Prospective study of serum 25(OH)-vitamin D concentration and risk of oesophageal and gastric cancers

Sex differences in vitamin D metabolism, serum levels and action

The ubiquity of vitamin D metabolising enzymes and vitamin D receptors in mammalian organisms suggests that vitamin D has pleiotropic effects. There are quite a few studies indicating the anticancer, cardioprotective and antidiabetic effects of vitamin D; however, the best-documented actions of vitamin D are the regulation of Ca-phosphate balance and its effect on immune function.Vitamin D levels in organisms are modulated by many environmental and non-environmental factors. One potential factor that may influence vitamin D levels and effects is the sex of the individuals studied. This review focuses on the scientific evidence indicating different synthesis and metabolism of vitamin D in females and males, mainly from PubMed database sources. The article verifies the sex differences in vitamin D levels reported around the world. Moreover, the different effects of vitamin D on the musculoskeletal, cardiovascular, nervous and immune systems, as well as cancer in males and females, were discussed.Most studies addressing sex differences in vitamin D levels and effects are observational studies with conflicting results. Therefore, carefully designed clinical trials and experiments on animal models should be carried out to determine the role of non-environmental factors that may differentiate vitamin D levels in females and males.

Correlation between Serum 25-Hydroxyvitamin D Levels and Gastric Cancer: A Systematic Review and Meta-Analysis

The purpose of this meta-analysis was to evaluate the relationship between serum 25-hydroxyvitamin D[25(OH)D] levels and gastric cancer. PubMed, Embase, Cochrane Library, Web of Science, The China Academic Journals full-text database, Wanfang Database of Chinese Academic Journals, VIP Chinese Science and Technology Periodicals database, and Chinese Biomedical Literature database were systematically searched. Case-control studies on the correlation between serum 25-hydroxyvitamin D levels and gastric cancer were retrieved, and the data extracted were analyzed. The results of 9 case-control studies containing 671 patients showed that serum 25(OH)D levels in the gastric cancer group were lower than those in the control group (weighted mean difference (WMD) = -8.90, 95% confidence interval (CI): -11.5, -6.32, p < 0.01); the risk of vitamin D deficiency in the gastric cancer group was higher than that in the control group (Odds ratio = 3.09, 95% CI: 1.96, 4.87, p < 0.01). The serum 25(OH)D levels in patients with well and moderately differentiated gastric cancer were higher than those in patients with poorly differentiated gastric cancer (WMD = -3.58, 95% CI: -6.41, -0.74, p = 0.01). Thus, low levels of vitamin D may increase the risk of gastric cancer. Systematic review registration: PROSPERO CRD42022327942.

Vitamin D intake and gastric cancer in Viet Nam: a case-control study

Background

Most recent laboratory studies have suggested a promising role of vitamin D and its analogs as novel chemotherapeutic agents for cancer treatment. However, epidemiological evidence, especially regarding the effects of vitamin D on gastric cancer is still inconsistent.

Objectives

Our research aimed to evaluate the associations between vitamin D intake and the risk of developing gastric cancer through a case-control study in North Vietnam.

Methods

We accessed databases of the previous completed case-control studies to derive 1182 incident gastric cancer cases and 2995 hospital controls selected from hospitals in Hanoi from 2003 to 2019. Vitamin D intake was computed by multiplying the food frequency intake with nutrient content based on the Viet Nam Food Composition Tables. Data were collected through face-to-face interviews by trained interviewers using the validated semi-quantitative food frequency and demographic lifestyle questionnaires. The odds ratio and 95% confidence interval (OR and 95%CI) were estimated using unconditional logistic regression analysis.

Results

We observed a continual decline in gastric cancer risk according to the level-up of vitamin D intake in both genders, men, and women [Fifth vs. bottom quintile, OR, 95%CI: 0.68 (0.53, 0.86), OR, 95%CI: 0.72 (0.53, 0.97), OR, 95%CI: 0.58 (0.38, 0.89), respectively. Per increment quintile, the statistically significant decreased risk was seen by 7% in men and 13% in women. The significant inverse association between vitamin D intake remained in the subgroups of ever and never tobacco smoking; negative and positive H. pylori infection.

Conclusion

The findings suggested that sufficient vitamin D intake was associated with a lower risk of Gastric Cancer in the Vietnamese population.

Vitamin D and Gastric Cancer: A Ray of Sunshine?

Gastric cancer (GC) is one of the most aggressive malignancies, currently ranking third among cancers leading to death worldwide. Despite the recent advancements in GC research, it is most often diagnosed during the terminal stages and with limited treatment modalities contributing to its poor prognosis and a lower survival rate.

Much research has provided conflicting results between a vitamin D deficient status and the development of GC. Vitamin D is a well-known and essential hormone classically known to regulate calcium and phosphate absorption, enabling adequate mineralization of the skeletal system. However, the function of vitamin D is multidimensional. It possesses unique roles, including acting as antioxidants or immunomodulators while crossing the cell membrane, performing several intracellular functions, participating in gene regulation, and controlling the proliferation and invasion of cancer cells, including those of GC.

In light of this, it is imperative to analyze the causes of GC, review the factors that can be used to enhance the effectiveness of treatments, and discover the tools to determine prognosis, reduce mortality, and prevent GC development. In this review, we have summarized recent investigations on multiple associations between vitamin D and GC, emphasizing genetic associations, vitamin D receptors, and the prevalence of hormone deficiency in those developing this aggressive malignancy.

Association between serum 25-hydroxy vitamin D level and gastric adenocarcinoma - a cross sectional study

Introduction

Vitamin D is found to have anti-cancer properties. Although the preventive role of vitamin D in cancer is proven, its role in gastric cancer is equivocal.

Aim

To evaluate vitamin D deficiency in patients with gastric adenocarcinoma and its relationship with the disease characteristics.

Material and methods

This single-centre, prospective, cross sectional study was carried out from February 2017 to December 2018. Serum 25-hydroxy vitamin D levels of 94 patients with gastric adenocarcinoma and 94 age- and sex-matched healthy controls were estimated. Among cases, vitamin D levels and disease characteristics such as TNM stage, tumour grade, clinical stage and patient demographics were analysed.

Results

The vitamin D levels among cases (13.83 ±5.97 ng/ml) were significantly lower (p < 0.0001) than the control group (29.15 ±4.13 ng/ml). Vitamin D deficiency was found in 88% of cases and in 3% of controls. Among cases, age, T stage and clinical stage had a significant inverse relationship with vitamin D levels. Cases with distant metastasis and cases with pain had significantly lower levels of vitamin D compared to the cases without distant metastasis and without pain respectively. Other study parameters did not have a significant relationship with vitamin D.

Conclusions

Vitamin D deficiency is associated with occurrence of gastric adenocarcinoma and correlates with the disease severity. However, to assign a causal relationship and to study the beneficial effect of vitamin D in gastric cancer, further research is needed.

Association between pre-chemotherapy serum levels of vitamin D and clinicopathologic findings in gastric cancer

BACKGROUND

To examine the serum levels of vitamin D in newly diagnosed gastric cancer (GC) patients compared with normal subjects and any possible association with prognostic variables.

METHODS

One-hundred subjects (50 GC and 50 controls) were enrolled and serum vitamin D levels were assessed using ELISA. Based on two definitions, vitamin D was classified as a sufficient level (≥30 ng/dL) and optimal level (25-80 ng/dL). The χ²and unpaired t-test was used for data analysis with a significance level of 0.05.

RESULTS

The mean serum levels of vitamin D in patients and controls were 26.86 (±14.6) and 31.72 (±13.4), respectively (P=0.09). The prevalence of vitamin D insufficiency and deficiency was higher in GC cases than controls (P=0.045 if sufficient level ≥30 and P=0.065 if sufficient level ≥25). According to histological grade analysis, grade 3 patients (poorly differentiated) were found with significantly lower vitamin D concentrations in serum than grade 1 and 2 subjects (22.25 vs 33.29 ng/dL, P=0.021). No significant differences were observed between the two groups in pathological tumor-node-metastasis (pTNM) stages, distant metastasis, and location of the tumor.

CONCLUSION

Higher prevalence of vitamin D insufficiency and deficiency in GC patients may reflect its role in malignancy; however, further studies are needed to confirm this relationship and any possible benefits to the patients.

Eldecalcitol increases bone mineral density in Chinese osteoporotic patients without vitamin D or calcium supplementation

Eldecalcitol increased bone mineral density (BMD) and prevented vertebral fractures in vitamin D-sufficient osteoporotic subjects. However, the effect of eldecalcitol on BMD under vitamin D insufficiency is unknown. We examined the effect of eldecalcitol on BMD compared with alfacalcidol in osteoporotic patients without vitamin D or calcium supplementation. This is a randomized, double-blind, active comparator trial. 265 Chinese osteoporotic patients were randomly assigned to receive 0.75 μg eldecalcitol or 1.0 μg alfacalcidol for 12 months without vitamin D or calcium supplementation. Baseline calcium intakes were less than 550 mg/day and mean serum 25-hydroxyvitamin D [25(OH)D] was below 43 nmol/L in both groups. Baseline BMD tended to be lower in patients with lower calcium intake and serum 25(OH)D. Lumbar BMD increased by 2.05% higher in eldecalcitol than alfacalcidol group at 12 months. Total hip and femoral neck BMD also increased by 1.33 and 1.78%, respectively, in the eldecalcitol than the alfacalcidol group. The effect of eldecalcitol on BMD was not affected by serum 25(OH)D or calcium intake. The incidence of adverse events was not different between the two groups. Incidence of hypercalcemia in the edecalcitol group was not affected by serum 25(OH)D. In conclusion, baseline BMD tended to be lower in patients with low calcium intake and serum 25(OH)D. Eldecalcitol increased lumbar and hip BMD more than alfacalcidol regardless of serum 25(OH)D or calcium intake without vitamin D or calcium supplementation. These results suggest that eldecalcitol is effective in increasing the BMD of osteoporotic patients regardless of vitamin D status or calcium intake.Clinical Trial Registration number JAPIC CTI 152904.

