Circulating 25-hydroxyvitamin D and risk of lung cancer: a dose-response meta-analysis

Multiplicative, additive, and interactive associations of 25-hydroxyvitamin D with lung and prostate cancer

Results regarding the epidemiological association of vitamin D with lung (LCA) and prostate cancer (PCA) are controversial. This study tested whether serum 25-hydroxyvitamin D [25(OH)D] concentrations have interactive epidemiological associations with smoking, the number-one risk factor for LCA, and age, the number-one risk factor for PCA. Also, this study investigated whether the associations of 25(OH)D, smoking, age, alcohol consumption, body mass index, diet (the healthy Nordic diet score), and physical activity with incident LCA and PCA are multiplicative or additive. The study of association types makes it easier to select appropriate statistical methods. The Kuopio Ischaemic Heart Disease Risk Factor Study provided the data of 2578 men with 112 LCA and 300 PCA cases over 35 years by the end of 2019. Serum 25(OH)D did not associate with LCA and PCA or interact with smoking and age. The association of smoking with LCA was additive; 13 extra cases per 1000 men every 10 years. Age and alcohol consumption multiplicatively increased the hazard of LCA (hazard ratio, 95% confidence interval for age >50: 3.56, 1.82-6.17; drink per week: 1.01, 1.00-1.03), whereas adherence to healthy Nordic diet decreased it (per score point: 0.95, 0.89-1.00). The association of age >50 with PCA was additive; 2.5 extra cases per 1000 men every 10 years. To conclude, there was no epidemiological relationship of pre-diagnostic 25(OH)D concentrations with the incidence of LCA and PCA. The respective associations of smoking and age >50 with LCA and PCA were additive rather than multiplicative.

Vitamin D and cancer

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

Associations Between Poor Oral Hygiene and Risk of Pancreatic Cancer: A Meta-analysis of Observational Studies

OBJECTIVES

Epidemiological studies have reported the association of poor oral hygiene, especially periodontal disease, and tooth loss with the risk of pancreatic cancer (PC). However, these studies have yielded inconsistent results. Therefore, this systematic review and meta-analysis aimed to investigate the relationship between oral disease and PC.

METHODS

We systematically searched the PubMed, Embase, and Cochrane Library databases for English literature since inception through May 2021. We used relative risks, hazard ratios, or odds ratios to measure the association between oral disease and PC. A fixed- or random-effects model was applied to evaluate pooled risk estimates, and sensitivity and subgroup analyses were performed to identify sources of heterogeneity and pooled estimation.

RESULTS

We identified 17 relevant observational studies involving 1,352,256 participants. Notably, oral disease correlated significantly with PC (hazard ratio [HR], 1.32; 95% confidence interval [CI], 1.13-1.54). In subgroup analyses, subjects with periodontal disease (HR, 1.38; 95% CI, 1.12-1.71) had a higher risk of developing PC than those with tooth loss (HR, 1.19; 95% CI, 0.97-1.46).

CONCLUSIONS

The results suggest that subjects with oral disease may face a significant and independent risk of PC. However, the mechanisms linking oral disease and PC are uncertain, and additional investigations of this correlation are warranted.

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.

Vitamin D and Cancer: An Historical Overview of the Epidemiology and Mechanisms

This is a narrative review of the evidence supporting vitamin D’s anticancer actions. The first section reviews the findings from ecological studies of cancer with respect to indices of solar radiation, which found a reduced risk of incidence and mortality for approximately 23 types of cancer. Meta-analyses of observational studies reported the inverse correlations of serum 25-hydroxyvitamin D [25(OH)D] with the incidence of 12 types of cancer. Case-control studies with a 25(OH)D concentration measured near the time of cancer diagnosis are stronger than nested case-control and cohort studies as long follow-up times reduce the correlations due to changes in 25(OH)D with time. There is no evidence that undiagnosed cancer reduces 25(OH)D concentrations unless the cancer is at a very advanced stage. Meta-analyses of cancer incidence with respect to dietary intake have had limited success due to the low amount of vitamin D in most diets. An analysis of 25(OH)D-cancer incidence rates suggests that achieving 80 ng/mL vs. 10 ng/mL would reduce cancer incidence rates by 70 ± 10%. Clinical trials have provided limited support for the UVB-vitamin D-cancer hypothesis due to poor design and execution. In recent decades, many experimental studies in cultured cells and animal models have described a wide range of anticancer effects of vitamin D compounds. This paper will review studies showing the inhibition of tumor cell proliferation, dedifferentiation, and invasion together with the sensitization to proapoptotic agents. Moreover, 1,25-(OH)₂D₃ and other vitamin D receptor agonists modulate the biology of several types of stromal cells such as fibroblasts, endothelial and immune cells in a way that interferes the apparition of metastases. In sum, the available mechanistic data support the global protective action of vitamin D against several important types of cancer.

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.

A Retrospective Cohort Study of Lung Cancer Incidences and Epidemiological Analysis in Saudi Arabian Population from 2006-2016

INTRODUCTION

Lung cancer is one of the leading causes of cancer-related deaths worldwide, including in Saudi Arabia. In the past few decades, the incidence and mortality has increased considerably among the Saudi population. The incidence of lung cancer has increased more than 3% in less than two decades. The current study focuses on analyzing the frequency of diagnosed lung cancer cases, age-standardized incidence rate (ASIR), and crude incidence rate (CIR) classified by year of diagnosis, age group, and different administrative regions of Saudi Arabia, based on the Saudi cancer registry (SCR) for the period of 10 years from 2006-2016.

METHODOLOGY

The present study is a cohort study that focuses on the epidemiological analysis of lung cancer cases. The statistical analysis was performed by t-test, sex ratio, Kruskal-Wallis, and descriptive statistics through SPSS version 20.0.

