Vitamin D baseline levels at diagnosis of breast cancer: A systematic review and meta-analysis

Epidemiological breast cancer prediction by country: A novel machine learning approach

Breast cancer remains a significant contributor to cancer-related deaths among women globally. We seek for this study to examine the correlation between the incidence rates of breast cancer and newly identified risk factors. Additionally, we aim to utilize machine learning models to predict breast cancer incidence at a country level. Following an extensive review of the available literature, we have identified a range of recently studied risk factors associated with breast cancer. Subsequently, we gathered data on these factors and breast cancer incidence rates from numerous online sources encompassing 151 countries. To evaluate the relationship between these factors and breast cancer incidence, we assessed the normality of the data and conducted Spearman's correlation test. Furthermore, we refined six regression models to forecast future breast cancer incidence rates. Our findings indicate that the incidence of breast cancer is most positively correlated with the average age of women in a country, as well as factors such as meat consumption, CO2 emissions, depression, sugar consumption, tobacco use, milk intake, mobile cells, alcohol consumption, pesticides, and oral contraceptive use. As for prediction, the CatBoost Regressor successfully predicted future breast cancer incidence with an R squared value of 0.84 ± 0.03. An increased incidence of breast cancer is mainly associated with dietary habits and lifestyle. Our findings and recommendations can serve as a baseline for developing educational programs intended to heighten awareness amongst women in countries with heightened risk.

Vitamin D and Breast Cancer Risk: Evaluating the Association and Effective Risk Reduction

Introduction

Breast cancer (BC) is the most common cancer among women globally. Vitamin D has been considered a protective factor; however, its relationship with any aspect of the disease remains controversial.

Methods

A cross-sectional, single-center clinical study was conducted between 2015 and 2018, including 141 women diagnosed with BC and 239 women in the control group, with mean ages of 43.1 and 41.7 years, respectively (p = 0.103). Serum levels of vitamin D and lipid profile were measured. Clinical and nutritional data were obtained through interviews and medical records.

Results

The vitamin D dosage presented an average value of 25.5 ng/mL and 31.0 ng/mL in the case and control groups, respectively (p < 0.001). The vitamin D cut-off point for discriminating the presence of BC was 27.45 ng/mL. Additionally, low-density lipoprotein cholesterol levels were higher in the case group (121.4 mg/dL) compared to the control group (110.7 mg/dL) (p = 0.002), whereas high-density lipoprotein cholesterol levels were lower in the case group (47.6 mg/dL) compared to the control group (53.3 mg/dL) (p = 0.001). Alcohol consumption was significantly higher in the case group than in the control group (2.7 vs. 5.3 doses/day; p < 0.001).

Conclusion

The results indicate a significant association between lower vitamin D levels and BC, persisting after multivariate analysis (p < 0.001). These findings could inform prevention strategies, highlighting the importance of maintaining adequate vitamin D levels and potentially identifying a risk group.

Association between consumption of small fish and all-cause mortality among Japanese: the Japan Multi-Institutional Collaborative Cohort Study

OBJECTIVE

Although small fish are an important source of micronutrients, the relationship between their intake and mortality remains unclear. This study aimed to clarify the association between intake of small fish and all-cause and cause-specific mortality.

DESIGN

We used the data from a cohort study in Japan. The frequency of the intake of small fish was assessed using a validated FFQ. The hazard ratio (HR) and 95 % confidence interval (CI) for all-cause and cause-specific mortality according to the frequency of the intake of small fish by sex were estimated using a Cox proportional hazard model with adjustments for covariates.

SETTING

The Japan Multi-Institutional Collaborative Cohort Study.

PARTICIPANTS

A total of 80 802 participants (34 555 males and 46 247 females), aged 35-69 years.

RESULTS

During a mean follow-up of 9·0 years, we identified 2482 deaths including 1495 cancer-related deaths. The intake of small fish was statistically significantly and inversely associated with the risk of all-cause and cancer mortality in females. The multivariable-adjusted HR (95 % CI) in females for all-cause mortality according to the intake were 0·68 (0·55, 0·85) for intakes 1-3 times/month, 0·72 (0·57, 0·90) for 1-2 times/week and 0·69 (0·54, 0·88) for ≥ 3 times/week, compared with the rare intake. The corresponding HR (95 % CI) in females for cancer mortality were 0·72 (0·54, 0·96), 0·71 (0·53, 0·96) and 0·64 (0·46, 0·89), respectively. No statistically significant association was observed in males.

CONCLUSIONS

Intake of small fish may reduce the risk of all-cause and cancer mortality in Japanese females.

The Power of Vitamin D: Is the Future in Precision Nutrition through Personalized Supplementation Plans?

In the last few decades, vitamin D has undeniably been one of the most studied nutrients. Despite our ability to produce vitamin D through sunlight exposure, its presence in several natural food sources and fortified foods, and its widespread availability as a dietary supplement, vitamin D deficiency is a serious public health problem, affecting nearly 50% of the global population. Low serum levels of vitamin D are being associated with increased susceptibility to numerous health conditions, including respiratory infections, mental health, autoimmune diseases, and different cancer types. Although the association between vitamin D status and health is well-established, the exact beneficial effects of vitamin D are still inconclusive and indefinite, especially when considering the prevention and treatment of different health conditions and the determination of an appropriate dosage to exert those beneficial effects in various population groups. Therefore, further research is needed. With constant improvements in our understanding of individual variations in vitamin D metabolism and requirements, in the future, precision nutrition and personalized supplementation plans could prove beneficial.

Long-Term Effect of Randomization to Calcium and Vitamin D Supplementation on Health in Older Women : Postintervention Follow-up of a Randomized Clinical Trial

BACKGROUND

Although calcium and vitamin D (CaD) supplementation may affect chronic disease in older women, evidence of long-term effects on health outcomes is limited.

OBJECTIVE

To evaluate long-term health outcomes among postmenopausal women in the Women's Health Initiative CaD trial.

DESIGN

Post hoc analysis of long-term postintervention follow-up of the 7-year randomized intervention trial of CaD. (ClinicalTrials.gov: NCT00000611).

SETTING

A multicenter (n = 40) trial across the United States.

PARTICIPANTS

36 282 postmenopausal women with no history of breast or colorectal cancer.

INTERVENTION

Random 1:1 assignment to 1000 mg of calcium carbonate (400 mg of elemental calcium) with 400 IU of vitamin D3 daily or placebo.

