Plasma 25-hydroxyvitamin D and premenopausal breast cancer risk in a German case-control study

Low Serum Vitamin D Associated With Increased Tumor Size and Higher Grade in Premenopausal Canadian Women With Breast Cancer

INTRODUCTION

This study investigated the association of Vitamin D with tumor characteristics in pre and postmenopausal women.

PATIENTS AND METHODS

A prospective cohort of 476 women with incident stage I-III breast cancer (BC) in Alberta, Canada comprised the study population. Vitamin D was measured as 25(OH)D concentration in serum samples collected at diagnosis (presurgery and prior to treatment initiation). Tumor characteristics including size, grade, receptor status, stage and nodal status were evaluated in regression models for association with Vitamin D and measured cytokines in models adjusted for menopausal status.

RESULTS

More than half of the women were diagnosed as stage I and Luminal A/B, most were postmenopausal, had sufficient Vitamin D levels, and were 56.6 years of age on average. Higher vitamin D levels were associated with decreased tumor size for all women with larger effect seen in premenopausal status. Insufficient vitamin D levels were significantly associated with increased risk of higher grade, but only in premenopausal women. Elevated human granulocyte macrophage colony-stimulating factor was an independent risk factor associated with increased risk of higher-grade tumors.

CONCLUSION

Women with sufficient Vitamin D levels at BC diagnosis had smaller and lower grade tumors compared to women with insufficient vitamin D, especially among premenopausal women. Maintaining adequate vitamin D levels in premenopausal women could improve prognostically important BC characteristics at diagnosis.

FokI polymorphism of Vitamin D receptor gene and deficiency of serum Vitamin D increases the risk of breast cancer in North Indian women

INTRODUCTION

Breast cancer is a leading cause of cancer morbidity and mortality in females. Decreased availability of Vitamin D within breast cells, contributed by deficiency of serum Vitamin D and polymorphisms of Vitamin D receptor genes are possible risk factors for breast cancer.

OBJECTIVES

To study the association of FokI polymorphism of the Vitamin D Receptor gene with breast cancer in females and to study the levels of Vitamin D in breast cancer patients.

MATERIALS AND METHODS

VDR gene FokI genotyping was done by PCR-RFLP method and levels of serum Vitamin D were estimated by ELISA. Statistical analysis was done with SPSS v.21.

RESULTS

Serum Vitamin D was significantly lower in newly diagnosed breast cancer patients than in healthy controls (P = 0.016). Females with serum Vitamin D levels in the highest quartile have a lesser risk of breast cancer than those with serum Vitamin D levels in the lowest quartile (O. R = 2.4421, C.I = 1.09-5.45, P = 0.029). The risk of developing breast cancer is higher in women with the polymorphic T allele for VDR FokI genotype (CT/TT) than those homozygous for the wild C allele (CC). (O.R. = 4.295, C.I. = 2.2110-8.3451, p-value = <0.0001). Levels of serum Vitamin D were significantly higher (p < 0.001) in ER + patients and significantly low in those presenting with higher stages of cancer (p = 0.009).

CONCLUSIONS

FokI polymorphism of VDR gene and low circulating Vitamin D levels increase the risk of developing breast cancer in North Indian females. Serum Vitamin D can be used as a prognostic factor.

Dietary phytochemicals/nutrients as promising protector of breast cancer development: a comprehensive analysis

Genetic change, particularly epigenetic alteration, is one of the imperative factors for sporadic breast cancer development in the worldwide population of women. The DNA methylation process is essential and natural for human cellular renewal and tissue homeostasis, but its dysregulation contributes to many pathological changes, including breast tumorigenesis. Chemopreventive agents mainly protect the abnormal DNA methylation either by hindering the division of pre-malignant cells or looming the DNA damage, which leads to malignancy. The present review article is about understanding the potential role of dietary phytochemicals in breast cancer prevention. Accordingly, a literature search of the published article until August 2021 has been performed. Further, we have investigated the binding affinity of different phytochemicals isolated from diverse dietary sources against the various oncogenic proteins related to breast cancer initiation to understand the common target(s) in breast cancer prevention mechanisms. Various small phytochemicals, especially dietary phytochemicals including sulforaphane, mahanine, resveratrol, linolenic acid, diallyl sulfide, benzyl/phenethyl isothiocyanate, etc. are being investigated as the chemopreventive agent to manage breast cancer development, and some of them have shown promising outcomes in the cited research. In this present review, we discuss the recent advancement in acceptance of such types of potential dietary phytochemicals as a chemopreventive agent against breast cancer development and their inner lining mechanism. The critical clinical trials and cohort studies have also been considered to understand the progress in contemporary perspectives.

Spline Analysis of Biomarker Data Pooled from Multiple Matched/Nested Case-Control Studies

Pooling biomarker data across multiple studies enables researchers to obtain precise estimates of the association between biomarker measurements and disease risks due to increased sample sizes. However, biomarker measurements often vary significantly across different assays and laboratories; therefore, calibration of the local laboratory measurements to a reference laboratory is necessary before pooling data. We propose two methods for estimating the dose-response curves that allow for a nonlinear association between the continuous biomarker measurements and log relative risk in pooling projects of matched/nested case-control studies. Our methods are based on full calibration and internalized calibration methods. The full calibration method uses calibrated biomarker measurements for all subjects, even for people with reference laboratory measurements, while the internalized calibration method uses the reference laboratory measurements when available and otherwise uses the calibrated biomarker measurements. We conducted simulation studies to compare these methods, as well as a naive method, where data are pooled without calibration. Our simulation and theoretical results suggest that, in estimating the dose-response curves for biomarker-disease relationships, the internalized and full calibration methods perform substantially better than the naive method, and the full calibration approach is the preferred method for calibrating biomarker measurements. We apply our methods in a pooling project of nested case-control studies to estimate the association of circulating Vitamin D levels with risk of colorectal cancer.

The African Female Breast Cancer Epidemiology Study Protocol

Breast cancer is now the commonest cancer in most sub-Saharan African countries. Few studies of the epidemiology and genomics of breast cancer and its molecular subtypes in these countries have been done. The African Female Breast Cancer Epidemiology (AFBRECANE) study, a part of the Human Heredity and Health in Africa (H3Africa) initiative, is designed to study the genomics and epidemiology of breast cancer and its molecular subtypes in Nigerian women. We link recruitment of breast cancer cases at study sites with population-based cancer registries activities to enable ascertainment of the incidence of breast cancer and its molecular subtypes. We use centralized laboratory processing to characterize the histopathological and molecular diagnosis of breast cancer and its subtypes using multiple technologies. By combining genome-wide association study (GWAS) data from this study with that generated from 12,000 women participating in our prospective cohort study of cervical cancer, we conduct GWAS of breast cancer in an entirely indigenous African population. We test associations between dietary intakes and breast cancer and focus on vitamin D which we measure using dietary intakes, serum vitamin D, and Mendelian randomization. This paper describes the AFBRECANE project, its design, objectives and anticipated contributions to knowledge and understanding of breast cancer.

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 Histological Features of Breast Cancer: Preliminary Data from an Observational Retrospective Italian Study

Background: Vitamin D (vitD) may be involved in different extraskeletal conditions as well as skeletal muscle diseases. It has been hypothesized that, at least in part, a low level of vitD could contribute to facilitating cancer development. Breast cancer (BC) seems to be associated with low levels of vitD. Materials and methods: This was an observational retrospective evaluation of 87 women (mean age: 54 ± 12 years old) who underwent surgery for the treatment of BC. Our main purpose was to correlate the types of BC and the levels of vitD. Results: A positive significant correlation (R > 0.7) was found between non-invasive carcinoma in situ and 25(OH)D levels and age (R = 0.82, p < 0.05). A positive, but nonsignificant, correlation was reported between invasive ductal carcinoma and 25(OH)D and age (R = 0.45, p > 0.05). A negative but nonsignificant correlation was found between invasive lobular carcinoma and 25(OH)D and age (R = 0.24, p > 0.05). Discussion and Conclusions: We did not find a significant relationship between vitD and BC subtypes. Considering the positive significant correlation between vitD levels and age for in situ BC, although preliminary, our results seem to suggest a possible role of vitD in in situ BC. However, these findings need to be confirmed in larger studies.

