Ecological study of solar radiation and cancer mortality in Japan

Vitamin D and Pancreatic Ductal Adenocarcinoma-A Review of a Complicated Relationship

INTRODUCTION

From the observation of a negative relationship between UV-B exposure and cancer rates, we hypothesized that vitamin D (VD) may play a protective role in oncogenesis. Moreover, repurposing a well-known and relatively safe drug for conditions with dismal prospects, such as pancreatic ductal adenocarcinoma (PDAC), is a tempting idea. Thus, we aimed to summarize the current knowledge regarding the role of VD in the prevention and treatment of PDAC.

METHODS

We conducted a systematic review of VD and PDAC using Medline-indexed studies accessed through PubMed as the primary data source. This study aimed to identify articles focusing on the role of VD as a risk and prognostic factor for PDAC, mechanistic studies evaluating the effects of VD or vitamin D analogs (VDAs) in PDAC models, and clinical trials on VDAs in PDAC. After the screening, 97 studies were included in the final manuscript.

CONCLUSION

Even though the results from epidemiologic studies were contradictory, basic research has demonstrated that VD can act on PDAC cells either directly, inhibiting proliferation, apoptosis, EMT, migration, invasion, and stemness, or indirectly, through stromal remodeling. A better understanding of the consequences of VD-induced tumor-stroma cross-talk alterations is needed to determine whether VD/VDAs can be used to our own advantage in the treatment of PDAC.

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.

Role of purinergic system and vitamin D in the anti-cancer immune response

For several years, scientists have recognized that vitamin D plays an important role in mineral and bone homeostasis. It was mostly used to treat osteoporosis and rickets in the past decades. Vitamin D has also been discovered to be modulator of the immune system and may play a role in a variety of diseases, including autoimmune diseases, in recent years. Vitamin D interaction with the vitamin D receptor (VDR), which has transcriptional imparts and is displayed on a variety of cell types, including those of the immune system, appears to be accountable for the immune-modulating effects. The action of tumor cells and vitamin D were the first to be investigated, but the spotlight is now on immunologic and purinergic systems. We conducted a systematic search in Pub Med as well as Google scholar for studies written in English. Vitamin D, cancer, purinergic signaling, and immune response were among the search words. Vitamin D has the potential to be a useful coadjuvant in cancer therapy and the purinergic system may be a potential treatment target to cancer therapy, according to our findings.

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.

Environmental and ecological factors of stomach cancer incidence and mortality: a systematic review study on ecological studies

OBJECTIVES

Stomach cancer (SC) is one of the most common and deadly types of cancer. It is the third leading cause of cancer deaths worldwide. The effect of environmental and ecological factors in SC have been assessed in some studies. Thus, we aimed to synthesize the environmental and ecological factors of SC incidence and mortality.

CONTENT

In this systematic review study, the scientific databases, including Web of Science, Scopus and PubMed, were searched from inception to November 2019 for all primary articles written in English by using relevant Medical Subject Heading (Mesh) terms. Two independent authors conducted the screening process to decide on the eligibility and inclusion of the articles in the study. The third author acted as an arbiter to resolve any disagreements.

SUMMARY AND OUTLOOK

A total of 157 potentially relevant articles were identified from the initial search 38 of which met the eligibility criteria; finally, 34 articles were included in the systematic review. The results revealed that soil arsenic exposure, coal and other opencast mining installations, living near incinerators and installations for the recovery or disposal of hazardous waste, installations for the production of cement, lime, plaster, and magnesium oxide, proximity to a metal industry sources, dietary iron, ingested asbestos, farming, arsenic in soil, altitude, organochlorines and environmental exposure to cadmium and lead have positive associations with SC incidence or death. Most of the ecological and environmental factors such as living near the mineral industries, the disposal of hazardous waste, metal industry sources and environmental exposure to cadmium and lead are positively related to SC mortality and incidence. However, solar UV-B, heat index and dietary zinc can be taken into account as protective factors against SC mortality and incidence.

The effect of climatic and geographical factors on breast cancer in Iran

OBJECTIVE

By studying the effect of environmental factors on health, it is clear that geographical, climatic and environmental factors have a significant impact on human health. This study, based on the data of the patients with breast cancer in Iran since 2010 to 2014 and using the statistical methods has determined the effect of geographical features of Iran (solar radiation status, radiation angle) on the frequency and distribution of this disease.

RESULTS

The maximum amount of total solar radiation occurs in the vicinity (surrounding) of the tropic of cancer, which covers some parts of the south of Iran and in the atmosphere of the northern latitudes of Iran. The amount of humidity and cloudiness is more than the southern latitudes, which causes more reflection of short waves of the sun during the day. Findings showed that the rate of breast cancer in low latitudes is higher than high latitudes. It was also found that with increasing longitude, the rate of cancer increases significantly due to the high thickness of the atmosphere and receiving more sunlight in the electromagnetic spectrum, as well as dry air and low water vapor in low altitude areas of eastern and southeastern Iran.

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.

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

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

Is there a causal relationship between vitamin D and melanoma risk? A Mendelian randomization study

BACKGROUND

Several preclinical studies have identified the antiproliferative effects of 25-hydroxyvitamin D [25(OH)D; vitamin D]. Ultraviolet radiation (UVR) is essential for vitamin D synthesis yet increases the risk of melanoma. Observational studies on the association of vitamin D levels with melanoma risk have reported inconclusive results, and are difficult to interpret owing to the potential confounding from the dual role of UVR.

OBJECTIVES

To determine whether there is a causal association between genetically predicted 25(OH)D concentrations and melanoma using a Mendelian randomization (MR) approach.

METHODS

We performed MR using summary data from a large genome-wide association study (GWAS) meta-analysis of melanoma risk, consisting of 12 874 cases and 23 203 controls. Five single nucleotide polymorphisms associated with 25(OH)D concentration - rs12785878, rs10741657, rs2282679, rs6013897 and rs116970203 - were selected as instrumental variables. An inverse variance weighted method was used to access the evidence for causality. MR results from the melanoma meta-analysis were combined with results from an MR study based on a melanoma risk GWAS using UK Biobank data.

RESULTS

A 20 nmol L^-1 decrease in 25(OH)D was not associated with melanoma risk [odds ratio (OR) 1·06, 95% confidence interval (CI) 0·95-1·19]. Results from the UK Biobank were concordant with this, with meta-analysis of our and UK Biobank-derived MR causal estimates showing no association (OR 1·02, 95% CI 0·92-1·13 for a 20 nmol L^-1 decrease).

