25-Hydroxyvitamin D and Total Cancer Incidence and Mortality: A Meta-Analysis of Prospective Cohort Studies

Risk of Malignant Neoplasm in Patients with Primary Hyperparathyroidism: A Systematic Review and Meta-analysis

This study aimed to evaluate the prevalence and risk of malignant neoplasm in primary hyperparathyroidism (PHPT) patients. Potentially eligible studies were retrieved from PubMed and Embase databases from inception to November 2023 using search strategy consisting of terms for "Primary hyperparathyroidism" and "Malignant neoplasm". Eligible study must report prevalence of malignant neoplasm among patients with PHPT or compare the risk of malignant neoplasm between patients with PHPT and comparators. Point estimates with standard errors were extracted from each study and combined using the generic inverse variance method.A total of 11,926 articles were identified. After two rounds of systematic review, 50 studies were included. The meta-analysis revealed that pooled prevalence rates of overall cancer was 0.19 (95%CI: 0.13-0.25; I2 94%). The two most prevalent types of malignancy among patients with PHPT ware papillary thyroid cancer (pooled prevalence: 0.07; 95%CI: 0.06-0.08; I2 85%) and breast cancer (pooled prevalence: 0.05; 95%CI: 0.03-0.07; I2 87%). Subgroup analysis of studies focusing on patients undergoing parathyroidectomy reported a fourfold higher prevalence of papillary thyroid cancer than the remaining studies (0.08 versus 0.02). The meta-analysis of cohort studies found a significant association between PHPT and overall cancer with the pooled risk ratio of 1.28 (95%CI: 1.23-1.33; I2 66.9%).We found that the pooled prevalence of malignant neoplasm in PHPT was 19%, with papillary thyroid cancer and breast cancer being the most prevalent types. The meta-analysis of cohort studies showed that patient with PHPT carried an approximately 28% increased risk of malignancy.

Vitamin D and cancer

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

Vitamin D and human health: evidence from Mendelian randomization studies

We summarized the current evidence on vitamin D and major health outcomes from Mendelian randomization (MR) studies. PubMed and Embase were searched for original MR studies on vitamin D in relation to any health outcome from inception to September 1, 2022. Nonlinear MR findings were excluded due to concerns about the validity of the statistical methods used. A meta-analysis was preformed to synthesize study-specific estimates after excluding overlapping samples, where applicable. The methodological quality of the included studies was evaluated according to the STROBE-MR checklist. A total of 133 MR publications were eligible for inclusion in the analyses. The causal association between vitamin D status and 275 individual outcomes was examined. Linear MR analyses showed genetically high 25-hydroxyvitamin D (25(OH)D) concentrations were associated with reduced risk of multiple sclerosis incidence and relapse, non-infectious uveitis and scleritis, psoriasis, femur fracture, leg fracture, amyotrophic lateral sclerosis, anorexia nervosa, delirium, heart failure, ovarian cancer, non-alcoholic fatty liver disease, dyslipidemia, and bacterial pneumonia, but increased risk of Behçet's disease, Graves' disease, kidney stone disease, fracture of radium/ulna, basal cell carcinoma, and overall cataracts. Stratified analyses showed that the inverse association between genetically predisposed 25(OH)D concentrations and multiple sclerosis risk was significant and consistent regardless of the genetic instruments GIs selected. However, the associations with most of the other outcomes were only pronounced when using genetic variants not limited to those in the vitamin D pathway as GIs. The methodological quality of the included MR studies was substantially heterogeneous. Current evidence from linear MR studies strongly supports a causal role of vitamin D in the development of multiple sclerosis. Suggestive support for a number of other health conditions could help prioritize conditions where vitamin D may be beneficial or harmful.

Vitamin D status during and after treatment and ovarian cancer survival

PURPOSE

Five-year relative survival for ovarian cancer remains below 50%. Strategies to improve outcomes are needed. Higher serum 25-hydroxyvitamin D [25(OH)D] concentrations [measure of vitamin D status] at and before diagnosis have been associated with longer survival in cancer patients; however, data for ovarian cancer are limited. We aimed to determine if 25(OH)D concentrations during and after primary treatment were associated with ovarian cancer-specific survival.

METHODS

We used data from a nationwide prospective cohort study of women with ovarian cancer. Among 886 participants treated with chemotherapy, 700 (79%) had a blood sample collected during (n = 591) and/or after (n = 458) primary treatment. These were tested for 25(OH)D. Clinical and survival data were abstracted from medical records. We used multivariable Cox proportional hazards regression to estimate hazard ratios (HR) and 95% confidence intervals (CI) for associations between 25(OH)D and ovarian cancer-specific survival.

RESULTS

Mean 25(OH)D concentrations were lower during than after primary treatment (82 and 91 nmol/L, respectively); only 14% and 8% had concentrations below 50 nmol/L during and after primary treatment, respectively. There was no association between 25(OH)D and ovarian cancer-specific survival during five years of follow-up [HR 1.10 (95% CI: 0.76, 1.61) and 0.95 (0.54, 1.68) for the highest vs. lowest quintile during and after treatment, respectively].

CONCLUSIONS

We did not observe any association between serum 25(OH)D concentration and ovarian cancer-specific survival. Our results suggest that, in the absence of vitamin D deficiency, vitamin D supplementation to improve ovarian cancer survival is not warranted.

Utilizing logistic regression to compare risk factors in disease modeling with imbalanced data: a case study in vitamin D and cancer incidence

Imbalanced data, a common challenge encountered in statistical analyses of clinical trial datasets and disease modeling, refers to the scenario where one class significantly outnumbers the other in a binary classification problem. This imbalance can lead to biased model performance, favoring the majority class, and affecting the understanding of the relative importance of predictive variables. Despite its prevalence, the existing literature lacks comprehensive studies that elucidate methodologies to handle imbalanced data effectively. In this study, we discuss the binary logistic model and its limitations when dealing with imbalanced data, as model performance tends to be biased towards the majority class. We propose a novel approach to addressing imbalanced data and apply it to publicly available data from the VITAL trial, a large-scale clinical trial that examines the effects of vitamin D and Omega-3 fatty acid to investigate the relationship between vitamin D and cancer incidence in sub-populations based on race/ethnicity and demographic factors such as body mass index (BMI), age, and sex. Our results demonstrate a significant improvement in model performance after our undersampling method is applied to the data set with respect to cancer incidence prediction. Both epidemiological and laboratory studies have suggested that vitamin D may lower the occurrence and death rate of cancer, but inconsistent and conflicting findings have been reported due to the difficulty of conducting large-scale clinical trials. We also utilize logistic regression within each ethnic sub-population to determine the impact of demographic factors on cancer incidence, with a particular focus on the role of vitamin D. This study provides a framework for using classification models to understand relative variable importance when dealing with imbalanced data.

Vitamin D Intake, Serum 25-Hydroxyvitamin-D (25(OH)D) Levels, and Cancer Risk: A Comprehensive Meta-Meta-Analysis Including Meta-Analyses of Randomized Controlled Trials and Observational Epidemiological Studies

It is a well-established fact that inadequate Vitamin D (Vit-D) levels have negative effects on the development and progression of malignant diseases, particularly cancer. The purpose of this paper was to elucidate the effects of Vit-D intake and serum 25-hydroxyvitamin-D (25(OH)D) levels on cancer incidence and mortality, the current evidence in this field, and the biases of this evidence, using the meta-meta-analysis method. Meta-analyses focusing on Vit-D intake, serum 25(OH)D levels, and cancer risk/mortality were identified. A structured computer literature search was undertaken in PubMed/Medline, Web of Science (WoS), and Scopus electronic databases using predetermined keyword combinations. Primary and secondary meta-meta-analyses were carried out, combining odds ratios (ORs), risk ratios (RRs), and hazard ratios (HRs) for outcomes reported in selected meta-analyses. A total of 35 eligible meta-analyses (59 reports yielded from these studies) assessing the association between Vit-D and cancer incidence and/or mortality were included in this study. In the pooled analysis, higher Vit-D intake and serum 25(OH)D levels were associated with lower cancer risk (OR = 0.93, 95% confidence interval (CI): 0.90-0.96, p < 0.001; OR = 0.80, 95% CI: 0.72-0.89, p < 0.001, respectively) and cancer-related mortality (RR = 0.89, 95% CI: 0.86-0.93, p < 0.001; RR = 0.67, 95% CI: 0.58-0.78, p < 0.001, respectively). When meta-analyses whose primary reports included only randomized controlled trials were pooled, there was no significant association between Vit-D intake and cancer risk (OR = 0.99, 95% CI: 0.97-1.01, p = 0.320). In subgroup analysis, Vit-D consumption was associated with a significant decrease in colorectal and lung cancer incidence (OR = 0.89, 95% CI: 0.83-0.96, p = 0.002; OR = 0.88, 95% CI: 0.83-0.94, p < 0.001, respectively). Taken together, both Vit-D intake and higher 25(OH)D levels may provide remarkable benefits in terms of cancer incidence and mortality; however, careful evaluation according to cancer types is critically important and recommended.