RESULTS

A total of 4530 lung cancer cases were reported from January 2006 to December 2016. Among males, the ASIR range was reported as 1.2 to 12.3 per 100,000 cases in different regions of Saudi Arabia. Moreover, among females, the ASIR range was reported from 0.2 to 3.1 per 100,000 cases in different regions of Saudi Arabia. Additionally, the overall age-standardized incidence sex ratio was 3.2 per 100,000 cases. The incidence of lung cancer increased with age as 23% was reported in the age group of more than 75 years.

CONCLUSIONS

The study concludes a rise in crude incidence rates and ASIR for lung cancer among Saudi population. Among males, the Eastern region had the highest overall ASIR followed by Tabuk region, and, among females, the highest overall ASIR was reported in the Eastern region followed by Riyadh and the Northern region.

Genetically predicted insomnia and lung cancer risk: a Mendelian randomization study

BACKGROUND

The relationship between insomnia and lung cancer is scanty. The Mendelian randomization approach provides the rationale for evaluating the potential causality between genetically-predicted insomnia and lung cancer risk.

METHODS

We extracted 148 insomnia-related single-nucleotide polymorphisms (SNPs) as instrumental variables (IVs) from published genome-wide association studies (GWASs). Summary data of individual-level genetic information of participants were obtained from the International Lung Cancer Consortium (ILCCO) (29,266 cases and 56,450 controls). MR analyses were performed using the inverse-variance-weighted approach, MR pleiotropy residual sum and outlier (MR-PRESSO) test, weighted median estimator, and MR-Egger regression. Sensitivity analyses were further performed using Egger intercept analysis, leave-one-out analysis, MR-PRESSO global test, and Cochran's Q test to verify the robustness of our findings.

RESULTS

The results of the MR analysis indicated an increased risk of lung cancer in insomnia patients (OR = 1.1671; 95% CI 1.0754-1.2666, p = 0.0002). The subgroup analyses showed increased risks of lung adenocarcinoma (OR = 1.1878; 95% CI 1.0594-1.3317, p = 0.0032) and squamous cell lung cancer (OR = 1.1595; 95% CI 1.0248-1.3119, p = 0.0188).

CONCLUSION

Our study indicated that insomnia is a causal risk factor in the development of lung cancer. Due to the lack of evidence on both the epidemiology and the mechanism level, more studies are needed to better elucidate the results of the study.

Is Vitamin D Deficiency Related to Increased Cancer Risk in Patients with Type 2 Diabetes Mellitus?

There is mounting evidence that type 2 diabetes mellitus (T2DM) is related with increased risk for the development of cancer. Apart from shared common risk factors typical for both diseases, diabetes driven factors including hyperinsulinemia, insulin resistance, hyperglycemia and low grade chronic inflammation are of great importance. Recently, vitamin D deficiency was reported to be associated with the pathogenesis of numerous diseases, including T2DM and cancer. However, little is known whether vitamin D deficiency may be responsible for elevated cancer risk development in T2DM patients. Therefore, the aim of the current review is to identify the molecular mechanisms by which vitamin D deficiency may contribute to cancer development in T2DM patients. Vitamin D via alleviation of insulin resistance, hyperglycemia, oxidative stress and inflammation reduces diabetes driven cancer risk factors. Moreover, vitamin D strengthens the DNA repair process, and regulates apoptosis and autophagy of cancer cells as well as signaling pathways involved in tumorigenesis i.e., tumor growth factor β (TGFβ), insulin-like growth factor (IGF) and Wnt-β-Cathenin. It should also be underlined that many types of cancer cells present alterations in vitamin D metabolism and action as a result of Vitamin D Receptor (VDR) and CYP27B1 expression dysregulation. Although, numerous studies revealed that adequate vitamin D concentration prevents or delays T2DM and cancer development, little is known how the vitamin affects cancer risk among T2DM patients. There is a pressing need for randomized clinical trials to clarify whether vitamin D deficiency may be a factor responsible for increased risk of cancer in T2DM patients, and whether the use of the vitamin by patients with diabetes and cancer may improve cancer prognosis and metabolic control of diabetes.

Vitamin D as a Potential Therapeutic Option in Cancer Treatment: Is There a Role for Chemoprevention?

BACKGROUND

Vitamin D (Vit D) serves as a precursor to the potent steroid hormone calcitriol, which regulates numerous genes that control homeostasis, epithelial cell differentiation, proliferation, and apoptosis. Low level of Vit D is implicated in the development and progression of several diseases including bone fractures, cardiovascular disease, diabetes mellitus, and cancers. The present review highlights the role of vitamin D in cancer with a particular emphasis on genetic variants related to Vit D metabolism as well as clinical trials of Vit D supplementation as a potential therapeutic option in the treatment of cancer patients.

METHODS

Data were collected following an electronic search in the Web of Science, Medline, PubMed, and Scopus databases by using some keywords such as "cancer", "tumor", "malignancy", "vitamin D", "cholecalciferol" and "calcitriol".

RESULTS

The collected evidence from the studies revealed a consistent and strong association between Vit D status and cancer risk and survival. The associations between Vit D-related genetic variants and cancer survival support the hypothesis that Vit D may affect cancer outcomes. The mechanisms whereby Vit D reduces cancer risk and increases survival are regulation of cellular differentiation, proliferation and apoptosis as well as decreased angiogenesis in tumor microenvironment and inhibition of metastasis.

CONCLUSION

There is a paucity of evidence-based recommendations for the optimal 25(OH)D levels in patients with cancer and the role of Vit D supplementation for primary or secondary prevention of cancer. Well-designed and sufficiently powered randomized clinical trials are necessary to assess the clinical application of Vit D in enhancing the clinical efficacy of standard and adjuvant chemotherapy regimens.

Aerosol 1,25-dihydroxyvitamin D3 supplementation: A strategy to boost anti-tumor innate immune activity

BACKGROUND

1,25-dihydroxyvitamin D3 [1,25(OH)2D3] plays a role in calcium homeostasis but can also exert immunomodulatory effects. In lungs, characterized by a particular immunosuppressive environment primarily due to the presence of alveolar macrophages (AM), 1,25(OH)2D3 has been shown to favor the immune response against pathogens. Here, we explored the ability of aerosolized 1,25(OH)2D3 to locally promote an anti-tumor phenotype in alveolar macrophages (AM) in the treatment of lung metastases.