MEASUREMENTS

Incidence of colorectal, invasive breast, and total cancer; disease-specific and all-cause mortality; total cardiovascular disease (CVD); and hip fracture by randomization assignment (through December 2020). Analyses were stratified on personal supplement use.

RESULTS

For women randomly assigned to CaD versus placebo, a 7% reduction in cancer mortality was observed after a median cumulative follow-up of 22.3 years (1817 vs. 1943 deaths; hazard ratio [HR], 0.93 [95% CI, 0.87 to 0.99]), along with a 6% increase in CVD mortality (2621 vs. 2420 deaths; HR, 1.06 [CI, 1.01 to 1.12]). There was no overall effect on other measures, including all-cause mortality (7834 vs. 7748 deaths; HR, 1.00 [CI, 0.97 to 1.03]). Estimates for cancer incidence varied widely when stratified by whether participants reported supplement use before randomization, whereas estimates on mortality did not vary, except for CVD mortality.

LIMITATION

Hip fracture and CVD outcomes were available on only a subset of participants, and effects of calcium versus vitamin D versus joint supplementation could not be disentangled.

CONCLUSION

Calcium and vitamin D supplements seemed to reduce cancer mortality and increase CVD mortality after more than 20 years of follow-up among postmenopausal women, with no effect on all-cause mortality.

PRIMARY FUNDING SOURCE

National Heart, Lung, and Blood Institute of the National Institutes of Health.

Pre- and Postoperative Antioxidant Use, Aryl Hydrocarbon Receptor (AhR) Activation and Clinical Outcome in Different Treatment Groups of Breast Cancer Patients

BACKGROUND

Cancer patients often use antioxidants that may interact with adjuvant treatments. The purpose was to investigate pre- and postoperative antioxidant use in relation to clinicopathological characteristics and prognosis in different breast cancer treatment groups.

METHODS AND PATIENTS

Pre- and postoperative antioxidant (vitamin A, C, E, carotenoids, or Q10) or multivitamin use was self-reported by patients from Lund (n = 1855) and Helsingborg (n=478), Sweden. Patients were followed for up to 15 years. Clinical data were obtained from patient charts. The aryl hydrocarbon receptor (AhR) was evaluated in tumor tissue arrays from 915 patients from Lund and with Western blot in MCF-7 and MDA-MB-231 cells.

RESULTS

About 10% of patients used antioxidants. Nuclear AhR (AhRnuc) positivity was twice as common in preoperative antioxidant users compared to non-users. In mechanistic studies vitamin C increased AhR levels and its downstream target CYP1B1, indicating AhR activation. There were significant interactions between tumor AhRnuc status and preoperative antioxidant use in relation to clinical outcome. In all patients, antioxidant use (other than multivitamins) at both visits was associated with poorer prognosis, while use only at the follow-up visit was associated with better prognosis, compared with no use at either visit.

CONCLUSION

The clinical impact of antioxidants depended on antioxidant type, timing of use, and tumor AhR activation. Antioxidants may influence clinical outcome by activation of the master regulator AhR in addition to interference with free radicals. Further studies are needed to identify breast patients that might improve or worsen their prognosis when using antioxidants postoperatively.

The Vitamin D Receptor as a Prognostic Marker in Breast Cancer-A Cohort Study

Previous research has indicated an association between the presence of the vitamin D receptor (VDR) in breast cancer tissue and a favorable prognosis. This study aimed to further evaluate the prognostic potential of VDR located in the nuclear membrane or nucleus (liganded). The VDR protein levels were analyzed using immunohistochemistry in tumor samples from 878 breast cancer patients from Lund, Sweden, included in the Breast Cancer and Blood Study (BCBlood) from October 2002 to June 2012. The follow-up for breast cancer events and overall survival was recorded until 30 June 2019. Univariable and multivariable survival analyses were conducted, both with complete case data and with missing data imputed using multiple imputation by chained equations (MICE). Tumor-specific positive nuclear membrane VDR(num) staining was associated with favorable tumor characteristics and a longer breast cancer free interval (BCFI; HR: 0.64; 95% CI: 0.44-0.95) and overall survival (OS; HR: 0.52; 95% CI: 0.34-0.78). Further analyses indicated that VDRnum status also was predictive of overall survival when investigated in relation to ER status. There were significant interactions between VDR and invasive tumor size (Pinteraction = 0.047), as well as mode of detection (Pinteraction = 0.049). VDRnum was associated with a longer BCFI in patients with larger tumors (HR: 0.36; 95% CI: 0.14-0.93) or clinically detected tumors (HR: 0.28; 95% CI: 0.09-0.83), while no association was found for smaller tumors and screening-detected tumors. Further studies are suggested to confirm our results and to evaluate whether VDR should and could be used as a prognostic and targetable marker in breast cancer diagnostics.

Healthy Lifestyle and Cancer Risk: Modifiable Risk Factors to Prevent Cancer

Cancer has become a serious problem worldwide, as it represents the main cause of death, and its incidence has increased over the years. A potential strategy to counter the growing spread of various forms of cancer is the adoption of prevention strategies, in particular, the use of healthy lifestyles, such as maintaining a healthy weight, following a healthy diet; being physically active; avoiding smoking, alcohol consumption, and sun exposure; and vitamin D supplementation. These modifiable risk factors are associated with this disease, contributing to its development, progression, and severity. This review evaluates the relationship between potentially modifiable risk factors and overall cancer development, specifically breast, colorectal, and prostate cancer, and highlights updated recommendations on cancer prevention. The results of numerous clinical and epidemiological studies clearly show the influence of lifestyles on the development and prevention of cancer. An incorrect diet, composed mainly of saturated fats and processed products, resulting in increased body weight, combined with physical inactivity, alcohol consumption, and smoking, has induced an increase in the incidence of all three types of cancer under study. Given the importance of adopting correct and healthy lifestyles to prevent cancer, global institutions should develop strategies and environments that encourage individuals to adopt healthy and regular behaviors.