Vitamin D Modulates the Response of Patient-Derived Metastatic Melanoma Cells to Anticancer Drugs

Melanoma is considered a lethal and treatment-resistant skin cancer with a high risk of recurrence, making it a major clinical challenge. Our earlier studies documented that 1,25(OH)₂D₃ and its low-calcaemic analogues potentiate the effectiveness of dacarbazine and cediranib, a pan-VEGFR inhibitor. In the current study, a set of patient-derived melanoma cultures was established and characterised as a preclinical model of human melanoma. Thus, patient-derived cells were preconditioned with 1,25(OH)₂D₃ and treated with cediranib or vemurafenib, a BRAF inhibitor, depending on the BRAF mutation status of the patients enrolled in the study. 1,25(OH)₂D₃ preconditioning exacerbated the inhibition of patient-derived melanoma cell growth and motility in comparison to monotherapy with cediranib. A significant decrease in mitochondrial respiration parameters, such as non-mitochondrial oxygen consumption, basal respiration and ATP-linked respiration, was observed. It seems that 1,25(OH)₂D₃ preconditioning enhanced cediranib efficacy via the modulation of mitochondrial bioenergetics. Additionally, 1,25(OH)₂D₃ also decreased the viability and mobility of the BRAF+ patient-derived cells treated with vemurafenib. Interestingly, regardless of the strict selection, cancer-derived fibroblasts (CAFs) became the major fraction of cultured cells over time, suggesting that melanoma growth is dependent on CAFs. In conclusion, the results of our study strongly emphasise that the active form of vitamin D, 1,25(OH)₂D₃, might be considered as an adjuvant agent in the treatment of malignant melanoma.

Low plasma 25-hydroxyvitamin D levels are associated with an increased risk of depressive symptoms in community-dwelling Japanese people aged between 40 and 74 years: The Murakami cohort study

BACKGROUND

Association between vitamin D levels and the occurrence of depression are not always consistent. The present cohort study aimed to determine this association in older adults, using a method for measuring vitamin D levels which is more accurate than those used in previous studies.

METHODS

Participants were 3447 individuals aged 40-74 years without depressive symptoms at baseline who participated in the 5-year follow-up survey. The baseline investigation, including a self-administered questionnaire survey and blood collection, was conducted in 2011-2013. Plasma 25-hydroxyvitamin D (25[OH]D) levels were measured, and divided into overall quartiles summed up by sub-quartiles and stratified by age, sex, and season. The outcome was depressive symptoms determined by the CES-D (11-item, cut-off score of 6/7) 5 years later. Covariates were demographics, lifestyles, baseline CES-D score, and disease history.

RESULTS

Mean plasma 25(OH)D levels were 58.0 nmol/L in men and 45.7 in women (P < 0.0001), and cumulative incidences of depressive symptoms were 249/1577 (15.8 %) in men and 313/1870 (16.7 %) in women (P = 0.4526). The lower 25(OH)D quartile group had higher adjusted ORs in men and women combined (P for trend = 0.0107) and women (P for trend = 0.0003), but not in men. Adjusted ORs of the lowest quartile group were significantly higher than the highest group in men and women combined (OR = 1.39, 95 % CI: 1.06-1.81) and women (OR = 1.89, 95 % CI: 1.31-2.72).

LIMITATION

Depressive symptoms were self-reported.

CONCLUSIONS

Low vitamin D levels were associated with a high risk of depressive symptoms, especially in women. Women are thus considered a major target for preventing vitamin D deficiency to address depression.

Vitamin D intake and all-cause and cause-specific mortality in Japanese men and women: the Japan Public Health Center-based prospective study

While higher circulating 25-hydroxyvitamin D concentrations have been reported to be associated with decreased risk of all-cause mortality, evidence on dietary vitamin D intake is limited and inconsistent. We investigated whether vitamin D intake is associated with all-cause and cause-specific mortality among Japanese adults. Participants were 42,992 men and 50,693 women who responded to the second survey of the Japan Public Health Center-based Prospective Study (1995-1998) and who were followed up for mortality through 2018. Dietary intake was ascertained using a validated food frequency questionnaire. Hazard ratios of deaths from the second survey to December 2018 were estimated using Cox proportional hazard regression analysis. During follow-up, we identified 22,630 deaths. Overall, the third and fourth quintiles, but not the highest quintile, of vitamin D intake were each associated with a significantly lower risk of all-cause mortality. In subgroups characterized by low sunlight exposure, risk of all-cause mortality decreased linearly with increasing vitamin D intake. The multivariable-adjusted hazard ratios (95% confidence intervals) of all-cause mortality for the highest versus lowest quintile of vitamin D intake were 0.87 (0.79-0.95) in women and 0.88 (0.79-0.97) in residents of higher latitude areas. Lower risk was also observed for all-cause mortality in participants with hypertension and for heart disease mortality in those with higher calcium intake. Higher vitamin D intake was associated with decreased risk of ischemic stroke and pneumonia mortality. Higher dietary vitamin D was associated with a lower risk of mortality among individuals with low sunlight exposure or hypertension. Individuals with potentially low vitamin D may benefit from increasing dietary vitamin D intake for the prevention of premature death.

Association of 25-hydroxyvitamin D with risk of overall and colorectal cancer among Japanese using a Mendelian randomization approach

The association between vitamin D and total and colorectal cancer risk was inconsistent in observational studies. We conducted Mendelian randomization approach in which the effect of confounding might be reduced. 110 single nucleotide polymorphisms (SNPs) associated with 25-hydroxyvitamin D concentrations were systematically selected according to the "GWAS Catalog" from all ethnic populations. For the SNP-vitamin D concentration association, 3978 individuals from two Japanese cohorts were included. Regarding SNP-total and colorectal cancer association, 4543 cancer cases and 14,224 controls and 7936 colorectal cancer cases and 38,042 controls, respectively were included from the Japanese Consortium of Genetic Epidemiology and other studies in Japan. There was no significant association between the genetically predicted plasma 25-hydroxyvitamin D concentration and total or colorectal cancer in any of the MR analyses. Odds ratios per doubling in vitamin D concentration were 0.83 (95% confidence interval [CI] 0.63-1.09) for total cancer and 1.00 (95% CI 0.80-1.24) for colorectal cancer in inverse variance weighted method, 0.83 (95% CI 0.57-1.19) for total cancer and 1.01 (95% CI 0.75-1.37) for colorectal cancer in MR-Egger method. Consistent with previous MR analyses among European ancestries, there was no significant association identified between 25-hydroxyvitamin D levels and total or colorectal cancer among Asians.

Adequate vitamin D level associated with reduced risk of sporadic colorectal cancer

Purpose

The effect of vitamin D level pertinent to colorectal cancer incidence, progression, or mortality risk is complicated, and study findings are mixed. Therefore, we evaluated whether serum vitamin D [25-hydroxyvitamin D, 25(OH)D] is associated with the incidence of sporadic colorectal cancer (CRC).

Methods

This study is a retrospective analysis of the relationship between serum 25(OH)D level and the risk of CRC. Age, sex, body mass index, history of polyp, disease conditions (i.e., diabetes), medications, and other eight vitamins were used as confounding factors. A total of 389 participants were enrolled in this study, including comprising 83 CRC patients without a family history and 306 healthy controls, between January 2020 and March 2021 at the Department of Colorectal Surgery and Endoscope Center at the Xinhua Hospital, Shanghai Jiao Tong University School of Medicine. Adjusted smoothing spline plots, subgroup analysis, and multivariate logistic regression analysis were conducted to estimate the relative risk between serum 25(OH)D and sporadic CRC risk.

Results

After fully adjusting the confounding factors, it was found that circulating 25(OH)D played a protective role in patients with CRC (OR = 0.76 [0.63, 0.92], p = 0.004) and that an adequate vitamin D level was significantly associated with a reduced CRC risk compared to vitamin D deficiency or sufficiency (OR = 0.31 [0.11, 0.9], p = 0.03). According to this study, statins did not affect the potential protective effects of vitamin D (OR = 1.02 [0.97, 1.08], p = 0.44) and may account for the inverse association between serum 25(OH)D and colorectal cancer.

Conclusion

An adequate level of serum 25(OH)D was associated with a reduced CRC risk, especially for the elderly. The finding on the absence of protective effect of vitamin D in the statin use subgroup, suggests it may be one of the substantial contributing confounders, and warrants further investigation.