Vitamin D-Mediated Anti-cancer Activity Involves Iron Homeostatic Balance Disruption and Oxidative Stress Induction in Breast Cancer

Background: Vitamin D deficiency associates with high risk of breast cancer (BRCA) and increased cellular iron. Vitamin D exerts some of its anti-cancer effects by regulating the expression of key iron regulatory genes (IRGs). The association between vitamin D and cellular iron content in BRCA remains ambiguous. Herein, we addressed whether vitamin D signaling exerts a role in cellular iron homeostasis thereby affecting survival of breast cancer cells. Methods: Expression profile of IRGs in vitamin D-treated breast cancer cells was analyzed using publicly available transcriptomic datasets. After treatment of BRCA cell lines MCF-7 and MDA-MB-231 with the active form of vitamin D, labile iron content, IRGs protein levels, oxidative stress, and cell survival were evaluated. Results: Bioinformatics analysis revealed several IRGs as well as cellular stress relates genes were differentially expressed in BRCA cells. Vitamin D treatment resulted in cellular iron depletion and differentially affected the expression of key IRGs protein levels. Vitamin D treatment exerted oxidative stress induction and alteration in the cellular redox balance by increasing the synthesis of key stress-related markers. Collectively, these effects resulted in a significant decrease in BRCA cell survival. Conclusion: These findings suggest that vitamin D disrupts cellular iron homeostasis leading to oxidative stress induction and cell death.

The Influence of Vitamin D on Mammographic Density: Results from CALGB 70806 (Alliance) a Randomized Clinical Trial

Current therapies for breast cancer prevention only prevent estrogen receptor positive (ER+) disease and toxicity limits use of these agents. Vitamin D is a potential prevention therapy for both ER+ and ER- disease and is safe with few side effects. This study evaluates the effect of 1-year of vitamin D supplementation on mammographic density (MD), a biomarker of breast cancer risk in a multicenter randomized controlled trial. Premenopausal women with ≥25% MD and no history of cancer were randomly assigned to 2,000 international units (IU) of vitamin D or placebo orally daily for 1 year. Change in percent MD was evaluated using Cumulus software after all participants completed treatment. Three hundred women enrolled between January 2011 and December 2013 with a mean age of 43 and diverse ethnicity [14% Hispanic, 12% African American (AA)]. Supplementation significantly increased vitamin D levels compared with placebo (14.5 ng/mL vs. -1.6 ng/mL; P < 0.0001) with all participants on the vitamin D arm achieving vitamin D sufficiency at 12 months. Vitamin D was safe and well tolerated. After adjustment for baseline MD, the mean between-arm difference (vitamin D vs. placebo) at 1 year was -0.75 (-0.26, 1.76; P = 0.56). A greater effect was seen for women with ≥50% MD and AA women, although neither reached significance. This randomized controlled trial demonstrated significant improvement in vitamin D levels with 2,000 IU for 1 year, with 100% of supplemented women achieving sufficiency. However, a null effect was seen regarding change in MD for premenopausal women (the primary outcome of the study). PREVENTION RELEVANCE: Current therapies for breast cancer prevention only prevent estrogen receptor positive (ER+) disease and are underutilized due to toxicity and side effects. Vitamin D is a potential prevention therapy for both ER+ and ER- disease and is safe with few side effects.

Association of vitamin D deficiency and insulin resistance with breast cancer in premenopausal Algerian women: A cross-sectional study

BACKGROUND

Low 25(OH)D levels are mainly related to breast cancer (BC) risk in postmenopausal women, while the impact of insulin resistance (IR) on BC prognosis is controversial.

OBJECTIVE

Considering the high prevalence of BC in younger Algerian women, this cross-sectional study analyzed whether vitamin D status and IR are biomarkers for breast tumor status in premenopausal women.

METHODS

In 96 women (mean age, 40.96±0.65years) newly diagnosed with BC, tumor status was determined immunohistochemically, classified by molecular subtype, then correlated with body-mass index, total plasma 25(OH)D, insulin and glucose levels and HOMA-IR, using chi², Student t, Spearman and ANOVA tests and multivariate logistic regression.

RESULTS

66 of the 98 patients (68.75%) showed vitamin D deficiency (9.74ng/mL). Overweight and obese patients with HOMA-IR >2.5, positive for HER2 and with high Ki-67 index had the most severe vitamin D deficiency. There was a significant association between vitamin D deficiency, high Ki-67 index (OR, 14.55; 95% CI, 3.43-82.59; p=0.00078) and IR (OR, 4.99; 95% CI, 1.27-24.47; p=0.03), and between IR and HER2-positivity (OR, 3.23; 95% CI, 1.05-10.56; p=0.04).

CONCLUSIONS

Vitamin D deficiency and IR are potential biomarkers for poorer prognosis in BC patients, independently of and/or synergically with high Ki-67 index and HER2-positivity in premenopausal overweight or obese women. The potential relationship of vitamin D receptor gene expression with breast cancer survival in Algerian patients will be investigated in a large cohort.

Circulating Vitamin D Levels and DNA Repair Capacity in Four Molecular Subtypes of Women with Breast Cancer

Vitamin D regulates estrogen synthesis among other mechanisms involved in breast cancer (BC) development; however, no evidence has been found regarding its relationship with DNA repair capacity (DRC). Therefore, the objective of this study was to elucidate whether DRC levels are linked with plasma 25(OH)D levels. BC cases and controls were selected from our BC cohort. DRC levels were assessed in lymphocytes through the host-cell reactivation assay. 25(OH)D levels were measured using the UniCel DxI 600 Access Immunoassay System. BC cases (n = 91) showed higher 25(OH)D levels than the controls (n = 92) (p = 0.001). When stratifying BC cases and controls into low and high DRC categories, BC cases with low DRC (n = 74) had the highest 25(OH)D levels (p = 0.0001). A positive correlation between 25(OH)D and DRC levels was found for the controls (r = 0.215, p = 0.043) while a negative correlation was found for BC cases (r = −0.236, p = 0.026). Significant differences in 25(OH)D levels were observed when stratifying by molecular subtypes (p = 0.0025). Our study provides evidence of a link between 25(OH)D and DRC in BC along with a description of to how 25(OH)D levels vary across subtypes. The positive correlation observed in the control group suggests that 25(OH)D contributes differently to DRC levels once the malignancy is developed.

Clinical significance of serum 25 hydroxyvitamin D in breast cancer: An Indian scenario

Recent evidences suggest a protective mechanism of vitamin D signaling against breast cancer by the autocrine/paracrine manner and may modestly reduce the risk of breast cancer. Despite lots of sunshine, vitamin D deficiency is widespread in India. Moreover, there are limited studies from Indian population regarding circulatory 25(OH) D and breast cancer risk. Thus, the aim of the present study is to investigate circulatory 25(OH) D in relation to breast cancer risk and its association with various clinico-pathological parameters from Indian population. Total 297 subjects, comprising of 157 controls and 140 breast cancer patients were enrolled for the study. Circulatory 25(OH) D was analyzed by HPLC. Statistical analysis was carried out by SPSS software version 15. Further, subjects were categorized into severe, moderate, mild vitamin D deficiency and sufficiency. The prevalence of severe and moderate 25(OH) D deficiency was higher in breast cancer patients as compared to controls. Mean values of 25(OH) D were lower in breast cancer patients as compared to controls in mild, moderate and severe deficient groups (p = 0.07, p = 0.003 and p = 0.001). Moreover, 25(OH) D was significantly lower in postmenopausal breast cancer patients as compared to premenopausal breast cancer patients, particularly in severe deficient group. The levels of 25(OH) D were lower in ER and PR negative receptor status as compared to the positive receptor in severe deficient category (p = 0.06 and p = 0.09 respectively). Whereas, the mean values of 25(OH) D were lower in HER 2 negative receptor status as compared to positive receptor status in the moderate deficient category (p = 0.09). Further, severe deficient group showed significantly lower levels of 25(OH) Din TNBC as compared to luminal A subtype (p = 0.01). Thus, Results indicate that 25(OH) D deficiency might be associated with increased risk of breast cancer. Moreover, severe 25(OH) D deficiency is associated with aggressive behavior of breast cancer.