A Narrative Role of Vitamin D and Its Receptor: With Current Evidence on the Gastric Tissues

Vitamin D is a major steroid hormone that is gaining attention as a therapeutic molecule. Due to the general awareness of its importance for the overall well-being, vitamin D deficiency (VDD) is now recognized as a major health issue. The main reason for VDD is minimal exposure to sunlight. The vitamin D receptor (VDR) is a member of the steroid hormone receptors that induces a cascade of cell signaling to maintain healthy Ca²⁺ levels that serve to regulate several biological functions. However, the roles of vitamin D and its metabolism in maintaining gastric homeostasis have not yet been completely elucidated. Currently, there is a need to increase the vitamin D status in individuals worldwide as it has been shown to improve musculoskeletal health and reduce the risk of chronic illnesses, including some cancers, autoimmune and infectious diseases, type 2 diabetes mellitus, neurocognitive disorders, and general mortality. The role of vitamin D in gastric homeostasis is crucial and unexplored. This review attempts to elucidate the central role of vitamin D in preserving and maintaining the overall health and homeostasis of the stomach tissue.

What have we learned from Linxian esophageal cancer etiological studies?

Esophageal cancer is the sixth leading cause of cancer death in the world. Esophageal squamous cell carcinoma (ESCC) accounts for 90% of esophageal cancer cases, over half of which occur in China. Linxian, a county located in the North Central Taihang Mountain range, has the highest ESCC mortality rate, which may be the leading cause of death in this area. In a decades-long research program in Linxian, Chinese and international scientists have exerted great efforts to describe the epidemiological characteristics and elucidate the etiology of ESCC. A systematic review and summary of the current knowledge gained from previous research is informative for future ESCC prevention and control in similar populations, and may be translated to other high-incidence countries, such as Brazil, Iran, Malawi, and South Africa. As ESCC is a major cause of cancer death, more research is required in China and in other high-incidence countries to deepen our understanding of the etiology of ESCC and develop preventative strategies.

Repurposing vitamin D for treatment of human malignancies via targeting tumor microenvironment

Tumor cells along with a small proportion of cancer stem cells exist in a stromal microenvironment consisting of vasculature, cancer-associated fibroblasts, immune cells and extracellular components. Recent epidemiological and clinical studies strongly support that vitamin D supplementation is associated with reduced cancer risk and favorable prognosis. Experimental results suggest that vitamin D not only suppresses cancer cells, but also regulates tumor microenvironment to facilitate tumor repression. In this review, we have outlined the current knowledge on epidemiological studies and clinical trials of vitamin D. Notably, we summarized and discussed the anticancer action of vitamin D in cancer cells, cancer stem cells and stroma cells in tumor microenvironment, providing a better understanding of the role of vitamin D in cancer. We presently re-propose vitamin D to be a novel and economical anticancer agent.

Vitamin D receptor as a marker of prognosis in oesophageal adenocarcinoma: a prospective cohort study

AIMS

Vitamin D receptor (VDR) expression has been associated with survival in several cancer sites. This study aims to evaluate the association between VDR expression and prognosis in oesophageal adenocarcinoma patients.

RESULTS

During a median of 2.5 (maximum 9) years of follow-up, 75 patients died. In analysis adjusted for confounders, higher VDR expression was associated with an improved overall survival (HR 0.49 95% CI 0.25-0.96) and disease-specific survival (HR 0.50 95% CI 0.26-0.99), when comparing the highest with the lowest tertile of expression. These associations were strongest in sensitivity analysis restricted to junctional tumours.

CONCLUSIONS

This study is the first to demonstrate that patients with higher VDR expression in oesophageal adenocarcinoma have a more favourable prognosis. Further work is needed to validate these findings, and to define the role of VDR in the aetiology, progression and management of oesophageal adenocarcinoma.

METHODS

Oesophageal adenocarcinoma specimens and clinical data were collected from 130 patients treated with neo-adjuvant chemotherapy prior to surgical resection at the Northern Ireland Cancer Centre between 2004 and 2012. Tissue microarrays were created and immunohistochemical staining for VDR was performed on triplicate tumour cores from each resection specimen. Cox proportional hazards models were applied to evaluate associations between VDR, according to tertiles of expression, and survival outcomes.

Polymorphisms of Genes Related to Function and Metabolism of Vitamin D in Esophageal Adenocarcinoma

PURPOSE

The vitamin D receptor (VDR) endocrine system has emerged as an endogenous pleiotropic biological cell regulator with anti-neoplastic effects on breast, colorectal, and prostatic adenocarcinomas. We studied the association of gene expression, polymorphisms of VDR, CYP27B1, and CYP24A1 genes and serum vitamin D levels as surrogate markers of disease progression in patients with acid reflux, Barrett's esophagus (BE), or esophageal adenocarcinoma (EAC).

METHODS

We analyzed blood and tissue samples from patients with biopsy-confirmed BE or EAC for vitamin D levels, gene expressions, and polymorphisms in VDR (FokI [F/f], BsmI [B/b], ApaI [A/a], and TaqI [T/t]), CYP27B1 (HinfI [H/h]), and CYP24A1 (Hpy1881 [Y/y]). Percentages of homozygous dominant/recessive or heterozygous traits were assessed for each polymorphism in all patient subgroups.

RESULTS

Genomic Bb and FF polymorphisms were highly prevalent in EAC patients, whereas BE patients had a high prevalence of wild-type Hpy1881 (YY polymorphism). Some polymorphisms (Yy for CYP24A1, bb for VDR) were noted only in EAC patients. Yy and bb forms were both uniquely present in some EAC patients without associated Barrett's lesions, but not in patients with concomitant BE. AA and bb polymorphisms were associated with decreased response to neoadjuvant therapy. A high level of VDR and CYP24A1 mRNA expression was observed in EAC tissue of non-responders. Serum vitamin D deficiency was common in EAC patients.

CONCLUSIONS

Specific polymorphisms in vitamin D metabolism-related genes are associated with the likelihood of reflux-BE-EAC progression. Identifying such polymorphisms may aid in development of better surveillance and diagnostic and therapeutic protocols.

Pathogenic roles of alterations in vitamin D and vitamin D receptor in gastric tumorigenesis

Gastric cancer is currently the second leading cause of cancer-related death worldwide, especially in Japan, Korea and China, and the 5-year survival rate of gastric cancer is less than 30%. Thus, it is important to shed more lights on novel agents to prevent gastric cancer or to improve survival rate of the patients. Vitamin D not only maintains calcium and bone homeostasis, but also mostly inhibits tumor genesis, invasion, and metastasis through activation of vitamin D receptor. Although epidemiological results are not consistent, accumulating evidence from gastric cancer cells, animal models, and clinical trials suggest that vitamin D deficiency may increase the risk and mortality of gastric cancer, but vitamin D supplement might be a safe and economical way to prevent or treat gastric cancer. Here, we reviewed the current studies on vitamin D and its receptor and focused on the pathogenic roles of their alterations in gastric tumorigenesis.

Annual Ambient UVB at Wavelengths that Induce Vitamin D Synthesis is Associated with Reduced Esophageal and Gastric Cancer Risk: A Nested Case-Control Study

Vitamin D has been shown to be beneficial at reducing the risk of cancer; however, studies examining esophageal and gastric cancer have been scarce and findings inconsistent. The UK Biobank cohort was used for this nested case-control study (N = 3732). Primary, incident esophageal and gastric cancer cases diagnosed after recruitment were identified via linkage to National Cancer Registries. Tropospheric Emissions Monitoring Internet Service database was used to calculate ambient annual UVB dose (D-UVB). Conditional logistic regression was used to investigate the relationship between annual ambient D-UVB and risk of esophageal and gastric cancer, and odds ratios (ORs) are reported. In total, 373 esophageal and 249 gastric cancer cases and 3110 age- and gender-matched controls were included in the study. We found a strong inverse association between annual ambient D-UVB and odds of developing esophageal or gastric cancer: Compared to the lowest tertile, OR for the highest tertile was 0.64 (95%CI:0.51-0.79) in adjusted analysis. The association was strengthened when restricted to esophageal cancer (OR = 0.60; 95%CI:0.45-0.80) and esophageal adenocarcinoma cases (OR = 0.48; 95%CI: 0.34-0.68). Similar results were found in unadjusted and stratified analysis. In conclusion, ambient UVB radiation is inversely associated with the development of esophageal and gastric cancer, even in a high-latitude country.