Prevention and Co-Management of Breast Cancer-Related Osteoporosis Using Resveratrol

Breast cancer (BC) is currently one of the most common cancers in women worldwide with a rising tendency. Epigenetics, generally inherited variations in gene expression that occur independently of changes in DNA sequence, and their disruption could be one of the main causes of BC due to inflammatory processes often associated with different lifestyle habits. In particular, hormone therapies are often indicated for hormone-positive BC, which accounts for more than 50-80% of all BC subtypes. Although the cure rate in the early stage is more than 70%, serious negative side effects such as secondary osteoporosis (OP) due to induced estrogen deficiency and chemotherapy are increasingly reported. Approaches to the management of secondary OP in BC patients comprise adjunctive therapy with bisphosphonates, non-steroidal anti-inflammatory drugs (NSAIDs), and cortisone, which partially reduce bone resorption and musculoskeletal pain but which are not capable of stimulating the necessary intrinsic bone regeneration. Therefore, there is a great therapeutic need for novel multitarget treatment strategies for BC which hold back the risk of secondary OP. In this review, resveratrol, a multitargeting polyphenol that has been discussed as a phytoestrogen with anti-inflammatory and anti-tumor effects at the epigenetic level, is presented as a potential adjunct to both support BC therapy and prevent osteoporotic risks by positively promoting intrinsic regeneration. In this context, resveratrol is also known for its unique role as an epigenetic modifier in the regulation of essential signaling processes-both due to its catabolic effect on BC and its anabolic effect on bone tissue.

The Impact of Vitamin D and Its Dietary Supplementation in Breast Cancer Prevention: An Integrative Review

Vitamin D deficiency is currently a significant public health issue closely linked to numerous diseases, such as breast cancer. This study aims to determine the estimated optimal serum levels of vitamin D to have a protective effect against breast cancer, in addition to exploring the biological mechanisms and risk factors involved. A literature search of articles published in the last 5 years was conducted, and simple statistical analyses using mean and standard deviation were performed to calculate the average concentration of vitamin D from different available studies. It has been observed that serum levels of vitamin D ≥ 40.26 ng/mL ± 14.19 ng/mL could exert a protective effect against breast cancer. Additionally, various biological mechanisms, such as those related to the immune system, and risk factors like diet implicated in this relationship were elucidated. Consequently, it can be concluded that proper serum levels of vitamin D may have a protective effect against breast cancer, and dietary supplementation may be an appropriate procedure to achieve these optimal vitamin D concentrations.

Dual effect of vitamin D3 on breast cancer-associated fibroblasts

BACKGROUND

Cancer-associated fibroblasts (CAFs) play an important role in the tumor microenvironment. Despite the well-known in vitro antitumoral effect of vitamin D3 (VD3), its impact on breast CAFs is almost unknown. In this study, we analyzed the ex vivo effects of calcitriol on CAFs isolated from breast cancer tissues.

METHODS

CAFs were cultured with 1 and 10 nM calcitriol and their phenotype; gene expression, protein expression, and secretion were assessed. Calcitriol-treated CAFs-conditioned media (CM) were used to analyze the effect of CAFs on the migration and protein expression of MCF-7 and MDA-MB-231 cells.

RESULTS

Tumor tissues from VD3-deficient patients exhibited lower levels of β-catenin and TGFβ1, along with higher levels of CYP24A1 compared to VD3-normal patients. In VD3-deficient patients, CAF infiltration was inversely associated with CYP24A1 levels and positively correlated with OPN levels. Calcitriol diminished CAFs' viability, but this effect was weaker in premenopausal and VD3-normal patients. Calcitriol reduced mRNA expression of CCL2, MMP9, TNC, and increased PDPN, SPP1, and TIMP1. It also decreased the secretion of CCL2, TNC, and the activity of MMP-2, while increasing cellular levels of TIMP1 in CAFs from all patient groups. In nonmetastatic and postmenopausal patients, PDPN surface expression increased, and CAFs CM from these groups decreased MCF-7 cell migration after ex vivo calcitriol treatment. In premenopausal and VD3-deficient patients, calcitriol reduced IDO1 expression in CAFs. Calcitriol-treated CAFs CM from these patients decreased OPN expression in MCF-7 and/or MDA-MB-231 cells. However, in premenopausal patients, calcitriol-treated CAFs CM also decreased E-cadherin expression in both cell lines.

CONCLUSION

The effects of calcitriol on breast CAFs, both at the gene and protein levels, are complex, reflecting the immunosuppressive or procancer properties of CAFs. The anticancer polarization of CAFs following ex vivo calcitriol treatment may result from decreased CCL2, TNC (gene and protein), MMP9, and MMP-2, while the opposite effect may result from increased PDPN, TIMP1 (gene and protein), and SPP1. Despite these multifaceted effects of calcitriol on molecule expression, CAFs' CMs from nonmetastatic and postmenopausal patients treated ex vivo with calcitriol decreased the migration of MCF-7 cells.

Calcitriol promotes M2 polarization of tumor-associated macrophages in 4T1 mouse mammary gland cancer via the induction of proinflammatory cytokines

Our research found that vitamin D3 (VD3) treatment increased lung metastasis in mice with 4T1 murine breast cancer (BC). This study aims to investigate the impact of VD3 on the activation of tumor-associated macrophages (TAMs) in BC. Mice bearing 4T1, E0771, 67NR BC cells, and healthy mice, were fed diets with varying VD3 contents (100-deficient, 1000-normal, and 5000 IU/kg-elevated). Some mice in the 1000 and 100 IU/kg groups received calcitriol. We studied bone metastasis and characterized TAMs and bone marrow-derived macrophages (BMDMs). 4T1 cells had higher bone metastasis potential in the 5000 IU/kg and calcitriol groups. In the same mice, an elevated tumor osteopontin level and M2 polarization of TAMs (MHCIIlow CD44high phenotype) were observed. Gene expression analysis confirmed M2 polarization of 4T1 (but not 67NR) TAMs and BMDMs, particularly in the 100 IU + cal group (increased Mrc1, Il23, and Il6). This polarization was likely due to COX-2/PGE2 induction in 4T1 calcitriol-treated cells, leading to increased proinflammatory cytokines like IL-6 and IL-23. Future studies will explore COX-2/PGE2 as a primary mediator of calcitriol-stimulated inflammation in the BC microenvironment, especially relevant for BC patients with VD3 deficiency and supplementation.