Research strategies in nutrition in health and disease: The failure of mechanistic research

This paper critically evaluates different research methods in order to assess their value for establishing which dietary changes are most effective for protecting health and preventing disease. The evidence demonstrates that the combined use of observational studies (mainly cohort studies) and randomized controlled trials (RCTs) is the most successful strategy. Studies of the details of body mechanisms in health and disease (mechanistic research) is another commonly used research strategy. However, much evidence demonstrates that it is a far less successful strategy. In order to support the above conclusions research studies from the following areas are discussed: obesity and dietary fat; heart disease and saturated fat; the Mediterranean diet and cardiovascular disease; type 2 diabetes and dietary fiber; and cancer and micronutrients. While mechanistic research has a poor track record in nutrition, it has achieved some success in other areas of biomedical science. This is shown by examining the role of mechanistic research in the discovery of new drugs.

Impact of hormone therapy on the bone density of women with premature ovarian insufficiency: A systematic review

INTRODUCTION

Women with premature ovarian insufficiency (POI) are exposed to a long period of estrogenic deficiency, which potentially brings higher health risks, especially regarding bone health. We performed a systematic review of the literature to evaluate the effect of hormone therapy (HT) on bone mineral density (BMD) in women with POI.

MATERIALS AND METHODS

A systematic search was performed of the MEDLINE and EMBASE databases up to September 2021. We included studies that analyzed women with idiopathic (spontaneous) POI treated with HT, and those who had BMD evaluated. Analysis of risk of bias of studies selected was performed.

RESULTS

We found 335 articles and selected 16 studies according to the inclusion criteria. Most of the studies revealed lower bone density in both the femoral neck and lumbar spine of women with POI compared with healthy women. Bone mass had the tendency to remain stable in women treated with estrogen + progestin therapy. However, in women already with bone mass loss, the therapy - in the doses most frequently used - was not able to revert the loss. Higher doses of estrogen seem to have a positive impact on BMD, as did combined oral contraceptives used continuously. Also, the interruption of HT for longer than one year was linked to significant bone loss.

CONCLUSION

Although HT brings clear benefits, further studies are needed to establish its long-term effects, as well as doses and formulations with better protective effects on the bone mass of these women.

The correlation between serum 25-hydroxy-vitamin D levels and anti-SARS-CoV-2 S-RBD IgG and neutralizing antibody levels among cancer patients receiving COVID-19 vaccines

Introduction

During the coronavirus disease 2019 (COVID-19) pandemic, vitamin D has been established as an immune-modulator that reduces pro-inflammatory damage which effectively diminish the severity of COVID-19. Vitamin D also has a significant effect against influenza and dengue and increase the seroconversion following influenza vaccination. To date, the role of vitamin D in optimizing the efficacy of COVID-19 vaccines remains unclear. This study aimed to analyze the correlation between serum 25-hydroxy-cholecalciferol or 25(OH)D levels and anti-SARS-CoV-2 S-RBD IgG and neutralizing antibody levels among cancer patients.

Methodology

A multicenter cross-sectional study was conducted among solid and hematologic cancer patients who were vaccinated with two doses of the same types of COVID-19 vaccines (either mRNA, non-replicating viral vector, or inactivated) within 6 months.

Result

The median serum 25(OH)D level in 119 cancer patients was 36.36 [IQR = 30.30] ng/mL. The seropositivity of S-RBD IgG and NAb reached 93.3 and 94.1%, respectively. The S-RBD IgG level was significantly higher in the sufficient group (median = 414.07 [1,441.83] AU/mL) than in the deficient group (median = 91.56 [652.00] AU/mL) (p-value = 0.049). Among non-chemotherapy subjects, the anti-SARS-CoV-2 S-RBD IgG levels had a significant positive correlation with 25(OH)D levels (p-value = 0.03; R = 0.588). The NAb levels also showed significantly positive correlation with 25(OH)D level (p-value = 0.005; R = 0.561). The 25(OH)D levels were positively correlated with S-RBD IgG levels among subjects younger than 60 years old (p-value = 0.047; R = 0.136). However, serum 25 (OH)D levels showed no such correlation with S-RBD IgG levels among subjects older than 60 years old (p-value = 0.933; R = 0.136).

Conclusion

Both anti-SARS-CoV-2 S-RBD IgG and NAb levels developed moderate correlation with 25(OH)D levels among subjects treated without chemotherapy. The S-RBD IgG levels also had positive correlation with 25(OH)D levels among subjects younger than 60 years old. Thus, we recommended cancer patients to maintain serum 25(OH)D levels above 30 ng/mL (75 nmol/L) to enhance the efficacy of COVID-19 vaccines.

Vitamin D supplementation for the prevention of total cancer incidence and mortality: An updated systematic review and meta-analysis

Introduction

Previous randomized controlled trials (RCTs) and meta-analyses of RCTs evaluating vitamin D supplementation for the prevention of cancer incidence and mortality have found inconsistent results and no meta-analysis has assessed the quality of the evidence available. We, therefore, aimed to perform an updated meta-analysis by including recent large-scale RCTs and assessing the quality of the pooled evidence.

Methods

We searched several databases and trial registers from inception to April 2022. We used a random-effects model to estimate pooled risk ratios (RRs) and 95% confidence intervals (CIs). We used the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) considerations to evaluate the certainty of evidence.

Results

We included 13 RCTs in our study. Vitamin D supplementation had no effect on the risk of total cancer incidence (RR 0.99, 95% CI: 0.94–1.04; I²= 0%), total cancer mortality (RR 0.93, 95% CI: 0.84–1.03; I²= 24%) and total mortality (RR 0.92, 95% CI: 0.82–1.04; I²= 36%). The overall quality of evidence was high for all outcomes.

Discussion

Vitamin D supplementation is ineffective in reducing total cancer incidence and mortality in largely vitamin D-replete older adult populations. Future research should be based on populations with a higher prevalence of vitamin D deficiency and should involve more extended follow-up periods.

Study protocol

PROSPERO database, CRD42021285401.

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We assessed the effect of vitamin D supplementation on total cancer incidence and mortality.

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We included 13 randomized controlled trials (RCTs) with 109,543 participants.

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Vitamin D is ineffective in reducing total cancer incidence and mortality in largely vitamin D-replete older adults.

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Future RCTs should focus on populations with a higher prevalence of vitamin D deficiency.

Vitamin D in Cancer Prevention: Gaps in Current Knowledge and Room for Hope

Intensive epigenome and transcriptome analyses have unveiled numerous biological mechanisms, including the regulation of cell differentiation, proliferation, and induced apoptosis in neoplastic cells, as well as the modulation of the antineoplastic action of the immune system, which plausibly explains the observed population-based relationship between low vitamin D status and increased cancer risk. However, large randomized clinical trials involving cholecalciferol supplementation have so far failed to show the potential of such interventions in cancer prevention. In this article, we attempt to reconcile the supposed contradiction of these findings by undertaking a thorough review of the literature, including an assessment of the limitations in the design, conduct, and analysis of the studies conducted thus far. We examine the long-standing dilemma of whether the beneficial effects of vitamin D levels increase significantly above a critical threshold or if the conjecture is valid that an increase in available cholecalciferol translates directly into an increase in calcitriol activity. In addition, we try to shed light on the high interindividual epigenetic and transcriptomic variability in response to cholecalciferol supplementation. Moreover, we critically review the standards of interpretation of the available study results and propose criteria that could allow us to reach sound conclusions in this field. Finally, we advocate for options tailored to individual vitamin D needs, combined with a comprehensive intervention that favors prevention through a healthy environment and responsible health behaviors.

Vitamin D supplementation and total cancer incidence and mortality by daily vs. infrequent large-bolus dosing strategies: a meta-analysis of randomised controlled trials

BACKGROUND

Efficacy of vitamin D supplementation may vary by dosing strategies and adiposity. To address such heterogeneity, we performed a meta-analysis of randomised controlled trials of vitamin D supplementation and total cancer outcomes.

METHODS

PubMed and Embase were searched through January 2022. Summary relative risk (SRR) and 95% confidence interval (CI) were estimated using the DerSimonian-Laird random-effects model.

RESULTS

For total cancer incidence (12 trials), the SRR for vitamin D supplementation vs. control group was 0.99 (95% CI, 0.94-1.03; P = 0.54; I² = 0%). No significant association was observed regardless of whether the supplement was given daily or infrequently in a large-bolus. Yet, among trials testing daily supplementation, a significant inverse association was observed among normal-weight individuals (SRR, 0.76; 95% CI, 0.64-0.90; P = 0.001, I² = 0%), but not among overweight or obese individuals (P_{heterogeneity} = 0.02). For total cancer mortality (six trials), the SRR was 0.92 (95% CI, 0.82-1.03; P = 0.17; I² = 33%). A significant inverse association emerged (SRR, 0.87; 95% CI, 0.78-0.96; P = 0.007; I² = 0%) among studies testing daily supplementations but not among studies that testing infrequent large-bolus supplementations (P_{heterogeneity} = 0.09).