CONCLUSIONS

The results suggest that vitamin D levels may not be causally associated with the risk of melanoma. What's already known about this topic? Antitumour activity of vitamin D has been identified in preclinical studies. Observational studies link vitamin D deficiency with an increased risk of a range of cancers. There is a growing public interest for vitamin D supplementation. Observational studies of melanoma are fraught with difficulties because while higher ultraviolet radiation levels increase vitamin D levels, such exposure is also associated with increased melanoma risk. Results from observational studies are inconclusive regarding the effect of vitamin D on melanoma risk. What does this study add? Using Mendelian randomization, an approach to causal inference, which is analogous to a natural randomized controlled trial, we found no causal association between vitamin D levels and melanoma.

The Association of Dietary Intake of Calcium and Vitamin D to Colorectal Cancer Risk among Iranian Population

Background:

Vitamin D and Calcium have a possible protective impact versus rectal neoplasm. Vitamin D, an important nutrient, is vital to regulate the absorption of calcium and bone mineralization; nevertheless, in a case-control study in Iran, we investigated the relationship among the dietary intake of vitamin D and calcium with the hazard of rectal neoplasm.

Methods:

363 subjects (162 cases and 201 controls) participated in the case- control Study from March 2017 to November 2018. Dietary intake of Calcium and Vitamin D was calculated using a 148-items food-frequency questionnaire.

Results:

Since altering the strong confounding agents, the multivariate risk proportion within the dietary vitamin D intake was OR=0.2, 95%CI 0.1-0.5, P-value <0.001 among cases. There was no association in case of calcium and rectal cancer.

Conclusions:

Taken together, a possible reduction in the hazard of rectal neoplasm with dietary intake of Vitamin D within Iranian patients was observed.

Plasma 25-hydroxyvitamin D concentrations and risk of incident cancer in adults with hypertension: A nested case-control study

BACKGROUND & AIMS

Evidence from epidemiologic studies on the association of circulating 25-hydroxyvitamin D [25(OH)D] concentrations with the incident risk of cancer has been inconsistent. We aimed to investigate the prospective relationship of baseline plasma 25(OH)D concentrations with the risk of cancer, and to examine possible effect modifiers.

METHODS

We employed a nested case-control study design, including 231 patients with incident cancer during a median 4.5 years of follow up, and 231 matched controls from the China Stroke Primary Prevention Trial (CSPPT).

RESULTS

The prevalence of plasma 25(OH)D <15, <20 and <30 ng/mL was 23.6%, 47.4% and 85.5%, respectively. Overall, there was an inverse relation between risk of cancer and plasma 25(OH)D. The Odds ratios (95% CI) for participants in the second (15.1 to <20.6 ng/mL), third (20.6 to <26.4 ng/mL) and fourth quartiles (≥26.4 ng/mL) were 0.45 (95% CI: 0.25-0.80), 0.53 (95% CI: 0.27-1.06) and 0.55 (95% CI: 0.27-1.10), respectively, compared with those in quartile 1. Conversely, low 25(OH)D (<15.1 ng/mL) concentrations were associated with increased risk of cancer (OR, 2.08; 95% CI: 1.20-3.59) compared to higher concentrations. These associations were consistent across subtypes of cancer. Several potential effect modifiers were identified, including plasma vitamin E concentrations and alcohol intake.

CONCLUSIONS

Low plasma 25(OH)D concentrations (<15.1 ng/mL) were associated with increased total cancer risk among Chinese hypertensive adults, compared to higher 25(OH)D concentrations. This finding and the possible effect modifiers warrant additional investigation.

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.

The role of vitamin D in hepatic metastases from colorectal cancer

Colorectal cancer (CRC) represents a significant health burden worldwide, comprising approximately 10% of annual cancer cases globally. Hepatic metastases are the most common site of CRC metastasis, and are the leading cause of death in CRC patients. There is strong epidemiologic evidence for an inverse association between vitamin D status and risk of CRC; however, the role of vitamin D in the natural history of liver metastases has not yet been investigated. Several researchers have proposed hallmarks of metastases; crucially, metastases can be blocked by interrupting just one rate-limiting step. Vitamin D status has been implicated in each proposed hallmark of metastasis. The aim of this review is to examine the potential role for vitamin D in reducing the development of hepatic metastases from CRC and outline the candidate mechanisms by which vitamin D may mediate these effects. The results of ongoing randomised intervention trials are eagerly awaited to determine whether addressing vitamin D insufficiency in CRC patients could reduce the occurrence of liver metastases, and the consequent morbidity and mortality.

Vitamin D Status in South Asian Populations - Risks and Opportunities

Human body acquires a significant amount of vitamin D by cutaneous synthesis under the action of sunlight and less is supplied through nutritional sources. Diversified sociocultural and economic determinants have been identified that limit the dietary intake of vitamin D and enough distribution of sunlight to maintain optimal levels of 25-hydroxyvitamin D (25(OH)D). Consequently, the world has witnessed a high prevalence of hypovitaminosis D in resource-limited South Asian countries. The purpose of this review is to provide a South Asian perspective of vitamin D status, critically examining India, Pakistan, Bangladesh, and Sri Lanka, and to shed light on potential determinants (latitude and season, sunshine exposure habits, age, gender, and genetic factors) leading to hypovitaminosis D among a variety of population groups. Literature search was carried out using bibliographic databases "PubMed," "Google Scholar," and "ScienceDirect.com." Serum 25(OH)D level, 20-50 nmol/L, was mainly taken as vitamin D deficiency, and determinants of low serum 25(OH)D concentration of the population under study were also considered. The review concludes that vitamin D deficiency is highly prevalent among South Asian populations and global efforts are needed to overcome hypovitaminosis in the region. In addition, dietary diversification, supplementation and fortification of foods with vitamin D, adequate exposure to sunlight, and consumption of animal foods were suggested as viable approaches to maintain 25(OH)D levels for optimal health.

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.

Cloud cover-adjusted ultraviolet B irradiance and pancreatic cancer incidence in 172 countries

BACKGROUND

Controversy exists regarding whether vitamin D deficiency could influence the etiology of pancreatic cancer. Several cohort studies have found that high serum 25-hydroxyvitamin D [25(OH)D] concentrations are associated with low risk of pancreatic cancer, while others have not.

HYPOTHESIS

Low ultraviolet B irradiance is associated with high incidence of pancreatic cancer.

