Prospective analysis of vitamin D and endometrial cancer risk

Variants in Vitamin D-related Genes and Prostate Cancer Risk in Black Men

BACKGROUND

The relationship between vitamin D and prostate cancer has primarily been characterized among White men. However, Black men have higher prostate cancer incidence and mortality rates, chronically low circulating vitamin D levels, and ancestry-specific genetic variants in vitamin D-related genes. Here, we examine six critical genes in the vitamin D pathway and prostate cancer risk in Black men.

METHODS

We assessed a total of 69 candidate variants in six genes ( GC, CYP27A1, CYP27B1, CYP24A1, VDR , and RXRA ) including functional variants previously associated with prostate cancer and circulating 25(OHD) in White men. Associations with prostate cancer risk were examined using genome-wide association study data for approximately 10,000 prostate cancer cases and 10,000 controls among Black men and over 85,000 cases and 91,000 controls among White men. A statistical significance threshold of 0.000724 was used to account for the 69 variants tested.

RESULTS

None of the variants examined were significantly associated with prostate cancer risk among Black men after multiple comparison adjustment. Four variants tested P<0.05 in Black men, including two in RXRA (rs41400444 OR=1.09, 95% CI: 1.01-1.17, P = 0.024 and rs10881574 OR = 0.93, 0.87-1.00, P = 0.046) and two in VDR (rs2853563 OR = 1.07, 1.01-1.13, P = 0.017 and rs1156882 OR = 1.06, 1.00-1.12, P = 0.045). Two variants in VDR were also positively associated with risk in White men (rs11568820 OR = 1.04, 1.02-1.06, P = 0.00024 and rs4516035 OR = 1.03, 1.01-1.04, P = 0.00055).

CONCLUSION

We observed suggestive non-significant associations between genetic variants in RXRA and VDR and prostate cancer risk in Black men. Future research exploring the relationship of vitamin D with cancer risk in Black men will need larger sample sizes to identify ancestry-specific variants relevant to risk in this population.

Association of serum 25-hydroxyvitamin D levels with all-cause and cause-specific mortality among postmenopausal females: results from NHANES

BACKGROUND

Vitamin D deficiency is common among the population, but its relationship with mortality of postmenopausal females is unclear. The aim of this study is to explore the association between serum 25-Hydroxyvitamin D (25(OH)D) and all-cause and cause-specific mortality among postmenopausal women in the United States.

METHODS

6812 participants of postmenopausal females from the National Health and Nutrition Examination Survey (2001-2018) were included in this study. The mortality status of the follow-up was ascertained by linkage to National Death Index (NDI) records through 31 December 2019. We used cox proportional hazards models to estimate the association of serum 25(OH)D concentrations and mortality of postmenopausal females.

RESULTS

The mean level of serum 25(OH)D was 72.57 ± 29.93 nmol/L, and 65.34% had insufficient vitamin D. In postmenopausal females, low serum 25(OH)D concentrations were significantly associated with higher levels of glycohemoglobin, glucose, and lower levels of HDL. During follow-up, 1448 all-cause deaths occurred, including 393 cardiovascular disease (CVD)-related deaths and 263 cancer deaths. After multivariate adjustment, higher serum 25(OH)D levels were significantly related with lower all-cause and CVD mortality. In addition, serum 25(OH)D presented a L-shaped relationship with all-cause mortality, while appeared a U-shaped with CVD mortality, and the cut-off value is 73.89 nmol/L and 46.75 nmol/L respectively.

CONCLUSIONS

Low serum 25(OH)D levels are associated with the higher risk of all-cause and CVD mortality in postmenopausal females. These findings provide new ideas and targets for the health management of postmenopausal women.

Total Sialic Acid, Antioxidant Enzyme Activities, Trace Elements, and Vitamin Status Before and After Surgery in Women with Uterine Myoma and Endometrial Cancer