CONCLUSIONS

For vitamin D supplementation, daily dosing, but not infrequent large-bolus dosing, reduced total cancer mortality. For total cancer incidence, bolus dosing did not reduce the risk and the benefits of daily dosing were limited to normal-weight individuals.

Low Vitamin D Status Is Associated with Increased Risk of Mortality in Korean Men and Adults with Hypertension: A Population-Based Cohort Study

Background Recent randomized controlled trials (RCTs) have shown no effect of vitamin D supplementation on cardiovascular disease, cancer events and mortality or all-cause mortality in Western populations. However, there has been a lack of research on populations with low vitamin D status, including Asians. In addition, there have been indications that an individual’s sex or hypertension status may affect the relationship between vitamin D status and mortality. In this study, we retrospectively assessed the association between vitamin D status and all-cause, cardiovascular, and cancer mortality in Koreans using a national database, and stratified participants according to sex and hypertension status. Methods Participants in the Korean Health and Nutrition Examination Survey 2008−2014, who consented to their data being synthesized with mortality data (up to December 2019), were included (n = 22,742; mean follow-up: 8.9 years). Participants’ level of serum 25-hydroxyvitamin D (25(OH)D) was measured by radioimmunoassay and categorized as <12, 12−19.9, and ≥20 ng/mL. A Cox proportional hazard model was used to assess the risk of mortality. Results In the total sample, risk of all-cause, cancer, and cardiovascular mortality was greater in adults with a serum 25(OH)D level below 12 and 12−19.9 ng/mL than those with ≥20 ng/mL. Men and adults with hypertension, who had low vitamin D status, had a higher risk of cancer and cardiovascular mortality, but not women or adults without hypertension. Similar results were observed when various cutoffs for 25(OH)D were employed, or extrinsic deaths were excluded. Conclusions Vitamin D status below 20 ng/mL is associated with a higher risk of mortality in Korean adults, especially in men and those with hypertension, on the basis of data from a nationally representative sample. Further RCTs on Asian adults with low vitamin D status are warranted.

Combined Vitamin D, Omega-3 Fatty Acids, and a Simple Home Exercise Program May Reduce Cancer Risk Among Active Adults Aged 70 and Older: A Randomized Clinical Trial

Objective: The aim of this study was to test the individual and combined benefit of vitamin D, omega-3, and a simple home strength exercise program on the risk of any invasive cancer.

Design: The DO-HEALTH trial is a three-year, multicenter, 2 × 2 × 2 factorial design double-blind, randomized-controlled trial to test the individual and combined benefit of three public health interventions.

Setting: The trial was conducted between December 2012 and December 2017 in five European countries.

Participants: Generally healthy community-dwelling adults ≥70 years were recruited.

Interventions: Supplemental 2000 IU/day of vitamin D₃, and/or 1 g/day of marine omega-3s, and/or a simple home strength exercise (SHEP) programme compared to placebo and control exercise.

Main outcome: In this pre-defined exploratory analysis, time-to-development of any verified invasive cancer was the primary outcome in an adjusted, intent-to-treat analysis.

Results: In total, 2,157 participants (mean age 74.9 years; 61.7% women; 40.7% with 25-OH vitamin D below 20 /ml, 83% at least moderately physically active) were randomized. Over a median follow-up of 2.99 years, 81 invasive cancer cases were diagnosed and verified. For the three individual treatments, the adjusted hazard ratios (HRs, 95% CI, cases intervention versus control) were 0.76 (0.49–1.18; 36 vs. 45) for vitamin D₃, 0.70 (0.44–1.09, 32 vs. 49) for omega-3s, and 0.74 (0.48–1.15, 35 vs. 46) for SHEP. For combinations of two treatments, adjusted HRs were 0.53 (0.28–1.00; 15 vs. 28 cases) for omega-3s plus vitamin D₃; 0.56 (0.30–1.04; 11 vs. 21) for vitamin D₃ plus SHEP; and 0.52 (0.28–0.97; 12 vs. 26 cases) for omega-3s plus SHEP. For all three treatments combined, the adjusted HR was 0.39 (0.18–0.85; 4 vs. 12 cases).

Conclusion: Supplementation with daily high-dose vitamin D₃ plus omega-3s, combined with SHEP, showed cumulative reduction in the cancer risk in generally healthy and active and largely vitamin D–replete adults ≥70 years.

Clinical Trial Registration:ClinicalTrials.gov, Identifier: NCT01745263.

An Empirical Evaluation of the Impact Scenario of Pooling Bodies of Evidence from Randomized Controlled Trials and Cohort Studies in Nutrition Research

Only very few Cochrane nutrition reviews include cohort studies (CSs), but most evidence in nutrition research comes from CSs. We aimed to pool bodies of evidence (BoE) from randomized controlled trials (RCTs) derived from Cochrane reviews with matched BoE from CSs. The Cochrane Database of Systematic Reviews and MEDLINE were searched for systematic reviews (SRs) of RCTs and SRs of CSs. BoE from RCTs were pooled together with BoE from CSs using random-effects and common-effect models. Heterogeneity, 95% prediction intervals, contributed weight of BoE from RCTs to the pooled estimate, and whether integration of BoE from CSs modified the conclusion from BoE of RCTs were evaluated. Overall, 80 diet-disease outcome pairs based on 773 RCTs and 720 CSs were pooled. By pooling BoE from RCTs and CSs with a random-effects model, for 45 (56%) out of 80 diet-disease associations the 95% CI excluded no effect and showed mainly a reduced risk/inverse association. By pooling BoE from RCTs and CSs, median I2 = 46% and the median contributed weight of RCTs to the pooled estimates was 34%. The direction of effect between BoE from RCTs and pooled effect estimates was rarely opposite (n = 17; 21%). The integration of BoE from CSs modified the result (by examining the 95% CI) from BoE of RCTs in 35 (44%) of the 80 diet-disease associations. Our pooling scenario showed that the integration of BoE from CSs modified the conclusion from BoE of RCTs in nearly 50% of the associations, although the direction of effect was mainly concordant between BoE of RCTs and pooled estimates. Our findings provide insights for the potential impact of pooling both BoE in Cochrane nutrition reviews. CSs should be considered for inclusion in future Cochrane nutrition reviews, and we recommend analyzing RCTs and CSs in separate meta-analyses, or, if combined together, with a subgroup analysis.

Clinical Practice in the Prevention, Diagnosis and Treatment of Vitamin D Deficiency: A Central and Eastern European Expert Consensus Statement

Vitamin D deficiency has a high worldwide prevalence, but actions to improve this public health problem are challenged by the heterogeneity of nutritional and clinical vitamin D guidelines, with respect to the diagnosis and treatment of vitamin D deficiency. We aimed to address this issue by providing respective recommendations for adults, developed by a European expert panel, using the Delphi method to reach consensus. Increasing the awareness of vitamin D deficiency and efforts to harmonize vitamin D guidelines should be pursued. We argue against a general screening for vitamin D deficiency but suggest 25-hydroxyvitamin D (25(OH)D) testing in certain risk groups. We recommend a vitamin D supplementation dose of 800 to 2000 international units (IU) per day for adults who want to ensure a sufficient vitamin D status. These doses are also recommended for the treatment of vitamin D deficiency, but higher vitamin D doses (e.g., 6000 IU per day) may be used for the first 4 to 12 weeks of treatment if a rapid correction of vitamin D deficiency is clinically indicated before continuing, with a maintenance dose of 800 to 2000 IU per day. Treatment success may be evaluated after at least 6 to 12 weeks in certain risk groups (e.g., patients with malabsorption syndromes) by measurement of serum 25(OH)D, with the aim to target concentrations of 30 to 50 ng/mL (75 to 125 nmol/L).

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.

Prediagnostic Serum Vitamin D, Vitamin D Binding Protein Isoforms, and Cancer Survival

BACKGROUND

Higher circulating vitamin D has been associated with improved overall cancer survival, but data for organ-specific cancers are mixed.

METHODS

We examined the association between prediagnostic serum 25-hydroxyvitamin D [25(OH)D], the recognized biomarker of vitamin D status, and cancer survival in 4038 men and women diagnosed with 1 of 11 malignancies during 22 years of follow-up (median = 15.6 years) within the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Multivariable-adjusted proportional hazards regression estimated hazard ratios (HR) and 95% confidence intervals (CI) for associations between baseline 25(OH)D concentration and subsequent cancer survival; we also stratified on the common vitamin D binding protein isoforms (Gc1f, Gc1s, and Gc2) defined by two single-nucleotide polymorphisms (rs7041 and rs4588) in the vitamin D binding protein gene GC. All P values were 2-sided.