A multicenter case control study of association of vitamin D with breast cancer among women in Karachi, Pakistan

Background

The prevalence of vitamin D inadequacy and breast cancer are both high among women living in Karachi, Pakistan.

Methods

A matched case control study was conducted in two hospitals of Karachi, Pakistan to evaluate the association of vitamin D (serum 25-hydroxyvitamin D) concentrations, vitamin D supplementation and sun exposure with breast cancer among Pakistani women. A total of 411 newly diagnosed histologically confirmed primary breast cancer cases were enrolled and 784 controls, free of breast and any other cancers, were matched by age (year of birth ± 5 years), residence in the same geographic area and study site. Information was collected on sociodemographic history, history of vitamin D supplementation, past medical and obstetrical history, family history of breast cancer, sun exposure history, histopathology reports and anthropometric measurement and venous blood was collected to measure serum 25-hydroxyvitamin D (25(OH)D) concentration.

Results

Compared to patients with sufficient serum vitamin D (>30 ng/ml), women with serum vitamin D deficiency (<20ng/ml), had a higher risk of breast cancer (OR = 1.65, 95%CI: 1.10, 2.50). Women with history of vitamin D supplementation one year prior to enrollment, had significant protective effect against breast cancer (OR = 0.32, 95% CI: 0.24, 0.43).

Conclusions and recommendation

Serum vitamin D deficiency was associated with increased risk of breast cancer, while vitamin D supplementation was associated with decreased risk of breast cancer. In Pakistani women, where vitamin D deficiency is common, raising and maintaining serum vitamin D at population level is a safe and affordable strategy. It may play a role in reducing the incidence of both vitamin D deficiency and breast cancer, particularly among poor women where the breast cancer mortality is highest due to limited resources for early detection, diagnosis, and treatment. The effects of vitamin D with regard to breast cancer risk in Karachi Pakistan should be further evaluated.

Vitamin D intake, blood vitamin D levels, and the risk of breast cancer: a dose-response meta-analysis of observational studies

Epidemiological studies have indicated that blood vitamin D levels are linked to cancer. Here we conducted a dose-response meta-analysis based on published observational studies to evaluate the association of vitamin D intake and blood vitamin D levels with breast cancer susceptibility. PubMed, EMBASE, and Web of Science databases were searched up to January 2019. The pooled odds ratio (OR) and 95% confidence intervals (CIs) were extracted to estimate the risk. We identified 70 relevant studies on blood vitamin D levels (50 studies) and vitamin D intake (20 studies), respectively. Linear and nonlinear trend analyses were performed and showed that an increase in blood vitamin D levels by 5 nmol/l was associated with a 6% decrease in breast cancer risk (OR = 0.94, 95% CI = 0.93-0.96). Similar results were obtained for premenopausal (OR = 0.96, 95% CI = 0.93-0.99) and postmenopausal women (OR = 0.96, 95% CI = 0.94-0.98). The pooled OR of breast cancer risk for a 400IU/day increase in vitamin D intake was 0.97 (95% CI = 0.92-1.02). In conclusion, we found that breast cancer risk was inversely related to blood vitamin D levels; however, no significant association was observed in vitamin D intake.

Histone deacetylase activity and vitamin D-dependent gene expressions in relation to sulforaphane in human breast cancer cells

It is relatively unknown how dietary bioactive compound, sulforaphane, in partnership with active vitamin D3, 1,25(OH)2D3, regulates vitamin D-dependent gene expression in breast cancer (BC). It has been suggested that the combination of various bioactive components with vitamins is crucial for their potential anticancer activities.

METHODS

This study employed a combinatorial chemopreventive strategy to investigate the impact of dietary histone deacetylase (HDAC) inhibitor, that is, sulforaphane on chromatin remodeling in BC. To understand the epigenetics-mediated changes in gene expression, MCF-7 cells were exposed for 24 hr to 1,25(OH)2D3 (100nM) either alone or in combination with L-sulforaphane and TSA (20μM and 1μM, respectively) at 70% confluency. Changes in VDR, CYP24A1, CYP27B1, and TRPV6 gene expressions were quantified using real-time PCR-based assays. HDAC inhibitor activity was assessed using HDAC I/II assay that measured global changes in acetylation status. Cell viability was measured using ATP and MT assays. Clonogenic and migration assays were performed to analyze the ability of single cells to grow into colonies and % closure (migration ability) upon treatments, respectively. Results were expressed as ΔCT ± standard error of means (SEM) from One-way ANOVA analyses for mRNA expressions and mean ± SEM for all other assays.

RESULTS

In MCF-7 cells, treatment with 1,25(OH)2D3 tended to decrease VDR (13 ± 0.4) and CYP27B1 (12 ± 0.96), while significantly increased TRPV6 (p = .02, 14 ± 0.1) and CYP24A1 (p < .0001, 0.38 ± 0.12) expression. D alone and D + TSA group had the opposite effects on HDAC inhibition from SFN alone, D + SFN, and TSA alone. The clonogenic assay showed a significant decrease in colony formation with no colonies for D + TSA (p < .03) and TSA alone groups (p < .03). Cell viability tended to decrease with D alone and in combination with TSA.

CONCLUSION

These data suggest that the effects of 1,25(OH)2D3 and sulforaphane are selective and gene-specific in MCF-7 cells.

PRACTICAL APPLICATIONS

Breast cancer (BC) affects a large number of the U.S. population each year. Like most cancers, nutrition does play a role in the prevention of BC. However, dietary advice that includes reducing alcohol intake, red meat, and saturated fat consumption, while increasing the intake of heart-healthy fats, dietary fiber, and lean protein, etc., is difficult to apply to all cancers from a preventative standpoint. Vitamin D has been implicated in BC, mostly as a protective factor, with mixed findings. This research focuses on the role of vitamin D as a protective intervention in human BC, along with a dietary bioactive compound-sulforaphane. The idea is to combine the known benefits of a micronutrient with potential benefits of the bioactive compound to establish a stronger intervention against BC progression, irrespective of the subtype.

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

CONTEXT

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

OBJECTIVES

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

DATA SOURCES AND EXTRACTION

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

DATA ANALYSIS

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

CONCLUSIONS

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

The Association of a Breast Cancer Diagnosis With Serum 25-Hydroxyvitamin D Concentration Over Time

Prospective and retrospective studies of vitamin D levels and breast cancer have produced discrepant results. This may be due to variations in serum 25-hydroxyvitamin D (25(OH)D) concentrations over time, including systematic changes after breast cancer diagnosis. We measured total serum 25(OH)D levels in participants from the Sister Study, a US cohort study of sisters of breast cancer patients, who provided samples at baseline (2003-2009) and 4-10 years later (2013-2015). This included 827 women with an intervening breast cancer and 771 women without one. Although 25(OH)D levels were modestly correlated over time (R = 0.42), 25(OH)D concentrations increased in both groups, with larger increases among cases (averaging 31.6 ng/mL at baseline and 43.5 ng/mL at follow-up) than among controls (32.3 ng/mL at baseline, 40.4 ng/mL at follow-up). Consequently, the estimated association between 25(OH)D and breast cancer depended on whether baseline measurements (per 10-ng/mL increase, odds ratio = 0.87, 95% confidence interval: 0.78, 0.98) or measurements from the second blood draw (per 10-ng/mL increase, odds ratio = 1.17, 95% confidence interval: 1.08, 1.26) were used. Concentrations were related to regular use (≥4 times/week) of vitamin D supplements, which became more common over time; increases in regular use were greater in cases (from 56% to 84%) than in controls (from 56% to 77%). Our results do not explain previously observed differences between retrospective and prospective studies, but they do demonstrate how reverse causation and temporal trends in exposure can distort inference.