Vitamin D and potential effects on cancers: a review

Cancer is characterized by the abnormal and uncontrollable division and growth of cells that can infiltrate tissues and alter normal physiological function, which will become crucial and life-threatening if left untreated. Cancer can be a result of genetics, such as mutations or environmental causes, including smoking, lack of physical activity, as well as nutritional imbalance in the body. Vitamin D is one of the foremost nutrients that play a crucial role in a variety of biochemical pathways, and it is an important key factor in several diseases. Vitamin D is an essential nutrient for preventing malignancies and a complementary treatment for cancer through direct and indirect biochemical pathways. In this article, we summarized the correlation between vitamin D and various cancers using an extensive search on PubMed, Google Scholar, and Scopus. This paper reviews the role of vitamin D in different types of cancer.

Vitamin D and Its Metabolites Status before and during Chemotherapy in Caucasian Breast Cancer Patients

BACKGROUND

The predictive role of vitamin D (VD) in breast cancer (BC) patients' survival is still being investigated. This paper aims to evaluate the changes in VD metabolites during chemotherapy (CTH) and the predictive role of VD status in Caucasian BC patients treated with CTH.

METHODS

Vitamin D and its metabolites were assessed with reference LC-MS/MS methodology in 98 consecutive BC patients starting CHT, after 3 and 6 months, and compared to the control group.

RESULTS

The frequency of VD deficiency in BC patients was greater than in the control group (56.1% vs. 37.2%). After 6 months of CTH, the number of VD-deficient BC patients slightly increased to 60%. The concentrations of VD active forms [25(OH)D2, 25(OH)D3], and catabolites [24,25(OH)2D3 and 3-epi-25(OH)D3] decreased after 3 and 6 months of CTH compared to the baseline values. Strong positive correlations between concentrations of 3-epi-25(OH)D3 and 25(OH)D in both groups were found. Similar correlations were also observed between 24,25(OH)2D3 and 25(OH)D levels. Kaplan-Meier survival analysis showed significantly longer survival in BC patients without deficiency (>20 ng/mL) at baseline (HR = 2.44 (95% CI 1.07-5.59), p = 0.026).

CONCLUSIONS

(1) Our data provide further evidence that BC patients before CTH are more VD-deficient than the general population and this deficiency increases further during CTH treatment, as observed using the reference LC-MS methodology. (2) Presented results show that VD catabolism is not affected in BC patients. (3) The poorer survival in VD-deficient BP patients supports the importance of VD supplementation in BC patients with 25(OH)D levels below 20 ng/mL.

Evaluation of the relationship between vitamin D levels with oocyte quality in breast cancer women: a cross-sectional study

Recent evidence suggests that vitamin D deficiency could play an important role in the development of non-skeletal diseases, including cancer. Vitamin D also affects the function of the reproductive system. In the present study, the relationship between 25(OH)D levels with oocyte quality in Breast Cancer (BC) women and control group have been investigated. After initial evaluations, ovarian stimulation began with the GnRH antagonist protocol in the BC group (N = 16) and control group (N = 16). The serum and follicular fluid (FF) 25(OH)D levels were measured at the time of oocyte retrieval and their relationship to oocyte quality was examined. The mean levels of serum and FF 25(OH)D in BC women were significantly lower than in the control group (22.26 ± 7.98 vs. 29.61 ± 9.12, P = 0.02, 21.65 ± 7.59 vs. 28.00 ± 9.05, P = 0.04, respectively). There was a significant correlation between the levels of 25(OH)D in FF and serum in BC women (r = 0.873, P < 0.001). But there was no correlation between the serum or FF 25(OH)D levels with the parameters related to oocytes (P > 0.05). In the BC women, the number of dysmorph and highly dysmorph oocytes was higher than in the control group (P < 0.001). Women with BC referring to infertility centers for fertility preservation are more likely to be deficient in serum 25(OH)D level; this subsequently affects the FF 25(OH)D level. However, serum and FF 25(OH)D levels may not be suitable indicators for examining maturity and quality of oocytes in terms of morphology in BC women, and the poor morphological quality of oocytes in BC women may be due to other factors.

The influence of vitamin D supplementation and strength training on health biomarkers and chromosomal damage in community-dwelling older adults

Older adults lack of proper physical activity which is often accompanied by vitamin D deficiency. Those factors are known to contribute to health issues in the later years of life. The main goal of this intervention study was to investigate the effect of different vitamin D supplementation strategies for 4 weeks solely or combined with a 10-week strength training program on chromosomal stability in peripheral blood mononuclear cells in community-dwelling older people. One hundred women and men (65-85 years) received either vitamin D3 daily (800 IU), a monthly dose (50.000 IU) or placebo for 17 weeks. All groups received 400 mg calcium daily. The fitness status of the study participants was measured using the 30- second chair stand test, the handgrip strength test and the 6-min walk test. The cytokinesis block micronucleus cytome (CBMN) assay was applied to analyze chromosomal anomalies, including cytotoxic and genotoxic parameters. Changes in antioxidant markers were measured in plasma. Walking distance and chair stand performance improved significantly. Increased levels of the parameters of the CBMN assay were detected for all intervention groups at study end. At baseline micronuclei (MNi) frequency correlated significantly with BMI in both sexes (females: r = 0.369, p = 0.034; males: r = 0.265, p = 0.035), but not with vitamin D serum levels. In females, body fat (r = 0.372, p < 0.001) and functional parameter using the 30-s chair stand test (r = 0.311, p = 0.002) correlated significantly with MNi frequency. Interestingly, not vitamin D supplementation but 10 weeks of resistance training increased MNi frequency indicating elevated chromosomal instability and also adverse effects on antioxidant markers including glutathione and FRAP were detected in the group of community-dwelling older adults.

Calcifediol: Why, When, How Much?

Vitamin D deficiency is a constantly growing health problem worldwide. Adults affected with hypovitaminosis D could experience negative consequences on their musculoskeletal system and extra-skeletal health. In fact, an optimal vitamin D status is essential to ensure the correct bone, calcium, and phosphate homeostasis. To improve vitamin D status, it is important to not only increase the intake of food fortified with vitamin D, but also to administer vitamin D supplementation when required. Vitamin D3 (cholecalciferol) is the most widely used supplement. In recent years, the administration of calcifediol (25(OH)D3), the direct precursor of the biologically active form of vitamin D3, as oral vitamin D supplementation has progressively grown. Here, we report the potential medical benefits of some peculiar biological actions of calcifediol, discussing the possible specific clinical scenarios in which the oral intake of calcifediol could be most effective to restore the correct serum levels of 25(OH)D3. In summary, the aim of this review is to provide insights into calcifediol-related rapid non-genomic responses and the possible use of this vitamin D metabolite as a supplement for the treatment of people with a higher risk of hypovitaminosis D.