RESULTS

Higher 25(OH)D concentrations were associated with greater overall cancer survival (HR for cancer mortality = 0.83, 95% CI = 0.70 to 0.98 for highest vs lowest quintile; Ptrend = .05) and lung cancer survival (HR = 0.63, 95% CI = 0.44 to 0.90; Ptrend = .03). These associations were limited to cases expressing the Gc2 isoform (HR = 0.38 for Gc2-2, 95% CI = 0.14 to 1.05 for highest vs lowest quintile; Ptrend = .02; and HR = 0.30 for Gc1-2/Gc2-2 combined, 95% CI = 0.16 to 0.56; Ptrend < .001 for overall and lung cancer, respectively).

CONCLUSIONS

Higher circulating 25(OH)D was associated with improved overall and lung cancer survival. As this was especially evident among cases with the genetically determined Gc2 isoform of vitamin D binding protein, such individuals may gain a cancer survival advantage by maintaining higher 25(OH)D blood concentrations.

A Narrative Review of the Evidence for Variations in Serum 25-Hydroxyvitamin D Concentration Thresholds for Optimal Health

Vitamin D3 has many important health benefits. Unfortunately, these benefits are not widely known among health care personnel and the general public. As a result, most of the world’s population has serum 25-hydroxyvitamin D (25(OH)D) concentrations far below optimal values. This narrative review examines the evidence for the major causes of death including cardiovascular disease, hypertension, cancer, type 2 diabetes mellitus, and COVID-19 with regard to sub-optimal 25(OH)D concentrations. Evidence for the beneficial effects comes from a variety of approaches including ecological and observational studies, studies of mechanisms, and Mendelian randomization studies. Although randomized controlled trials (RCTs) are generally considered the strongest form of evidence for pharmaceutical drugs, the study designs and the conduct of RCTs performed for vitamin D have mostly been flawed for the following reasons: they have been based on vitamin D dose rather than on baseline and achieved 25(OH)D concentrations; they have involved participants with 25(OH)D concentrations above the population mean; they have given low vitamin D doses; and they have permitted other sources of vitamin D. Thus, the strongest evidence generally comes from the other types of studies. The general finding is that optimal 25(OH)D concentrations to support health and wellbeing are above 30 ng/mL (75 nmol/L) for cardiovascular disease and all-cause mortality rate, whereas the thresholds for several other outcomes appear to range up to 40 or 50 ng/mL. The most efficient way to achieve these concentrations is through vitamin D supplementation. Although additional studies are warranted, raising serum 25(OH)D concentrations to optimal concentrations will result in a significant reduction in preventable illness and death.

The D-Health Trial: a randomised controlled trial of the effect of vitamin D on mortality

BACKGROUND

The effect of supplementing unscreened adults with vitamin D₃ on mortality is unclear. We aimed to determine whether monthly doses of vitamin D₃ influenced mortality in older Australians.

METHODS

We did a randomised, double-blind, placebo-controlled trial of oral vitamin D₃ supplementation (60 000 IU per month) in Australians 60 years or older who were recruited across the country via the Commonwealth electoral roll. Participants were randomly assigned (1:1), using automated computer-generated permuted block randomisation, to receive one oral gel capsule of either 60 000 IU vitamin D₃ or placebo once a month for 5 years. Participants, staff, and investigators were blinded to study group allocation. The primary endpoint was all-cause mortality assessed in all participants who were randomly assigned. We also analysed mortality from cancer, cardiovascular disease, and other causes. Hazard ratios (HRs) and 95% CIs were generated using flexible parametric survival models. This trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12613000743763.

FINDINGS

Between Feb 14, 2014, and June 17, 2015, we randomly assigned 21 315 participants, including 10 662 to the vitamin D group and 10 653 to the placebo group. In 4441 blood samples collected from randomly sampled participants (N=3943) during follow-up, mean serum 25-hydroxy-vitamin D concentrations were 77 (SD 25) in the placebo group and 115 (SD 30) nmol/L in the vitamin D group. Following 5 years of intervention (median follow-up 5·7 years [IQR 5·4-6·7]), 1100 deaths were recorded (placebo 538 [5·1%]; vitamin D 562 [5·3%]). 10 661 participants in the vitamin D group and 10 649 participants in the placebo group were included in the primary analysis. Five participants (one in the vitamin D group and four in the placebo group) were not included as they requested to be withdrawn and their data to be destroyed. The HR of vitamin D₃ effect on all-cause mortality was 1.04 [95% CI 0·93 to 1·18]; p=0·47)and the HR of vitamin D₃ effect on cardiovascular disease mortality was 0·96 (95% CI 0·72 to 1·28; p=0·77). The HR for cancer mortality was 1·15 (95% CI 0·96 to 1·39; p=0·13) and for mortality from other causes it was 0·83 (95% CI 0·65 to 1·07; p=0·15). The odds ratio for the per-protocol analysis was OR 1·18 (95% CI 1·00 to 1·40; p=0·06). In exploratory analyses excluding the first 2 years of follow-up, those randomly assigned to receive vitamin D had a numerically higher hazard of cancer mortality than those in the placebo group (HR 1·24 [95% CI 1·01-1·54]; p=0·05).

INTERPRETATION

Administering vitamin D₃ monthly to unscreened older people did not reduce all-cause mortality. Point estimates and exploratory analyses excluding the early follow-up period were consistent with an increased risk of death from cancer. Pending further evidence, the precautionary principle would suggest that this dosing regimen might not be appropriate in people who are vitamin D-replete.

FUNDING

The D-Health Trial is funded by National Health and Medical Research Council.

25-Hydroxyvitamin D in Cancer Patients Admitted to Palliative Care: A Post-Hoc Analysis of the Swedish Trial 'Palliative-D'

The purpose of this study is to explore 25-hydroxyvitamin D (25-OHD) levels in patients with cancer in the palliative phase in relation to season, sex, age, tumor type, colectomy, and survival. To this end, we performed a post-hoc analysis of ‘Palliative-D’, a randomized placebo-controlled, double-blind trial investigating the effect of daily supplementation with 4000 IU of vitamin D for 12 weeks on pain in patients in palliative cancer care. In the screening cohort (n = 530), 10% of patients had 25-OHD levels < 25 nmol/L, 50% < 50, and 84% < 75 nmol/L. Baseline 25-OHD did not differ between seasons or tumor type and was not correlated with survival time. In vitamin D deficient patients supplemented with vitamin D (n = 67), 86% reached sufficient levels, i.e., >50 nmol/L, after 12 weeks. An increase in 25-OHD was larger in supplemented women than in men (53 vs. 37 nmol/L, p = 0.02) and was not affected by season. In the placebo-group (n = 83), decreased levels of 25-OHD levels were noted during the study period for patients recruited during the last quarter of the year. In conclusion, cancer patients in palliative phase have adequate increase in 25-OHD after vitamin D supplementation regardless of season, age, tumor type, or colectomy.

Critical Appraisal of Large Vitamin D Randomized Controlled Trials

As a consequence of epidemiological studies showing significant associations of vitamin D deficiency with a variety of adverse extra-skeletal clinical outcomes including cardiovascular diseases, cancer, and mortality, large vitamin D randomized controlled trials (RCTs) have been designed and conducted over the last few years. The vast majority of these trials did not restrict their study populations to individuals with vitamin D deficiency, and some even allowed moderate vitamin D supplementation in the placebo groups. In these RCTs, there were no significant effects on the primary outcomes, including cancer, cardiovascular events, and mortality, but explorative outcome analyses and meta-analyses revealed indications for potential benefits such as reductions in cancer mortality or acute respiratory infections. Importantly, data from RCTs with relatively high doses of vitamin D supplementation did, by the vast majority, not show significant safety issues, except for trials in critically or severely ill patients or in those using very high intermittent vitamin D doses. The recent large vitamin D RCTs did not challenge the beneficial effects of vitamin D regarding rickets and osteomalacia, that therefore continue to provide the scientific basis for nutritional vitamin D guidelines and recommendations. There remains a great need to evaluate the effects of vitamin D treatment in populations with vitamin D deficiency or certain characteristics suggesting a high sensitivity to treatment. Outcomes and limitations of recently published large vitamin D RCTs must inform the design of future vitamin D or nutrition trials that should use more personalized approaches.

Vitamin D Deficiency at Diagnosis Increases All-Cause and Prostate Cancer-specific Mortality in Jamaican Men

Background

25 hydroxyvitamin D [25(OH)D] and serum calcium have been associated with incident prostate cancer (PCa). However, there is limited data on whether these metabolites predict survival in men of African descent, a population disproportionately affected by PCa. We studied the relationship of 25(OH)D at PCa diagnosis with all-cause and cancer-specific mortality among Jamaican men and examined whether serum calcium modified any associations.

Methods

Serum 25(OH)D from 152 Jamaican men with incident PCa within the Prostate Cancer Risk Evaluation (PROSCARE) study were re-evaluated approximately 11 years after enrollment. 25(OH)D analyses were stratified using the using Holick criteria. PCa-specific and all-cause mortality were examined in Kaplan–Meier survival curves and Cox regression models adjusted for age, body mass index (BMI), smoking and Gleason score. Restricted cubic splines evaluated nonlinear associations. Serum calcium was assessed as an effect modifier of the association between 25(OH)D and mortality.

