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

Vitamin D and risk of developing type 2 diabetes in the SUN project: a prospective cohort study

PURPOSE

Vitamin D deficiency has been associated with multiple chronic diseases, including metabolic disorders such as insulin resistance and type 2 diabetes (T2D). The aim of the study was to analyze the association between validated predicted serum vitamin D status and the risk of developing T2D in a large prospective cohort based on a Mediterranean population.

METHODS

The SUN project is a prospective and dynamic Spanish cohort that gathers university graduates who have answered lifestyle questionnaires, including a validated Food Frequency Questionnaire. The association between predicted serum vitamin D and the risk of T2D was assessed through Cox regression models according to quartiles (Q) of predicted vitamin D at baseline. The models were adjusted for potential confounders and sensitivity analyses were performed to ensure the robustness of our findings.

RESULTS

Our study included a total of 18,594 participants and after a total follow-up of 238,078 person-years (median follow-up of 13.5 years), 209 individuals were diagnosed with incident T2D. We found a significant inverse association between predicted levels of serum vitamin D and the risk of developing T2D, after adjusting for potential confounders and performing different sensitivity analyses (hazard ratio Q4 vs. Q1: 0.48, 95% CI 0.26-0.88; p for trend = 0.032).

CONCLUSION

The outcomes suggest that higher levels of vitamin D at baseline may be associated with a reduced risk of developing T2D.

Vitamin D and risk of hypertension among Black women

Evidence of an association between plasma 25-hydroxyvitamin D [25(OH)D] levels and risk of hypertension, predominantly from studies of White individuals, suggests an inverse relationship. Limited data are available on Black individuals, who are more likely to have vitamin D deficiency. In the Black Women's Health Study (BWHS), a prospective study of 59 000 self-identified Black women from across the US, we assessed levels of a validated predicted vitamin D score in relation to incident hypertension. We followed 42 239 participants who were free of cardiovascular disease and cancer from 1995 to 2019, during which time 19 505 incident cases of hypertension were identified. Cox proportional hazards model were used to calculate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the association of predicted vitamin D with the risk of incident hypertension. In age-adjusted analyses, there was a strong inverse dose-response association between predicted vitamin D score and hypertension risk, with an HR of .66 (95% CI: .63-.68, p trend < .0001) for the highest quartile of predicted vitamin D relative to the lowest. After control for potential confounders including body mass index, physical activity, and cigarette smoking, the HR was attenuated to .91 (95% CI: .87-.95, p trend = .002). In this prospective cohort study of Black women, predicted vitamin D score was weakly inversely associated with the incidence of hypertension. This observed association may reflect an inability to fully control for confounding factors.

Cell-free SLC30A10 messenger ribonucleic acid (mRNA) expression and their association with vitamin-D level among non-small cell lung cancer (NSCLC) patients

BACKGROUND

Lung cancer has been major cause of cancer related death and day by day Non-small cell lung cancer (NSCLC) cases are increasing globally. Present study explored the link between SLC30A10 mRNA expression with vitamin-D level among the NSCLC patients.

METHODS

Present study included newly diagnosed 100 NSCLC patients and 100 healthy controls. Quantitative real time PCR was performed to check the SLC30A10 mRNA expression after cDNA synthesis from extracted total RNA from serum sample. Vitamin-D level was also analyzed in all the NSCLC patients by electrochemiluminscence based immunoassay method.

RESULTS

Present research work observed decreased SLC30A10 mRNA expression (0.16 fold) among the NSCLC patients, decreased SLC30A10 mRNA expression was linked with advanced stage (0.15 fold, P < 00001) of disease and distant organ metastases (0.11 fold, P < 00001) compared to its contrast. Decreased level of vitamin-D was also observed with advanced stage (17.98 ng/ml, P < 00001) of disease and distant organ metastases (16.23 ng/ml, P < 00001) compared to its contrast. Positive correlation was observed between SLC30A10 mRNA expression with vitamin-D level among the NSCLC patients suggesting decrease or increase in SLC30A10 mRNA expression mau decreases or increase the vitamin-D level. NSCLC patients with vitamin-D deficiency had 0.14 reduced SCL30A10 mRNA expression while insufficient (P = 0 .06) and sufficient (P = 0.03) showed comparatively high SCL30A10 mRNA expression.

CONCLUSION

Study concluded that down regulation of SLC30A10 mRNA and vitamin-D deficiency may involve in advancement of disease and distant organ metastases. It was also suggested that the decrease of increase in SLC30A10 expression may cause the decrease of increase in vitamin-D level among the NSCLC patients may be involved in disease severity and worseness of NSCLC disease.