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.

Blood biomarkers for early diagnosis of oesophageal cancer: a systematic review

BACKGROUND

Oesophageal cancer prognosis remains poor owing to the inability to detect the disease at an early stage. Nontissue (serum, urinary or salivary) biomarkers potentially offer less invasive methods to aid early detection of oesophageal cancer. We aimed to systematically review studies assessing the relationship between nontissue biomarkers and subsequent development of oesophageal cancer.

METHODS

Using terms for biomarkers and oesophageal cancer, Medline, EMBASE and Web of Science were systematically searched for longitudinal studies, published until April 2016, which assessed the association between nontissue biomarkers and subsequent oesophageal cancer risk. Random effects meta-analyses were used to calculate pooled relative risk (RR) and 95% confidence intervals (CIs), where possible.

RESULTS

A total of 39 studies were included. Lower serum pepsinogen I concentrations were associated with an increased risk of oesophageal squamous cell carcinoma (n=3 studies, pooled RR=2.20, 95% CI: 1.31-3.70). However, the association for the pepsinogen I : II ratio was not statistically significant (n=3 studies, pooled RR=2.22, 95% CI: 0.77-6.40), with a large degree of heterogeneity observed (I=68.0%). Higher serum glucose concentrations were associated with a modestly increased risk of total oesophageal cancer (n=3 studies, pooled RR=1.27, 95% CI: 1.02-1.57). No association was observed for total cholesterol and total oesophageal cancer risk (n=3 studies, pooled RR=0.95, 95% CI: 0.58-1.54). Very few studies have assessed other biomarkers for meta-analyses.

CONCLUSION

Serum pepsinogen I concentrations could aid early detection of oesophageal squamous cell carcinoma. More prospective studies are needed to determine the use of other nontissue biomarkers in the early detection of oesophageal cancer.

Vitamin D in esophageal cancer: Is there a role for chemoprevention?

Vitamin D has emerged as a promising anti-cancer agent due to its diverse biological effects on tumor differentiation, apoptosis and suppression of cellular proliferation. Current evidence suggests a protective role of vitamin D in colon cancer. The effect of vitamin D on esophageal cancer remains controversial. Multiple studies investigated the association between vitamin D and esophageal cancer, employing different modes of assessment of vitamin D status such as serum 25-hydroxyvitamin D levels, vitamin D dietary intake or exposure to ultraviolet B (UVB) radiation. Genetic variations of the vitamin D receptor (VDR) gene and VDR expression in esophageal specimens have also been investigated. Ecological studies evaluating exposure to UVB radiation yielded an inverse correlation with esophageal cancer. When vitamin D dietary intake was assessed, direct association with esophageal cancer was observed. However, circulating 25-hydroxyvitamin D concentrations showed inconsistent results. In this review article, we present a detailed summary of the current data on the effects of vitamin D on various histological subtypes of esophageal cancer and their precursor lesions. Well-powered prospective studies with accurate measurement of vitamin D status are needed before chemoprevention with vitamin D is recommended, as current evidence does not support a chemopreventive role of vitamin D against esophageal cancer. Future studies looking at the incidence of esophageal cancer in patients with pre-cancerous lesions (Barrett's esophagus and squamous cell dysplasia) receiving vitamin D supplementation are needed.

Association of UV radiation with Parkinson disease incidence: A nationwide French ecologic study

BACKGROUND

Vitamin D is thought to contribute to brain health, but it is unclear whether low vitamin D levels are associated with increased incidence of Parkinson's disease (PD). Using ultraviolet B (UV-B) as a surrogate for vitamin D levels, we conducted a nationwide ecologic study in France in order to examine the association of UV-B with PD incidence.

METHODS

We used French national drug claims databases to identify PD cases using a validated algorithm. UV-B data from the solar radiation database were derived from satellite images. We estimated PD incidence (2010-2012) at the canton level (small administrative French unit) and used multilevel Poisson regression to examine its association with UV-B (2005 annual average), after adjustment for age, sex, deprivation index, density of neurologists, smoking, proportion of agricultural land, and vitamin D supplementation.

RESULTS

Analyses are based on 69,010 incident PD patients. The association between UV-B and PD incidence was quadratic (P<0.001) and modified by age (P<0.001). Below 70y, incidence was higher in the bottom quintile (relative risk, RR_Q1:45-49y=1.18, 95% CI=1.08-1.29) compared with the middle UV-B quintile, and lower in the top quintile (RR_Q5:45-49y=0.85 [0.77-0.94]). An opposite pattern was observed in older subjects (RR_Q1:85-89y=0.92 [0.89-0.96]; RR_Q5:85-89y=1.06 [1.02-1.11]). Analysis based on continuous UV-B yielded similar conclusions.

CONCLUSIONS

In this nationwide study, there was an age-dependent quadratic association between UV-B and PD incidence. This study suggests that reasonable UV-B exposure is associated with lower PD risk in younger persons and that future studies should examine dose-response relations and take age into account.

Vitamin D Signaling Pathways Confer the Susceptibility of Esophageal Squamous Cell Carcinoma in a Northern Chinese Population

Experimental studies have determined the chemopreventive effects of vitamin D against the esophageal squamous cell carcinoma (ESCC); however, results from the epidemiological studies are not yet well established. The current study aimed to evaluate the associations between plasma vitamin D levels and variants on vitamin D metabolic-related genes with the risks for ESCC. A hospital-based case-control study was performed. Five hundred eighty-two ESCC patients and 569 controls were recruited in a Northern Chinese population. Common variants on vitamin D metabolism-related genes CYP24A1, DHCR7, GC, CYP27B1, and vitamin D receptor (VDR) and the plasma 25(OH)D level were determined. The unconditional logistic regression method was applied to determine the associations between the variants and vitamin D level and ESCC. Higher plasma 25(OH)D was associated with a reduced risk for ESCC, especially for rs2296241, rs11568820, and rs4646536. The variants rs2296241 on CYP24A1 and rs11568820 on VDR are significantly associated with ESCC cancer. Vitamin D signaling pathways may participate in the ESCC development. Further studies with larger sample size are warranted to confirm the results. Intervention studies are needed to determine whether vitamin D supplementation may reduce the ESCC risk in the Chinese population.

Lifestyle and Other Factors Explain One-Half of the Variability in the Serum 25-Hydroxyvitamin D Response to Cholecalciferol Supplementation in Healthy Adults

BACKGROUND

Many factors have been associated with serum 25-hydroxyvitamin D [25(OH)D] concentrations in observational studies, with variable consistency. However, less information is available on factors affecting the magnitude of changes in serum 25(OH)D resulting from vitamin D supplementation.

OBJECTIVE

This study aimed to identify factors associated with the serum 25(OH)D response to supplementation with 1000 IU cholecalciferol/d during the first year of a large, multicenter, randomized, placebo-controlled colorectal adenoma chemoprevention trial.

METHODS

Eligible older adults who were not vitamin D-deficient [serum 25(OH)D ≥12 ng/mL] were randomly assigned in a modified 2 × 2 factorial design to 1 of 4 groups: daily 1000 IU cholecalciferol, 1200 mg Ca as carbonate, both, or placebo. Women could elect 2-group (calcium ± cholecalciferol) random assignment. In secondary analyses, we used multivariable models to assess factors associated with serum 25(OH)D concentrations in all enrollees (n = 2753) and with relative changes in serum 25(OH)D after 1 y cholecalciferol supplementation among those randomly assigned (n = 2187).

RESULTS

In multivariable models, 8 factors accounted for 50% of the variability of proportional change in serum 25(OH)D after cholecalciferol supplementation. Larger increases were associated with being female (34.5% compared with 20.5%; P < 0.001) and with lower baseline serum 25(OH)D (P < 0.0001), optimal adherence to study pill intake (P = 0.0002), wearing long pants and sleeves during sun exposure (P = 0.0002), moderate activity level (P = 0.01), use of extra vitamin D-containing supplements during the trial (P = 0.03), and seasons of blood draw (P ≤ 0.002). Several genetic polymorphisms were associated with baseline serum 25(OH)D and/or serum response, but these did not substantially increase the models' R² values. Other factors, including body mass index, were associated with serum 25(OH)D at baseline but not with its response to supplemental cholecalciferol.

CONCLUSIONS

The factors that most affected changes in serum 25(OH)D concentrations in response to cholecalciferol supplementation included sex, baseline serum 25(OH)D, supplement intake adherence, skin-covering clothes, physical activity, and season. Genetic factors did not play a major role. This trial was registered at www.clinicaltrials.gov as NCT00153816.

25-Hydroxyvitamin D and TSH as Risk Factors or Prognostic Markers in Thyroid Carcinoma

Objective

The increasing incidence of thyroid nodules demands identification of risk factors for malignant disease. Several studies suggested the association of higher TSH levels with cancer, but influence of 25-hydroxyvitamin D (25OHD) is controversial. This study aimed to identify the relationship of thyroid cancer with higher TSH levels and hypovitaminosis D and to evaluate their influence on prognostic characteristics of papillary thyroid carcinomas (PTC).

Methods

We retrospectively evaluated 433 patients submitted to thyroidectomy for thyroid nodules. Patients were categorized according to quartiles of TSH and 25OHD levels. Clinicopathological features were analyzed.