Breast cancer risk markedly lower with serum 25-hydroxyvitamin D concentrations ≥60 vs <20 ng/ml (150 vs 50 nmol/L): Pooled analysis of two randomized trials and a prospective cohort

Background

While numerous epidemiologic studies have found an association between higher serum 25-hydroxyvitamin D [25(OH)D] concentrations and lower breast cancer risk, few have assessed this association for concentrations >40 ng/ml.

Objective

To investigate the relationship between 25(OH)D concentration and breast cancer risk across a broad range of 25(OH)D concentrations among women aged 55 years and older.

Methods

Analyses used pooled data from two randomized clinical trials (N = 1129, N = 2196) and a prospective cohort (N = 1713) to examine a broad range of 25(OH)D concentrations. The outcome was diagnosis of breast cancer during the observation periods (median: 4.0 years). Three analyses were conducted: 1) Incidence rates were compared according to 25(OH)D concentration from <20 to ≥60 ng/ml (<50 to ≥150 nmol/L), 2) Kaplan-Meier plots were developed and 3) multivariate Cox regression was used to examine the association between 25(OH)D and breast cancer risk using multiple 25(OH)D measurements.

Results

Within the pooled cohort (N = 5038), 77 women were diagnosed with breast cancer (age-adjusted incidence: 512 cases per 100,000 person-years). Results were similar for the three analyses. First, comparing incidence rates, there was an 82% lower incidence rate of breast cancer for women with 25(OH)D concentrations ≥60 vs <20 ng/ml (Rate Ratio = 0.18, P = 0.006). Second, Kaplan-Meier curves for concentrations of <20, 20–39, 40–59 and ≥60 ng/ml were significantly different (P = 0.02), with the highest proportion breast cancer-free in the ≥60 ng/ml group (99.3%) and the lowest proportion breast cancer-free in the <20 ng/ml group (96.8%). The proportion with breast cancer was 78% lower for ≥60 vs <20 ng/ml (P = 0.02). Third, multivariate Cox regression revealed that women with 25(OH)D concentrations ≥60 ng/ml had an 80% lower risk of breast cancer than women with concentrations <20 ng/ml (HR = 0.20, P = 0.03), adjusting for age, BMI, smoking status, calcium supplement intake, and study of origin.

Conclusions

Higher 25(OH)D concentrations were associated with a dose-response decrease in breast cancer risk with concentrations ≥60 ng/ml being most protective.

Vitamin D exposure and Risk of Breast Cancer: a meta-analysis

The relationship between vitamin D and breast cancer is still controversial. The present meta-analysis examines the effects of the 25(OH)D, 1,25(OH)2D and vitamin D intake on breast cancer risk. For this purpose, a PubMed, Scopus and Web of Science-databases search was conducted including all papers published with the keywords “breast cancer” and “vitamin D” with at least one reported relative risk (RR) or odds ratio (OR). In total sixty eight studies published between 1998 and 2018 were analyzed. Information about type of study, hormonal receptors and menopausal status was retrieved. Pooled OR or RR were estimated by weighting individual OR/RR by the inverse of their variance Our study showed a protective effect between 25 (OH) D and breast cancer in both cohort studies (RR = 0.85, 95%CI:0.74–0.98) and case-control studies (OR = 0.65, 95%CI: 0.56–0.76). However, analyzing by menopausal status, the protective vitamin D – breast cancer association persisted only in the premenopausal group (OR = 0.67, 95%CI: 0.49–0.92) when restricting the analysis to nested case-control studies. No significant association was found for vitamin D intake or 1,25(OH)2D. Conclusion: This systematic review suggests a protective relationship between circulating vitamin D (measured as 25(OH) D) and breast cancer development in premenopausal women.

Serum Vitamin D Status and Breast Cancer Risk by Receptor Status: A Systematic Review

BACKGROUND

The association between vitamin D status and breast cancer risk is equivocal. No systematic reviews or meta-analyses have examined this association stratified by receptor status. Our objective is to conduct a systematic review to answer the question, "Is there a relationship between lower serum/plasma vitamin D levels and increased risk of triple negative breast cancer (TNBC) specifically?"

METHODS

We systematically searched Embase and PubMed databases for published original research studies examining the risk of a breast cancer diagnosis according to vitamin D status. We excluded studies that did not provide risk estimates stratified by receptor status.

RESULTS

Fourteen studies met our criteria, including case-control, nested case-control, and case-series studies, reflecting the cumulative results of 13,135 breast cancer cases. When grouped by relevancy to TNBC, the proportion of analyses across all study types showing a significant association between vitamin D status and breast cancer diagnosis was 37% for non-TNBC analyses, 48% for analyses that included some TNBC cases, and 88% for TNBC analyses.

CONCLUSIONS

Our results suggest that low vitamin D status may particularly increase the risk of TNBC, although more research is needed to determine if this association is causative. Women should be routinely screened for 25(OH)D deficiency.

Vitamin D: And its role in breast cancer

Vitamin D is a fat soluble vitamin that plays a role in calcium and phosphorus homeostasis. Recently, extensive research on its extraskeletal actions has linked vitamin D deficiency to an increased risk of infection, diabetes mellitus types 1 and 2, cardiovascular disease, obesity, asthma, inflammatory bowel disease, colon, breast, prostate and ovarian cancer and some neurological diseases. There are various mechanisms by which vitamin D influences the natural history of cancer. These include the role of vitamin D in the induction of apoptosis, stimulation of cell differentiation, anti-inflammatory and antiproliferative effects and inhibition of angiogenesis, invasion and metastasis. The aim of this review is to clarify the true role of vitamin D in the onset of breast cancer and evolution of the disease after treatment. A further aim is to suggest new research directions to identify indications and requirements for vitamin D supplementation in patients with breast cancer.

Single-Nucleotide Polymorphisms in Vitamin D-Related Genes May Modify Vitamin D-Breast Cancer Associations

Background: We previously observed that high serum 25-hydroxyvitamin D (25(OH)D; >38.0 ng/mL) was inversely associated with breast cancer. Here, we examined effect modification by SNPs in vitamin D-related genes.Methods: The Sister Study enrolled 50,884 U.S. women who had a sister with breast cancer, but who had never had breast cancer themselves. Using a case-cohort design, we compared 1,524 women who developed breast cancer within 5 years to 1,810 randomly selected participants. We estimated ratios of HRs (RHRs) for the 25(OH)D-breast cancer association per copy of the minor allele using Cox proportional hazards models. We considered 82 SNPs in 7 vitamin D-related genes (CYP24A1, CYP27B1, CYP2R1, GC, DHCR7/NADSYN1, RXRA, and VDR). We also tested gene-based interactions with 25(OH)D.Results: The SNP with the smallest interaction P value was rs4328262 in VDR (P = 0.0008); the 25(OH)D HR was 0.92 [95% confidence interval (CI), 0.68-1.24] among those homozygous for the common allele, and the minor allele was estimated to decrease the HR by 33% per copy (RHR = 0.67; 95% CI, 0.53-0.85). Five other VDR SNPs showed evidence of interaction at P < 0.05, as did one SNP in CYP2R1 and one in RXRA As a group, the 82 SNPs showed evidence of multiplicative interaction with 25(OH)D (P = 0.04). In gene-based tests, only VDR showed strong evidence of interaction (P = 0.04).Conclusions: SNPs in vitamin D-related genes may modify the association between serum 25(OH)D and breast cancer.Impact: This work strengthens the evidence for protective effects of vitamin D. Cancer Epidemiol Biomarkers Prev; 26(12); 1761-71. ©2017 AACR.