METHODS

Cytotoxicity assay has been used to assess the capability of AM, in vitro treated of not with 1,25(OH)2D3, to stimulate NK cells. Sulforhodamine B (SRB) assay has been used to assess the effect of 1,25(OH)2D3 on MC-38 and B16 tumor cells in vitro growth. 1,25(OH)2D3 was aerosolized in immunocompetent mouse models to evaluate the effect of local administration of 1,25(OH)2D3 on in vivo growth of MC-38 and B16 tumor cells within lungs and on infiltrating immune cells.

RESULTS

In vitro incubation of naïve AM with 1,25(OH)2D3 improved their ability to stimulate NK cell cytotoxicity. In vivo aerosolized 1,25(OH)2D3 significantly reduced the metastatic growth of MC-38 colon carcinoma, a tumor histotype that frequently metastasizes to lung in human. Immune infiltrate obtained from digested lungs of 1,25(OH)2D3-treated mice bearing MC-38 metastases revealed an increased expression of MHCII and CD80 on AM and an up-modulation of CD69 expression on effector cells that paralleled a strong increased ability of these cells to kill MC-38 tumor in vitro.

CONCLUSIONS

Together, these data show that aerosol delivery can represent a feasible and novel approach to supplement 1,25(OH)2D3 directly to the lungs promoting the activation of local immunity against cancer.

Lung cancer risk in patients with multiple sclerosis: a Mendelian randomization analysis

BACKGROUND

The relationship of multiple sclerosis (MS) with lung cancer is under debate. Conventional observational studies have reported conflicting findings, but such studies are susceptible to confounding and reverse causation. With a Mendelian Randomization approach, we were able to evaluate the causality between MS and lung cancer.

METHODS

According to published genome-wide association studies (GWASs), we obtained 35 MS-related single-nucleotide polymorphisms, which were used as instrumental variables in our study. Summary data of individual-level genetic information were obtained from the International Lung Cancer Consortium (ILCCO), with a total of 15,861 controls and 11,348 cases; the latter is composed of patients with lung adenocarcinoma and squamous cell lung cancer. The inverse variance-weighted method was applied to estimate the causation between MS and lung cancer. To further evaluate the pleiotropy, the MR-Egger and Weighted median methods were implemented.

RESULTS

The results of MR analysis suggested a causal effect of MS on lung cancer incidence, with evidence of an increased risk for overall lung cancer [odds ratio (OR): 1.0648; 95% confidence interval (CI): 1.0163-1.1156; p = 0.0082]. However, subgroup analyses showed no significant causal relationships between MS and lung adenocarcinoma (OR = 1.0716; 95% CI 0.9840-1.1671, p = 0.1119) and squamous cell lung cancer (OR = 1.0284; 95% CI 0.9575-1.1045, p = 0.4424). In addition, no pleiotropy was found in our study.

CONCLUSION

Our study indicated that MS is a causal risk factor in the development of lung cancer. Further work is needed to elucidate the potential mechanisms.

Effect of Selected Factors on the Serum 25(OH)D Concentration in Women Treated for Breast Cancer

Maintaining an optimal vitamin D concentration reduces the risk of recurrence and extends survival time in patients after breast cancer treatment. Data on vitamin D deficiency among Polish women after breast cancer therapy are limited. Thus, the aim of the study was the analysis of vitamin D status in post-mastectomy patients, considering such factors as seasons, social habits, vitamin D supplementation and its measurements. The study involved 94 women after breast cancer treatment. Serum vitamin D concentration was measured, and a questionnaire, gathering demographic and clinical data regarding cancer, diet, exposure to sun radiation, and knowledge of recommendations on vitamin D supplementation, was delivered twice, in both winter and in summer. The control group consisted of 94 age-matched women with no oncological history. In women after breast cancer treatment, 25-hydroxyvitamin D (25(OH)D) deficiency was much more frequent than in the general population. Only about half of the patients supplemented vitamin D at the beginning of the study. After the first test and the issuing of recommendations on vitamin D supplementation, the percentage of vitamin D supplemented patients increased by about 30% in study groups. The average dose of supplement also increased. None of the women that were not supplementing vitamin D and were tested again in winter had optimal 25(OH)D concentration. It was concluded that vitamin deficiency is common in women treated for breast cancer. Medical advising about vitamin D supplementation and monitoring of 25(OH)D concentration should be improved.

Associations between osteoporosis and risk of periodontitis: A pooled analysis of observational studies

Background

Periodontitis and osteoporosis are most popular among aging population and both conditions might be linked, even though, this suggestion still until now debated.

Objectives

A meta‐analysis on previous investigations has been used to evaluate the correlation between periodontitis and osteoporosis to determine whether osteoporosis is a local indicator of bone loss, or whether it is depending on or related to periodontitis causes.

Methods

The literature database, including but not excluding, The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CINAHL, and Science Citation Index Expanded, was searched in this work during Feb, 2020. We conducted the investigations contain cohort studies, cross‐sectional studies, as well as case–control studies with relative risk (RR) or odds ratio (OR) and 95% confidence intervals (CIs). Subgroup and Sensitivity analysis were also applied to identify heterogeneity sources.

Results

23 observational studies with 12 cohorts, 7 cross‐sectional and 4 case–control studies, were included, together with 2,157,037 participants. Osteoporosis patients were more exposed to periodontitis (OR, 1.96; 95% CI, 1.50–2.54). Subgroup analyses showed that the higher risk of osteoporosis in periodontitis patients exists in both cross‐sectional studies (OR, 2.17; 95% CI, 1.80–2.61) and case–control studies (OR 2.63; 95% CI, 1.69–4.09), and marginally in cohort studies (OR, 1.70; 95% CI, 1.16–2.49).

Conclusion

Review analyses have shown that osteoporosis is closely related to the increased risk of periodontitis in the future. Dental specialists better to understand the potential association between periodontitis and osteoporosis.