Results

Subjects with thyroid carcinomas were more frequently male and younger compared to those with benign disease. Their median TSH levels were higher and adjusted odds-ratio (OR) for cancer in the highest-quartile of TSH (> 2.4 mUI/mL) was 2.36 (1.36–4.09). Although vitamin D deficiency/insufficiency was prevalent in our cohort (84%), no significant differences in 25OHD levels or quartile distribution were observed between benign and malignant cases. Among 187 patients with PTC, analyses of prognostic features revealed increased risk of lymph nodes metastases for subjects with highest-quartile TSH levels (OR = 3.7, p = 0.029). Decreased 25OHD levels were not overtly associated with poor prognosis in PTC.

Conclusions

In this cross-sectional cohort, higher TSH levels increased the risk of cancer in thyroid nodules and influenced its prognosis, particularly favoring lymph nodes metastases. On the other hand, no association was found between 25OHD levels and thyroid carcinoma risk or prognosis, suggesting that serum 25OHD determination may not contribute to risk assessment workup of thyroid nodules.

Association between serum vitamin D levels and gastric cancer: A retrospective chart analysis

AIM

To determine whether there is an increased risk of gastric adenocarcinoma associated with vitamin D deficiency (VDd).

METHODS

A retrospective case control study was performed of all patients diagnosed with gastric adenocarcinoma between 2005 and 2015. After we excluded the patients without a documented vitamin D level, 49 patients were included in our study.

RESULTS

The average age of patients with gastric adenocarcinoma and documented vitamin D level was 64 years old (95%CI: 27-86) and average vitamin D level was 20.8 mg/dL (95%CI: 4-44). Compared to a matched control group, the prevalence of VDd/insufficiency in patients with gastric adenocarcinoma was significantly higher than normal vitamin D levels (83.7% vs 16.3%). Forty-one patients (83.7%) with adenocarcinoma showed VDd/insufficiency compared to 18 (37%) patients with normal vitamin D level without gastric cancer (OR: 8.8, 95%CI: 5-22, P value < 0.0001). The average age of males with gastric adenocarcinoma diagnosis was 60 years old vs 68 years old for females (P = 0.01). Stage II gastric adenocarcinoma was the most prevalent in our study (37%).

CONCLUSION

We reported a positive relationship between VDd and gastric adenocarcinoma, that is to say, patients with decreased VDd levels have an increased propensity for gastric adenocarcinoma.

Markers of Vitamin D Exposure and Esophageal Cancer Risk: A Systematic Review and Meta-analysis

Vitamin D has been associated with reduced risk of many cancers, but evidence for esophageal cancer is mixed. To clarify the role of vitamin D, we performed a systematic review and meta-analysis to evaluate the association of vitamin D exposures and esophageal neoplasia, including adenocarcinoma, squamous cell carcinoma (SCC), Barrett's esophagus, and squamous dysplasia. Ovid MEDLINE, EMBASE, and Web of Science were searched from inception to September 2015. Fifteen publications in relation to circulating 25-hydroxyvitamin D [25(OH)D; n = 3], vitamin D intake (n = 4), UVB exposure (n = 1), and genetic factors (n = 7) were retrieved. Higher [25(OH)D] was associated with increased risk of cancer [adenocarcinoma or SCC, OR = 1.39; 95% confidence interval (CI), 1.04-1.74], with the majority of participants coming from China. No association was observed between vitamin D intake and risk of cancer overall (OR, 1.03; 0.65-1.42); however, a nonsignificantly increased risk for adenocarcinoma (OR, 1.45; 0.65-2.24) and nonsignificantly decreased risk for SCC (OR, 0.80; 0.48-1.12) were observed. One study reported a decreased risk of adenocarcinoma with higher UVB exposure. A decreased risk was found for VDR haplotype rs2238135(G)/rs1989969(T) carriers (OR, 0.45; 0.00-0.91), and a suggestive association was observed for rs2107301. In conclusion, no consistent associations were observed between vitamin D exposures and occurrence of esophageal lesions. Further adequately powered, well-designed studies are needed before conclusions can be made. Cancer Epidemiol Biomarkers Prev; 25(6); 877-86. ©2016 AACR.

Changes in fat-soluble vitamin levels after gastrectomy for gastric cancer

Several authors have reported the relationship between gastric cancer risk and vitamins. However, there are few reports on fat-soluble vitamins after gastrectomy for gastric cancer. Fat malabsorption and suppression of food intake after gastrectomy for gastric cancer have been previously documented. Because of fat malabsorption and suppression of food intake, a potential deficiency in fat-soluble vitamins, such as vitamins A, D, E, and K, has been readily suggested. In about 20 % of patients, the serum vitamin E levels were decreased. Indeed, vitamin E deficiency is a common complication after gastrectomy. Continuous vitamin E deficiency could develop from neurological symptoms, i.e., peripheral neuropathy, limb or truncal ataxia. The total cholesterol level is associated with the vitamin E levels. However, the serum vitamin A levels were decreased in only 1.8 % of patients. In total gastrectomy cases, the serum vitamin A level may readily decrease. In contrast, 1,25(OH)₂ vitamin D deficiency, which is the most active vitamin D metabolite, is rare. Additionally, vitamin K deficiency after gastrectomy has not been reported thus far. Evidence that serum fat-soluble vitamin levels may decrease after gastrectomy for gastric cancer has not been established yet. Future research must explore fat-soluble vitamin deficiency after gastrectomy.

Serum 25-Hydroxyvitamin D Levels and the Risk of Dysplasia and Esophageal Adenocarcinoma in Patients with Barrett's Esophagus

BACKGROUND

To date, there are no studies reporting an association between vitamin D and Barrett's esophagus (BE), the precursor for esophageal adenocarcinoma (EAC).

AIMS

Our aim was to study the association between serum 25-hydroxyvitamin D (25(OH)D) levels and prevalence and incidence of dysplasia/EAC in BE.

METHODS

Patients from our BE Registry cohort seen between 2000 and 2012 who had serum 25(OH)D levels measured were included. Age, gender, race, BE length, hiatal hernia size, and histological findings were recorded. Patients without high-grade dysplasia (HGD)/EAC at or within 1 year of index biopsy and who had follow-up endoscopies and 25(OH)D levels were studied for incidence of dysplasia/EAC.

RESULTS

Among 429 patients with BE, the mean 25(OH)D level was 72 ± 31.2 nmol/L. Hundred and one (23.6 %) patients had deficiency (<50 nmol/L), 149 (34.7 %) had insufficiency (50-74.9 nmol/L), and 179 (41.7 %) had normal levels of 25(OH)D. There was no association between serum 25(OH)D levels and dysplasia (p = 0.90). In the incidence cohort of 246 patients with median follow-up of 46 months, there were 34 cases of low-grade dysplasia, 12 of HGD, and 5 of EAC. Change in 25(OH)D levels did not impact progression to dysplasia/EAC (every 5 nmol/L increase from baseline, hazard ratio 0.98; p = 0.62).

CONCLUSIONS

Serum 25(OH)D levels were low in 58.3 % of our BE cohort. There was no association between 25(OH)D levels and prevalence or incidence of HGD/EAC in patients with BE. Further long-term studies are needed to study the association between vitamin D status and progression of dysplasia in BE.

Vitamin D intake, serum Vitamin D levels, and risk of gastric cancer: A systematic review and meta-analysis

Background:

We are aware of no systematic review or meta-analysis of published findings about the association between Vitamin D status and risk of gastric cancer (GC). We systematically reviewed the current evidence on the association between Vitamin D intake as well as serum 25-hydroxy Vitamin D (25(OH)D) levels and risk of GC.

Materials and Methods:

Published evidence in this area was searched to August 2014 through the use of ISI Web of Science, Scopus, PubMed/Medline, Ovid Database, EMBASE, and Google Scholar for relevant articles by cross-referencing. Seven articles had reported odds ratios (ORs) or relative risks (RR) as their effect size; four papers had reported the ORs between Vitamin D intake and GC; and three papers had reported the association between serum 25(OH)D and risk of GC.

Results:

Pooled effect size for comparison of highest versus lowest intakes of Vitamin D was 1.09 (95% confidence interval [CI]: 0.94, 1.25; P = 0.26) indicating no significant association between Vitamin D intake and risk of GC. We failed to find a significant association between serum Vitamin D levels and risk of GC (OR: 0.92; 95% CI: 0.74-1.14; P = 0.429). Among men, the pooled effect size or highest versus lowest category of serum Vitamin D levels was 0.92 (95% CI: 0.71, 1.18, P = 0.49). The corresponding figures in women were 1.04 and 95% CI: 0.74-1.47 (P = 0.80).

Conclusion:

We found no evidence for the significant association between Vitamin D status and risk of GC. However, due to limited data in this field, further studies are required to reach a definite conclusion.

Prospective associations between vitamin D status, vitamin D-related gene polymorphisms, and risk of tobacco-related cancers

BACKGROUND

Experimental evidence has suggested that vitamin D may be protective against tobacco-related cancers through the inhibition of the formation of tumors induced by tobacco carcinogens. To our knowledge, only one previous epidemiologic study investigated the association between vitamin D status and tobacco-related cancer risk, and no study has focused on vitamin D-related gene polymorphisms.