Results

Of cases with available 25(OH)D, 64 men with PCa survived, 38 deaths were PCa specific and 36 died of other causes. At baseline, 9.9% of cases were vitamin D deficient and 61.2% were vitamin D sufficient. Compared to 25(OH)D sufficient men, those with 25(OH)D <20.0 ng/mL concentrations were associated with higher PCa-specific mortality (adjusted HR, 4.95; 95% CI, 1.68, 14.63, P = .004) and all-cause mortality (adjusted HR, 2.40; 95%CI, 1.33, 4. 32, P = .003). Serum calcium was not associated with survival and did not modify any associations with 25(OH)D.

Conclusions

25(OH)D deficiency at PCa diagnosis predicted decreased survival for overall and PCa-specific cancer in Caribbean men of African ancestry.

Vitamin D: Dosing, levels, form, and route of administration: Does one approach fit all?

The 4^th International Conference on Controversies in Vitamin D was held as a virtual meeting in September, 2020, gathering together leading international scientific and medical experts in vitamin D. Since vitamin D has a crucial role in skeletal and extra-skeletal systems, the aim of the Conference was to discuss improved management of vitamin D dosing, therapeutic levels and form or route of administration in the general population and in different clinical conditions. A tailored approach, based on the specific mechanisms underlying vitamin D deficiency in different diseases that were discussed, was recommended. Specifically, in comparison to healthy populations, higher levels of vitamin D and greater amounts of vitamin D were deemed necessary in osteoporosis, diabetes mellitus, obesity (particularly after bariatric surgery), and in those treated with glucocorticoids. Emerging and still open issues were related to target vitamin D levels and the role of vitamin D supplementation in COVID-19 since low vitamin D may predispose to SARS-CoV-2 infection and to worse COVID-19 outcomes. Finally, whereas oral daily cholecalciferol appears to be the preferred choice for vitamin D supplementation in the general population, and in most clinical conditions, active vitamin D analogs may be indicated in patients with hypoparathyroidism and severe kidney and liver insufficiency. Parenteral vitamin D administration could be helpful in malabsorption syndromes or in states of vitamin D resistance.Specific guidelines for desired levels of vitamin D should be tailored to the different conditions affecting vitamin D metabolism with the goal to define disease-specific normative values.

Prediagnostic Serum 25-Hydroxyvitamin D and Mortality Among Bladder Cancer Patients in the Janus Serum Bank Cohort

Purpose

Circulating 25-hydroxyvitamin D (25(OH)D) is inversely associated with overall cancer mortality and selected cancers, while for urothelial bladder cancer (BC) this relationship is unclear. We aimed to examine the association between 25(OH)D and BC mortality.

Materials and Methods

We used prediagnostic serum from 378 BC cases within the population-based Janus Cohort. Cox regression models estimated hazard ratios (HRs), with 95% confidence intervals (CIs), for the association between 25(OH)D and BC-specific and all-cause mortality. Restricted cubic splines were assessed to examine non-linear risk associations. Analyses were stratified by tumor invasiveness (non-muscle invasive BC (NMIBC) and muscle invasive BC (MIBC)). Additionally, the association between 25(OH)D and all-cause mortality was assessed for 378 cancer-free matched controls.

Results

25(OH)D deficiency (<50 nmol/L) was associated with higher BC-specific mortality (HR 1.87, 95% CI 1.10-3.20), when compared with insufficient levels (50-74 nmol/L). Stratification by tumor invasiveness revealed that this result was evident for NMIBC only, both with respect to BC-specific mortality (HR 2.84, 95% CI 1.14-7.12) and all-cause mortality (HR 1.97, 95% CI 1.06-3.65). No association between 25(OH)D levels and all-cause mortality was found in cancer-free controls.

Conclusion

25(OH)D deficiency (<50 nmol/L) prior to a BC diagnosis was associated with increased risk of BC-specific mortality, when compared to insufficient levels (50-74 nmol/L). The results were evident among NMIBC patients only, suggesting a more critical role of vitamin D deficiency in an early stage of the disease.

Evaluating agreement between bodies of evidence from randomised controlled trials and cohort studies in nutrition research: meta-epidemiological study

OBJECTIVE

To evaluate the agreement between diet-disease effect estimates of bodies of evidence from randomised controlled trials and those from cohort studies in nutrition research, and to investigate potential factors for disagreement.

DESIGN

Meta-epidemiological study.

DATA SOURCES

Cochrane Database of Systematic Reviews, and Medline.

REVIEW METHODS

Population, intervention or exposure, comparator, outcome (PI/ECO) elements from a body of evidence from cohort studies (BoE(CS)) were matched with corresponding elements of a body of evidence from randomised controlled trials (BoE(RCT)). Pooled ratio of risk ratios or difference of mean differences across all diet-disease outcome pairs were calculated. Subgroup analyses were conducted to explore factors for disagreement. Heterogeneity was assessed through I2 and τ2. Prediction intervals were calculated to assess the range of possible values for the difference in the results between evidence from randomised controlled trials and evidence from cohort studies in future comparisons.

RESULTS

97 diet-disease outcome pairs (that is, matched BoE(RCT) and BoE(CS)) were identified overall. For binary outcomes, the pooled ratio of risk ratios comparing estimates from BoE(RCT) with BoE(CS) was 1.09 (95% confidence interval 1.04 to 1.14; I2=68%; τ2=0.021; 95% prediction interval 0.81 to 1.46). The prediction interval indicated that the difference could be much more substantial, in either direction. We further explored heterogeneity and found that PI/ECO dissimilarities, especially for the comparisons of dietary supplements in randomised controlled trials and nutrient status in cohort studies, explained most of the differences. When the type of intake or exposure between both types of evidence was identical, the estimates were similar. For continuous outcomes, small differences were observed between randomised controlled trials and cohort studies.

CONCLUSION

On average, the difference in pooled results between estimates from BoE(RCT) and BoE(CS) was small. But wide prediction intervals and some substantial statistical heterogeneity in cohort studies indicate that important differences or potential bias in individual comparisons or studies cannot be excluded. Observed differences were mainly driven by dissimilarities in population, intervention or exposure, comparator, and outcome. These findings could help researchers further understand the integration of such evidence into prospective nutrition evidence syntheses and improve evidence based dietary guidelines.

Association Between Vitamin D Exposure and Head and Neck Cancer: A Systematic Review With Meta-Analysis

Background

Vitamin D deficiency is a well-described preventable cause of many cancers; the association of vitamin D use with the development of head and neck cancer (HNC) is not clear. We aim to conduct a systematic review of the studies assessing the relation between vitamin D exposure and the prevention and prognosis of the HNC using meta-analysis.

Methods

PubMed, EMBASE, Cochrane Library, Web of Science up to 1 January 2021, and reference lists of related studies were searched. We extracted observational studies reporting the association between vitamin D (vitamin D receptor gene polymorphisms, 25-hydroxyvitamin D concentrations, and vitamin D intake) and the outcomes of interest (HNC incidence and HNC mortality) in HNC patients aged 18 or older. Fixed effects models were used to calculate pooled effect sizes and 95% confidence intervals (CIs) by RevMan (version 5.3).

Results

Sixteen studies with a total of 81,908 participants were enrolled in our meta-analysis. Based on the pooled genomic analysis, comparing with participants with the genotypes of Ff + FF or FF, the pooled odds ratio (OR) of participants with the genotype of ff was 0.77 (95% CI: 0.61 to 0.97) and 0.75 (0.58 to 0.97), respectively. A similar trend was noted when comparing tt with Tt + TT or TT, in which OR (95% CI) was 0.70 (0.55 to 0.90) and 0.72 (0.55 to 0.95). No significant association was identified between BsmI polymorphism and HNC. Furthermore, the OR of HNC incidence was 0.77 (0.65 to 0.92) for participants with vitamin D intake over the ones with a regular diet. High concentrations of circulated 25-hydroxyvitamin D (25-OHD) significantly decreased by 32% of HNC incidence (OR (95% CI): 0.68 (0.59 to 0.78)) and increased HNC survival (pooled hazard ratio 1.13, 1.05 to 1.22) during a 4-5 years follow-up. High concentrations of circulating 25-OHD in patients with HNC led to a decreased risk of mortality to 0.75 (0.60 to 0.94) as the follow-up extends to 8-12 years.

Conclusions

Elevated activities of vitamin D by diet intake, genomic polymorphisms, or circulated 25-OHD may protect people from HNC and improve the prognosis of patients with HNC.

Systematic Review Registration

PROSPERO, identifier CRD42020176002 (https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=176002).