Association between Metabolites and the Risk of Lung Cancer: A Systematic Literature Review and Meta-Analysis of Observational Studies

Globally, lung cancer is the most prevalent cancer type. However, screening and early detection is challenging. Previous studies have identified metabolites as promising lung cancer biomarkers. This systematic literature review and meta-analysis aimed to identify metabolites associated with lung cancer risk in observational studies. The literature search was performed in PubMed and EMBASE databases, up to 31 December 2019, for observational studies on the association between metabolites and lung cancer risk. Heterogeneity was assessed using the I² statistic and Cochran’s Q test. Meta-analyses were performed using either a fixed-effects or random-effects model, depending on study heterogeneity. Fifty-three studies with 297 metabolites were included. Most identified metabolites (252 metabolites) were reported in individual studies. Meta-analyses were conducted on 45 metabolites. Five metabolites (cotinine, creatinine riboside, N-acetylneuraminic acid, proline and r-1,t-2,3,c-4-tetrahydroxy-1,2,3,4-tetrahydrophenanthrene) and five metabolite groups (total 3-hydroxycotinine, total cotinine, total nicotine, total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (sum of concentrations of the metabolite and its glucuronides), and total nicotine equivalent (sum of total 3-hydroxycotinine, total cotinine and total nicotine)) were associated with higher lung cancer risk, while three others (folate, methionine and tryptophan) were associated with lower lung cancer risk. Significant heterogeneity was detected across most studies. These significant metabolites should be further evaluated as potential biomarkers for lung cancer.

Association of various dietary habits and risk of lung cancer: an updated comprehensive literature review

Lung cancer remains the leading cause of cancer death in both men and women worldwide. Tobacco smoking remains the single most important factor. Recent research has focused on the role of nutrition and dietary habits on lung tumorigenesis. With many individual reports on separate dietary aspects, no single review is available in the literature that summarizes the updated studies. To our knowledge, this is the first review that comprehensively reviews the updated literature on the effect of dietary habits on lung cancer. This review was concluded in February 2019 and included all meta-analyses, systematic reviews, and literature reviews. Thirty studies were retrieved in total. Items in the diet that offer a protective effect on lung parenchyma are fruits, vegetables, fish, nuts, soy, B vitamins, vitamin D, vitamin E, vitamin C, and zinc. Changing dietary habits to decrease the risk of lung cancer can be performed in parallel with smoking cessation programs. There is a need for future studies with large sample sizes to accurately evaluate some aspects of nutrition and their effect on lung cancer risk. Physicians are encouraged to provide nutritional advice to their patients.

Association between gastroesophageal reflux disease and atrial fibrillation: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

associations between gastroesophageal reflux disease (GERD) and atrial fibrillation (AF) are inconclusive. Some studies found that AF was a risk factor for GERD whereas other studies showed opposite results. The primary objective of this study was to systematically evaluate whether GERD and AF have a bidirectional association using a meta-analysis.

METHODS

a systematic review was conducted of studies on the association between GERD and AF, written in the English language and included in Cochrane CENTRAL, PubMed and EMBASE until February 2017. The search was limited to longitudinal, case-control, and cross-sectional studies.

RESULTS

among 548 studies found in the above-mentioned databases, seven fulfilled the inclusion criteria. Among these seven studies, two were longitudinal studies, two were case-control studies, and three were cross-sectional studies. The summary adjusted relative risks (RRs) for AF-induced GERD and GERD-induced AF were 1.54 (95% CI, 1.08-2.17) and 1.06 (95% CI, 0.86-1.31), respectively. The subgroup analysis showed that the associations were not significantly modified by sample size, study design, age, or geographic area.

CONCLUSIONS

this meta-analysis supported the association of AF with increased risk of GERD.

Vitamin D and overall cancer risk and cancer mortality: a Mendelian randomization study

There is considerable debate regarding the role that 25-hydroxyvitamin D [25(OH)D] concentrations play in cancer risk or mortality, with earlier studies drawing mixed conclusions. Using data from the UK Biobank (UKB), we evaluate whether genetically predicted 25(OH)D concentrations are associated with overall cancer susceptibility and cancer mortality using five 25(OH)D genetic markers. Data comprised 438 870 white British UKB participants aged 37-73, including 46 155 cancer cases and 6998 cancer-specific deaths. Participants with keratinocyte cancers and/or benign tumors were excluded from the analysis. Odds ratios were calculated per 20 nmol/L increase in genetically predicted 25(OH)D for cancer risk and cancer mortality. For individual cancer risks, estimates were meta-analyzed with publicly available data using a fixed-effect inverse-variance-weighted model. We demonstrated that genetically low plasma 25(OH)D concentrations were not associated with increased cancer risk nor cancer mortality. Stratification by sex or cancer types did not reveal any meaningful differences albeit wider confidence intervals. Fixed-effect meta-analysis of our individual cancer risk estimates with those derived from publicly available cancer consortia data and previous studies further reinforced our null Mendelian randomization findings on prostate, lung, colorectal and breast cancers with tight confidence intervals; for ovarian and pancreatic cancers, our estimates were less precise despite being not statistically significant. Taken altogether, our results provide no genetic evidence for an association between vitamin D and overall cancer outcomes, with tight confidence intervals to exclude all but very small effect sizes.

Pre-diagnostic 25-hydroxyvitamin D levels and survival in cancer patients

PURPOSE

Our main aim was to explore whether pre-diagnostic circulating levels of 25-hydroxyvitamin D (25(OH)D) among older individuals with cancer were associated with overall and cancer-specific survival after diagnosis.

DESIGN

We used data from the Reykjavik-AGES Study on participants (n = 4,619) without cancer at entry, when blood samples were taken for 25(OH)D standardized measurements. The association with cancer risk, all-cause- and cancer-specific mortality was assessed among those later diagnosed with cancer, comparing four 25(OH)D categories, using 50-69.9 nmol/L as the reference category.