METHODS

Age-standardized pancreatic cancer incidence rates were obtained from GLOBOCAN in 2008. The association between cloud-adjusted UVB irradiance and age-standardized incidence rates of pancreatic cancer was analyzed using regression.

RESULTS

Overall, the lower the cloud-adjusted UVB irradiance, the higher the incidence rate of pancreatic cancer. Residents of countries with low UVB irradiance had approximately 6 times the incidence rates as those in countries with high UVB irradiance (p<0.0001 for males and p<0.0001 for females). This association persisted after adjustment for traditional risk factors of pancreatic cancer (p=0.0182 for males and p=0.0029 for females).

CONCLUSIONS

There was an inverse association of cloud-adjusted UVB irradiance with incidence of pancreatic cancer that persisted after adjustment. This result is consistent with an inverse association of overall vitamin D deficiency in countries with lower UVB irradiance with risk of pancreatic cancer. Further research on the role of 25(OH)D in reduction of pancreatic cancer in individuals would be desirable to expand the limited avenues available for prevention of this highly fatal disease. This article is part of a Special Issue entitled '17th Vitamin D Workshop'.

Could vitamin D sufficiency improve the survival of colorectal cancer patients?

PURPOSE

To determine whether a higher serum 25-hydroxyvitamin D [25(OH)D] concentration at diagnosis is associated with longer survival of colorectal cancer patients.

METHODS

A meta-analysis was performed of studies of the relationship between 25(OH)D and mortality of patients with colorectal cancer. A random-effects model was used to calculate a pooled hazards ratio. Homogeneity was evaluated through a DerSimonian-Laird test.

RESULTS

Higher serum concentrations of 25(OH)D were associated with lower mortality in patients with colorectal cancer. Patients in the highest quintile of 25(OH)D had 37% lower mortality from colorectal cancer compared to those in the lowest quintile of 25(OH)D (pooled odds ratio=0.63, p<0.0001). Dose-response curves showed lower hazard ratios for mortality with higher serum 25(OH)D through at least 40ng/ml. There were no exceptions.

CONCLUSIONS

Higher serum 25(OH)D was associated with lower mortality of patients with colorectal cancer. These results suggest that colorectal cancer patients with deficient levels of serum 25(OH)D should have their levels restored to a normal range (30-80ng/ml). This could be done with regular testing of serum 25(OH)D to be confident that an adequate serum level is being maintained. Additional studies would be worthwhile to evaluate confounding or the possibility of reverse causation.

Vitamin D metabolic pathway genes and pancreatic cancer risk

Evidence on the association between vitamin D status and pancreatic cancer risk is inconsistent. This inconsistency may be partially attributable to variation in vitamin D regulating genes. We selected 11 vitamin D-related genes (GC, DHCR7, CYP2R1, VDR, CYP27B1, CYP24A1, CYP27A1, RXRA, CRP2, CASR and CUBN) totaling 213 single nucleotide polymorphisms (SNPs), and examined associations with pancreatic adenocarcinoma. Our study included 3,583 pancreatic cancer cases and 7,053 controls from the genome-wide association studies of pancreatic cancer PanScans-I-III. We used the Adaptive Joint Test and the Adaptive Rank Truncated Product statistic for pathway and gene analyses, and unconditional logistic regression for SNP analyses, adjusting for age, sex, study and population stratification. We examined effect modification by circulating vitamin D concentration (≤50, >50 nmol/L) for the most significant SNPs using a subset of cohort cases (n = 713) and controls (n = 878). The vitamin D metabolic pathway was not associated with pancreatic cancer risk (p = 0.830). Of the individual genes, none were associated with pancreatic cancer risk at a significance level of p<0.05. SNPs near the VDR (rs2239186), LRP2 (rs4668123), CYP24A1 (rs2762932), GC (rs2282679), and CUBN (rs1810205) genes were the top SNPs associated with pancreatic cancer (p-values 0.008-0.037), but none were statistically significant after adjusting for multiple comparisons. Associations between these SNPs and pancreatic cancer were not modified by circulating concentrations of vitamin D. These findings do not support an association between vitamin D-related genes and pancreatic cancer risk. Future research should explore other pathways through which vitamin D status might be associated with pancreatic cancer risk.

Recurrence season impacts the survival of epithelial ovarian cancer patients

BACKGROUND

Several studies indicated that the diagnosis season affects the prognosis of some cancers, such as examples in the prostate, colon and breast This retrospective study aimed to investigate whether the diagnosis and recurrent season impacts the prognosis of epithelial ovarian cancer patients.

METHODS

From January 2005 to August 2010, 161 epithelial ovarian cancer patients were analyzed and followed up until August 2013. Kaplan- Meier survival curves and the log-rank test were used to make the survival analysis. Multivariate analysis was conducted to identify independent prognostic factors.

RESULTS

The prognostic factors of overall survival in epithelial ovarian cancer patients included age, clinical stage, pathological type, histological grade, residual disease after primary surgery, recurrent season and adjuvant chemotherapy cycles. Moreover, clinical stage, histological grade, residual disease after primary surgery, recurrent season and adjuvant chemotherapy cycles also impacted the progression-free survival of epithelial ovarian cancer patients. The diagnosis season did not have a significantly relationship with the survival of operable epithelial ovarian cancer patients. Median overall survival of patients with recurrent month from April to November was 47 months, which was longer (P < 0.001) than that of patients with recurrence month from December to March (19 months). Median progression-free survival of patients with recurrence month from April to November and December to March was 20 and 8 months, respectively (P < 0.001).

CONCLUSION

The recurrence season impacts the survival of epithelial ovarian cancer patients. However, the diagnosed season does not appear to exert a significant influence.

Sunlight exposure during leisure activities and risk of prostate cancer in Montréal, Canada, 2005-2009

Background

Prostate cancer (PCa) is the leading cause of cancer in men in many developed countries, but no modifiable risk factors have been identified. A handful of analytical studies have suggested a possible etiological role for sunlight exposure. We report here on the association between leisure-time sunlight exposure during adulthood and PCa risk in the context of a population-based case–control study.

Methods

In all, 1,904 PCa cases were ascertained across Montreal French hospitals between 2005 and 2009. Concurrently, 1,962 population controls, frequency matched to cases by age (±5 years), were selected from the electoral list for French-speakers in Greater Montreal. Interviews elicited the frequency of engagement in any leisure activity during adulthood. This was used to derive cumulative sunlight exposure indices: a cumulative number of leisure activities events entailing sunlight exposure and a cumulative duration of sunlight exposure during leisure activities. Unconditional logistic regression was conducted to yield odds ratios (OR) and 95% confidence intervals (CI) for estimating the association between sunlight exposure indices and PCa risk, adjusting for age, ancestry, family history of PCa, PCa screening, education, solar protection, body mass index and physical activity.