Vitamin D supplements: The pharmacists' perspective

OBJECTIVE

The purpose of this narrative review was to provide guidance for pharmacists concerning vitamin D supplementation.

METHODS

Relevant studies were identified in a search of MEDLINE/PubMed, EBSCOhost, and Google Scholar from January 1966 to September 2020 using the search terms vitamin D, vitamin D₂, vitamin D₃, calcitriol, and vitamin D deficiency. Abstracts were reviewed for relevance and, if relevant, full-text articles were retrieved and reviewed. References were checked, and citation searches using identified studies were conducted. The literature search included English-language studies involving administration of vitamin D monotherapy compared with placebo.

RESULTS

Serum 25-hydroxyvitamin D levels of less than 12 ng/mL indicate a vitamin D deficiency. The Institute of Medicine recommends a daily intake of 600 IU of vitamin D in individuals aged up to 70 years and 800 IU in those aged above 70 years. Vitamin D is labeled for rickets, osetomalacia, hypophosphatemia (familial or secondary), renal osteodystrophy, and corticosteroid-induced osteoporosis. When used for these indications, vitamin D should be prescribed with appropriate monitoring by a qualified health care practitioner. There is evidence for vitamin D supplementation in individuals aged 75 years or older and in those with problems associated with mobility, gait, or balance. There is insufficient evidence to support vitamin D supplementation in the prevention of cardiovascular disease, cancer, asthma, chronic obstructive pulmonary disease exacerbations, new-onset type 2 diabetes, infectious lung diseases, cognitive dysfunction, Alzheimer disease, and depression, or in prenatal use.

CONCLUSION

Pharmacists can provide evidence-based recommendations concerning the indications, dosing, monitoring, and adverse effects of vitamin D supplements.

Age-adjusted mortality from pancreatic cancer increased NINE-FOLD in japan from 1950 to 1995 - Was a low-protein quasi-vegan diet a key factor in their former low risk?

During the last half of the twentieth century, age-adjusted mortality from pancreatic cancer in Japan rose about nine-fold in both sexes. Well-characterized risk factors such as smoking, obesity/metabolic syndrome, and heavy alcohol use appear to explain only a modest part of this rise. It is proposed that a diet relatively low in protein, and particularly low in animal protein, was a key determinant of the low risk for pancreatic cancer in mid-century Japan. It is further proposed that pancreatic acinar cells, owing to their extraordinarily high rate of protein synthesis, are at high risk for ER stress; that such stress plays a fundamental role in the induction of most pancreatic cancers; and that low-protein diets help to offset such stress by modulating activities of the kinases GCN2 and mTORC1 while increasing autocrine and systemic production of fibroblast growth factor 21. This model appears to clarify the role of various risk factors and protective factors in pancreatic cancer induction. A vegan or quasi-vegan low-protein diet may have broader potential for decreasing risk for a range of common "Western" cancers.

Role of vitamin D in regulating COVID-19 severity-An immunological perspective

Vitamin D, a key nutrient/prohormone classically associated with skeletal health, is also an important immunomodulator, with pleotropic effects on innate and adaptive immune cells. Outcomes of several chronic, autoimmune, and infectious diseases are linked to vitamin D. Emergent correlations of vitamin D insufficiency with coronavirus‐induced disease 2019 (COVID‐19) severity, alongside empirical and clinical evidence of immunoregulation by vitamin D in other pulmonary diseases, have prompted proposals of vitamin D supplementation to curb the COVID‐19 public health toll. In this review paper, we engage an immunological lens to discuss potential mechanisms by which vitamin D signals might regulate respiratory disease severity in severe acute respiratory syndrome coronavirus 2 (SARS‐CoV2) infections, vis a vis other pulmonary infections. It is proposed that vitamin D signals temper lung inflammatory cascades during SARS‐CoV2 infection, and insufficiency of vitamin D causes increased inflammatory cytokine storm, thus leading to exacerbated respiratory disease. Additionally, analogous to studies of reduced cancer incidence, the dosage of vitamin D compounds administered to patients near the upper limit of safety may serve to maximize immune health benefits and mitigate inflammation and disease severity in SARS‐CoV2 infections. We further deliberate on the importance of statistically powered clinical correlative and interventional studies, and the need for in‐depth basic research into vitamin D‐dependent host determinants of respiratory disease severity.

The role of vitamin D in head and neck cancer

OBJECTIVE

Head and neck squamous cell carcinoma (HNSCC) describes a set of malignancies of the head and neck that continue to inflict considerable morbidity and mortality. Because HNSCC often presents at an advanced stage, patients frequently undergo intensive multi-modal therapy with an intent to cure. Vitamin D is a precursor to the biologically active hormone calcitriol which governs bone and calcium physiology that is obtained from diet and UV-B exposure. Vitamin D is known to have pleiotropic effects on health and disease. In this review, we examine the role of vitamin D in cancer with emphasis on HNSCC and discuss potential avenues for further research that might better elucidate the role of vitamin D in the management of HNSCC.

REVIEW METHODS

A review of MEDLINE database indexed literature concerning the role and biology of vitamin D in HNSCC was conducted, with special consideration of recently published work and research involving immunobiology and HNSCC.

CONCLUSIONS

The available evidence suggests that vitamin D may play a role in protecting against HNSCC, particularly in persons who smoke, although conflicting and limited data exists. Promising initial work encourages the pursuit of further study.

IMPLICATIONS FOR PRACTICE

The significant morbidity and mortality that HNSCC brings warrants continued research in available and safe interventions that improve patient outcomes. With the rise of immunotherapy as an effective modality for treatment, continued research of vitamin D as an adjunct in the treatment of HNSCC is supported.

The relationship between Vitamin D deficiency and polycystic ovary syndrome

BACKGROUND

Vitamin D deficiency is frequently seen in patients with polycystic ovary syndrome (PCOS) and has been shown to exhibit multiple effects on the disease process. The purpose of this study was to investigate the role of vitamin D deficiency in complex PCOS pathophysiological pathways.

METHODS

Two hundred sixty-seven patients with PCOS were divided into two groups Group 1 with 25(OH)D3 deficiency, and Group 2 with normal 25(OH)D3. Biochemical and hormonal parameters (androgen hormones, gonadotropins, and thyroid function tests) were compared between the two groups.

RESULTS

Eighty-six percent of the patients (n=231) were in Group 1 and 14% (n=36) in Group 2. Statistically significantly higher concentrations of serum testosterone, dehydroepiandrosterone-sulfate and LH were determined in Group 1 (p<0.05). 25(OH)D3 concentrations were negatively correlated with body mass index (r=-0.459), serum testosterone (r =-0.374) and dehydroepiandrosterone-sulfate levels (r=-0.418); (all; p< 0.05).

CONCLUSION

The study findings show that low 25(OH)D3 levels are associated with high androgen levels in women with PCOS. Vitamin D deficiency should be considered as an additional risk factor in the development of PCOS. We think that providing vitamin D supplementation for women from identified deficiency areas can reduce the risk of PCOS development.

Vitamin D and Clinical Cancer Outcomes: A Review of Meta-Analyses

The relationship between vitamin D status or supplementation and cancer outcomes has been examined in several meta‐analyses. To address remaining knowledge gaps, we conducted a systematic overview and critical appraisal of pertinent meta‐analyses. For meta‐analyses of trials, we assessed their quality using AMSTAR‐2 (A Measurement Tool to Assess Systematic Reviews), strength of associations using umbrella review methodology and credibility of evidence using GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) criteria. Meta‐analyses of observational studies reported inverse associations of 25OHD with risk of cancer incidence and cancer mortality and, particularly for colorectal cancer, fulfilled some of Bradford‐Hill's causation criteria. In meta‐analyses of trials, vitamin D supplementation did not affect cancer incidence. However, we found credible evidence that vitamin D supplementation reduced total cancer mortality risk, with five out of six meta‐analyses reporting a relative risk (RR) reduction of up to 16%: RR, 0.84 (95% CI, 0.74–0.95). The strength of the association, however, was classified as weak. This was true among meta‐analyses of high, moderate, and lower quality (AMSTAR‐2–rated). Trials did not include large numbers of vitamin D‐deficient participants; many tested relatively low doses and lacked sufficiently powered data on site‐specific cancers. In conclusion, meta‐analyses show that, although observational evidence indicates that low vitamin D status is associated with a higher risk of cancer outcomes, randomized trials show that vitamin D supplementation reduces total cancer mortality, but not cancer incidence. However, trials with larger proportions of vitamin D‐insufficient participants and longer durations of follow‐up, plus adequately powered data on site‐specific common cancers, would provide further insight into the evidence base. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Effect of Vitamin D3 Supplements on Development of Advanced Cancer: A Secondary Analysis of the VITAL Randomized Clinical Trial

IMPORTANCE

Epidemiologic and trial data suggest that vitamin D supplementation may reduce metastatic cancer and cancer mortality, reflecting shared biological pathways.