Vitamin D Levels in Ethnic Minority Adolescents in Primary Care

INTRODUCTION

This pilot study examined the distribution of low vitamin D levels among ethnic minority adolescents in primary care to elucidate the clinical needs of this diverse population.

METHOD

A cross-sectional study was conducted using a retrospective patient chart review. Participants were a consecutive sample of 119 ethnically diverse adolescents aged 12-18 years, attending a primary care clinic, who had a wellness examination in 2018 and documented vitamin D levels on the basis of previously collected blood work.

RESULTS

Sixty-one percent of adolescents had low vitamin D levels. Vitamin D deficiency increased with age, independently of ethnicity or gender.

DISCUSSION

A significant number of ethnically diverse adolescents presented with low vitamin D levels. A need exists to raise awareness among clinicians regarding social determinants of health and culturally sensitive dietary practices to improve vitamin D levels and prevent long-term complications, focusing on adolescent at-risk ethnic groups.

Vitamin D concentrations and breast cancer incidence among Black/African American and non-Black Hispanic/Latina women

BACKGROUND

Vitamin D may protect against breast cancer. Although Black/African American women and Hispanic/Latina women have lower circulating vitamin D levels than non-Hispanic White women, few studies have examined the association between vitamin D and breast cancer within these racial/ethnic groups.

METHODS

The vitamin D-breast cancer association was evaluated using a case-cohort sample of self-identified Black/African American and non-Black Hispanic/Latina women participating in the US-wide Sister Study cohort. Circulating 25-hydroxyvitamin D (25(OH)D) and 24,25-dihydroxyvitamin D (24,25(OH)2D) were measured using liquid chromatography-tandem mass spectrometry in blood samples collected at the baseline from 415 women (290 Black/African American women and 125 non-Black Hispanic/Latina women) who developed breast cancer. These were compared to concentrations in 1545 women (1084 Black/African American women and 461 Hispanic/Latina women) randomly selected from the cohort. Multivariable-adjusted Cox regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Over a mean follow-up of 9.2 years, women with circulating 25(OH)D concentrations above the clinical cut point for deficiency (20.0 ng/mL) had lower breast cancer rates than women with concentrations ≤ 20 ng/mL (HR, 0.79; 95% CI, 0.61-1.02). The inverse association was strongest among Hispanic/Latina women (HR, 0.52; 95% CI, 0.29-0.93), with a weaker association observed among Black/African American women (HR, 0.89; 95% CI, 0.68-1.18; P for heterogeneity = 0.13). There were no clear differences by menopausal status, follow-up time, estrogen receptor status, or invasiveness. Neither 24,25(OH)₂ D nor the 24,25(OH)₂ D to 25(OH)D ratio were independently associated with breast cancer risk.

CONCLUSIONS

This prospective study supports the hypothesis that vitamin D may be protective against breast cancer incidence in women, including non-Black Hispanic/Latina and Black/African American women.; LAY SUMMARY: Vitamin D may protect against breast cancer. Although women of color have lower average vitamin D levels than non-Hispanic White women, few studies have considered the role of race/ethnicity. In a sample of self-identified Black/African American and Hispanic/Latina women, we observed that vitamin D concentrations measured in blood were inversely associated with breast cancer, particularly among Latinas. These findings indicate that vitamin D may protect women against breast cancer, including those in racial/ethnic groups with low average circulating levels.

Identify factors for insufficient (> 2 yr) mammogram screening among Oregonian women

PURPOSE

Women with breast cancer diagnosed from mammogram screenings have a lower mortality risk than women diagnosed from symptoms. Currently, the U.S Preventive Services Task Force recommends biannual screening for women aged 50-74 years old. In this study, we aimed to identify factors associated with inadequate screening defined as "no mammogram screening within past 2 years" to guide cancer prevention and early detection efforts.

METHODS

This study utilized area-based probabilistic sampling survey data, collected across Oregon in 2019. Dataset weights were calculated using a raking approach. Demographic and behavior information were collected with existing validated questionnaire items from national surveys. Weighted multivariable logistic regression analyses with missing-value imputations were conducted to identify factors associated with inadequate mammogram screening.

RESULTS

The study included 254 women 50-74 years old without previous breast or ovarian cancer history. 19.29% of the sample reported no mammogram within two years, including 1.57% with no previous mammograms. Following unadjusted analyses, the significant factors included education, occupation status, health insurance and smoking and were therefore included into the adjusted model. In the multivariate adjusted model education remained significant while occupation status, health insurance and smoking were no longer significant. Compared to women with a college graduate degree, women with less than college graduate degree were at higher risk of inadequate screening [OR (95% CI) = 3.23 (1.54, 6.74)].