Results

Compared with men in the upper quartile category for the number of sunlight exposure events, men never exposed during leisure time had an OR of 1.32 (95% CI: 0.82-2.14). ORs were 1.11, 0.91 and 1.00 for the first to the third quartiles of exposure, respectively. Similar results were observed for cumulative duration of exposure to sunlight, and by PCa aggressiveness.

Conclusion

These findings provide little evidence of an association between sunlight exposure during leisure-time and PCa risk. Men with no sunlight exposure appeared at somewhat higher risks but none of the estimates achieved statistical significance.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2458-14-756) contains supplementary material, which is available to authorized users.

Seasonality pattern of breast, colorectal, and prostate cancer is dependent on latitude

Background

The season of diagnosis of several forms of cancer has been observed to impact survival, supporting the hypothesis that vitamin D₃ has a protective role in cancer survival. All previous studies demonstrating this seasonality were performed in European populations residing at latitudes upwards of 50°N. This study investigated whether seasonality of prognosis persists in populations residing in the lower latitudes of the contiguous United States (Latitude 21°N to 48°N).

Material/Methods

The 5-year survival data of 19 204 female breast cancer, 6740 colorectal cancer, and 1644 prostate cancer cases was analyzed.

Results

Female breast cancer patients exhibited improved survival when diagnosed in the summer as compared to the winter at all latitudes (Hazard Ratio [HR]: 0.940, 95%; Confidence Interval [CI]: 0.938 to 0.941, P=0.002). Colorectal cancer and prostate cancer also exhibited a similar seasonal pattern (HR: 0.978, 95% CI: 0.975 to 0.980, P=0.008 and HR: 0.935, 95%, CI 0.929 to 0.943, P=0.006), respectively, when the analysis was restricted to northern regions.

Conclusions

These observations contribute to the mounting evidence that vitamin D₃ may affect the progression of cancer. Data also suggest that vitamin D₃ status at the onset of treatment may synergistically improve the prognosis of several cancer types.

Role of Vitamin D Metabolism and Activity on Carcinogenesis

The vitamin D endocrine system regulates a broad variety of independent biological processes, and its deficiency is associated with rickets, bone diseases, diabetes, cardiovascular diseases, and tuberculosis. Cellular and molecular studies have also shown that it is implicated in the suppression of cancer cell invasion, angiogenesis, and metastasis. Sunlight exposure and consequent increased circulating levels of vitamin D are associated with reduced occurrence and a reduced mortality in different histological types of cancer, including those resident in the skin, prostate, breast, colon, ovary, kidney, and bladder. The vitamin D receptor (VDR) as a steroid hormone superfamily of nuclear receptors is highly expressed in epithelial cells at risk for carcinogenesis, providing a direct molecular link by which vitamin D status impacts on carcinogenesis. Because VDR expression is retained in many human tumors, vitamin D status may be an important modulator of cancer progression in persons living with cancer. The aim of this review is to highlight the relationship between vitamin D, VDR, and cancer, summarizing several mechanisms proposed to explain the potential protective effect of vitamin D against the development and progression of cancer.

A multicountry ecological study of cancer incidence rates in 2008 with respect to various risk-modifying factors

Observational and ecological studies are generally used to determine the presence of effect of cancer risk-modifying factors. Researchers generally agree that environmental factors such as smoking, alcohol consumption, poor diet, lack of physical activity, and low serum 25-hdyroxyvitamin D levels are important cancer risk factors. This ecological study used age-adjusted incidence rates for 21 cancers for 157 countries (87 with high-quality data) in 2008 with respect to dietary supply and other factors, including per capita gross domestic product, life expectancy, lung cancer incidence rate (an index for smoking), and latitude (an index for solar ultraviolet-B doses). The factors found to correlate strongly with multiple types of cancer were lung cancer (direct correlation with 12 types of cancer), energy derived from animal products (direct correlation with 12 types of cancer, inverse with two), latitude (direct correlation with six types, inverse correlation with three), and per capita gross national product (five types). Life expectancy and sweeteners directly correlated with three cancers, animal fat with two, and alcohol with one. Consumption of animal products correlated with cancer incidence with a lag time of 15–25 years. Types of cancer which correlated strongly with animal product consumption, tended to correlate weakly with latitude; this occurred for 11 cancers for the entire set of countries. Regression results were somewhat different for the 87 high-quality country data set and the 157-country set. Single-country ecological studies have inversely correlated nearly all of these cancers with solar ultraviolet-B doses. These results can provide guidance for prevention of cancer.

Relationship between sun exposure and kidney cancer: preliminary experience with the evaluation of recreational UV exposure

INTRODUCTION

Recent findings reported an inverse relationship between solar ultraviolet-B (UV-B) exposure and mortality from various types of cancers, including renal cancer.

METHODS

We reviewed the literature concerning the relationship between sun exposure and incidence of kidney cancer. We performed a case-control study, evaluating recreational sun exposure in 50 kidney cancer patients and 50 controls.A questionnaire concerning sun exposure habits during childhood, adult life and in the previous 2 years was filled in by every patient. The questionnaire focused on: hours/day spent in the sun during summer; hours/day spent sunbathing (considering as well which kind of UV protection was used); sunburns; holidays in tropical countries.

RESULTS

We found and analyzed few articles concerning the relationship between kidney cancer and sunlight exposure. The two cohorts of patients we evaluated were homogeneous for age, phototype, origin and living area.We found no statistically significant differences between sun exposure in patients affected by kidney cancer and controls, both during childhood and adult life; no differences were found in the use of sunscreens either.

CONCLUSIONS

Recreational sunlight exposure does not differ in our cohorts of patients and controls; studies on greater cohorts are needed to evaluate the effect of recreational sun exposure in the development of kidney cancer.