A Scoping Review of Vitamin D for Nonskeletal Health: A Framework for Evidence-Based Clinical Practice

BACKGROUND

Low serum 25-hydroxy-vitamin D [25(OH)D] levels are prevalent worldwide. Although the benefits of vitamin D supplementation have focused on skeletal disorders (eg, rickets, osteomalacia, osteoporosis), emerging evidence for nonskeletal health merits further discussion.

PURPOSE

The purpose of this review was to critically examine the vitamin D supplementation literature pertaining to nonskeletal health to help guide clinicians.

METHODS

A scoping review that included observational studies and randomized clinical trials (RCTs) was performed. Evidence from meta-analyses and individual RCTs are discussed, and controversies and future directions are considered.

FINDINGS

25(OH)D deficiency is a ubiquitous condition associated with multiple nonskeletal diseases, including cardiometabolic (heart disease, diabetes, and kidney disease), immune (HIV/AIDS and cancer), lung (from traditional chronic disorders to coronavirus disease 2019), and gut diseases. Vitamin D deficiency also affects health across the life span (children, pregnant, and elderly), mental illness, and reproduction in both men and women. In contrast, vitamin D supplementation does not necessarily improve major medical outcomes, even when low 25(OH)D levels are treated. Screening for 25(OH)D status remains an important practice, primarily for high-risk patients (eg, elderly, women with osteoporosis, people with low exposure to sunlight). It is reasonable to supplement with vitamin D to treat 25(OH)D deficiency, such that if beneficial nonskeletal health occurs, this may be considered as a coadjutant instead of the central tenet of the disease. Furthermore, optimizing dosing regimens is an important clinical consideration.

IMPLICATIONS

Although 25(OH)D deficiency is prevalent in nonskeletal diseases, there is no uniform evidence that vitamin D supplementation improves major medical outcomes, even when low 25(OH)D levels are corrected. Findings from RCTs warrant caution due to possible selection bias. Overall, vitamin D supplementation must be guided by circulating levels as a reasonable medical practice to correct 25(OH)D deficiency.

Interplay of Vitamin D and SIRT1 in Tissue-Specific Metabolism-Potential Roles in Prevention and Treatment of Non-Communicable Diseases Including Cancer

The importance of the prevention and control of non-communicable diseases, including obesity, metabolic syndrome, type 2 diabetes, cardiovascular diseases, and cancer, is increasing as a requirement of the aging population in developed countries and the sustainability of healthcare. Similarly, the 2013-2030 action plan of the WHO for the prevention and control of non-communicable diseases seeks these achievements. Adequate lifestyle changes, alone or with the necessary treatments, could reduce the risk of mortality or the deterioration of quality of life. In our recent work, we summarized the role of two central factors, i.e., appropriate levels of vitamin D and SIRT1, which are connected to adequate lifestyles with beneficial effects on the prevention and control of non-communicable diseases. Both of these factors have received increased attention in relation to the COVID-19 pandemic as they both take part in regulation of the main metabolic processes, i.e., lipid/glucose/energy homeostasis, oxidative stress, redox balance, and cell fate, as well as in the healthy regulation of the immune system. Vitamin D and SIRT1 have direct and indirect influence of the regulation of transcription and epigenetic changes and are related to cytoplasmic signaling pathways such as PLC/DAG/IP3/PKC/MAPK, MEK/Erk, insulin/mTOR/cell growth, proliferation; leptin/PI3K-Akt-mTORC1, Akt/NFĸB/COX-2, NFĸB/TNFα, IL-6, IL-8, IL-1β, and AMPK/PGC-1α/GLUT4, among others. Through their proper regulation, they maintain normal body weight, lipid profile, insulin secretion and sensitivity, balance between the pro- and anti-inflammatory processes under normal conditions and infections, maintain endothelial health; balance cell differentiation, proliferation, and fate; and balance the circadian rhythm of the cellular metabolism. The role of these two molecules is interconnected in the molecular network, and they regulate each other in several layers of the homeostasis of energy and the cellular metabolism. Both have a central role in the maintenance of healthy and balanced immune regulation and redox reactions; therefore, they could constitute promising targets either for prevention or as complementary therapies to achieve a better quality of life, at any age, for healthy people and patients under chronic conditions.

Association Between Expression of Vitamin D Receptor and Insulin-Like Growth Factor 1 Receptor Among Breast Cancer Patients

Background

Vitamin D receptor (VDR) and insulin-like growth factor 1 receptor (IGF1R) are known to be involved in breast cancer (BC) progression. Our previous work reported a correlation of differential localization of IGF1R with hormone receptor status in BC. A recent report described VDR and IGF1R as potential indicators of BC prognosis, but their interplay was not discussed. The present study focused on understanding the association of VDR expression with IGF1R activation, different molecular markers, and subtypes of BC.

Methods

A retrospective study was designed to evaluate the VDR expression among 48 BC patients pathologically diagnosed as invasive BC and were surgically treated at Sharjah Breast Care Center, University Hospital Sharjah (UHS), United Arab Emirates (UAE). Formalin-fixed paraffin-embedded (FFPE) tumor blocks with appropriate clinicopathological data were subjected to immunohistochemistry (IHC), and VDR protein expression was interpreted based on the staining intensity (SI) and the percentage of the positively stained cells (PP).

Results

Nearly 44% of cases in the study were vitamin D deficient. A positive VDR expression with strong intensity (score > 4) was seen in 27 cases (56.3%). The expression pattern for VDR was equally distributed in cytoplasm and nucleus. For the IGF1R intensity, 24 cases (50%) of total cohort showed strong expression. A significant association was detected between IGF1R and VDR expression (P = 0.031).

Conclusions

The present study identified positive association between IGF1R and VDR expression where most of the cases with strong VDR expression displayed strong IGF1R expression. These findings may contribute to current understanding on the role of VDR in BC and its interaction with IGF1R.

Vitamin D Receptor Expression Is Significantly Decreased in Bone Metastases Compared to Matched Primary Breast Cancer Tumours

There is ample evidence today that vitamin D signalling via the vitamin D receptor (VDR) plays a pivotal role in cancer growth and metastasis. The aim of this study was to analyse VDR expression of primary breast cancer and corresponding bone metastases tissue samples. Collectively, 15 sample pairs and 11 samples of patients that did not develop metastases were analysed histologically for VDR expression (n = 41). Overall, VDR expression was significantly lower in bone metastases compared to primary tumour samples (p < .0001). Downregulation of the VDR in breast cancer cells may define a critical turning point in oncogenesis that accelerates cancer cell dissemination and metastases.