Phytotherapy and Nutritional Supplements on Breast Cancer

Breast cancer is the most frequent type of nonskin malignancy among women worldwide. In general, conventional cancer treatment options (i.e., surgery, radiotherapy, chemotherapy, biological therapy, and hormone therapy) are not completely effective. Recurrence and other pathologic situations are still an issue in breast cancer patients due to side effects, toxicity of drugs in normal cells, and aggressive behaviour of the tumours. From this point of view, breast cancer therapy and adjuvant methods represent a promising and challenging field for researchers. In the last few years, the use of some types of complementary medicines by women with a history of breast cancer has significantly increased such as phytotherapeutic products and nutritional supplements. Despite this, the use of such approaches in oncologic processes may be problematic and patient's health risks can arise such as interference with the efficacy of standard cancer treatment. The present review gives an overview of the most usual phytotherapeutic products and nutritional supplements with application in breast cancer patients as adjuvant approach. Regardless of the contradictory results of scientific evidence, we demonstrated the need to perform additional investigation, mainly well-designed clinical trials in order to establish correlations and allow for further validated outcomes concerning the efficacy, safety, and clinical evidence-based recommendation of these products.

Prevalence of Low Vitamin D in Patients with Breast Cancer in a Predominantly Hispanic Population at the American-Mexican Border

INTRODUCTION

Low level of vitamin D (VD) has been linked with a higher risk of cancers. The aim of this study was to assess the prevalence of low VD in patients with breast cancer in a predominantly Mexican Hispanic/Latino patient population, a fast growing and relatively understudied population.

MATERIALS/METHODS

We sought to evaluate the serum VD levels in breast cancer patients diagnosed at the Texas Tech University Breast Cancer Center in El Paso, TX, between May 2013 and May2014 via a retrospective chart review of the Electronic Medical Records.

RESULTS

We identified a total of 83 consecutive breast cancer patients with available VD levels. Mean age 57 yr, 94% were Hispanics. VD was insufficient (<30 ng/ml) in 86% of patients (95% CI: 0.76-0.92) and it was deficient (<20 ng/ml) in 39% (95% CI: 0.28-0.50).

CONCLUSION

VD deficiency is widely prevalent in Hispanic/Latino patients with breast cancer. This is quite alarming in view of possible increased risk of cancer with low VD and potentially worse cancer outcomes. This calls for increased efforts to screen for, diagnose, and treat VD deficiency in this patient population. Further pharmacogenomics studies are warranted to explore the underlying etiology of VD deficiency in this paradoxically sunny region.

Serum Vitamin D and Risk of Breast Cancer within Five Years

BACKGROUND

Vitamin D is an environmental and dietary agent with known anticarcinogenic effects, but protection against breast cancer has not been established.

OBJECTIVE

We evaluated the association between baseline serum 25-hydroxyvitamin D [25(OH)D] levels, supplemental vitamin D use, and breast cancer incidence over the subsequent 5 y of follow-up.

METHODS

From 2003-2009, the Sister Study enrolled 50,884 U.S. women 35-74 y old who had a sister with breast cancer but had never had breast cancer themselves. Using liquid chromatography-mass spectrometry, we measured 25(OH)D in serum samples from 1,611 women who later developed breast cancer and from 1,843 randomly selected cohort participants. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for the risk of developing breast cancer using Cox proportional hazards models.

RESULTS

We found that 25(OH)D levels were associated with a 21% lower breast cancer hazard (highest versus lowest quartile: adjusted ; CI: 0.63, 0.98). Analysis of the first 5 y of follow-up for all 50,884 Sister Study participants showed that self-reported vitamin D supplementation was associated with an 11% lower hazard [ (CI: 0.81, 0.99)]. These associations were particularly strong among postmenopausal women [ (CI: 0.57, 0.93) and (CI: 0.74, 0.93), respectively].

CONCLUSIONS

In this cohort of women with elevated risk, high serum 25(OH)D levels and regular vitamin D supplement use were associated with lower rates of incident, postmenopausal breast cancer over 5 y of follow-up. These results may help to establish clinical benchmarks for 25(OH)D levels; in addition, they support the hypothesis that vitamin D supplementation is useful in breast cancer prevention. https://doi.org/10.1289/EHP943.

Vitamin D Intake and Risk of Skin Cancer in US Women and Men

Previous studies suggested a protective effect of vitamin D against skin cancer development. However, epidemiologic studies on orally taken vitamin D and risk of skin cancer (basal cell carcinoma [BCC], squamous cell carcinoma [SCC], and melanoma) are few. We prospectively evaluated whether total, dietary and supplemental vitamin D intake were associated with skin cancer risk based on 63,760 women in the Nurses' Health Study (1984–2010) and 41,530 men in the Health Professionals Follow-up Study (1986–2010). Dietary information on vitamin D intake was assessed every 2 to 4 years during the follow-up and cumulative averaged intake was used. We used Cox proportional hazard models to compute the hazard ratios (HR) and 95% confidence intervals (CI). Pooled HR of cohort-specific results were calculated using a random-effects model. During the follow-up, we documented 20,840 BCC, 2,329 SCC and 1,320 melanoma cases. Vitamin D consumption was not associated with the risk of SCC or melanoma but was modestly positively associated with BCC; the pooled HRs of BCC for extreme quintiles of vitamin D intake were 1.10 (95%CI = 1.05–1.15; P_trend = 0.05) for total vitamin D and 1.13 (95% CI = 1.07 to 1.20; P_trend <0.01) for dietary vitamin D. Stratified analysis according to sun exposure related factors showed similar results. In conclusion, vitamin D intake was positively associated with risk of BCC, while null associations were found with SCC and melanoma. Our data do not support a beneficial role of orally taken vitamin D on skin cancer carcinogenesis.

Predicted 25-hydroxyvitamin D in relation to incidence of breast cancer in a large cohort of African American women

BACKGROUND

Vitamin D deficiency, which has been linked to an increased risk of colorectal cancer, is particularly common among African Americans. Previous studies of vitamin D status and breast cancer risk, mostly conducted in white women, have had conflicting results. We examined the relationship between predicted vitamin D status and incidence of breast cancer in a cohort of 59,000 African American women.

METHODS

Participants in the Black Women's Health Study have been followed by biennial mail questionnaires since 1995, with self-reported diagnoses of cancer confirmed by hospital and cancer registry records. Repeated five-fold cross-validation with linear regression was used to derive the best 25-hydroxyvitamin D (25(OH)D) prediction model based on measured 25(OH)D in plasma specimens obtained from 2856 participants in 2013-2015 and questionnaire-based variables from the same time frame. In the full cohort, including 1454 cases of incident invasive breast cancer, Cox proportional hazards models were used to compute the incidence rate ratio (IRR) for each quartile of predicted vitamin D score relative to the highest quartile. Predicted vitamin D score for each two-year exposure period was a cumulative average of predicted scores from all exposure periods up to that time.

RESULTS

Twenty-two percent of women with measured 25(OH)D were categorized as "deficient" (<20 ng/mL) and another 25 % as "insufficient" (20-29 ng/mL). The prediction model explained 25 % of variation in measured 25(OH)D and the correlation coefficient for predicted versus observed 25(OH)D averaged across all cross-validation runs was 0.49 (SD 0.026). Breast cancer risk increased with decreasing quartile of predicted 25(OH)D, p for trend 0.015; the IRR for the lowest versus highest quartile was 1.23 (95 % confidence interval 1.04, 1.46).

CONCLUSIONS

In prospective data, African American women in the lowest quartile of cumulative predicted 25(OH)D were estimated to have a 23 % increased risk of breast cancer relative to those with relatively high levels. Preventing vitamin D deficiency may be an effective means of reducing breast cancer incidence in African American women.

Serum 25-Hydroxyvitamin D Concentrations ≥40 ng/ml Are Associated with >65% Lower Cancer Risk: Pooled Analysis of Randomized Trial and Prospective Cohort Study

Background

Higher serum 25-hydroxyvitamin D [25(OH)D] concentrations have been associated with a lower risk of multiple cancer types across a range of 25(OH)D concentrations.