Surrogates of long-term vitamin d exposure and ovarian cancer risk in two prospective cohort studies

Experimental evidence and ecologic studies suggest a protective role of vitamin D in ovarian carcinogenesis. However, epidemiologic studies using individual level data have been inconsistent. We evaluated ultraviolet (UV)-B radiation, vitamin D intake, and predicted plasma 25-hydroxyvitamin D [25(OH)D] levels as long-term surrogates of vitamin D exposure within the Nurses’ Health Study (NHS) and NHSII. We estimated incidence rate ratios (RRs) and 95% confidence intervals (CIs) for risk of overall ovarian cancer and by histologic subtype using Cox proportional hazards models. Between 1976 and 2010 in NHS and 1989 and 2011 in NHSII, we identified a total of 1,225 incident epithelial ovarian cancer cases (NHS: 970, NHSII: 255) over 4,628,648 person-years of follow-up. Cumulative average UV-B exposure was not associated with ovarian cancer risk in NHS (P_trend = 0.08), but was associated with reduced risk in NHSII (highest vs. lowest category RR = 0.67; 95% CI: 0.50, 0.89; P_trend < 0.01). When stratified by histologic subtype, UV-B flux was positively associated with risk of serous tumors in NHS (P_trend < 0.01), but inversely associated in NHSII (P_trend = 0.01). Adjusted for confounders, ovarian cancer risk was not associated with vitamin D intake from food or supplements or with predicted 25(OH)D levels. Our study does not strongly support a protective role for vitamin D in ovarian cancer risk.

[Vitamin D and breast cancer: physiopathology, biological and clinical implications]

There is a recent increase in interest of vitamin D and breast cancer, facing the number of publications on the subject. This increase have several reasons, on the one hand, vitamin D deficiency is more and more prevalent and, on the other hand, there are new data that highlights the extra-bone effects of vitamin D, especially in breast cancer, the vitamin D is involved in the breast cancer risk factor, the prognosis, and the interaction with breast cancer treatments. This combination between vitamin D deficiency and breast cancer is extremely usual, and combined with all cancer clinical parameters: the incidence, the tumour biology, the clinical presentation, the prognosis, and the antineoplastic treatment tolerance. This vitamin D deficiency is increased after adjuvant cancer treatments. And yet, this problem increases bone metabolism disruptions in breast cancer patients, inducing osteoporotic risk at long time, even though this population is curable. This problem is therefore serious in the adjuvant breast cancer treatment. Unfortunately, in this population, the current recommendations are clearly insufficient, and the current randomized clinical trial results would contribute to define the best way to correct the vitamin D deficiency, quickly and secure.

Molecular link between vitamin D and cancer prevention

The metabolite of vitamin D, 1α,25-dihydroxyvitamin D₃ (also known as calcitriol), is a biologically active molecule required to maintain the physiological functions of several target tissues in the human body from conception to adulthood. Its molecular mode of action ranges from immediate nongenomic responses to longer term mechanisms that exert persistent genomic effects. The genomic mechanisms of vitamin D action rely on cross talk between 1α,25-dihydroxyvitamin D₃ signaling pathways and that of other growth factors or hormones that collectively regulate cell proliferation, differentiation and cell survival. In vitro and in vivo studies demonstrate a role for vitamin D (calcitriol) in modulating cellular growth and development. Vitamin D (calcitriol) acts as an antiproliferative agent in many tissues and significantly slows malignant cellular growth. Moreover, epidemiological studies have suggested that ultraviolet-B exposure can help reduce cancer risk and prevalence, indicating a potential role for vitamin D as a feasible agent to prevent cancer incidence and recurrence. With the preventive potential of this biologically active agent, we suggest that countries where cancer is on the rise--yet where sunlight and, hence, vitamin D may be easily acquired--adopt awareness, education and implementation strategies to increase supplementation with vitamin D in all age groups as a preventive measure to reduce cancer risk and prevalence.

Vitamin D: Update 2013: From rickets prophylaxis to general preventive healthcare

Vitamin D has received a lot of attention recently as a result of a meteoric rise in the number of publications showing that vitamin D plays a crucial role in a plethora of physiological functions and associating vitamin D deficiency with many acute and chronic illnesses including disorders of calcium metabolism, autoimmune diseases, some cancers, type 2 diabetes mellitus, infectious diseases and cardiovascular disease. The recent data on vitamin D from experimental, ecological, case-control, retrospective and prospective observational studies, as well as smaller intervention studies, are significant and confirm the sunshine vitamin's essential role in a variety of physiological and preventative functions. The results of these studies justify the recommendation to improve the general vitamin D status in children and adults by means of a healthy approach to sunlight exposure, consumption of foods containing vitamin D and supplementation with vitamin D preparations. In general, closer attention should therefore be paid to vitamin D deficiency in medical and pharmaceutical practice than has been the case hitherto.

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.

Sunlight and Vitamin D: A global perspective for health

Vitamin D is the sunshine vitamin that has been produced on this earth for more than 500 million years. During exposure to sunlight 7-dehydrocholesterol in the skin absorbs UV B radiation and is converted to previtamin D3 which in turn isomerizes into vitamin D3. Previtamin D3 and vitamin D3 also absorb UV B radiation and are converted into a variety of photoproducts some of which have unique biologic properties. Sun induced vitamin D synthesis is greatly influenced by season, time of day, latitude, altitude, air pollution, skin pigmentation, sunscreen use, passing through glass and plastic, and aging. Vitamin D is metabolized sequentially in the liver and kidneys into 25-hydroxyvitamin D which is a major circulating form and 1,25-dihydroxyvitamin D which is the biologically active form respectively. 1,25-dihydroxyvitamin D plays an important role in regulating calcium and phosphate metabolism for maintenance of metabolic functions and for skeletal health. Most cells and organs in the body have a vitamin D receptor and many cells and organs are able to produce 1,25-dihydroxyvitamin D. As a result 1,25-dihydroxyvitamin D influences a large number of biologic pathways which may help explain association studies relating vitamin D deficiency and living at higher latitudes with increased risk for many chronic diseases including autoimmune diseases, some cancers, cardiovascular disease, infectious disease, schizophrenia and type 2 diabetes. A three-part strategy of increasing food fortification programs with vitamin D, sensible sun exposure recommendations and encouraging ingestion of a vitamin D supplement when needed should be implemented to prevent global vitamin D deficiency and its negative health consequences.