Vitamin D Receptor Gene Polymorphisms and the Risk of CIN2+ in Shanxi Population

Cervical cancer is one of the most common malignancies in women with high morbidity and mortality. Human papillomavirus (HPV) infection is the primary cause of cervical cancer, of which HPV 16 is the predominant. Early detection and effective treatment of cervical precancerous lesions are the key to preventing cervical cancer. Vitamin D receptor (VDR) gene polymorphism is considered to be an important cause of cancer development. Here, we studied the association of VDR polymorphisms (FOKI, BsmI, ApaI, and TaqI) in HPV16-positive cervical intraepithelial neoplasia (CIN)2+ patients. HPV16-positive patients who visited the Colposcopy Clinic of Obstetrics and Gynecology, the Second Hospital of Shanxi Medical University for biopsy due to abnormal HPV and/or Thinprep cytologic test (TCT) from September 1, 2020 to October 1, 2021 were grouped by pathological results. The fasting blood samples were collected and VDR polymorphisms were detected using TaqMan fluorescent probes, and the three sites of BsmI-ApaI-TaqI were subjected to haplotype analysis. FOKI ff genotype (OR = 2.01; 95% CI = 1.12 - 3.59; p = 0.019) and f allele (OR = 1.48; 95% CI = 1.10 - 1.98; p = 0.009) were found to be associated with the risk of CIN2+. TaqI Tt genotype (OR = 2.03; 95% CI = 1.20 - 3.43; p = 0.008), tt genotype (OR = 2.09; 95% CI = 1.09 - 4.02; p = 0.028), and t allele (OR = 1.35; 95% CI = 1.01 - 1.80; p = 0.041) were associated with the risk of CIN2+. No haplotype was associated with CIN2+ risk. According to the results, FOKI and TaqI polymorphisms are associated with CIN2+ risk.

Vitamin D Levels in Newly Diagnosed Breast Cancer Patients according to Tumor Sub-Types

Vitamin D is an important regulator of bone health. In addition, as a ligand for a nuclear receptor expressed in breast cancer cells, vitamin D exerts neoplasia modulating effects in breast cancer. However, despite extensive investigations, associations of vitamin D levels with breast cancer patient characteristics and disease sub-types are conflicting. A retrospective review of medical records of consecutive breast cancer patients treated and followed in a single cancer center was undertaken. All patients with 25-hydroxyvitamin D (25-OHD, the circulating form of vitamin D) measurements available within 3 months of their diagnosis and before the start of any systemic treatment were included. Characteristics of patients and tumors with sufficient levels of 25-OHD were compared with those of patients with 25-OHD insufficiency. Two hundred ninety-two patients were included in the study. Almost two-thirds of the patients were 25-OHD insufficient, defined as having 25-OHD levels below 75 nmol/L. Compared with the group of patients who were 25-OHD sufficient, patients with 25-OHD insufficiency were younger and more often obese. Tumors of patients with 25-OHD insufficiency were more often ductal, of higher grade, and ER negative. 25-OHD insufficiency is prevalent in breast cancer patients and even more prevalent in younger and obese patients. 25-OHD insufficiency is associated with cancers that have aggressive characteristics, including higher grade and ER negativity.

Modulation of Fibroblast Activity via Vitamin D3 Is Dependent on Tumor Type—Studies on Mouse Mammary Gland Cancer

Simple Summary

This study, which was conducted in healthy mice and mice bearing three mouse mammary gland cancers—4T1, 67NR, and E0771—showed that the divergent effects of vitamin D₃ supplementation (5000 IU) or deficiency (100 IU of vitamin D₃) observed in healthy mice led to the formation of various body microenvironments depending on the mouse strain. Developing tumors themselves modified the microenvironments by producing higher concentrations of osteopontin, SDF-1 (4T1), TGF-β (4T1 and E0771), CCL2, VEGF, FGF23 (E0771), and IL-6 (67NR), which influences the response to vitamin D₃ supplementation/deficiency and calcitriol administration and leads to enhanced/decreased activation of lung fibroblasts and modulation of tumor tissue blood flow.

Abstract

Vitamin D₃ and its analogs are known to modulate the activity of fibroblasts under various disease conditions. However, their impact on cancer-associated fibroblasts (CAFs) is yet to be fully investigated. The aim of this study was to characterize CAFs and normal fibroblasts (NFs) from the lung of mice bearing 4T1, 67NR, and E0771 cancers and healthy mice fed vitamin-D₃-normal (1000 IU), -deficient (100 IU), and -supplemented (5000 IU) diets. The groups receiving control (1000 IU) and deficient diets (100 IU) were gavaged with calcitriol (+cal). In the 4T1-bearing mice from the 100 IU+cal group, increased NFs activation (increased α-smooth muscle actin, podoplanin, and tenascin C (TNC)) with a decreased blood flow in the tumor was observed, whereas the opposite effect was observed in the 5000 IU and 100 IU groups. CAFs from the 5000 IU group of E0771-bearing mice were activated with increased expression of podoplanin, platelet-derived growth factor receptor β, and TNC. In the 100 IU+cal group of E0771-bearing mice, a decreased blood flow was recorded with decreased expression of fibroblast growth factor 23 (FGF23) and C-C motif chemokine ligand 2 (CCL2) in tumors and increased expression of TNC on CAFs. In the 67NR model, the impact of vitamin D₃ on blood flow or CAFs and lung NFs was not observed despite changes in plasma and/or tumor tissue concentrations of osteopontin (OPN), CCL2, transforming growth factor-β, vascular endothelial growth factor, and FGF23. In healthy mice, divergent effects of vitamin D₃ supplementation/deficiency were observed, which lead to the creation of various body microenvironments depending on the mouse strain. Tumors developing in such microenvironments themselves modified the microenvironments by producing, for example, higher concentrations of OPN and stromal-cell-derived factor 1 (4T1), which influences the response to vitamin D₃ supplementation/deficiency and calcitriol administration.