The objective of present study was to examine endometrial tissue Be, As, Cr, Mo, Sr, Ti, Tl, Cu, Co, Se, Zn, Mn, Fe, Cd, Pb, Mg, P, erythrocytes CAT, SOD, GSH-Px, GSH, MDA, serum retinol, cholecalciferol, phylloquinone, TSA, LSA, TOS, and TAS status and to evaluate the relationships between the variables. The study had 110 participants; of these, 50 were women with uterine myoma (UM), 10 were women with endometrial cancer (EC), and 50 were healthy female subjects. In the study, vitamin analyses by HPLC and element analyses were determined using ICP-OES method. It was observed that EC group was significantly lower than healthy group in terms of levels of cholecalciferol (p < 0.05), phylloquinone (p < 0.01), GSH (p < 0.05), Fe (p < 0.05), and had a significant rise in Mg/Fe (p < 0.01) and Zn/Fe (p < 0.05) in preoperative period. UM group had significantly lower retinol (p < 0.05), phylloquinone (p < 0.001), GSH-Px (p < 0.01), GSH (p < 0.01), Cr (p < 0.01), Cu (p < 0.05), Mg (p < 0.01), and Zn (p < 0.01) levels than control group in preoperative period and significantly higher levels of MDA (p < 0.01), TSA (p < 0.01), and LSA (p < 0.01) than control group. It was found that significant associations were observed between Cu-CA 15-3 (r = 0.558, p = 0.016), Mn-CA 15-3 (r = 0.511, p = 0.030), P-CA 15-3(r =  - 0.502, p = 0.034) and with UM, also between GSH-CA-125 (r =  - 0.825, p = 0.022) and with EC group. The results of correlation analysis observed that concentrations of Cu, Mn, P, and GSH together with CA 15-3 and CA-125 levels might be important for monitoring patients with UM and EC before surgery.

EMAS position statement: Vitamin D and menopausal health

INTRODUCTION

There is increasing evidence that vitamin D has widespread tissue effects. In addition to osteoporosis, vitamin D deficiency has been associated with cardiovascular disease, diabetes, cancer, infections and neurodegenerative disease. However, the effect of vitamin D supplementation on non-skeletal outcomes requires clarification, especially in postmenopausal women.

AIM

This position statement provides an evidence-based overview of the role of vitamin D in the health of postmenopausal women based on observational and interventional studies.

MATERIALS AND METHODS

Literature review and consensus of expert opinion.

RESULTS AND CONCLUSIONS

Vitamin D status is determined by measuring serum 25-hydroxyvitamin D levels. Concentrations <20 ng/ml (<50 nmol/l) and <10 ng/ml (<25 nmol/l) are considered to constitute vitamin D deficiency and severe deficiency, respectively. Observational data suggest an association between vitamin D deficiency and adverse health outcomes in postmenopausal women, although they cannot establish causality. The evidence from randomized controlled trials concerning vitamin D supplementation is not robust, since many studies did not consider whether people were deficient at baseline. Moreover, high heterogeneity exists in terms of the population studied, vitamin D dosage, calcium co-administration and duration of intervention. Concerning skeletal health, vitamin D deficiency is associated with low bone mass and an increased risk of fractures. Vitamin D supplementation at maintenance doses of 800-2000 IU/day (20-50 μg/day), after repletion of vitamin D status with higher weekly or daily doses, may be of benefit only when co-administered with calcium (1000-1200 mg/day), especially in the elderly populations and those with severe vitamin D deficiency. Concerning cardiovascular disease, vitamin D deficiency is associated with an increased prevalence of cardiovascular risk factors, mainly metabolic syndrome, type 2 diabetes mellitus and dyslipidemia. Vitamin D deficiency, especially its severe form, is associated with an increased risk of cardiovascular events (coronary heart disease, stroke, mortality), independently of traditional risk factors. Vitamin D supplementation may have a modestly beneficial effect on lipid profile and glucose homeostasis, especially in obese individuals or those ≥60 years old and at doses of ≥2000 IU/day (≥50 μg/day). However, it has no effect on the incidence of cardiovascular events. Concerning cancer, vitamin D deficiency is associated with increased incidence of and mortality from several types of cancer, such as colorectal, lung and breast cancer. However, the data on other types of gynecological cancer are inconsistent. Vitamin D supplementation has no effect on cancer incidence, although a modest reduction in cancer-related mortality has been observed. Concerning infections, vitamin D deficiency has been associated with acute respiratory tract infections, including coronavirus disease 2019 (COVID-19). Vitamin D supplementation may decrease the risk of acute respiratory tract infections and the severity of COVID-19 (not the risk of infection). Concerning menopausal symptomatology, vitamin D deficiency may have a negative impact on some aspects, such as sleep disturbances, depression, sexual function and joint pains. However, vitamin D supplementation has no effect on these, except for vulvovaginal atrophy, at relatively high doses, i.e., 40,000-60,000 IU/week (1000-1500 IU/week) orally or 1000 IU/day (25 μg/day) as a vaginal suppository.