The VITamin D and OmegA-3 TriaL (VITAL): rationale and design of a large randomized controlled trial of vitamin D and marine omega-3 fatty acid supplements for the primary prevention of cancer and cardiovascular disease

Data from laboratory studies, observational research, and/or secondary prevention trials suggest that vitamin D and marine omega-3 fatty acids may reduce risk for cancer or cardiovascular disease (CVD), but primary prevention trials with adequate dosing in general populations (i.e., unselected for disease risk) are lacking. The ongoing VITamin D and OmegA-3 TriaL (VITAL) is a large randomized, double-blind, placebo-controlled, 2 x 2 factorial trial of vitamin D (in the form of vitamin D(3) [cholecalciferol], 2000 IU/day) and marine omega-3 fatty acid (Omacor fish oil, eicosapentaenoic acid [EPA]+docosahexaenoic acid [DHA], 1g/day) supplements in the primary prevention of cancer and CVD among a multi-ethnic population of 20,000 U.S. men aged ≥ 50 and women aged ≥ 55. The mean treatment period will be 5 years. Baseline blood samples will be collected in at least 16,000 participants, with follow-up blood collection in about 6000 participants. Yearly follow-up questionnaires will assess treatment compliance (plasma biomarker measures will also assess compliance in a random sample of participants), use of non-study drugs or supplements, occurrence of endpoints, and cancer and vascular risk factors. Self-reported endpoints will be confirmed by medical record review by physicians blinded to treatment assignment, and deaths will be ascertained through national registries and other sources. Ancillary studies will investigate whether these agents affect risk for diabetes and glucose intolerance; hypertension; cognitive decline; depression; osteoporosis and fracture; physical disability and falls; asthma and other respiratory diseases; infections; and rheumatoid arthritis, systemic lupus erythematosus, thyroid diseases, and other autoimmune disorders.

Availability of vitamin D photoconversion weighted UV radiation in southern South America

Ultraviolet radiation (UVR) plays a key role in several biological functions, including human health. Skin exposure to UVR is the main factor in vitamin D photoconversion. There is also evidence relating low levels of vitamin D with certain internal cancers, mainly colon, breast and prostate, as well as other diseases. Several epidemiological studies have shown an inverse relationship between the above-mentioned diseases and latitude, in accordance with the ultraviolet radiation latitudinal gradient. The aim of this study is to determine whether UV irradiance levels in the southern South America are sufficient to produce suitable levels of vitamin D year around. For this purpose, vitamin D photoconversion weighted-irradiance was analyzed between S.S. de Jujuy (24.17°S, 65.02°W) and Ushuaia (54° 50'S, 68° 18'W). In addition to irradiance, skin type and area of body exposed to sunlight are critical factors in vitamin D epidemiology. Due to a broad ethnic variability, it was assumed that the skin type in this region varies between II and V (from the most to the less sensitive). All sites except South Patagonia indicate that skin II under any condition of body area exposure and skin V when exposing head, hands, arms and legs, would produce suitable levels of vitamin D year round (except for some days in winter at North Patagonian sites). At South Patagonian sites, minimum healthy levels of vitamin D year round can be reached only by the more sensitive skin II type, if exposing head, hands, arms and legs, which is not a realistic scenario during winter. At these southern latitudes, healthy vitamin D levels would not be obtained between mid May and beginning of August if exposing only the head. Skin V with head exposure is the most critical situation; with the exception of the tropics, sun exposure would not produce suitable levels of vitamin D around winter, during a time period that varies with latitude. Analyzing the best exposure time during the day in order to obtain a suitable level of vitamin D without risk of sunburn, it was concluded that noon is best during winter, as determined previously. For skin type II when exposing head, exposure period in winter varies between 30 and 130 min, according to latitude, except for South Patagonian sites. During summer, noon seems to be a good time of day for short periods of exposure, while during leisure times, longer periods of exposure without risk of sunburn are possible at mid-morning and mid-afternoon. At 3 h from noon, solar zenith angles are almost the same for sites between the tropics and North Patagonia, and at 4 h from noon, for all sites. Then, in these cases, the necessary exposure periods varied slightly between sites, only due to meteorological differences.

An estimate of the global reduction in mortality rates through doubling vitamin D levels

BACKGROUND/OBJECTIVES

The goal of this work is to estimate the reduction in mortality rates for six geopolitical regions of the world under the assumption that serum 25-hydroxyvitamin D (25(OH)D) levels increase from 54 to 110 nmol/l.

SUBJECTS/METHODS

This study is based on interpretation of the journal literature relating to the effects of solar ultraviolet-B (UVB) and vitamin D in reducing the risk of disease and estimates of the serum 25(OH)D level-disease risk relations for cancer, cardiovascular disease (CVD) and respiratory infections. The vitamin D-sensitive diseases that account for more than half of global mortality rates are CVD, cancer, respiratory infections, respiratory diseases, tuberculosis and diabetes mellitus. Additional vitamin D-sensitive diseases and conditions that account for 2 to 3% of global mortality rates are Alzheimer's disease, falls, meningitis, Parkinson's disease, maternal sepsis, maternal hypertension (pre-eclampsia) and multiple sclerosis. Increasing serum 25(OH)D levels from 54 to 110 nmol/l would reduce the vitamin D-sensitive disease mortality rate by an estimated 20%.

RESULTS

The reduction in all-cause mortality rates range from 7.6% for African females to 17.3% for European females. Reductions for males average 0.6% lower than for females. The estimated increase in life expectancy is 2 years for all six regions.

CONCLUSIONS

Increasing serum 25(OH)D levels is the most cost-effective way to reduce global mortality rates, as the cost of vitamin D is very low and there are few adverse effects from oral intake and/or frequent moderate UVB irradiance with sufficient body surface area exposed.

Racial disparity in death from colorectal cancer: does vitamin D deficiency contribute?

BACKGROUND

The reasons blacks have higher mortality rates from colorectal cancer (CRC) than non-Hispanic whites are not fully understood. Blacks have higher rates of vitamin D deficiency than non-Hispanic whites, and vitamin D deficiency has been associated with CRC. The authors of this report investigated the association of vitamin D deficiency with excess risk for CRC mortality for blacks in the Third National Health and Nutrition Examination Survey (NHANES III) that was conducted from 1988 to 1994.

METHODS

The association between serum 25(OH)D levels and CRC mortality and its contribution to elevated risk among blacks were studied using baseline data from NHANES III and CRC mortality data through 2006 from the National Death Index. By using survival models, the adjusted risk of death from CRC for African Americans was examined with and without adjusting for vitamin D deficiency, which was defined as an 25(OH)D level <20 ng/dL.

RESULTS

Black race (hazard ratio [HR], 2.03; 95% confidence interval [95% CI], 1.04-3.95), age (HR, 1.12; 95% CI, 1.09-1.15), not having health insurance (HR, 2.45; 95% CI, 1.12-5.36), and a history of CRC (HR, 7.22; 95% CI, 2.12-24.6) predicted CRC mortality. When added to the model, vitamin D deficiency was associated significantly with CRC mortality (HR, 2.11; 95% CI, 1.11-4.00), and the effect of race was decreased (HR, 1.60; 95% CI, 0.87-2.93); the 40% attenuation was statistically significant (F(1) (,49) = 4.85; P = .03). Similar results were observed when participants who had a history of CRC were excluded from the analysis.

