscle mass is associated with colorectal neoplasm (CRN) risk.

BACKGROUND

CRN and sarcopenia have common pathophysiological mechanisms such as insulin resistance, chronic inflammation, and physical inactivity. However, the direct relationship between the 2 diseases has not been investigated.

STUDY

A cross-sectional study was performed on 81,885 examinees who underwent colonoscopy as part of a health check-up. The skeletal muscle mass index (SMI) [SMI (%)=total skeletal muscle mass (kg)/body weight (kg)×100] was estimated using a bioelectrical impedance analyzer.

RESULTS

Of 81,885 participants, 52,272 were men and 29,613 were women. The prevalence rate of CRN in subjects in quartiles 1, 2, 3, and 4 of SMI was 22.8%, 20.5%, 18.2%, and 14.9% among men, and 14.8%, 11.8%, 9.7%, and 8.2% among women, respectively (Ptrend<0.001). In a multivariable-adjusted model, the inverse associations between SMI and prevalence of CRN remained significant. In men, the adjusted odds ratios (95% confidence interval) for overall CRN comparing each of the quartiles 1, 2, and 3 of SMI with the quartile 4 were 1.41 (1.32 to 1.52), 1.24 (1.16 to 1.33), and 1.12 (1.04 to 1.20), and those for advanced CRN were 1.64 (1.34 to 2.01), 1.38 (1.12 to 1.70), and 1.12 (0.90 to 1.40), respectively (all Ptrend<0.001). In women, those for overall CRN were 1.18 (1.04 to 1.33), 1.15 (1.01 to 1.30), and 1.05 (0.93 to 1.20), respectively (Ptrend=0.006).

CONCLUSIONS

Relative muscle mass was negatively associated with CRN prevalence, supporting low muscle mass as an independent risk factor for CRN. Our results may provide a novel insight into the mechanisms linking low muscle mass and CRN.

Dietary Supplements Commonly Used by Cancer Survivors: Are There Any Benefits?

Following a cancer diagnosis, dietary supplements are reportedly used by 20%-80% of individuals. Supplements are most commonly used by breast cancer survivors, followed by patients with prostate, colorectal, and lung cancers, which is not surprising since these are the most common types of cancer diagnosed in adults. Reasons cited for such use include improving quality of life, reducing symptoms related to treatment and/or the disease process, and recommendation from medical practitioners; family and friends may also be an influence. However, controversy surrounds the use of dietary supplements, particularly during treatment-specifically, whether supplements affect treatment efficacy is unknown. This article discusses the evidence related to common dietary supplements used to prevent cancer or a recurrence.