OBJECTIVE

Our objective was to prospectively study the association between plasma 25-hydroxyvitamin D [25(OH)D] concentrations, vitamin D-related gene polymorphisms, and risk of tobacco-related cancers.

DESIGN

A total of 209 tobacco-related cancers were diagnosed within the SU.VI.MAX (Supplémentation en vitamines et minéraux antioxydants) cohort (1994-2007) and were matched with 418 controls as part of a nested case-control study. Tobacco-related cancers (i.e., cancers for which tobacco is one of the risk factors) included several sites in the respiratory, digestive, reproductive, and urinary systems. Total plasma 25(OH)D was assessed with the use of an electrochemoluminescent assay. Polymorphisms were determined with the use of a TaqMan assay. Conditional logistic regression models were computed.

RESULTS

A 25(OH)D concentration ≥30 ng/mL was associated with reduced risk of tobacco-related cancers (OR for ≥30 compared with <30 ng/mL: 0.59; 95% CI 0.35, 0.99; P = 0.046). This association was observed in former and current smokers (OR for ≥30 compared with <30 ng/mL: 0.43; 95% CI: 0.23, 0.84; P = 0.01) but not in never smokers (P = 0.8). The vitamin D receptor (VDR) FokI AA genotype and retinoid X receptor (RXR) rs7861779 TT genotype were associated with increased risk of tobacco-related cancers [OR for homozygous mutant type (MT) compared with wild type (WT): 1.87; 95% CI: 1.08, 3.23; P-trend = 0.02; OR for heterozygous type (HT) plus MT compared with WT: 1.60; 95% CI: 1.07, 2.38; P = 0.02].

CONCLUSIONS

In this prospective study, high vitamin D status [25(OH)D concentration ≥30 ng/mL] was associated with decreased risk of tobacco-related cancers, especially in smokers. These results, which are supported by mechanistic plausibility, suggest that vitamin D may contribute to the prevention of tobacco-induced cancers in smokers and deserve additional investigation. The SU.VI.MAX trial was registered at clinicaltrials.gov as NCT00272428.

Alterations in vitamin D signaling pathway in gastric cancer progression: a study of vitamin D receptor expression in human normal, premalignant, and malignant gastric tissue

Amount of studies in cells and animal models have proved vitamin D has multifarious antitumor effects. However, epidemiological studies showed inconsistent result on gastric cancer. The antitumor role is mainly mediated by the vitamin D receptor (VDR). Our hypothesis is that VDR may be abnormally (poorly) expressed in gastric cancer tissue. Present study is aimed at discovering and analyzing VDR expression in a series of human gastric tissues, including normal, premalignant, and malignant gastric tissue, and correlated VDR to the clinicopathological parameters of gastric cancer patients. VDR expression was detected by immunohistochemistry. The χ(2) test was used to analyze the VDR expression as well as the relationship between VDR and the clinicopathological factors of gastric cancer patients. Compared with normal (82.61%) and premalignant tissues (73.64%), VDR was lower expressed in cancer tissues (57.61%), with a statistically significant difference (P = 0.001). Among cancer tissues, VDR was higher expressed in well and moderate differentiated tissues contrasted with tissues with poor differentiation, and higher expressed in small tumors (< 5 cm) compared with large tumors (≥ 5 cm), with a statistically significant difference respectively (P = 0.016, P = 0.009). A decline linear trend appeared when analyzing the statistical difference of VDR expression among normal, premalignant, and malignant gastric tissues. VDR expression has been on the decline from the premalignant stage, finally low expressed in gastric cancer tissues, especial in poorly differentiated tissues. VDR could be a potential prognostic factor for patients with gastric cancer.

Diet and upper gastrointestinal malignancies

Diet is believed to modulate cancer risk and this relationship has been widely studied in the gastrointestinal tract. Observational epidemiologic studies have provided most of the evidence about the effects of diet on cancer risk because clinical trials to determine nutritional exposures are often impossible, impractical, or unaffordable. Although a few foods or nutrients are thought to protect against specific types of cancer, it seems clear that the strength and even direction of dietary associations (increasing or decreasing risk) is organ-site- and even histology-specific, along the gastrointestinal tract. Although some hypotheses are supported by a substantial body of observational data (drinking hot maté [an infusion of the herb Ilex Paraguarensis] contributes to esophageal cancer), there are not much data to support others. We discuss some highly touted hypotheses and draw interim conclusions about what is known and what could be done to improve the level of evidence. The complex nature of diet and its associations can be productively investigated with disease-specific studies. However, public health recommendations for normal-risk individuals regarding diet and gastrointestinal cancer should probably emphasize the importance of eating for overall health rather than eating specific foods to reduce risk for specific cancers.

Multivitamin and mineral supplementation is associated with the reduction of fracture risk and hospitalization rate in Chinese adult males: a randomized controlled study

Controversy exists in the literature regarding the efficacy of bone health-related nutrients, especially calcium and vitamin D, in preventing fractures. The aim of our present study was to determine the effect of multivitamin and mineral supplementation on fracture incidence among 3,318 participants from a nutritional intervention trial in Linxian, China. A total of 1,461 men and 1,857 women were enrolled and randomized to daily supplementation with 26 vitamins and minerals tablet or placebo pills for 6 years, followed by a 16-year post-interventional follow-up. The dates, sites, and causes of the fractures were collected retrospectively via a standardized questionnaire. Cox proportional hazard model was used to estimate hazard ratios and 95% confidence intervals of fracture incidence in the intervention versus the placebo group. A total of 221 fractures (57 in men and 164 in women) occurred during the entire study period of 21 years and 9 months. In men, the supplement reduced the risk of fracture by 63% during the trial period, and this protective effect was sustained and statistically significant when analysis included both the trial period and 5- or 10-year post-intervention follow-up (years 0-11, P = 0.04; years 0-16, P = 0.02, respectively). The protection against fracture was not apparent >10 years after cessation of the intervention. In women, no significant effect of supplementation on fracture incidence was seen in any of the study periods. These results demonstrate that a 6-year multivitamin and mineral intervention was associated with significant reduction of fracture risk and fracture-related hospitalization in men, but not in women.

Vitamin D Receptor Polymorphisms Are Associated with Reduced Esophageal Vitamin D Receptor Expression and Reduced Esophageal Adenocarcinoma Risk

Epidemiological studies indicate that vitamin D exerts a protective effect on the development of various solid cancers. However, concerns have been raised regarding the potential deleterious role of high vitamin D levels in the development of esophageal adenocarcinoma (EAC). This study investigated genetic variation in the vitamin D receptor (VDR) in relation to its expression and risk of Barrett esophagus (BE) and EAC. VDR gene regulation was investigated by immunohistochemistry, reverse transcriptase-polymerase chain reaction (RT-PCR) and gel shift assays. Fifteen haplotype tagging single-nucleotide polymorphisms (SNPs) of the VDR gene were analyzed in 858 patients with reflux esophagitis (RE), BE or EAC and 202 healthy controls. VDR mRNA expression was higher in BE compared with squamous epithelium. VDR protein was located in the nucleus in BE. An rs1989969T/rs2238135G haplotype was identified in the 5' regulatory region of the VDR gene. It was associated with an approximately two-fold reduced risk of RE, BE and EAC. Analysis of a replication cohort was done for BE that confirmed this. The rs1989969T allele causes a GATA-1 transcription factor binding site to appear. The signaling of GATA-1, which is regarded as a negative transcriptional regulator, could explain the findings for rs1989969. The rs2238135G allele was associated with a significantly reduced VDR expression in BE; for the rs1989969T allele, a trend in reduced VDR expression was observed. We identified a VDR haplotype associated with reduced esophageal VDR expression and a reduced incidence of RE, BE and EAC. This VDR haplotype could be useful in identifying individuals who benefit most from vitamin D chemoprevention.

Common genetic variants related to vitamin D status are not associated with esophageal squamous cell carcinoma risk in China

BACKGROUND

Few studies have examined the association of common genetic variants related to vitamin D metabolism and signaling to esophageal squamous cell carcinoma (ESCC).

METHODS

We evaluated the association between 12 single nucleotide polymorphisms (SNPs) in four genes related to vitamin D levels and ESCC risk using data from a genome-wide association study. Participants were recruited from the Shanxi Upper Gastrointestinal Cancer Genetics Project and the Linxian Nutrition Intervention Trials, and included 1942 ESCC cases and 2111 controls. We used logistic models to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the SNP associations, after controlling for age and gender.

RESULTS

None of the 12 evaluated SNPs in the four vitamin D-related genes were significantly associated with risk of ESCC. The strongest associations were for rs3794060 (P=0.07) and rs12800438 (P=0.08) in the DHCR7/NADSYN1 gene. No association between vitamin D-related SNPs and risk of ESCC was observed in a genotype score analysis that included all 12 SNPs. ORs for quartiles 2, 3 and 4 of the genotype scores were 0.83 (95% CI: 0.68, 1.01), 1.02 (0.85, 1.21), and 1.08 (0.89, 1.30), respectively, with no evidence for a significant monotonic trend (P=0.120).

CONCLUSIONS

Our results suggested that common genetic variants related to vitamin D levels are not associated with risk of ESCC in this Chinese population.