CONCLUSIONS

The current findings were consistent with the hypothesis that vitamin D deficiency contributes to excess African-American mortality from CRC. Cancer 2011.

Role of vitamin d in the prevention of pancreatic cancer

Pancreatic cancer is a malignancy of poor prognosis which is mostly diagnosed at advanced stages. Current treatment modalities are very limited creating great interest for novel preventive and therapeutic options. Vitamin D seems to have a protective effect against pancreatic cancer by participating in numerous proapoptotic, antiangiogenic, anti-inflammatory, prodifferentiating, and immunomodulating mechanisms. 25-hydroxyvitamin D [25(OH)D] serum concentrations are currently the best indicator of vitamin D status. There are three main sources of vitamin D: sun exposure, diet,and dietary supplements. Sun exposure has been associated with lower incidence of pancreatic cancer in ecological studies. Increased vitamin D levels seem to protect against pancreatic cancer, but caution is needed as excessive dietary intake may have opposite results. Future studies will verify the role of vitamin D in the prevention and therapy of pancreatic cancer and will lead to guidelines on adequate sun exposure and vitamin D dietary intake.

Vitamin d and pancreatic cancer-an update

The non-classical actions of vitamin D, namely anti-proliferation, pro-differentiation, immune function modulation, and anti-inflammation, have received great attention during the past decade, in particular, the potential of vitamin D analogs alone or in combination with other anticancer agents for the treatment of a variety of cancers. The association between vitamin D status and the higher incidence of many forms of cancer has suggested that vitamin D may play a role in the etiology of these types of cancer. Although it is still controversial whether this association exists for pancreatic cancer, biochemical evidence clearly indicates pancreatic cancer cells are responsive to the inhibitory effect of vitamin D and its analogs. In this review, we discuss briefly the origin and current therapy of pancreatic cancer, the history, source, metabolism and functions of vitamin D, the recent progress in the epidemiological studies of sunlight, and vitamin D status, and biochemical studies of vitamin D analogs in the prevention and treatment of pancreatic cancer.

Association of serum 25-hydroxyvitamin D with the risk of death in a general older population in Finland

PURPOSE

To investigate the association between serum 25-hydroxyvitamin D [25(OH)D] concentration, a marker of vitamin D status, and risk of all-cause and cardiovascular mortality in a general older population with relatively low average serum 25(OH)D concentrations.

METHODS

The study population included 552 men and 584 women aged 53-73 years who were free of CVD and cancer at baseline in 1998-2001 from the prospective, population-based Kuopio Ischaemic Heart Disease Risk Factor (KIHD) Study. Deaths were ascertained by a computer linkage to the national cause of death register. All deaths that occurred from the study entry to December 31, 2008, were included. Cox proportional hazards regression models were used to analyze the association between serum 25(OH)D and risk of death.

RESULTS

The mean serum 25(OH)D concentration was 43.7 nmol/L (SD 17.8), with a strong seasonal variation. During the average follow-up of 9.1 years, 87 participants died, 35 from cardiovascular disease (CVD). After multivariable-adjustments, the hazard ratios (HR) for all cause death in the tertiles of serum 25(OH)D were 1, 1.68 (95% CI: 0.92, 3.07) and 2.06 (95% CI: 1.12, 3.80), p for trend = 0.02.

CONCLUSIONS

Our study supports the accumulating evidence from epidemiological studies that vitamin D deficiency is associated with increased risk of death. Large-scale primary prevention trials with vitamin D supplementation are warranted.

Prevention of colorectal cancer with vitamin D

The fact that colorectal cancer (CRC) is the second leading cause of cancer mortality in the United States emphasizes the need for more effective preventive and therapeutic modalities. There is growing evidence that vitamin D may reduce the incidence of CRC. Results of epidemiologic, in vitro, in vivo animal and clinical studies suggest that a low serum vitamin D level may be a serious risk factor for CRC and a high serum vitamin D level may reduce the risk of CRC. On a molecular level, vitamin D suppresses CRC development and growth by affecting cell proliferation, differentiation, apoptosis, and angiogenesis. Vitamin D insufficiency and CRC are common in the elderly population. Vitamin D insufficiency is simple to screen for and treatable with vitamin D supplementation. Serum 25-hydroxyvitamin D (calcidiol) is the best measure of vitamin D status and should be checked routinely for individuals with risk factors for CRC. Maintaining serum concentrations of calcidiol above 32 ng/ml (80 nmol/l) in individuals whose serum calcidiol level is low may help prevent CRC as well as osteoporosis, fractures, infections, and cardiovascular disease. Daily calcidiol intake of 1000 International Units can increase serum vitamin D to sufficient levels in most elderly persons and, based on available data, may substantially lower the incidence of CRC with minimal risks.

A systematic literature review of vitamin D and ovarian cancer

OBJECTIVE

We assessed the evidence supporting a reduction in risk for ovarian cancer occurrence or mortality with greater vitamin D exposures.

STUDY DESIGN

This review followed standard guidelines for systematic literature reviews. The diverse study designs precluded a quantitative metaanalysis. Therefore studies are summarized via tables and abstracted information.

RESULTS

Approximately half of the ecologic and case-control studies reported reductions in incidence or mortality with increasing geographic latitude, solar radiation levels, or dietary/supplement consumption of vitamin D, whereas the other half reported null associations. The cohort studies reported no overall risk reduction with increasing dietary/supplement consumption of vitamin D or with plasma levels of vitamin D prior to diagnosis, although vitamin D intakes were relatively low in all studies.

CONCLUSION

There is no consistent or strong evidence to support the claim made in numerous review articles that vitamin D exposures reduce the risk for ovarian cancer occurrence or mortality.

Epidemiology of vitamin D and colorectal cancer: casual or causal link?

INTRODUCTION

Since Garland and Garland hypothesized that better vitamin D status lowered risk of colorectal cancer in 1980, the relation between vitamin D status and colorectal cancer risk has been investigated in epidemiologic studies. These studies are reviewed.

MATERIALS AND METHODS

Various approaches have been used to estimate vitamin D status, including direct measures of circulating 25(OH)vitamin D levels, surrogates or determinants of vitamin D (including region of residence, intake, and sun exposure estimates, or a combination of these). These measures of vitamin D status have been studied in relation to colorectal adenoma, cancer incidence and mortality.