Lower vitamin D levels and VDR variants are risk factors for breast cancer: an updated meta-analysis

Inadequate vitamin D levels and vitamin D variants have been shown to be associated with breast cancer (BC), however the results are inconsistent. To reach a definitive conclusion the present meta-analysis was conducted. When compared to healthy controls, BC patients had reduced vitamin D levels (standard difference in means = -0.564, p = 0.003). The meta-analysis revealed that the FokI mutation was linked with an increased BC susceptibility (CC vs. TT: OR = 1.107, p = 0.001, CC vs. TC + TT: OR = 1.114, p = 0.020). There was no role of other VDR variants (BsmI, TaqI, and ApaI). FokI mutation and diminished vitamin D increase the likelihood of developing BC.

Vitamin D: an essential adjuvant therapeutic agent in breast cancer

Low serum levels of vitamin D have been reported as a risk factor for breast cancer. This narrative review provides an update on the impact of vitamin D on hormone receptors, notably estrogen receptor subunits, and gives insights on possible therapeutic interventions to overcome breast cancer. In addition, evidence that supports the beneficial use of vitamin D as adjuvant treatment of breast cancer is summarized. Vitamin D deficiency is significantly widespread in patients with triple-negative tumors. Several studies have observed a possible modulatory effect of vitamin D or its analogues on the expression of different hormone receptors in breast cancer and increased sensitivity to tamoxifen. Vitamin D possesses anti-inflammatory and immunomodulatory effects in patients with breast cancer, and the mechanism of action of vitamin D in patients with breast cancer is discussed. In conclusion, vitamin D appears to have a beneficial role in the prevention and management of breast cancer, however, large-scale, randomized controlled trials are needed to confirm the effects of vitamin D in breast cancer prevention or treatment.

Association of Serum 25-Hydroxyvitamin D Concentration with Breast Cancer Risk in Postmenopausal Women in the US

The association between serum 25-hydroxyvitamin D [25(OH)D] concentration and breast cancer risk in postmenopausal women is not well understood. The aim of this study was to investigate the association between serum 25(OH)D concentration and breast cancer in postmenopausal women in the United States using nationally representative sample surveys. We used the data from seven cycles of National Health and Nutrition Examination Surveys from 2001 to 2014. Participants were non-institutionalized postmenopausal women (n = 8108). In restricted cubic spline analysis, a significant, nonlinear, invert ‘U’ relationship was observed between serum 25(OH)D concentrations and breast cancer in postmenopausal women (p = 0.029). Overall, breast cancer risk was highest (OR = 1.5) between 70 nmol/L and 80 nmol/L of serum 25(OH)D concentration. Then after serum 25(OH)D 80 nmol/L concentration, the breast cancer risk declined. In multivariate-adjusted logistic regression, the risk of having breast cancer was significantly higher in serum 25(OH)D 75−˂100 nmol/L category compared to the 25(OH)D < 30 nmol/L category [OR and 95% CI: 2.4 (1.4−4.0)]. In conclusion, serum vitamin D concentrations ≥ 100 nmol/L are associated with reduced risk of breast cancer in postmenopausal women. Controlled trials are required to verify if serum 25(OH)D ≥ 100 nmol/L offers protection against breast cancer in postmenopausal women.

Negative Impact of Vitamin D Deficiency at Diagnosis on Breast Cancer Survival: A Prospective Cohort Study

Objective. We prospectively evaluated the association between vitamin D concentration at diagnosis and overall survival (OS), disease-free survival (DFS), and cancer-specific survival (CSS) in postmenopausal women treated for breast cancer. Methods. This study included 192 patients newly diagnosed with invasive breast cancer, aged ≥45 years, and serum 25-hydroxy vitamin D (25 (OH)D) concentration assessment at diagnosis. Patients were classified into groups according to 25 (OH)D concentrations: sufficient (≥30 ng/mL), insufficient (between 20 and 29 ng/mL), and deficient (<20 ng/mL). The primary outcome was OS, and the secondary outcomes were DFS and CSS. The Kaplan–Meier curve and Cox regression model were used to assess the association between 25 (OH)D concentrations and survival rates. Differences in survival were evaluated by hazard ratios (HRs). Results. The mean age was 61.3 ± 9.6 years, 25 (OH)D concentration was 26.9 ± 7.5 ng/mL (range 12.0–59.2 ng/mL), and the follow-up period was between 54 and 78 months. Sufficient 25 (OH)D was detected in 33.9% of patients, insufficient in 47.9%, and deficient in 18.2%. A total of 51 patients (26.6%) died during the study period, with a mean OS time of 54.4 ± 20.2 months (range 9–78 months). Patients with 25 (OH)D deficiency and insufficiency at diagnosis had a significantly lower OS, DFS, and CSS compared with patients with sufficient values ( $p<\text{0}.001$ ). After adjustment for clinical and tumoral prognostic factors, patients with 25 (OH)D concentrations considered deficient at diagnosis had a significantly higher risk of global death (HR, 4.65; 95% CI, 1.65–13.12), higher risk of disease recurrence (HR, 6.87; 95% CI, 2.35–21.18), and higher risk of death from the disease (HR, 5.91; 95% CI, 1.98–17.60) than the group with sufficient 25(OH)D concentrations. Conclusion. In postmenopausal women treated for breast cancer, vitamin D deficiency and insufficiency at diagnosis were independently associated with lower OS, DFS, and CSS compared with patients with sufficient 25(OH)D concentrations.

Significance of the Vitamin D Receptor on Crosstalk with Nuclear Receptors and Regulation of Enzymes and Transporters

The vitamin D receptor (VDR), in addition to other nuclear receptors, the pregnane X receptor (PXR) and constitutive androstane receptor (CAR), is involved in the regulation of enzymes, transporters and receptors, and therefore intimately affects drug disposition, tissue health, and the handling of endogenous and exogenous compounds. This review examines the role of 1α,25-dihydroxyvitamin D₃ or calcitriol, the natural VDR ligand, on activation of the VDR and its crosstalk with other nuclear receptors towards the regulation of enzymes and transporters, notably many of the cytochrome P450s including CYP3A4 and sulfotransferase 2A1 (SULT2A1) as well as cholesterol 7α-hydroxylase (CYP7A1). Moreover, the VDR upregulates the intestinal channel, TRPV6, for calcium absorption, LDL receptor-related protein 1 (LRP1) and receptor for advanced glycation end products (RAGE) in brain for β-amyloid peptide efflux and influx, the sodium phosphate transporters (NaP_i), the apical sodium-dependent bile acid transporter (ASBT) and organic solute transporters (OSTα-OSTβ) for bile acid absorption and efflux, respectively, the renal organic anion transporter 3 (OAT3) and several of the ATP-binding cassette protein transporters-the multidrug resistance protein 1 (MDR1) and the multidrug resistance-associated proteins (MRPs). Hence, the role of the VDR is increasingly being recognized for its therapeutic potential and pharmacologic activity, giving rise to drug-drug interactions (DDI). Therapeutically, ligand-activated VDR shows anti-inflammatory effects towards the suppression of inflammatory mediators, improves cognition by upregulating amyloid-beta (Aβ) peptide clearance in brain, and maintains phosphate, calcium, and parathyroid hormone (PTH) balance and kidney function and bone health, demonstrating the crucial roles of the VDR in disease progression and treatment of diseases.