Dietary habits and esophageal cancer

Cancer of the esophagus is an underestimated, poorly understood, and changing disease. Its overall 5-year survival is less than 20%, even in the United States, which is largely a function of a delay in diagnosis until its more advanced stages. Additionally, the epidemiologic complexities of esophageal cancer are vast, rendering screening and prevention limited at best. First, the prevalence of esophageal cancer is unevenly distributed throughout the world. Second, the two histological forms (squamous cell and adenocarcinoma) vary in terms of their geographic prevalence and associated risk factors. Third, some populations appear at particular risk for esophageal cancer. And fourth, the incidence of esophageal cancer is in continuous flux among groups. Despite the varied prevalence and risks among populations, some factors have emerged as consistent associations while others are only now becoming more fully recognized. The most prominent, scientifically supported, and long-regarded risk factors for esophageal cancer are tobacco, alcohol, and reflux esophagitis. Inasmuch as the above are regarded as important risk factors for esophageal cancer, they are not the sole contributors. Dietary habits, nutrition, local customs, and the environment may be contributory. Along these lines, vitamins, minerals, fruits, vegetables, meats, fats, salted foods, nitrogen compounds, carcinogens, mycotoxins, and even the temperature of what we consume are increasingly regarded as potential etiologies for this deadly although potentially preventable disease. The goal of this review is to shed light on the less known role of nutrition and dietary habits in esophageal cancer.

Vitamin D supplementation for prevention of cancer in adults

BACKGROUND

The evidence on whether vitamin D supplementation is effective in decreasing cancers is contradictory.

OBJECTIVES

To assess the beneficial and harmful effects of vitamin D supplementation for prevention of cancer in adults.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, LILACS, Science Citation Index Expanded, and the Conference Proceedings Citation Index-Science to February 2014. We scanned bibliographies of relevant publications and asked experts and pharmaceutical companies for additional trials.

SELECTION CRITERIA

We included randomised trials that compared vitamin D at any dose, duration, and route of administration versus placebo or no intervention in adults who were healthy or were recruited among the general population, or diagnosed with a specific disease. Vitamin D could have been administered as supplemental vitamin D (vitamin D₃ (cholecalciferol) or vitamin D₂ (ergocalciferol)), or an active form of vitamin D (1α-hydroxyvitamin D (alfacalcidol), or 1,25-dihydroxyvitamin D (calcitriol)).

DATA COLLECTION AND ANALYSIS

Two review authors extracted data independently. We conducted random-effects and fixed-effect model meta-analyses. For dichotomous outcomes, we calculated the risk ratios (RRs). We considered risk of bias in order to assess the risk of systematic errors. We conducted trial sequential analyses to assess the risk of random errors.

MAIN RESULTS

Eighteen randomised trials with 50,623 participants provided data for the analyses. All trials came from high-income countries. Most of the trials had a high risk of bias, mainly for-profit bias. Most trials included elderly community-dwelling women (aged 47 to 97 years). Vitamin D was administered for a weighted mean of six years. Fourteen trials tested vitamin D₃, one trial tested vitamin D₂, and three trials tested calcitriol supplementation. Cancer occurrence was observed in 1927/25,275 (7.6%) recipients of vitamin D versus 1943/25,348 (7.7%) recipients of control interventions (RR 1.00 (95% confidence interval (CI) 0.94 to 1.06); P = 0.88; I² = 0%; 18 trials; 50,623 participants; moderate quality evidence according to the GRADE instrument). Trial sequential analysis (TSA) of the 18 vitamin D trials shows that the futility area is reached after the 10th trial, allowing us to conclude that a possible intervention effect, if any, is lower than a 5% relative risk reduction. We did not observe substantial differences in the effect of vitamin D on cancer in subgroup analyses of trials at low risk of bias compared to trials at high risk of bias; of trials with no risk of for-profit bias compared to trials with risk of for-profit bias; of trials assessing primary prevention compared to trials assessing secondary prevention; of trials including participants with vitamin D levels below 20 ng/mL at entry compared to trials including participants with vitamin D levels of 20 ng/mL or more at entry; or of trials using concomitant calcium supplementation compared to trials without calcium. Vitamin D decreased all-cause mortality (1854/24,846 (7.5%) versus 2007/25,020 (8.0%); RR 0.93 (95% CI 0.88 to 0.98); P = 0.009; I² = 0%; 15 trials; 49,866 participants; moderate quality evidence), but TSA indicates that this finding could be due to random errors. Cancer occurrence was observed in 1918/24,908 (7.7%) recipients of vitamin D₃ versus 1933/24,983 (7.7%) in recipients of control interventions (RR 1.00 (95% CI 0.94 to 1.06); P = 0.88; I² = 0%; 14 trials; 49,891 participants; moderate quality evidence). TSA of the vitamin D₃ trials shows that the futility area is reached after the 10th trial, allowing us to conclude that a possible intervention effect, if any, is lower than a 5% relative risk reduction. Vitamin D₃ decreased cancer mortality (558/22,286 (2.5%) versus 634/22,206 (2.8%); RR 0.88 (95% CI 0.78 to 0.98); P = 0.02; I² = 0%; 4 trials; 44,492 participants; low quality evidence), but TSA indicates that this finding could be due to random errors. Vitamin D₃ combined with calcium increased nephrolithiasis (RR 1.17 (95% CI 1.03 to 1.34); P = 0.02; I² = 0%; 3 trials; 42,753 participants; moderate quality evidence). TSA, however, indicates that this finding could be due to random errors. We did not find any data on health-related quality of life or health economics in the randomised trials included in this review.

AUTHORS' CONCLUSIONS

There is currently no firm evidence that vitamin D supplementation decreases or increases cancer occurrence in predominantly elderly community-dwelling women. Vitamin D₃ supplementation decreased cancer mortality and vitamin D supplementation decreased all-cause mortality, but these estimates are at risk of type I errors due to the fact that too few participants were examined, and to risks of attrition bias originating from substantial dropout of participants. Combined vitamin D₃ and calcium supplements increased nephrolithiasis, whereas it remains unclear from the included trials whether vitamin D₃, calcium, or both were responsible for this effect. We need more trials on vitamin D supplementation, assessing the benefits and harms among younger participants, men, and people with low vitamin D status, and assessing longer duration of treatments as well as higher dosages of vitamin D. Follow-up of all participants is necessary to reduce attrition bias.

Vitamin D receptor is highly expressed in precancerous lesions and esophageal adenocarcinoma with significant sex difference

Bile acid reflux into the esophagus is important in the development of esophageal adenocarcinoma (EAC). Recently, vitamin D receptor (VDR) was recognized as a bile acid receptor as well as a vitamin receptor. Expression of VDR is reported to influence the development of various types of cancer, such as those of the breast, liver, and colon. However, little is known about the role of VDR in esophageal neoplasms. We investigated the clinicopathological role of VDR in esophageal tumors. We analyzed genomic DNA from 116 EACs for copy number aberrations. The VDR locus was amplified in 7% of EACs. Expression of the VDR protein was also detected by immunohistochemistry from tissue microarrays created from tissues of Barrett esophagus (BE), low-grade (LGD) and high-grade dysplasia (HGD), columnar cell metaplasia (CCM), squamous epithelium (SE), EAC, and esophageal squamous cell carcinoma (ESCC). The protein was highly expressed in 88% of CCM (58/66), 95% of BE (35/37), 100% of the 19 LGD, 94% of HGD (15/16), and 79% of EAC (86/109), but expression in SE and ESCC was rare. Female patients with EAC and CCM were significantly less likely to have high VDR expression than male patients. The overall survival rate was significantly different for patients with tumors exhibiting VDR amplification versus nonamplification. Our findings suggest that VDR plays a role in the early development of EAC through a bile acid ligand. The sex difference in VDR expression may help to explain why men have a high incidence of EAC.

Vitamin D supplementation for prevention of mortality in adults

BACKGROUND

Available evidence on the effects of vitamin D on mortality has been inconclusive. In a recent systematic review, we found evidence that vitamin D3 may decrease mortality in mostly elderly women. The present systematic review updates and reassesses the benefits and harms of vitamin D supplementation used in primary and secondary prophylaxis of mortality.

OBJECTIVES

To assess the beneficial and harmful effects of vitamin D supplementation for prevention of mortality in healthy adults and adults in a stable phase of disease.

SEARCH METHODS

We searched The Cochrane Library, MEDLINE, EMBASE, LILACS, the Science Citation Index-Expanded and Conference Proceedings Citation Index-Science (all up to February 2012). We checked references of included trials and pharmaceutical companies for unidentified relevant trials.

SELECTION CRITERIA

Randomised trials that compared any type of vitamin D in any dose with any duration and route of administration versus placebo or no intervention in adult participants. Participants could have been recruited from the general population or from patients diagnosed with a disease in a stable phase. Vitamin D could have been administered as supplemental vitamin D (vitamin D3 (cholecalciferol) or vitamin D2 (ergocalciferol)) or as an active form of vitamin D (1α-hydroxyvitamin D (alfacalcidol) or 1,25-dihydroxyvitamin D (calcitriol)).