Vitamin D, Menopausal Health and COVID-19: Critical Appraisal of Current Data

Inconsistency exists across studies conducted in postmenopausal women regarding the effect of vitamin D deficiency (VDD) and supplementation on several aspects of menopausal health, such as fractures, vasomotor symptomatology, cardiovascular disease (CVD), cancer and infections, including coronavirus disease 2019 (COVID-19). The aim of this review is to critically summarize the evidence provided by observational studies and randomized controlled trials (RCTs) of vitamin D supplementation in postmenopausal women with VDD. Observational studies have found that VDD is associated with an increased risk of falls and fractures after the menopause. VDD also has a negative effect on menopausal symptomatology. VDD, especially its severe form, is associated with an increased risk of CVD risk factors and CVD events. VDD is associated with increased risk and mortality from several cancer types and risk of infections. The evidence from RCTs regarding the effect of vitamin D supplementation on falls, fractures, menopausal symptoms, cardiovascular disease, cancer and infections is not robust. Thus, skeletal health may benefit only when vitamin D is co-administered with calcium, especially in those ≥70 years old and with severe VDD. There is no evidence of a favorable effect on menopausal symptoms or risk of CVD or cancer, except for a modest reduction in cancer-related mortality. Inconsistency still exists regarding its effect on infection risk, disease severity and mortality due to COVID-19.

Role of vitamin D3 in selected malignant neoplasms

Vitamin D₃ is a fat-soluble essential nutrient that affects multiple biologic functions in the organism through calcitriol and the vitamin D₃ receptor. This review article focuses on the results of studies on the relationship between the level of vitamin D₃ and cancer incidence or mortality, but also on the anticancer properties of vitamin D₃ that support its significant role in the prevention, clinical course, and overall survival rates of selected cancers (colorectal, prostate, breast, ovarian, endometrial, bladder, and malignant melanoma). The mechanisms of vitamin D₃ action involve, among others, polymorphism of vitamin D₃ receptor, cell cycle, caspases, and cancer stem cells. The level of vitamin D₃ has been also demonstrated to serve as a biomarker in some cancers, and high levels of vitamin D₃ can be conducive to successful cancer therapy.

Polymorphisms and haplotypes in VDR gene are associated with female idiopathic infertility

Unexplained infertility refers to the absence of a definable cause of reproductive failure. Vitamin D receptor (VDR) acts as a transcription factor and regulates a number of vitamin D-responsive genes, including those involved in the immune system. Recent finding that VDR is expressed in reproductive tissues suggests a possible importance of vitamin D in pregnancy. We conducted a case-control study to examine the association of polymorphisms in VDR gene with reproductive success. DNA from 117 female patients with unexplained infertility and 130 fertile controls was isolated from peripheral blood and VDR genotypes (FokI, BsmI, ApaI and TaqI) were detected by PCR-RFLP. Haplotypes were determined using Haploview software. Our results show significant association of FokI and BsmI polymorphisms with infertility (p < 0.05). The haplotype analysis confirmed strong linkage disequilibrium between closely positioned BsmI, ApaI and TaqI polymorphisms. Two haplotypes were associated with infertility: (i) haplotype bAT was increasing the risk for secondary infertility; while (ii) haplotype BAT had a protective role against primary infertility (p < 0.05). By changing the expression and the activity of VDR gene, which leads to the change in expression of vitamin D-responsive genes, these polymorphisms and haplotypes could possibly have an effect on immune system in the female reproductive tract.

Vitamin D and VDR in Gynecological Cancers-A Systematic Review

In recent years, a vast amount of studies have centered on the role of vitamin D in the pathogenesis of certain types of cancers such as breast, colorectal and lung cancer. Increasing evidence suggests that vitamin D and its receptor play a crucial role in the development of gynecological cancers. In this review, we systematically analyzed the effect of vitamin D and the vitamin D receptor on endometrial, ovarian, cervical, vulvar and vaginal cancer. Our literature research shows that vitamin D levels and vitamin-D-related pathways affect the risk of gynecological cancers. Numerous ecological studies give evidence on the inverse relationship between UVB exposure and gynecological cancer risk. However, epidemiologic research is still inconclusive for endometrial and ovarian cancer and insufficient for rarer types of gynecological cancers. The vitamin D receptor (VDR) is upregulated in all gynecological cancers, indicating its influence on cancer etiology. The VDR polymorphism FokI (rs2228570) seems to increase the risk of ovarian cancer. Other nuclear receptors, such as the RXR, also influence gynecological cancers. Although there is limited knowledge on the role of the VDR/RXR on the survival of endometrial, cervical, vulvar or vaginal cancer patients, some studies showed that both receptors influence survival. Therefore, we suggest that further studies should focus on the vitamin D- and its hetero dimer receptor RXR in gynecological cancers.