Objectives

To investigate whether the previously reported inverse association between 25(OH)D and cancer risk could be replicated, and if a 25(OH)D response region could be identified among women aged 55 years and older across a broad range of 25(OH)D concentrations.

Methods

Data from two cohorts representing different median 25(OH)D concentrations were pooled to afford a broader range of 25(OH)D concentrations than either cohort alone: the Lappe cohort (N = 1,169), a randomized clinical trial cohort (median 25(OH)D = 30 ng/ml) and the GrassrootsHealth cohort (N = 1,135), a prospective cohort (median 25(OH)D = 48 ng/ml). Cancer incidence over a multi-year period (median: 3.9 years) was compared according to 25(OH)D concentration. Kaplan-Meier plots were developed and the association between 25(OH)D and cancer risk was examined with multivariate Cox regression using multiple 25(OH)D measurements and spline functions. The study included all invasive cancers excluding skin cancer.

Results

Age-adjusted cancer incidence across the combined cohort (N = 2,304) was 840 cases per 100,000 person-years (1,020 per 100,000 person-years in the Lappe cohort and 722 per 100,000 person-years in the GrassrootsHealth cohort). Incidence was lower at higher concentrations of 25(OH)D. Women with 25(OH)D concentrations ≥40 ng/ml had a 67% lower risk of cancer than women with concentrations <20 ng/ml (HR = 0.33, 95% CI = 0.12–0.90).

Conclusions

25(OH)D concentrations ≥40 ng/ml were associated with substantial reduction in risk of all invasive cancers combined.

Diet and risk of breast cancer

Diet may play a role in both promoting and inhibiting human breast cancer development. In this review, nutritional risk factors such as consumption of dietary fat, meat, fiber, and alcohol, and intake of phytoestrogen, vitamin D, iron, and folate associated with breast cancer are reviewed. These nutritional factors have a variety of associations with breast cancer risk. Type of fat consumed has different effects on risk of breast cancer: consumption of meat is associated with heterocyclic amine (HCA) exposure; different types of plant fiber have various effects on breast cancer risk; alcohol consumption may increase the risk of breast cancer by producing acetaldehyde and reactive oxygen species (ROS); intake of phytoestrogen may reduce risk of breast cancer through genomic and non-genomic action; vitamin D can reduce the risk of breast cancer by inhibiting the process of cancer invasion and metastasis; intake of dietary iron may lead to oxidative stress, DNA damage, and lipid peroxidation; and lower intake of folate may be linked to a higher risk of breast cancer.

Weight Status and Alcohol Intake Modify the Association between Vitamin D and Breast Cancer Risk

BACKGROUND

Mechanistic hypotheses suggest that vitamin D may contribute to the prevention of breast cancer. However, epidemiologic evidence is inconsistent, suggesting a potential effect modification by individual factors.

OBJECTIVE

Our objective was to perform exploratory analyses on the prospective associations between the plasma 25-hydroxyvitamin D [25(OH)D] concentration, polymorphisms of genes encoding for the vitamin D receptor (VDR) and vitamin D-binding protein (also known as gc-globulin or group-specific component, GC), and breast cancer risk, along with 2 potential modifiers: body mass index (BMI; in kg/m(2)) and alcohol intake.

METHODS

A nested case-control study was set up in the SUpplémentation en VItamines et Minéraux Anti-oXydants (SU.VI.MAX) cohort (1994-2007), involving 233 women with breast cancer and 466 matched controls (mean ± SD age: 49 ± 6 y). The plasma total 25(OH)D concentration and gene polymorphisms were assessed on samples obtained at baseline. Conditional logistic regression models were computed.

RESULTS

A higher plasma 25(OH)D concentration was associated with a decreased risk of breast cancer for women with a BMI < the median of 22.4 [OR quartile (Q)4 compared with Q1: 0.46; 95% CI: 0.23, 0.89; P-trend = 0.01, P-interaction = 0.002], whereas it was associated with an increased risk for women with a BMI ≥ the median (OR Q4 compared with Q1: 2.45; 95% CI: 1.13, 5.28; P-trend = 0.02, P-interaction = 0.002). A plasma 25(OH)D concentration ≥ 10 ng/mL was associated with a decreased risk of breast cancer for women with alcohol intakes ≥ the median of 7.1 g/d (OR ≥10 compared with <10 ng/mL: 0.50; 95% CI: 0.26, 0.95; P = 0.03, P-interaction = 0.03). The genetic analyses were consistent with the results observed with plasma 25(OH)D.

CONCLUSION

In this prospective study, BMI and alcohol intake modified the association between vitamin D [plasma 25(OH)D and vitamin D-related gene polymorphisms] and breast cancer risk. These effect modifications suggest explanations for discrepancies in results of previous studies. This trial was registered at clinicaltrials.gov as NCT00272428.

Vitamin D, Cancer Risk, and Mortality

Antiproliferative effects of 1,25-dihydroxyvitamin D, the biologically active form of vitamin D, are well established in various cell types by influencing cell differentiation and decreasing cell proliferation, growth, invasion, angiogenesis, and metastasis. Several meta-analyses showed that low serum levels of 25(OH)D was associated with colorectal cancer and overall mortality, while the association with cancer mortality was less consistent. VDR is a crucial mediator for the cellular effects of vitamin D and conflicting data have been reported for most malignancies. Beyond VDR, the biological effects of vitamin D are mediated by the vitamin D-binding protein. The GC (group-specific component) gene, encoding DBP, is highly polymorphic and several polymorphisms were investigated in association with cancer development with controversial results. Vitamin D supplementation was found to be associated with a reduced risk of overall mortality, reviewing all published trials on healthy subjects, whereas the evidence of an effect on cancer risk and mortality is less clear. Furthermore, long-term health effects of high doses of vitamin D, extended duration of supplementation, and the association with different baseline vitamin D levels remain to be investigated. In summary, epidemiological and preclinical studies support the development of vitamin D as preventative and therapeutic anticancer agents, with significant associations especially found for low vitamin D status with overall mortality and cancer outcome, more than cancer incidence. However, a definitive conclusion cannot be drawn and only large randomized clinical trials, both in healthy subjects and in cancer patients, will allow to draw definitive conclusions on the effect of vitamin D supplementation on cancer risk, prognosis, and mortality.

Serum 25-hydroxyvitamin D deficiency and increased risk of breast cancer among Korean women: a case-control study

Despite the emerging literature supporting the beneficial role of vitamin D on various health outcomes including carcinogenesis, current evidence on the association between vitamin D and breast cancer is still largely inconsistent. Furthermore, this relationship is particularly under explored among Asian population. We conducted a large case-control study with Korean women. We obtained and compared serum 25-hydroxyvitamin D (25(OH)D) between breast cancer patients (N = 3634) and general population (N = 17,133). Moreover, we further examined the association between serum 25(OH)D and breast cancer risk stratified by menopausal status and hormone receptor (HR) status of the tumor. Adjusted odds ratio (OR) for breast cancer comparing women with deficient level of serum 25(OH)D to women with sufficient level of serum 25(OH)D was 1.27 [95 % confidence interval (CI) 1.15-1.39]. This association did not significantly vary by menopausal status [pre-menopause: 1.26 (95 % CI 1.09-1.45) vs. post-menopause: 1.25 (95 % CI 1.10-1.41)]. When stratified by HR status, the inverse association remained significant in both positive and negative statuses. However, this association was more pronounced in HR-negative breast cancer, particularly with triple-negative breast cancer patients (1.45, 95 % CI 1.15-1.82). Given the growing burden of breast cancer in Asia and dearth of studies examining the association between vitamin D and breast cancer risk in Asian women thus far, this study provides a meaningful evidence for potential preventive effect of vitamin D on breast cancer for this particular population.