RESULTS

Cancer was diagnosed in 919 participants on average 8.3 years after blood draw. No association was observed between the reference group and other 25(OH)D groups and total cancer incidence. Mean age at diagnosis was 80.9 (± 5.7) years. Of those diagnosed, 552 died during follow-up, 67% from cancer. Low pre-diagnostic levels of 25(OH)D < 30 nmol/L were significantly associated with increased total mortality (HR: 1.39, 95% CI 1.03, 1.88) and non-significantly with cancer-specific mortality (HR: 1.33, 95% CI 0.93, 1.90). Among patients surviving more than 2 years after diagnosis, higher pre-diagnostic 25(OH)D levels (≥ 70 nmol/L) were associated with lower risk of overall (HR: 0.68, 95% CI 0.46, 0.99) and cancer-specific mortality (HR: 0.47, 95% CI 0.26, 0.99).

CONCLUSIONS

Among elderly cancer patients, low pre-diagnostic serum 25(OH)D levels (< 30 nmol/L) were associated with increased overall mortality.

Associations Between Poor Oral Health and Risk of Squamous Cell Carcinoma of the Head and Neck: A Meta-Analysis of Observational Studies

PURPOSE

Many epidemiologic studies have reported an association of poor oral health, especially periodontal disease (PD) and tooth loss, with the risk of squamous cell carcinoma of the head and neck (SCCHN). However, these studies have yielded inconsistent results. Therefore, the present study investigated whether poor oral health is an independent predictor of SCCHN through a meta-analysis of observational studies.

MATERIALS AND METHODS

The PubMed, EMBASE, and Cochrane Library databases were systematically searched for relevant observational studies of the association between oral health and risk of SCCHN conducted up to October 2017. The meta-analysis was conducted using STATA 12.0 (StataCorp, College Station, TX). A fixed- or random-effects model was applied to evaluate pooled risk estimates, and sensitivity and subgroup analyses were performed to identify sources of heterogeneity and pooled estimation. Publication bias was assessed using the Begg test, the Egger test, and funnel plots.

RESULTS

Twenty-seven relevant observational studies were identified, consisting of 24 case-and-control studies, 2 prospective studies, and 1 cross-sectional study, with 26,750 participants. Notably, oral health correlated meaningfully with SCCHN (odds ratio [OR] = 2.24; 95% confidence interval [CI], 1.77-2.82). In subgroup analyses, participants with PD (OR = 2.52; 95% CI, 1.43-4.44) had a higher risk of developing SCCHN than those with tooth loss (OR = 2.13; 95% CI, 1.63-2.78). The risk estimates exhibited substantial heterogeneity. Evidence of publication bias was limited.

CONCLUSIONS

The results of this meta-analysis suggest that patients with tooth loss or PD might face a substantial and independent risk of SCCHN, even after adjusting for smoking and alcohol consumption. However, the pooled estimates from observational studies could not establish a causative relation among PD, tooth loss, and SCCHN. Additional investigations of this correlation are warranted.

Associations of the risk of lung cancer with serum 25-hydroxyvitamin D level and dietary vitamin D intake: A dose-response PRISMA meta-analysis

The associations of the risk of lung cancer with the vitamin D intake and serum level are controversial. We performed a comprehensive dose-response meta-analysis to evaluate the precise relationships between the above mentioned parameters.We performed a web search of the PubMed, Medline, and Embase databases to identify potential studies that evaluated the relationships between vitamin D intake or serum 25-hydroxyvitamin D (25([OH]D) levels and the risk of lung cancer on December 5, 2017. According to the inclusion and exclusive criteria, 16 studies were included in this meta-analysis. The pooled relative risks (RRs) with 95% confidence intervals (CIs) were used to assess the strength of the associations. A dose-response analysis was conducted to quantitate the relationship between the serum 25(OH)D or vitamin D intake and the risk of lung cancer.The pooled RR (highest level vs lowest level) showed that the serum 25(OH)D level was not associated with the risk of lung cancer (RR = 1.046, 95% CI = 0.945-1.159). A high vitamin D intake was inversely correlated with the lung cancer risk (RR = 0.854, 95% CI = 0.741-0.984). No significant dose-response relationship was observed between the serum 25(OH)D level and the lung cancer risk. The linearity model of the dose-response analysis indicated that with every 100 IU/day increase in vitamin D intake, the risk of lung cancer decreased by 2.4% (RR = 0.976, 95% CI = 0.957-0.995, P = .018).A high vitamin D intake provides limited protection against lung cancer carcinogenesis.

No association between circulating concentrations of vitamin D and risk of lung cancer: an analysis in 20 prospective studies in the Lung Cancer Cohort Consortium (LC3)

Background

There is observational evidence suggesting that high vitamin D concentrations may protect against lung cancer. To investigate this hypothesis in detail, we measured circulating vitamin D concentrations in prediagnostic blood from 20 cohorts participating in the Lung Cancer Cohort Consortium (LC3).

Patients and methods

The study included 5313 lung cancer cases and 5313 controls. Blood samples for the cases were collected, on average, 5 years before lung cancer diagnosis. Controls were individually matched to the cases by cohort, sex, age, race/ethnicity, date of blood collection, and smoking status in five categories. Liquid chromatography coupled with tandem mass spectrometry was used to separately analyze 25-hydroxyvitamin D2 [25(OH)D2] and 25-hydroxyvitamin D3 [25(OH)D3] and their concentrations were combined to give an overall measure of 25(OH)D. We used conditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for 25(OH)D as both continuous and categorical variables.

Results

Overall, no apparent association between 25(OH)D and risk of lung cancer was observed (multivariable adjusted OR for a doubling in concentration: 0.98, 95% CI: 0.91, 1.06). Similarly, we found no clear evidence of interaction by cohort, sex, age, smoking status, or histology.

Conclusion

This study did not support an association between vitamin D concentrations and lung cancer risk.