RESULTS

In general, all lines of inquiry from observational studies indicate that an association between better vitamin D status and lower colorectal cancer risk exists. While most of the studies have examined vitamin D status in relation to risk of cancer, some evidence suggests that vitamin D may be additionally important for colorectal cancer progression and mortality.

DISCUSSION

Although confounding factors cannot be entirely excluded, the consistency of the association using various approaches to measure vitamin D, for diverse endpoints and in diverse populations shows high consistency and is suggestive of a causal association. Thus, improving vitamin D status could be potentially beneficial against colorectal cancer incidence and mortality.

Circulating 25-hydroxyvitamin D and the risk of rarer cancers: Design and methods of the Cohort Consortium Vitamin D Pooling Project of Rarer Cancers

The Cohort Consortium Vitamin D Pooling Project of Rarer Cancers (VDPP), a consortium of 10 prospective cohort studies from the United States, Finland, and China, was formed to examine the associations between circulating 25-hydroxyvitamin D (25(OH)D) concentrations and the risk of rarer cancers. Cases (total n = 5,491) included incident primary endometrial (n = 830), kidney (n = 775), ovarian (n = 516), pancreatic (n = 952), and upper gastrointestinal tract (n = 1,065) cancers and non-Hodgkin lymphoma (n = 1,353) diagnosed in the participating cohorts. At least 1 control was matched to each case on age, date of blood collection (1974-2006), sex, and race/ethnicity (n = 6,714). Covariate data were obtained from each cohort in a standardized manner. The majority of the serum or plasma samples were assayed in a central laboratory using a direct, competitive chemiluminescence immunoassay on the DiaSorin LIAISON platform (DiaSorin, Inc., Stillwater, Minnesota). Masked quality control samples included serum standards from the US National Institute of Standards and Technology. Conditional logistic regression analyses were conducted using clinically defined cutpoints, with 50-<75 nmol/L as the reference category. Meta-analyses were also conducted using inverse-variance weights in random-effects models. This consortium approach permits estimation of the association between 25(OH)D and several rarer cancers with high accuracy and precision across a wide range of 25(OH)D concentrations.

Circulating 25-hydroxyvitamin D and risk of pancreatic cancer: Cohort Consortium Vitamin D Pooling Project of Rarer Cancers

Results from epidemiologic studies examining pancreatic cancer risk and vitamin D intake or 25-hydroxyvitamin D (25(OH)D) concentrations (the best indicator of vitamin D derived from diet and sun) have been inconsistent. Therefore, the authors conducted a pooled nested case-control study of participants from 8 cohorts within the Cohort Consortium Vitamin D Pooling Project of Rarer Cancers (VDPP) (1974-2006) to evaluate whether prediagnostic circulating 25(OH)D concentrations were associated with the development of pancreatic cancer. In total, 952 incident pancreatic adenocarcinoma cases occurred among participants (median follow-up, 6.5 years). Controls (n = 1,333) were matched to each case by cohort, age, sex, race/ethnicity, date of blood draw, and follow-up time. Conditional logistic regression analysis was used to calculate smoking-, body mass index-, and diabetes-adjusted odds ratios and 95% confidence intervals for pancreatic cancer. Clinically relevant 25(OH)D cutpoints were compared with a referent category of 50-<75 nmol/L. No significant associations were observed for participants with lower 25(OH)D status. However, a high 25(OH)D concentration (> or =100 nmol/L) was associated with a statistically significant 2-fold increase in pancreatic cancer risk overall (odds ratio = 2.12, 95% confidence interval: 1.23, 3.64). Given this result, recommendations to increase vitamin D concentrations in healthy persons for the prevention of cancer should be carefully considered.

Ultraviolet B irradiance and vitamin D status are inversely associated with incidence rates of pancreatic cancer worldwide

OBJECTIVES

To determine if an inverse association exits between latitude, ultraviolet B (UVB) irradiance and incidence rates of pancreatic cancer worldwide.

METHODS

Multiple linear regression was used to investigate the relationship and between UVB irradiance incidence rates of pancreatic cancer and while controlling for cigarette, alcohol and sugar consumption, and proportion overweight. Serum 25-hydroxyvitamin D [25(OH)D] levels were estimated, and their association with incidence rates also was analyzed.

RESULTS

Incidence rates were higher at higher latitudes (R2 for latitude for men, 0.51; P < 0.001; R2 for latitude for women, 0.32; P < 0.001). Ultraviolet B irradiance also was independently inversely associated with incidence in men (P < 0.01) and women (P = 0.02). Alcohol (P < 0.0001) and cigarette (P < or = 0.01) consumption were positively associated with incidence in men (R2 for overall model for men, 0.76; P < 0.0001). Alcohol (P < 0.0001) and sugar (P = 0.001) consumption were positively associated with incidence rates in women (R2 for overall model for women, 0.64; P < 0.0001). Incidence rates were half as high in countries with estimated serum 25(OH)D >30 ng/mL (75 nmol/L) than in those with < or =30 ng/mL.

CONCLUSIONS

Countries with lower UVB irradiance had higher incidence rates of pancreatic cancer in both hemispheres, with occasional exceptions.

Predicted vitamin D status and pancreatic cancer risk in two prospective cohort studies

Background:

Studies evaluating vitamin D status in relation to pancreatic cancer risk have yielded inconsistent results.

Methods:

We prospectively followed 118 597 participants in the Nurses' Health Study and Health Professionals Follow-up Study from 1986 to 2006. We calculated a 25-hydroxyvitamin D (25(OH)D) score from known predictors of vitamin D status for each individual and then examined the predicted 25(OH)D levels in relation to pancreatic cancer risk. Relative risks (RRs) and 95% confidence intervals (95% CIs) were estimated using Cox proportional hazards models adjusted for age, sex, race, height, smoking, and diabetes. We then further adjusted for body mass index (BMI) and physical activity in a sensitivity analysis.

Results:

During 20 years of follow-up, we identified 575 incident pancreatic cancer cases. Higher 25(OH)D score was associated with a significant reduction in pancreatic cancer risk; compared with the lowest quintile, participants in the highest quintile of 25(OH)D score had an adjusted RR of 0.65 (95% CI=0.50–0.86; P_trend=0.001). Results were similar when we further adjusted for BMI and physical activity.

Conclusions:

Higher 25(OH)D score was associated with a lower risk of pancreatic cancer in these two prospective cohort studies.