Vitamin D receptor gene polymorphisms and steroid receptor status among Saudi women with breast cancer

The vitamin D receptor (VDR) is a mediator for the cellular effects of vitamin D and interacts with other cell signaling pathways that influence cancer development. We evaluated the associations of the FOK1 and Taq1 VDR polymorphisms and breast cancer risk and possible effect modification by steroid receptor status of the tumor. This case-control study includes 95 breast cancer patients and 100 age-matched controls. Genotyping for VDR FOK1 and Taq1 polymorphisms was performed using polymerase chain reaction-based restriction fragment length polymorphism. Level of 25(OH)D in serum was determined using ELISA. Immunohistochemical studies were performed for estrogen receptors (ER) and progesterone receptors (PR). The frequencies of ff genotype were significantly increased in the breast cancer group compared to the control group. Carriers of the f allele were significantly more likely to develop BC. We observed a statistically significant interaction for the Fok1 polymorphism and ER status. Our results demonstrated that FOK1 f. genotype and f allele have an important role in breast cancer risk in Saudi patients.

Serum vitamin D levels and hypogonadism in men

There is inconsistent evidence on a possible association of vitamin D and androgen levels in men. We therefore aim to investigate the association of 25-hydroxyvitamin D (25(OH)D) with androgen levels in a cohort of middle-aged men. This cross-sectional study included 225 men with a median (interquartile range) age of 35 (30-41) years. We measured 25(OH)D, total testosterone (TT) and SHBG concentrations. Hypogonadism was defined as TT <10.4 nmol/L. We found no significant correlation of 25(OH)D and androgen levels. Furthermore, androgen levels were not significantly different across 25(OH)D quintiles. The overall prevalence of hypogonadism was 21.5% and lowest in men within 25(OH)D quintile 4 (82-102 nmol/L). We found a significantly increased risk of hypogonadism in men within the highest 25(OH)D quintile (>102 nmol/L) compared to men in quintile 4 (reference) in crude (OR 5.10, 1.51-17.24, p = 0.009) as well as in multivariate adjusted analysis (OR 9.21, 2.27-37.35, p = 0.002). We found a trend towards increased risk of hypogonadism in men within the lowest 25(OH)D quintile (≤43.9 nmol/L). In conclusion, our data suggest that men with very high 25(OH)D levels (>102 nmol/L) might be at an increased risk of hypogonadism. Furthermore, we observed a trend towards increased risk of hypogonadism in men with very low vitamin D levels indicating a U-shaped association of vitamin D levels and hypogonadism. With respect to risk of male hypogonadism, our results suggest optimal serum 25(OH)D concentrations of 82-102 nmol/L.

Prospective population-based study of the association between serum 25-hydroxyvitamin-D levels and the incidence of specific types of cancer

BACKGROUND

Observational studies have suggested an inverse association between vitamin D status and cancer. We investigated the prospective associations between vitamin D status and the total and specific type of cancer in three cohorts from the general Danish population.

METHODS

A total of 12,204 individuals 18 to 71 years old were included. The level of 25-hydroxyvitamin D was measured at baseline, and information about cancer was obtained from the Danish Cancer Registry.

RESULTS

During the 11.3-year median follow-up time, there were 1,248 incident cancers. HRs [95% confidence intervals (CI)] per 10 nmol/L higher baseline vitamin D level were: for all cancers (HR = 1.02; 95% CI, 0.99-1.04), all cancers excluding non-melanoma skin cancer, NMSC (HR = 1.00; 95% CI, 0.97-1.03), head and neck cancer (HR = 0.97; 95% CI, 0.84-1.12), colorectal cancer (HR = 0.95; 95% CI, 0.88-1.02), cancer of bronchus and lung (HR = 0.98; 95% CI, 0.91-1.05), breast cancer (HR = 1.02; 95% CI, 0.96-1.09), cancer of the uterus (HR = 1.10; 95% CI, 0.95-1.27), prostate cancer (HR = 1.00; 95% CI, 0.93-1.08), cancer of the urinary organs (HR = 1.01; 95% CI, 0.90-1.14), NMSC (HR = 1.06; 95% CI, 1.02-1.10), and malignant melanoma (HR = 1.06; 95% CI, 0.95-1.17).

CONCLUSIONS

Apart from a significantly higher risk for NMSC with higher vitamin D status, we found no statistically significant associations between vitamin D status and total or specific cancers.

IMPACT

Our results do not indicate that there is an impact of vitamin D on total cancer incidence.

Osteomalacia induced by vitamin D deficiency in hemodialysis patients: the crucial role of vitamin D correction

Vitamin D deficiency/insufficiency is significantly prevalent in chronic kidney disease. Data in the literature are however scarce about the effects of this deficiency on bone metabolism in hemodialysis (HD) patients. Moreover, it is still debated whether low vitamin D levels should be normalized in HD patients. In this paper, we report two cases showing the deleterious consequences of vitamin D deficiency in HD patients which is characterised by hypophosphatemia, hypocalcemia and osteomalacia (OM) leading to bone fractures. As vitamin D repletion is an easy way to treat OM, this report underlines the importance of monitoring and correction of vitamin D deficiency in this population.

Meta-analysis of long-term vitamin D supplementation on overall mortality

Introduction

It has been suggested that vitamin D is effective to prevent mortality. However, there is no consistent conclusion that the effects of vitamin D supplementation on all-cause mortality are associated with duration of treatment. We conducted a meta-analysis regarding this issue in an effort to provide a more robust answer.

Methods

A comprehensive search in a number of databases, including MEDLINE, Embase and The Cochrane Central Register of Controlled Trials, was conducted for collecting randomized controlled trials (RCTs) on vitamin D supplementation preventing mortality. Two investigators independently screened the literature according to the inclusive and exclusive criteria and the relative data were extracted. Data analysis was performed by using Review Manager 5.0 software.

Results

Data from forty-two RCT s were included. Vitamin D therapy significantly decreased all-cause mortality with a duration of follow-up longer than 3 years with a RR (95% CI) of 0.94 (0.90–0.98). No benefit was seen in a shorter follow-up periods with a RR (95% CI) of 1.04 (0.97–1.12). Results remain robust after sensitivity analysis. The following subgroups of long-term follow-up had significantly fewer deaths: female only, participants with a mean age younger than 80, daily dose of 800 IU or less, participants with vitamin D insufficiency (baseline 25-hydroxyvitamin D level less than 50 nmol/L) and cholecalciferol therapy. In addition, the combination of vitamin D and calcium significantly reduced mortality and vitamin D alone also had a trend to decrease mortality in a longer time follow up.

Conclusions

The data suggest that supplementation of vitamin D is effective in preventing overall mortality in a long-term treatment, whereas it is not significantly effective in a treatment duration shorter than 3 years. Future studies are needed to identify the efficacy of vitamin D on specific mortality, such as cancer and cardiovascular disease mortality in a long-term treatment duration.

Associations between vitamin D deficiency and risk of aggressive breast cancer in African-American women

Although breast cancer incidence in the US is highest for women of European ancestry (EA), women of African ancestry (AA) have higher incidence of cancer diagnosed before age 40 and tumors with more aggressive features (high grade and negative for estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor (HER2)), which precludes targeted therapies and leads to poorer outcomes. It is unclear what underlies these disparities. It has been hypothesized that dark skin with high melanin content is the ancestral skin color of origin, with adaptation to northern environs resulting in lighter skin. Although intense sunlight in sub-Saharan Africa may compensate for low sun absorption through skin, an urban or western lifestyle may result in less synthesis of vitamin D with higher skin pigmentation. Laboratory and preclinical data indicate that vitamin D is involved in preventing breast carcinogenesis and progression. Vitamin D receptor (VDR) knock-out mice are more likely to develop tumors that are ER-negative, and we have shown that serum levels of 25OHD are lowest among EA women with triple-negative tumors (negative for ER, PR and HER2); and among non-cancer patients, vitamin D levels are lower in AAs than in EAs. Thus, it is plausible to hypothesize that low vitamin D levels could be associated with the higher prevalence of more aggressive tumors among AA women. In this paper, we review the current literature on vitamin D and aggressive breast cancer subtypes, discuss vitamin D in AA women from a perspective of evolution and adaption, and examine the potential role of vitamin D in cancer racial disparities. We present our recently published data showing two single nucleotide polymorphisms in vitamin D catabolic enzyme CYP24A1 associated with higher risk of estrogen ER-negative risk in AA than in EA women. The relationship of vitamin D with breast cancer risk may be subtype-specific, with emerging evidence of stronger effects of vitamin D for more aggressive breast cancer, particularly in women of African ancestry.