Inverse association of vitamin D3 levels with lung cancer mediated by genetic variation

Vitamin D is an essential micronutrient required for normal physiological function and recognized for its role regulating calcium metabolism. Recent work is beginning to emerge demonstrating a role for vitamin D in chronic illnesses, such as cancer. Circulating serum levels of 25(OH)D_2/3 were quantitatively measured using sensitive ultraperformance liquid chromatography coupled to tandem mass spectrometry (UPLC‐MS/MS) in 406 lung cancer cases and 437 population controls, while 1,25(OH)₂D_2/3 levels were measured in a subset of 90 cases and 104 controls using the same method, from the NCI‐MD case–control cohort. 25(OH)D₃ levels were inversely associated with lung cancer status across quartiles (Q2 vs. Q1: OR_adjusted = 0.5, 95% CI = 0.3–0.8; Q3 vs. Q1: OR_adjusted = 0.5, 95% CI = 0.3–0.8; Q4 vs. Q1: OR_adjusted = 0.5, 95% CI = 0.2–0.9; P_trend = 0.004). Levels of 1,25(OH)₂D₃ were also inversely associated with lung cancer status (Q2 vs. Q1: OR_adjusted = 0.2, 95% CI = 0.03–0.7; Q3 vs. Q1: OR_adjusted = 0.1, 95% CI = 0.01–0.4; Q4 vs. Q1: OR_adjusted = 0.04, 95% CI = 0.01–0.3; P_trend<0.0001). Although the observed trends were similar for the 25(OH)D₂ (P_trend = 0.08), no significant associations were seen between vitamin D₂ and lung cancer status. Additionally, genotyping of 296 SNPs in the same subjects resulted in findings that 27 SNPs, predominantly in CYP24A1 and VDR genes, were significantly associated with lung cancer status, affected mRNA expression, and modulated vitamin D levels. These findings suggest a protective role for vitamin D₃ in lung cancer, with similar trends but insignificant findings for D₂. Vitamin D₃ levels appeared to be modulated by genetic variation in CYP24A1 and VDR genes. Additional research to illuminate the mechanism(s) through which vitamin D exacerbates effects against lung carcinogenesis is warranted.

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.

Circulating vitamin D concentration and risk of seven cancers: Mendelian randomisation study

Objective To determine if circulating concentrations of vitamin D are causally associated with risk of cancer.Design Mendelian randomisation study.Setting Large genetic epidemiology networks (the Genetic Associations and Mechanisms in Oncology (GAME-ON), the Genetic and Epidemiology of Colorectal Cancer Consortium (GECCO), and the Prostate Cancer Association Group to Investigate Cancer Associated Alterations in the Genome (PRACTICAL) consortiums, and the MR-Base platform).Participants 70 563 cases of cancer (22 898 prostate cancer, 15 748 breast cancer, 12 537 lung cancer, 11 488 colorectal cancer, 4369 ovarian cancer, 1896 pancreatic cancer, and 1627 neuroblastoma) and 84 418 controls.Exposures Four single nucleotide polymorphisms (rs2282679, rs10741657, rs12785878 and rs6013897) associated with vitamin D were used to define a multi-polymorphism score for circulating 25-hydroxyvitamin D (25(OH)D) concentrations.Main outcomes measures The primary outcomes were the risk of incident colorectal, breast, prostate, ovarian, lung, and pancreatic cancer and neuroblastoma, which was evaluated with an inverse variance weighted average of the associations with specific polymorphisms and a likelihood based approach. Secondary outcomes based on cancer subtypes by sex, anatomic location, stage, and histology were also examined.Results There was little evidence that the multi-polymorphism score of 25(OH)D was associated with risk of any of the seven cancers or their subtypes. Specifically, the odds ratios per 25 nmol/L increase in genetically determined 25(OH)D concentrations were 0.92 (95% confidence interval 0.76 to 1.10) for colorectal cancer, 1.05 (0.89 to 1.24) for breast cancer, 0.89 (0.77 to 1.02) for prostate cancer, and 1.03 (0.87 to 1.23) for lung cancer. The results were consistent with the two different analytical approaches, and the study was powered to detect relative effect sizes of moderate magnitude (for example, 1.20-1.50 per 25 nmol/L decrease in 25(OH)D for most primary cancer outcomes. The Mendelian randomisation assumptions did not seem to be violated.Conclusions There is little evidence for a linear causal association between circulating vitamin D concentration and risk of various types of cancer, though the existence of causal clinically relevant effects of low magnitude cannot be ruled out. These results, in combination with previous literature, provide evidence that population-wide screening for vitamin D deficiency and subsequent widespread vitamin D supplementation should not currently be recommended as a strategy for primary cancer prevention.

Serum 25-hydroxyvitamin D concentrations and lung cancer risk in never-smoking postmenopausal women

PURPOSE

Vitamin D has been implicated in lowering lung cancer risk, but serological data on the association among never-smoking women are limited. We report results examining the association of serum 25-hydroxyvitamin D [25(OH)D] concentrations with lung cancer risk among female never smokers. We also examined whether the association was modified by vitamin D supplementation and serum vitamin A concentrations.

METHODS

In the Women's Health Initiative, including the calcium/vitamin D (CaD) Trial, we selected 298 incident cases [191 non-small cell lung cancer (NSCLC) including 170 adenocarcinoma] and 298 matched controls of never smokers. Baseline serum 25(OH)D was assayed by a chemiluminescent method. Logistic regression was used to estimate odds ratios (ORs) for quartiles and predefined clinical cutoffs of serum 25(OH)D concentrations.

RESULTS

Comparing quartiles 4 versus 1 of serum 25(OH)D concentrations, ORs were 1.06 [95% confidence interval (CI) 0.61-1.84] for all lung cancer, 0.94 (95% CI 0.52-1.69) for NSCLC, and 0.91 (95% CI 0.49-1.68) for adenocarcinoma. Comparing serum 25(OH)D ≥ 75 (high) versus <30 nmol/L (deficient), ORs were 0.76 (95% CI 0.31-1.84) for all lung cancer, 0.71 (95% CI 0.27-1.86) for NSCLC, and 0.81 (95% CI 0.31-2.14) for adenocarcinoma. There is suggestive evidence that CaD supplementation (1 g calcium + 400 IU D3/day) and a high level of circulating vitamin A may modify the associations of 25(OH)D with lung cancer overall and subtypes (p interaction <0.10).