DATA COLLECTION AND ANALYSIS

Six review authors extracted data independently. Random-effects and fixed-effect meta-analyses were conducted. For dichotomous outcomes, we calculated the risk ratios (RRs). To account for trials with zero events, we performed meta-analyses of dichotomous data using risk differences (RDs) and empirical continuity corrections. We used published data and data obtained by contacting trial authors.To minimise the risk of systematic error, we assessed the risk of bias of the included trials. Trial sequential analyses controlled the risk of random errors possibly caused by cumulative meta-analyses.

MAIN RESULTS

We identified 159 randomised clinical trials. Ninety-four trials reported no mortality, and nine trials reported mortality but did not report in which intervention group the mortality occurred. Accordingly, 56 randomised trials with 95,286 participants provided usable data on mortality. The age of participants ranged from 18 to 107 years. Most trials included women older than 70 years. The mean proportion of women was 77%. Forty-eight of the trials randomly assigned 94,491 healthy participants. Of these, four trials included healthy volunteers, nine trials included postmenopausal women and 35 trials included older people living on their own or in institutional care. The remaining eight trials randomly assigned 795 participants with neurological, cardiovascular, respiratory or rheumatoid diseases. Vitamin D was administered for a weighted mean of 4.4 years. More than half of the trials had a low risk of bias. All trials were conducted in high-income countries. Forty-five trials (80%) reported the baseline vitamin D status of participants based on serum 25-hydroxyvitamin D levels. Participants in 19 trials had vitamin D adequacy (at or above 20 ng/mL). Participants in the remaining 26 trials had vitamin D insufficiency (less than 20 ng/mL).Vitamin D decreased mortality in all 56 trials analysed together (5,920/47,472 (12.5%) vs 6,077/47,814 (12.7%); RR 0.97 (95% confidence interval (CI) 0.94 to 0.99); P = 0.02; I(2) = 0%). More than 8% of participants dropped out. 'Worst-best case' and 'best-worst case' scenario analyses demonstrated that vitamin D could be associated with a dramatic increase or decrease in mortality. When different forms of vitamin D were assessed in separate analyses, only vitamin D3 decreased mortality (4,153/37,817 (11.0%) vs 4,340/38,110 (11.4%); RR 0.94 (95% CI 0.91 to 0.98); P = 0.002; I(2) = 0%; 75,927 participants; 38 trials). Vitamin D2, alfacalcidol and calcitriol did not significantly affect mortality. A subgroup analysis of trials at high risk of bias suggested that vitamin D2 may even increase mortality, but this finding could be due to random errors. Trial sequential analysis supported our finding regarding vitamin D3, with the cumulative Z-score breaking the trial sequential monitoring boundary for benefit, corresponding to 150 people treated over five years to prevent one additional death. We did not observe any statistically significant differences in the effect of vitamin D on mortality in subgroup analyses of trials at low risk of bias compared with trials at high risk of bias; of trials using placebo compared with trials using no intervention in the control group; of trials with no risk of industry bias compared with trials with risk of industry bias; of trials assessing primary prevention compared with trials assessing secondary prevention; of trials including participants with vitamin D level below 20 ng/mL at entry compared with trials including participants with vitamin D levels equal to or greater than 20 ng/mL at entry; of trials including ambulatory participants compared with trials including institutionalised participants; of trials using concomitant calcium supplementation compared with trials without calcium; of trials using a dose below 800 IU per day compared with trials using doses above 800 IU per day; and of trials including only women compared with trials including both sexes or only men. Vitamin D3 statistically significantly decreased cancer mortality (RR 0.88 (95% CI 0.78 to 0.98); P = 0.02; I(2) = 0%; 44,492 participants; 4 trials). Vitamin D3 combined with calcium increased the risk of nephrolithiasis (RR 1.17 (95% CI 1.02 to 1.34); P = 0.02; I(2) = 0%; 42,876 participants; 4 trials). Alfacalcidol and calcitriol increased the risk of hypercalcaemia (RR 3.18 (95% CI 1.17 to 8.68); P = 0.02; I(2) = 17%; 710 participants; 3 trials).

AUTHORS' CONCLUSIONS

Vitamin D3 seemed to decrease mortality in elderly people living independently or in institutional care. Vitamin D2, alfacalcidol and calcitriol had no statistically significant beneficial effects on mortality. Vitamin D3 combined with calcium increased nephrolithiasis. Both alfacalcidol and calcitriol increased hypercalcaemia. Because of risks of attrition bias originating from substantial dropout of participants and of outcome reporting bias due to a number of trials not reporting on mortality, as well as a number of other weaknesses in our evidence, further placebo-controlled randomised trials seem warranted.

1,25-dihydroxyvitamin D in the pathogenesis of Barrett's esophagus and esophageal adenocarcinoma

The incidence of reflux-related esophageal disease - Barrett's esophagus and esophageal adenocarcinoma - is rising, and the prognosis remains poor. Evidence exists that 1,25-dihydroxyvitamin D may augment the course of colon, breast and prostate cancer but little knowledge exists regarding its impact on disease of the esophagus. Important immune cells involved in reflux-related esophageal disease include CD4(+) T cells, macrophages and dendritic cells, and key signaling pathways include Wnt, Hedgehog, NFκ-B and IL-6-JAK-STAT. There is an inter-relationship between these entities and 1,25-dihydroxyvitamin D, which has been described in animal models and some human tissue. Despite this, there is an incomplete understanding of how the immune cell population and signaling pathways contribute to the course and prognosis of Barrett's esophagus and esophageal adenocarcinoma. More investigation with a focus on the clinical outcomes of patients with Barrett's esophagus and esophageal adenocarcinoma and the immune cell population and cell signaling activity in the diseased esophagus is necessary to determine the immunomodulatory role of 1,25-dihydroxyvitamin D in the pathogenesis of esophageal diseases.

Prediagnostic plasma vitamin C and risk of gastric adenocarcinoma and esophageal squamous cell carcinoma in a Chinese population

BACKGROUND

China has some of the highest incidence rates for gastric adenocarcinoma (GA) and esophageal squamous cell carcinoma (ESCC) in the world. Prospective studies suggested that vitamin C may reduce risks; however, associations are unclear because of limited sample size.

OBJECTIVE

The objective was to examine the relation between prediagnostic plasma vitamin C and the risk of GA and ESCC.

DESIGN

A case-cohort study was used to assess the association between prediagnostic plasma vitamin C and incidence of GA (n = 467) and ESCC (n = 618) in the General Population Nutrition Intervention Trial. With the use of multivariate Cox proportional hazards models, we estimated the HRs and 95% CIs. We also conducted a meta-analysis of the literature up to 1 October 2012 on the relation between circulating vitamin C and gastric cancer incidence. Two cohort studies and the current study were included to assess the body of evidence.

RESULTS

For GA, each 20-μmol/L increase in plasma vitamin C was associated with a 14% decrease in risk (HR: 0.86; 95% CI: 0.76, 0.96). Compared with individuals with low plasma vitamin C concentrations (≤28 μmol/L), those with normal concentrations (>28 μmol/L) had a 27% reduced risk of GA (HR: 0.73; 95% CI: 0.56, 0.94). No association between vitamin C concentrations and ESCC was seen. Meta-analysis showed that the risk of incident GA among those with the highest concentration of plasma vitamin C was 31% lower (random-effects-pooled-odds ratio 0.69; 95% CI: 0.54, 0.89) than those in the lowest category.

CONCLUSION

Our data provide evidence that higher circulating vitamin C was associated with a reduced risk of incident GA, but no association was seen for ESCC.

Association between serum 25(OH) vitamin D, incident liver cancer and chronic liver disease mortality in the Linxian Nutrition Intervention Trials: a nested case-control study

BACKGROUND

Although vitamin D deficiency has been noted in cross-sectional studies of chronic liver disease and laboratory studies suggest possible benefits of vitamin D in preventing liver cancer, little epidemiologic data are available.

METHODS

We performed a nested case-control study in the Linxian Nutrition Intervention Trials on participants developing incident liver cancer or dying from chronic liver disease over 22 years of follow-up. Baseline serum 25(OH) vitamin D was measured for 226 incident liver cancer cases, 282 chronic liver disease deaths and 1063 age-, sex- and trial-matched controls. Unconditional logistical regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

The median serum vitamin D level in controls was low (20 nmol l(-1)). Compared with the lowest quartile, subjects in the fourth quartile had lower risk of chronic liver disease death (OR=0.34, 95% CI=0.21-0.55). For liver cancer incidence, risk estimates were below one, but were not statistically significant. Associations, however, were significant among participants with higher serum calcium levels (Q4 vs Q1, OR=0.43, 95% CI=0.21-0.89). Results for chronic liver disease did not vary by serum calcium level.

CONCLUSION

In a low vitamin D population, higher serum 25(OH) vitamin D concentrations were associated with significantly lower risk of chronic liver disease deaths, and among those with higher serum calcium, incident liver cancer. Our results suggest a possible protective role for vitamin D in these diseases.