Vitamin D status and breast cancer in Saudi Arabian women: case-control study

BACKGROUND

The role of vitamin D in breast cancer prevention is equivocal. Saudi Arabian women may be at greater risk of vitamin D deficiency because of a darker skin type and a greater likelihood of reduced ultraviolet B radiation exposure. Data regarding the vitamin D status of Saudi Arabian women and its relation to breast cancer risk are lacking.

OBJECTIVE

The purpose of this research was to evaluate the association between circulating concentrations of 25-hydroxyvitamin D [25(OH)D] and breast cancer risk in Saudi Arabian women.

DESIGN

A case-control study was conducted among 120 breast cancer cases and 120 controls. The study population was drawn from patients admitted to King Fahd Hospital in Jeddah, Saudi Arabia, from June to August 2009. Participants completed questionnaires on diet and medical history, and serum samples were collected from all women to measure circulating 25(OH)D concentrations.

RESULTS

The participants had a mean age of 47.8 y and a mean body mass index (BMI; in kg/m(2)) of 30.0. Breast cancer cases had significantly lower (mean ± SD) serum concentrations of 25(OH)D (9.4 ± 6.4 ng/mL) than did controls (15.4 ± 12.3 ng/mL; P = 0.001). In comparison with those in the highest category of vitamin D status for this population (≥20 ng/mL), the adjusted ORs (95% CIs) for invasive breast cancer were 6.1 (2.4, 15.1) for women with a serum 25(OH)D concentration <10 ng/mL and 4.0 (1.6, 10.4) for women with a serum concentration of ≥10 to <20 ng/mL (P-trend = 0.0001).

CONCLUSION

An inverse association exists between serum 25(OH)D concentrations and breast cancer risk in Saudi Arabian women. This trial was registered at clinicaltrials.gov as NCT01817231.

[Vitamin D and breast cancer: is there a link?]

OBJECTIVE

The aim of this review is to know the relationship between breast cancer and vitamin D, synthesised by skin or brought by food or supplementation.

MATERIAL AND METHODS

The selected articles were extracted from the Pubmed database between 1998 and 2012. The keywords used were: "25-hydroxyvitamin D", "breast cancer recurrence", "breast cancer risk", "serum levels of vitamin D", "vitamin D intake". A total of 37 articles were selected.

RESULTS

The sun exposure, via the skin vitamin D synthesis, is associated with a decreased risk of breast cancer. This decrease seems also likely for food contributions and an over 400IU per day vitamin D supplementation. An inverse relationship between plasma 25-hydroxyvitamin D (25-OH-D) level and breast cancer risk has been suggested. An increased 25-OH-D level seems associated with a decreased risk of breast cancer recurrence.

CONCLUSION

Recommendations concerning a vitamin D supplementation could be established, but should be supported by additional studies.

Circulating levels of 25-hydroxyvitamin D and risk of breast cancer: a nested case-control study

Introduction

Experimental evidence suggests a protective role for circulating 25-hydroxyvitamin D (25(OH)D) in breast cancer development, but the results of epidemiological studies have been inconsistent.

Methods

We conducted a case-control study nested within two prospective cohorts, the New York University Women's Health Study and the Northern Sweden Mammary Screening Cohort. Blood samples were collected at enrollment, and women were followed up for breast cancer ascertainment. In total, 1,585 incident breast cancer cases were individually-matched to 2,940 controls. Of these subjects, 678 cases and 1,208 controls contributed two repeat blood samples, at least one year apart. Circulating levels of 25(OH)D were measured, and multivariate odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using conditional logistic regression.

Results

No association was observed between circulating levels of 25(OH)D and overall breast cancer risk (multivariate-adjusted model OR = 0.94, 95% CI = 0.76-1.16 for the highest vs. lowest quintile, p_trend = 0.30). The temporal reliability of 25(OH)D measured in repeat blood samples was high (intraclass correlation coefficients for season-adjusted 25(OH)D > 0.70). An inverse association between 25(OH)D levels and breast cancer risk was observed among women who were ≤ 45 years of age (OR_Q5-Q1 = 0.48, 95% CI = 0.30-0.79, p_trend = 0.01) or premenopausal at enrollment (OR_Q5-Q1 = 0.67, 95% CI = 0.48-0.92, p_trend = 0.03).

Conclusions

Circulating 25(OH)D levels were not associated with breast cancer risk overall, although we could not exclude the possibility of a protective effect in younger women. Recommendations regarding vitamin D supplementation should be based on considerations other than breast cancer prevention.

Vitamin d: are we ready to supplement for breast cancer prevention and treatment?

Vitamin D deficiency is a potentially modifiable risk factor that may be targeted for breast cancer prevention and treatment. Preclinical studies support various antitumor effects of vitamin D in breast cancer. Numerous observational studies have reported an inverse association between vitamin D status, including circulating 25-hydroxyvitamin D (25(OH)D) levels, and breast cancer risk. The relationship between vitamin D and mammographic density, a strong predictor of breast cancer risk, remains unclear. Studies analyzing the link between genetic polymorphisms in vitamin D pathway genes and breast cancer incidence and prognosis have yielded inconsistent results. Vitamin D deficiency among breast cancer patients has been associated with poorer clinical outcomes and increased mortality. Despite a number of clinical trials of vitamin D supplementation, the efficacy, optimal dosage of vitamin D, and target blood level of 25(OH)D for breast cancer prevention have yet to be determined. Even with substantial literature on vitamin D and breast cancer, future studies need to focus on gaining a better understanding of the biologic effects of vitamin D in breast tissue. Despite compelling data from experimental and observational studies, there is still insufficient data from clinical trials to make recommendations for vitamin D supplementation for breast cancer prevention or treatment.

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.

Higher blood 25(OH)D level may reduce the breast cancer risk: evidence from a Chinese population based case-control study and meta-analysis of the observational studies

Experimental data suggest a protective effect of vitamin D on breast cancer; however, epidemiologic results remain inclusive. With a Chinese population-based case-control study and meta-analysis of the observational studies, we here systematically evaluated the association of blood 25(OH)D level and breast cancer risk. With 593 breast cancer cases and 580 cancer-free controls from Shanghai, China, we found that 80% of the normal women had severe vitamin D deficiency (less than 20 ng/mL) and 15.2% had mild deficiency (20 to 30 ng/mL) and only 4.8% of women had sufficient vitamin D level (>30 ng/mL) while the proportion was 96.1%, 3.2% and 0.7% respectively for the breast cancer patients. Compared to those with the lowest quartile of plasma 25(OH)D level, women with highest quartile 25(OH)D level showed a significant decreased breast cancer risk (Q4 vs.Q1: OR = 0.10, 95% CI = 0.06–0.15) and every 1 ng/ml increment of plasma 25(OH)D level led to a 16% lower odds of breast cancer (OR = 0.84, 95% CI = 0.81–0.87; P<0.001). From the meta-analysis of the observational studies, we found that women with highest quantile of blood 25(OH)D level was associated with a significantly reduced breast cancer risk compared to those with lowest quantile of blood 25(OH)D level for the 11 nested case-control and retrospective studies (pooled OR = 0.86, 95% CI = 0.75–1.00) and 10 case-control studies (7 population based, OR = 0.35, 95% CI = 0.24–0.52; 3 hospital based, OR = 0.08, 95% CI = 0.02–0.33). These results suggest that vitamin D may have a chemo-preventive effect against breast cancer.