The association between Vitamin D and health outcomes in women: A review on the related evidence

Background:

Vitamin D has a wide range of physiological functions in skeletal and nonskeletal tissues which may play a role in many diseases. The aim of this study was to evaluate the recent evidence regarding the effects of Vitamin D on several health outcomes in women including breast cancer, ovarian and endometrial cancers, hypertension, and osteoporosis.

Materials and Methods:

We searched PubMed and Google Scholar databases through March 2016. We included the most current systematic reviews and meta-analyses assessing the associations of Vitamin D intake and/or serum 25-hydroxyvitamin D (25(OH)D) levels with the risk of incidence of breast cancer, ovarian and endometrial cancers, hypertension, and osteoporosis.

Results:

Many studies have represented that Vitamin D supplementation and high 25(OH)D levels can decrease the risk of breast cancer occurrence or mortality. However, there is no strong evidence to support the existence of a relationship between Vitamin D and ovarian or endometrial cancers. Furthermore, the results regarding the effects of Vitamin D on hypertension were inconsistent. Although observational studies have shown an association between Vitamin D and hypertension, there is no evidence regarding effectiveness of Vitamin D in lowering blood pressure in several clinical trials. On the other hand, the findings associating the impact of Vitamin D on osteoporosis were more definitive and most studies have represented that Vitamin D may have beneficial effects on osteoporosis.

Conclusion:

Although the adequate Vitamin D level can play a protective role in the incidence and development of breast cancer, hypertension, and osteoporosis, there is limited evidence regarding ovarian and endometrial cancers.

Meta-analysis of vitamin D-binding protein and cancer risk

BACKGROUND

Epidemiologic evidence supported a role for vitamin D and vitamin D receptor (VDR) polymorphisms in cancer risk. Beyond VDR, the biologic effects of vitamin D are mediated by the vitamin D-binding protein (DBP), a key protein in vitamin D metabolism. Furthermore, the gene encoding the DBP (GC, group-specific component) has an important role in the vitamin D pathway. Several studies investigated DBP serologic levels and GC polymorphisms in association with cancer risk with controversial results. Thus, we carried out a meta-analysis to investigate these associations.

METHODS

We included 28 independent studies concerning the following tumors: basal cell carcinoma, bladder, breast, colon-rectum, endometrium, liver, esophagus, stomach, melanoma, pancreas, prostate, and kidney. Through random-effect models, we calculated the summary odds ratios (SOR) for serum DBP and the GC polymorphisms rs2282679, rs12512631, rs7041, rs4588, rs17467825, rs1155563, and rs1352844.

RESULTS

We found a borderline decrease in cancer risk for subjects with high compared with low levels of DBP [SOR, 0.75; 95% confidence interval (CI), 0.56-1.00]. Dose-response meta-analysis indicates a nonsignificant decrease risk for an increase of 1,000 nmol/L of DBP (SOR, 0.96; 95% CI, 0.91-1.01). We found no significant alterations in cancer risk for subjects carrying any of the studied GC polymorphisms compared with wild-type subjects both in the main analysis and in analyses stratified by cancer type and ethnicity.

CONCLUSIONS

We found trends toward significance, suggesting a role of DBP in cancer etiology, which should be confirmed in further studies.

IMPACT

To our knowledge, this is the first study to investigate GC polymorphisms and DBP serologic levels in association with any type of cancer.

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.

Tightrope Walking: Using Predictors of 25(OH)D Concentration Based on Multivariable Linear Regression to Infer Associations with Health Risks

The debate on the causal association between vitamin D status, measured as serum concentration of 25-hydroxyvitamin D (25[OH]D), and various health outcomes warrants investigation in large-scale health surveys. Measuring the 25(OH)D concentration for each participant is not always feasible, because of the logistics of blood collection and the costs of vitamin D testing. To address this problem, past research has used predicted 25(OH)D concentration, based on multivariable linear regression, as a proxy for unmeasured vitamin D status. We restate this approach in a mathematical framework, to deduce its possible pitfalls. Monte Carlo simulation and real data from the National Health and Nutrition Examination Survey 2005-06 are used to confirm the deductions. The results indicate that variables that are used in the prediction model (for 25[OH]D concentration) but not in the model for the health outcome (called instrumental variables), play an essential role in the identification of an effect. Such variables should be unrelated to the health outcome other than through vitamin D; otherwise the estimate of interest will be biased. The approach of predicted 25(OH)D concentration derived from multivariable linear regression may be valid. However, careful verification that the instrumental variables are unrelated to the health outcome is required.