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

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

The efficacy of a comprehensive bone health program in maintaining bone mineral density in postmenopausal women with early-stage breast cancer treated with endocrine therapy: real-world data

BACKGROUND

Aromatase inhibitors (AI) are the gold standard treatment option for hormone-sensitive postmenopausal women with breast cancer. Several studies had documented the accelerated bone loss associated with AI.

AIMS

In this study, we present real-world data describing the efficacy of implementing a comprehensive bone health program to maintain bone mineral density (BMD) in postmenopausal patients with early-stage breast cancer treated with AI.

METHODS

A comprehensive bone health program that includes counseling, exercise, nutritional advice, vitamin D supplements and, when needed, intravenous bisphosphonate infusion was implemented following the initiation of endocrine therapy with AI. Postmenopausal women with hormone-sensitive, early-stage breast cancer treated with endocrine therapy using AI were retrospectively identified. All patients had BMD measurements before and at least 1 year after ET initiation.

RESULTS

A total of 210 patients were included, median (range) age 67 (43-86) years. At baseline, osteoporosis was documented in 38 (18.1%) and osteopenia in 101 (48.1%) patients. Despite the known negative effect of AI, 32 (84.2%) patients with baseline osteoporosis and 69 (68.3%) of those with osteopenia, had a stable or better BMD. On the other hand, 41 (57.7%) of those with normal baseline BMD had a drop in their follow up BMD, p < 0.001. Vertebral fractures were reported in 3 (11.1%) patients with osteoporosis compared to none in patients with normal BMD, p = 0.021.

CONCLUSIONS

Despite the known negative effect of ET on bone health of breast cancer patients, implementing a comprehensive bone health program stabilized or improved BMD.

The TSH/Thyroid Hormones Axis and Breast Cancer

Breast cancer, the most prevalent female carcinoma, is characterized by the expression of steroid nuclear receptors in a subset of cases. The most important nuclear receptor with prognostic and therapeutic implications is the Estrogen Receptor (ER), which is expressed in about three out of four breast cancers. The Progesterone Receptor (PR) and the Androgen Receptor (AR) are also commonly expressed. Moreover, non-steroid nuclear receptors, including the vitamin D receptor (VDR) and the thyroid receptors (TRs), are also present in breast cancers and have pathophysiologic implications. Circulating thyroid hormones may influence breast cancer risk and breast cancer cell survival, through ligating their canonical receptors TRα and TRβ but also through additional membrane receptors that are expressed in breast cancer. The expression of TR subtypes and their respective isotypes have diverse effects in breast cancers through co-operation with ER and influence on other cancer-associated pathways. Other components of the TSH/thyroid hormone axis, such as TSH and selenoiodinase enzymes, have putative effects in breast cancer pathophysiology. This paper reviews the pathophysiologic and prognostic implications of the thyroid axis in breast cancer and provides a brief therapeutic perspective.

Vitamin D and Breast Cancer: Mechanistic Update

The presence of the vitamin D receptor (VDR) in mammary gland and breast cancer has long been recognized, and multiple preclinical studies have demonstrated that its ligand, 1,25-dihydroxyvitamin D (1,25D), modulates normal mammary gland development and inhibits growth of breast tumors in animal models. Vitamin D deficiency is common in breast cancer patients, and some evidence suggests that low vitamin D status enhances the risk for disease development or progression. Although many 1,25D-responsive targets in normal mammary cells and in breast cancers have been identified, validation of specific targets that regulate cell cycle, apoptosis, autophagy, and differentiation, particularly in vivo, has been challenging. Model systems of carcinogenesis have provided evidence that both VDR expression and 1,25D actions change with transformation, but clinical data regarding vitamin D responsiveness of established tumors is limited and inconclusive. Because breast cancer is heterogeneous, the relevant VDR targets and potential sensitivity to vitamin D repletion or supplementation will likely differ between patient populations. Detailed analysis of VDR actions in specific molecular subtypes of the disease will be necessary to clarify the conflicting data. Genomic, proteomic, and metabolomic analyses of in vitro and in vivo model systems are also warranted to comprehensively understand the network of vitamin D-regulated pathways in the context of breast cancer heterogeneity. This review provides an update on recent studies spanning the spectrum of mechanistic (cell/molecular), preclinical (animal models), and translational work on the role of vitamin D in breast cancer. © 2021 The Author. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

High prevalence of vitamin D deficiency in Asia: A systematic review and meta-analysis

Vitamin D deficiency is a worldwide health problem. However, the prevalence of vitamin D deficiency in Asian populations is unclear. The aims of our study were to investigate the prevalence of vitamin D deficiency and its association with different health outcomes in Asia. Searches for studies published from January 2009 to January 2021 were performed in the MEDLINE (via PubMed), EMBASE, and Web of Science databases. This study was registered in the PROSPERO database (CRD42021229841). In total, 472 studies with 746,564 subjects were included in the meta-analysis. The mean serum 25-hydroxyvitamin D (25[OH]D) concentration was 49.39 nmol/L; 20.93% of the participants had 25(OH)D levels <25 nmol/L, 22.82% had levels <30 nmol/L, 57.69% had levels <50 nmol/L, and 76.85% had levels <75 nmol/L. This review found that the prevalence of vitamin D deficiency in Asia is high. The factors significantly related to vitamin D deficiency were gender, age, altitude, region, and specific diseases (diabetes, cancer, fracture, systemic lupus erythematosus [SLE], fatty liver disease, osteopenia, thyroiditis, anemia, hepatitis, metabolic diseases, and dermatitis). These findings may serve as the foundation for more detailed public health strategies and policies on this issue.