A systematic review of vitamin D status in populations worldwide

Vitamin D deficiency is associated with osteoporosis and is thought to increase the risk of cancer and CVD. Despite these numerous potential health effects, data on vitamin D status at the population level and within key subgroups are limited. The aims of the present study were to examine patterns of 25-hydroxyvitamin D (25(OH)D) levels worldwide and to assess differences by age, sex and region. In a systematic literature review using the Medline and EMBASE databases, we identified 195 studies conducted in forty-four countries involving more than 168 000 participants. Mean population-level 25(OH)D values varied considerably across the studies (range 4·9-136·2 nmol/l), with 37·3 % of the studies reporting mean values below 50 nmol/l. The highest 25(OH)D values were observed in North America. Although age-related differences were observed in the Asia/Pacific and Middle East/Africa regions, they were not observed elsewhere and sex-related differences were not observed in any region. Substantial heterogeneity between the studies precluded drawing conclusions on overall vitamin D status at the population level. Exploratory analyses, however, suggested that newborns and institutionalised elderly from several regions worldwide appeared to be at a generally higher risk of exhibiting lower 25(OH)D values. Substantial details on worldwide patterns of vitamin D status at the population level and within key subgroups are needed to inform public health policy development to reduce risk for potential health consequences of an inadequate vitamin D status.

Vitamin D and the epidemiology of upper gastrointestinal cancers: a critical analysis of the current evidence

Prospective analyses have yet to uncover a consistent relationship between vitamin D status and incidence and mortality of rarer cancers including esophageal and upper gastrointestinal cancers. We searched PubMed for literature about the epidemiology of upper gastrointestinal cancers and vitamin D published over the last decade and then summarized and critiqued the results of these studies in this review. The search yielded nine relevant studies. Overall, no consistent relationship was reported between serum vitamin D levels or a surrogate and upper gastrointestinal cancers. Four studies reported negative correlations between vitamin D status and upper gastrointestinal cancer, three reported positive correlations, one reported no correlation, and one reported both positive and negative correlations. No relationship has been established on the basis of epidemiologic data, but studies examining sun exposure consistently report an inverse association with esophageal cancer. The current literature is limited by the methods used to assess vitamin D status, lack of specific data for the types of upper gastrointestinal cancer, and failure to establish a temporal relationship between vitamin D status assessment and presentation of upper gastrointestinal cancer. It is possible that the lack of a consistent relationship is a consequence of inaccurate and imprecise assessment of vitamin D status.

Is high dose vitamin D harmful?

With the potential to minimize the risk of many chronic diseases and the apparent biochemical safety of ingesting doses of oral vitamin D several-fold higher than the current recommended intakes, recent research has focussed on supplementing individuals with intermittent, high-dose vitamin D. However, two recent randomized controlled trials (RCTs) both using annual high-dose vitamin D reported an increase, rather than a decrease, in the primary outcome of fractures. This review summarises the results from studies that have used intermittent, high doses of vitamin D, with particular attention to those finding evidence of adverse effects. Results from observational, population-based studies with evidence of a U- or J-shaped curve are also presented as these findings suggest an increased risk in those with the highest serum 25D levels. Speculative mechanisms are discussed and biochemical results from studies using high-dose vitamin D are also presented. Emerging evidence from both observational studies and RCTs suggests there should be a degree of caution about recommending high serum 25D concentrations for the entire population. Furthermore, benefit of the higher doses commonly used in clinical practice on falls risk reduction needs to be demonstrated. The safety of loading doses of vitamin D should be demonstrated before these regimens become recommended as routine clinical practice. The current dilemma of defining vitamin D insufficiency and identifying safe and efficacious repletion regimens needs to be resolved.

Sunlight, vitamin D and the prevention of cancer: a systematic review of epidemiological studies

The number of studies reporting beneficial effects of sunlight and vitamin D on several types of cancer with a high mortality rate is growing rapidly. Present health recommendations on sun exposure are mainly based on the increased risks for skin cancer. We reviewed all published studies concerning cancer and sun exposure and vitamin D, respectively, excluding those about skin cancer. Most identified ecological, case-control and prospective studies on the incidence and mortality of colorectal, prostate, breast carcinoma and non-Hodgkin lymphoma reported a significantly inverse association with sun exposure. The results of the included studies on the association between cancer risk and vitamin D were much less consistent. Only those studies that prospectively examined the 25-hydroxyvitamin D serum levels in relation to risk of colorectal cancer are homogeneous: they all reported inverse associations, although not all reaching statistical significance. The results of the intervention studies are suggestive of a protective role of high doses of vitamin D in cancer, but they have been criticized in the literature. We, therefore, conclude that there is accumulating evidence for sunlight as a protective factor for several types of cancer. The same conclusion can be made concerning high vitamin D levels and the risk of colorectal cancer. This evidence, however, is not conclusive, because the number of (good quality) studies is still limited and publication biases cannot be excluded. The discrepancies between the epidemiological evidence for a possible preventive effect of sunlight and vitamin D and the question of how to apply the findings on the beneficial effects of sunlight to (public) health recommendations are discussed.

Prospective study of serum 25-hydroxyvitamin D concentration and mortality in a Chinese population

Prospective epidemiologic data on the association between vitamin D and mortality are limited, particularly in Asian populations. Among subjects in Linxian, China, the authors aimed to test whether baseline serum 25-hydroxyvitamin D (25(OH)D) concentrations in a prospective cohort were associated with all-cause mortality and cause-specific mortality rates over 24 years of follow-up (1986-2010). Serum 25(OH)D concentrations were measured in 1,101 subjects using an immunoassay. Hazard ratios and 95% confidence intervals were calculated using Cox regression models that were adjusted for age, sex, tobacco smoking, alcohol drinking, and hypertension. The 25th, 50th, and 75th percentile concentrations of 25(OH)D were 19.6, 31.9, and 48.4 nmol/L, respectively. During follow-up, 793 subjects died, including 279 who died of cerebrovascular accident, 217 who died of cancer, and 200 cardiovascular disease deaths. All-cause mortality was not associated with 25(OH)D concentrations using continuous models (for every 15 nmol/L, hazard ratio = 1.01, 95% confidence interval: 0.97, 1.05) or quartile models (fourth vs. first quartiles, hazard ratio = 1.06, 95% confidence interval: 0.87, 1.30; P for trend = 0.731). The authors also found no association with the cause-specific mortality outcomes. Results were similar for men and women. This study showed that prediagnostic serum 25(OH)D concentrations were not associated with all-cause or cause-specific mortality rates in this Chinese population who had low levels of vitamin D.

Association between ambient ultraviolet radiation and risk of esophageal cancer

OBJECTIVES

Ecological studies have suggested an inverse relationship between latitude and risks of some cancers. However, associations between solar ultraviolet radiation (UVR) exposure and esophageal cancer risk have not been fully explored. We therefore investigated the association between nevi, freckles, and measures of ambient UVR over the life-course with risks of esophageal cancers.

METHODS

We compared estimated lifetime residential ambient UVR among Australian patients with esophageal cancer (330 esophageal adenocarcinoma (EAC), 386 esophago-gastric junction adenocarcinoma (EGJAC), and 279 esophageal squamous cell carcinoma (ESCC)), and 1471 population controls. We asked people where they had lived at different periods of their life, and assigned ambient UVR to each location based on measurements from NASA's Total Ozone Mapping Spectrometer database. Freckling and nevus burden were self-reported. We used multivariable logistic regression models to estimate the magnitude of associations between phenotype, ambient UVR, and esophageal cancer risk.

RESULTS

Compared with population controls, patients with EAC and EGJAC were less likely to have high levels of estimated cumulative lifetime ambient UVR (EAC odds ratio (OR) 0.59, 95% confidence interval (CI) 0.35-0.99, EGJAC OR 0.55, 0.34-0.90). We found no association between UVR and risk of ESCC (OR 0.91, 0.51-1.64). The associations were independent of age, sex, body mass index, education, state of recruitment, frequency of reflux, smoking status, alcohol consumption, and H. pylori serostatus. Cases with EAC were also significantly less likely to report high levels of nevi than controls.

CONCLUSIONS

These data show an inverse association between ambient solar UVR at residential locations and risk of EAC and EGJAC, but not ESCC.

A global representation of vitamin D status in healthy populations

PURPOSE

This paper visualizes the available data on vitamin D status on a global map, examines the existing heterogeneities in vitamin D status and identifies research gaps.

METHODS

A graphical illustration of global vitamin D status was developed based on a systematic review of the worldwide literature published between 1990 and 2011. Studies were eligible if they included samples of randomly selected males and females from the general population and assessed circulating 25-hydroxyvitamin D [25(OH)D] levels. Two different age categories were selected: children and adolescents (1-18 years) and adults (>18 years). Studies were chosen to represent a country based on a hierarchical set of criteria.

RESULTS

In total, 200 studies from 46 countries met the inclusion criteria, most coming from Europe. Forty-two of these studies (21 %) were classified as representative. In children, gaps in data were identified in large parts of Africa, Central and South America, Europe, and most of the Asia/Pacific region. In adults, there was lack of information in Central America, much of South America and Africa. Large regions were identified for which the mean 25(OH)D levels were below 50 nmol/L.

CONCLUSIONS

This study provides an overview of 25(OH)D levels around the globe. It reveals large gaps in information in children and adolescents and smaller but important gaps in adults. In view of the importance of vitamin D to musculoskeletal growth, development, and preservation, and of its potential importance in other tissues, we strongly encourage new research to clearly define 25(OH)D status around the world.