CONCLUSIONS

In this group of never-smoking postmenopausal women, the results did not support the hypothesis of an association between serum 25(OH)D and lung cancer risk.

Plasma 25-hydroxyvitamin D levels, vitamin D intake, and pancreatic cancer risk or mortality: a meta-analysis

BACKGROUND

The associations between vitamin D status, including plasma 25-hydroxyvitamin D [25(OH)D] levels and vitamin D intake, and pancreatic cancer risk and mortality are inconsistent. The aims of this study are to evaluate the antitumor and therapeutic effects of vitamin D status for pancreatic cancer patients.

METHODS

A literature search for relevant studies was conducted using PubMed and Embase databases. Risk ratio (RR), hazard ratio (HR), and 95% confidence interval (CI) were used as the effect measures. All statistical analyses were performed using Stata software 12.0.

RESULTS

Our results indicated that high plasma 25(OH)D levels were inversely associated with pancreatic cancer mortality without significant heterogeneity (HR=0.81, 95% CI=0.68-0.96). However, high plasma 25(OH)D levels could not reduce pancreatic cancer risk (RR=1.02, 95% CI=0.66-1.57). Moreover, vitamin D intake was also not associated with pancreatic cancer risk (RR=1.11, 95% CI=0.67-1.86).

CONCLUSIONS

Our results indicate that high plasma 25(OH)D levels were significantly associated with improved survival in pancreatic cancer patients. However, there were no significant associations between vitamin D intake or plasma 25(OH)D levels and pancreatic cancer risk.

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.

Meta-analysis of the correlation between vitamin D and lung cancer risk and outcomes

In this meta-analysis, we analyzed the association between vitamin D levels and lung carcinoma risk and outcomes. Two authors independently searched the Web of Science, Pubmed, EBSCO and Ovid MEDLINE resources with the key words “vitamin D, lung cancer, solar and latitude” and enrolled 22 studies that satisfied the inclusion criteria. The summary odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using the random (or fixed)-effects model. Potential confounders were carefully adjusted. High vitamin D (or calcium) intake and serum 25(OH)D levels each correlated inversely with lung cancer risk [OR = 0.72 (95% CI: 0.61–0.85, p < 0.001) and OR = 0.89 (95% CI: 0.83–0.97, p < 0.05)]. High circulating 25(OH)D levels also reduced lung cancer mortality with the pooled OR reached 0.39 (95% CI: 0.28–0.54, p < 0.001)]. A positive trend was presented in the relationship between serum 25(OH) D and survival (OR = 1.01, 95% CI: 0.87–1.18, p = 0.87). Subgroup analysis revealed that nonsmokers had higher vitamin D levels, which correlated negatively with lung cancer risk (OR = 0.76, 95% CI: 0.65–0.88, p < 0.01). Moreover, lower sun exposure and high latitude associated with lower vitamin D levels. This meta-analysis shows that high vitamin D (or calcium) intake and serum 25(OH)D levels correlate with lower lung cancer risk and better prognosis. UVB and latitude may play a vital role in lung cancer occurrence and progression, although a direct evidence hasn't been obtained.

The roles of UVB and vitamin D in reducing risk of cancer incidence and mortality: A review of the epidemiology, clinical trials, and mechanisms

Global cancer incidence and mortality rates are high and increasing. Thus, it is imperative to find novel solutions to preventing cancer incidence and treating it at an affordable yet efficacious manner. The solar UVB-vitamin D-cancer hypothesis was first proposed in 1980 based on a geographical ecological study. Since then, numerous ecological and observational studies as well as studies of mechanisms have provided support for the hypothesis. However, observational studies have not provided consistent support, in part due to using a single blood draw from any season to use for serum 25-hydroxyvitamin D [25(OH)D] concentration in prospective studies with long follow-up times. Case-controls studies, in which blood is drawn near time of diagnosis, and prospective studies in which blood is drawn in the sunnier half of the year, are more likely to find significant inverse relations between 25(OH)D and cancer incidence. Three vitamin D plus calcium clinical trials have found significant reduction in all-cancer incidence. This paper reviews the evidence for vitamin D in reducing incidence of and increasing survival from breast, colorectal, lung, ovarian, pancreatic, and prostate cancer. The epidemiological evidence provides strong support for all of these types of cancer except for non-aggressive prostate cancer. Studies of the cellular mechanisms of vitamin D action in different cancer cell types, strongly indicate that vitamin D can exert protective and anti-tumorigenic activities that would retard cellular transformation, hyperplasia and cancer progression. Based on the scientific evidence reviewed in this paper, individuals and health providers can consider increasing 25(OH)D concentrations through sensible sun exposure and/or vitamin D supplementation to reduce risk of and, in conjunction with standard care, treat cancer. Public health acceptance of vitamin D for cancer prevention and treatment requires stronger support from vitamin D clinical trials.

Serum 25(OH)D concentration, common variants of the VDR gene and lung cancer occurrence

The first aim of our study was to examine the association between common variants in VDR [rs2228570 (FokI), rs1544410 (BsmI), rs7975232 (ApaI), rs731236 (TaqI) and rs11568820 (Cdx2)] and lung cancer risk in the Polish population. Genotyping and statistical analysis which included Chi-square test with Yates correction and haplotype frequency analysis were performed on a series of 840 consecutively collected lung cancer patients and 920 healthy controls. The second aim was to evaluate the link between serum 25(OH)D concentration and the number of lung cancers in a subgroup of 200 patients. A separate control group that consisted of 400 matched (by age, sex, smoking habits and the season of blood collection) healthy individuals was used to avoid posterior adjustment on the matched variables. Statistical analysis with the use of Chi-square test with Yates was performed. We found no statistically significant difference in the distribution of the allels of studied VDR variants among cases and controls. A statistically significant over-representation of VDR haplotypes: rs731236_A + rs1544410_T [odds ratio (OR) = 2.43, 95% confidence interval (CI) = 1.11-5.32, p < 0.001], rs731236_G + rs1544410_T (OR = 1.54, 95% CI = 1.31-1.81, p < 0.001) and rs731236_G + rs1544410_C (OR = 0.04, 95% CI = 0.03-0.07, p < 0.001) was detected. We found a tendency toward an increased number of lung cancers among individuals with low serum levels of 25(OH)D. To answer the question, whether VDR can be regarded as lung cancer susceptibility gene and low 25(OH)D serum levels is associated with lung cancer occurrences, additional, multicenter study needs to be performed.