OBJECTIVE

To follow up on the possible reduction in cancer death in the Vitamin D and Omega-3 Trial (VITAL) with an evaluation of whether vitamin D reduces the incidence of advanced (metastatic or fatal) cancer and an examination possible effect modification by body mass index.

DESIGN, SETTING, AND PARTICIPANTS

VITAL is a randomized, double-blind, placebo-controlled, 2 × 2 factorial clinical trial of vitamin D3 (cholecalciferol, 2000 IU/d) and marine omega-3 fatty acids (1 g/d). This multicenter clinical trial was conducted in the United States; participants included men aged 50 years or older and women aged 55 years or older who were free of cancer and cardiovascular disease at baseline. Randomization took place from November 2011 through March 2014, and study medication ended on December 31, 2017. Data for this secondary analysis were analyzed from November 1, 2011, to December 31, 2017.

INTERVENTIONS

Vitamin D3 (cholecalciferol, 2000 IU/d) and marine omega-3 fatty acids (1 g/d) supplements.

MAIN OUTCOMES AND MEASURES

For the present analysis, the primary outcome was a composite incidence of metastatic and fatal invasive total cancer, because the main VITAL study showed a possible reduction in fatal cancer with vitamin D supplementation and effect modification by body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) for total cancer incidence reduction for individuals with normal BMI, but not for individuals with overweight or obesity. Secondary analyses included examination of BMI (<25, 25 to < 30, and ≥30) as effect modifiers of the observed associations.

RESULTS

Among 25 871 randomized VITAL participants (51% female; mean [SD] age, 67.1 [7.1] years), 1617 were diagnosed with invasive cancer over a median intervention period of 5.3 years (range, 3.8-6.1 years). As previously reported, no significant differences for cancer incidence by treatment arm were observed. However, a significant reduction in advanced cancers (metastatic or fatal) was found for those randomized to vitamin D compared with placebo (226 of 12 927 assigned to vitamin D [1.7%] and 274 of 12 944 assigned to placebo [2.1%]; HR, 0.83 [95% CI, 0.69-0.99]; P = .04). When stratified by BMI, there was a significant reduction for the vitamin D arm in incident metastatic or fatal cancer among those with normal BMI (BMI<25: HR, 0.62 [95% CI, 0.45-0.86]) but not among those with overweight or obesity (BMI 25-<30: HR, 0.89 [95% CI, 0.68-1.17]; BMI≥30: HR, 1.05 [95% CI, 0.74-1.49]) (P = .03 for interaction by BMI).

CONCLUSIONS AND RELEVANCE

In this randomized clinical trial, supplementation with vitamin D reduced the incidence of advanced (metastatic or fatal) cancer in the overall cohort, with the strongest risk reduction seen in individuals with normal weight.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01169259.

Vitamin D Status and Risk of All-Cause and Cause-Specific Mortality in a Large Cohort: Results From the UK Biobank

CONTEXT

Although an inverse association between vitamin D status and mortality has been reported in observational studies, the precise association shape and optimal vitamin D status remain undetermined.

OBJECTIVE

To investigate the association between vitamin D status and risk of all-cause and cause-specific mortality and estimate optimal serum 25-hydroxyvitamin D [25(OH)D] concentrations.

DESIGN

Prospective cohort study.

SETTING

UK Biobank.

PARTICIPANTS

365 530 participants who had serum 25(OH)D measurements and no history of cardiovascular disease (CVD), cancer, or diabetes at baseline (2006-2010).

MAIN OUTCOME MEASURES

All-cause and cause-specific mortality.

RESULTS

During a median follow-up of 8.9 (interquartile range: 8.3-9.5) years, 10 175 deaths occurred, including 1841 (18.1%) due to CVD and 5737 (56.4%) due to cancer. The multivariate analyses revealed nonlinear inverse associations, with a decrease in mortality risk appearing to level off at 60 nmol/L of 25(OH)D for all-cause and CVD deaths and at 45 nmol/L for cancer deaths. Compared to participants with 25(OH)D concentrations below the cutoffs, those with higher concentrations had a 17% lower risk for all-cause mortality (hazard ratio [HR]: 0.83, 95% confidence interval [CI]: 0.79-0.86), 23% lower risk for CVD mortality (HR: 0.77, 95% CI: 0.68-0.86), and 11% lower risk for cancer mortality (HR: 0.89, 95% CI: 0.84-0.95).

CONCLUSIONS

Higher 25(OH)D concentrations are nonlinearly associated with lower risk of all-cause, CVD, and cancer mortality. The thresholds of 45 to 60 nmol/L might represent an intervention target to reduce the overall risk of premature death, which needs further confirmation in large clinical trials.

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.

Association between blood cadmium and vitamin D levels in the Yangtze Plain of China in the context of rapid urbanization

BACKGROUND

China has experienced rapid urbanization in the past 30 years. We aimed to report blood cadmium level (BCL) in the rapidly urbanized Yangtze Plain of China, and explore the association between BCL and 25-hydroxyvitamin D (25(OH)D).

METHODS

Our data source was the Survey on Prevalence in East China for Metabolic Diseases and Risk Factors (SPECT-China) cross-sectional study (ChiCTR-ECS-14005052, www.chictr.org). We enrolled 3234 subjects from 12 villages in the Yangtze Plain. BCLs were measured by atomic absorption spectrometry. 25(OH)D was measured with a chemiluminescence assay.

RESULTS

A total of 2560 (79.2%) subjects were diagnosed with vitamin D deficiency. The median (interquartile range) BCL was 1.80 μg/L (0.60-3.42) for men and 1.40 μg/L (0.52-3.10) for women. In women, mean 25(OH)D concentrations were inversely associated with BCL (0.401, 95% confidence interval: -0.697 to -0.105 nmol/L lower with each doubling of the BCL) after adjustment for age, educational status, current smoking, body mass index, diabetes, and season. However, there was no significant difference in 25(OH)D across the BCL tertiles for men.

CONCLUSIONS

BCL in Chinese residents in the Yangtze Plain were much higher than that in developed countries. An inverse association between BCL and 25(OH)D was found in general Chinese women after multivariable adjustment. Future prospective cohort and animal studies are warranted to resolve the direction and temporality of these relationships, and to elucidate the exact mechanisms involved.

Vitamin D and Cancer Survival: Does Vitamin D Supplementation Improve the Survival of Patients with Cancer?

PURPOSE OF REVIEW

Clinical evidence suggesting the beneficial effects of vitamin D on survival of patients with cancer has been accumulating. Recent articles were thoroughly reviewed to determine if there is enough evidence to conclude that vitamin D supplementation improves survival of patients with cancer.

RECENT FINDINGS

Meta-analyses of observational studies showed that higher blood 25-hydroxyvitamin D levels in patients with cancer at a variety of sites were associated with lower cancer-specific and overall mortalities. Moreover, meta-analyses of randomized clinical trials (RCTs) also suggested that vitamin D supplementation improved the survival of patients with cancer. However, each RCT used in these meta-analyses, as well as very recent RCTs, e.g., the SUNSHINE and the AMATERASU trial, did not show statistical significance in the primary results. For now, compelling evidence that vitamin D supplementation effectively improves survival of patients with cancer is lacking. Thus, confirmatory RCTs are still obligatory for the future.

Effect of Vitamin D Supplementation on Survival of Digestive Tract Cancer Patients with Low Bioavailable 25-Hydroxyvitamin D levels: A Post Hoc Analysis of the AMATERASU Randomized Clinical Trial

Vitamin D has been shown to suppress the growth of cancer cells. Cancer cells are believed to take up bioavailable 25-hydroxyvitamin D (25[OH]D) (i.e., not bound to vitamin-D-binding protein (DBP)) more efficiently than DBP-bound 25(OH)D. Our aim was to use this bioavailable 25(OH)D, rather than total 25(OH)D, as a biomarker of vitamin D deficiency to investigate whether vitamin D supplementation improves the relapse-free survival (RFS) of patients with digestive tract cancer from the esophagus to the rectum by conducting a post hoc analysis of the AMATERASU trial (UMIN000001977). The bioavailable 25(OH)D levels were calculated via an equation using data of serum total 25(OH)D, albumin, and DBP levels, and DBP genotypes (rs7041 and rs4588). We estimated bioavailable 25(OH) levels in 355 patients. In a subgroup of patients with low bioavailable 25(OH)D levels (<median) (n = 177), 5 year RFS was 77% in the vitamin D group vs. 58% in the placebo group (hazard ratio, 0.54; 95% confidence interval, 0.31-0.95; p = 0.03), whereas no significant difference was seen in a subgroup of patients with high bioavailable 25(OH)D levels (p for interaction = 0.046). We hypothesize that vitamin D supplementation may be effective in improving RFS among digestive tract cancer patients with low bioavailable 25(OH)D levels.