How Is Third Molar Status Associated With the Occurrence of Mandibular Angle and Condyle Fractures?

PURPOSE

Third molars (M3s) have been hypothesized to be associated with the risk of mandibular angle fracture and mandibular condylar fracture. The authors systematically estimated the relative risk (RR) of M3 status for the development of mandibular angle fracture and mandibular condylar fracture through a meta-analysis of cohort studies.

MATERIALS AND METHODS

In this systematic review, the PubMed, EMBASE, and Cochrane Library databases were searched from inception to October 2016. The predictor of risk was the presence or absence of M3s. The primary outcome was the RR of mandibular angle or condylar fracture. A fixed- or a random-effects model was applied to evaluate the pooled risk estimates. Sensitivity analysis also was performed to identify the potential sources of heterogeneity. Publication bias was assessed by the Begg and Egger tests.

RESULTS

Overall, 13 retrospective cohort studies were included. Of these, 13 reported the association between M3s and mandibular angle fracture, and 5 reported the association with mandibular condylar fracture. Patients with M3s had an increased risk of mandibular angle fractures (RR = 2.63; 95% confidence interval [CI], 2.15-3.21) but a decreased risk of mandibular condylar fractures (RR = 0.47; 95% CI, 0.25-0.86). Substantial heterogeneity in the risk estimates was found. No evidence of publication bias was found.

CONCLUSION

The present meta-analysis provides further evidence associating the presence of M3s with an increased risk of mandibular angle fractures and a simultaneously decreased risk of mandibular condylar fracture. Because of potentially more serious complications associated with condylar fracture, clinicians should carefully consider the decision to remove M3s to decrease the risk of mandibular angle fracture.

Role of Vitamin D in Cognitive Function in Chronic Kidney Disease

Both vitamin D deficiency and cognitive impairment are common in patients with chronic kidney disease (CKD). Vitamin D exerts neuroprotective and regulatory roles in the central nervous system. Hypovitaminosis D has been associated with muscle weakness and bone loss, cardiovascular diseases (hypertension, diabetes and hyperlipidemia), inflammation, oxidative stress, immune suppression and neurocognitive impairment. The combination of hypovitaminosis D and CKD can be even more debilitating, as cognitive impairment can develop and progress through vitamin D-associated and CKD-dependent/independent processes, leading to significant morbidity and mortality. Although an increasingly recognized comorbidity in CKD, cognitive impairment remains underdiagnosed and often undermanaged. Given the association of cognitive decline and hypovitaminosis D and their deleterious effects in CKD patients, determination of vitamin D status and when appropriate, supplementation, in conjunction with neuropsychological screening, should be considered integral to the clinical care of the CKD population.

Micronutrients in Oncological Intervention

Nutritional supplements are widely used among patients with cancer who perceive them to be anticancer and antitoxicity agents. Depending on the type of malignancy and the gender 30%-90% of the cancer patients supplement their diets with antioxidant and immuno-stabilizing micronutrients, such as selenium, vitamin C, and vitamin D, often without the knowledge of the treating physician. From the oncological viewpoint, there are justifiable concerns that dietary supplements decrease the effectiveness of chemotherapy and radiotherapy. Recent studies, however, have provided increasing evidence that treatment is tolerated better-with an increase in patient compliance and a lower rate of treatment discontinuations-when micronutrients, such as selenium, are added as appropriate to the patient's medication. Nutritional supplementation tailored to an individual's background diet, genetics, tumor histology, and treatments may yield benefits in subsets of patients. Clinicians should have an open dialogue with patients about nutritional supplements. Supplement advice needs to be individualized and come from a credible source, and it is best communicated by the physician.

Estimated economic benefit of increasing 25-hydroxyvitamin D concentrations of Canadians to or above 100 nmol/L

Mounting evidence from observational and clinical trials indicates that optimal vitamin D reduces the risk of many diseases. We used observational studies and recent data on 25-hydroxyvitamin D [25(OH)D] concentrations of Canadians from Cycle 3 of the Canadian Health Measures Survey to estimate the reduction in disease incidence, mortality rates, and the total economic burden (direct plus indirect) of disease if 25(OH)D concentrations of all Canadians were raised to or above 100 nmol/L. Recently, the mean 25(OH)D concentration of Canadians varied depending on age and season (51-69 nmol/L), with an overall mean of 61 nmol/L. The diseases affected by 25(OH)D concentration included cancer, cardiovascular disease, dementia, diabetes mellitus, multiple sclerosis, respiratory infections, and musculoskeletal disorders. We used 25(OH)D concentration-health outcome relations for breast cancer and cardiovascular disease and results of clinical trials with vitamin D for respiratory infections and musculoskeletal disorders to estimate the reductions in disease burden for increased 25(OH)D concentrations. If all Canadians attained 25(OH)D concentrations>100 nmol/L, the calculated reduction in annual economic burden of disease was $12.5 ± 6 billion on the basis of economic burdens for 2016 and a reduction in annual premature deaths by 23,000 (11,000-34,000) on the basis of rates for 2011. However, the effects on disease incidence, economic burden, and mortality rate would be phased in gradually over several years primarily because once a chronic disease is established, vitamin D affects its progression only modestly. Nevertheless, national policy changes are justified to improve vitamin D status of Canadians through promotion of safe sun exposure messages, vitamin D supplement use, and/or facilitation of food fortification.