CONCLUSIONS

Lack of education was significantly associated with inadequate mammogram screening even after adjusting for occupation status, health insurance and smoking, which should prompt further outreach and education.

Place Is Power: Investing in Communities as a Systemic Leverage Point to Reduce Breast Cancer Disparities by Race

Racial disparities in breast cancer present a vexing and complex challenge for public health. A diverse array of factors contributes to disparities in breast cancer incidence and outcomes, and, thus far, efforts to improve racial equity have yielded mixed results. Systems theory offers a model that is well-suited to addressing complex issues. In particular, the concept of a systemic leverage point offers a clue that may assist researchers, policymakers, and interventionists in formulating innovative and comprehensive approaches to eliminating racial disparities in breast cancer. Naming systemic racism as a fundamental cause of disparities, we use systems theory to identify residential segregation as a key leverage point and a driver of racial inequities across the social, economic, and environmental determinants of health. We call on researchers, policymakers, and interventionists to use a systems-informed, community-based participatory approach, aimed at harnessing the power of place, to engage directly with community stakeholders in coordinating efforts to prevent breast cancer, and work toward eliminating disparities in communities of color.

Vitamin D Supplement Use and Risk of Breast Cancer by Race-Ethnicity

BACKGROUND

Vitamin D has anticarcinogenic properties, but a relationship between vitamin D supplement use and breast cancer is not established. Few studies have accounted for changes in supplement use over time or evaluated racial-ethnic differences.

METHODS

The Sister Study is a prospective cohort of 50,884 women with 35-74 years of age who had a sister with breast cancer, but no breast cancer themselves at enrollment (2003-2009). We used Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between vitamin D supplement use and incident breast cancer (3,502 cases; median follow-up 10.5 years).

RESULTS

Vitamin D supplement use was common, with 64% reporting ever use (at least once per month) in the year before enrollment. Considering supplement use over time, ever use of vitamin D supplements was not meaningfully associated with breast cancer (HR = 0.96, 95% CI = 0.88, 1.0), relative to never use. However, after adjusting for prior use, recent use of vitamin D supplements ≥1/month was inversely associated with breast cancer (HR = 0.88, 95% CI = 0.78, 1.0), relative to nonrecent use. The inverse association was stronger for ductal carcinoma in situ (HR = 0.67, 95% CI = 0.52, 0.87) than invasive breast cancer (HR = 0.94, 95% CI = 0.72, 1.1, p-for-heterogeneity = 0.02). Supplement use was less common among African American/Black (56%) and non-Black Hispanic/Latina (50%) women than non-Hispanic White women (66%), but there was limited evidence of racial-ethnic differences in HRs (p-for-heterogeneity = 0.16 for ever use, P = 0.55 for recent).

CONCLUSIONS

Our findings are consistent with the hypothesis that recent vitamin D use is inversely associated with breast cancer risk.

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.

Predicted Vitamin D Status and Colorectal Cancer Incidence in the Black Women's Health Study

BACKGROUND

Observational studies, mostly among White populations, suggest that low vitamin D levels increase colorectal cancer risk. African Americans, who are disproportionately burdened by colorectal cancer, often have lower vitamin D levels compared with other populations.

METHODS

We assessed predicted vitamin D score in relation to colorectal cancer among 49,534 participants in the Black Women's Health Study, a cohort of African American women followed from 1995 to 2017 through biennial questionnaires. We derived predicted vitamin D scores at each questionnaire cycle for all participants using a previously validated prediction model based on actual 25-hydroxyvitamin D values from a subset of participants. We calculated cumulative average predicted vitamin D score at every cycle by averaging scores from cycles up to and including that cycle. Using Cox proportional hazards regression, we estimated hazard ratios (HR) and 95% confidence intervals (CI) for colorectal cancer incidence according to predicted score quartiles.

RESULTS

Over follow-up, 488 incident colorectal cancers occurred. Compared with women in the highest quartile of predicted vitamin D score, those in the lowest had an estimated 41% (HR = 1.41; 95% CI, 1.05-1.90) higher colorectal cancer risk. Comparable HRs were 1.44 (95% CI, 1.02-2.01) for colon and 1.34 (95% CI, 0.70-2.56) for rectal cancer.

CONCLUSIONS

Low vitamin D status may lead to elevated colorectal cancer risk in African American women.

IMPACT

Our findings, taken together with established evidence that vitamin D levels are generally lower in African Americans than other U.S. groups, suggest that low vitamin D status may contribute to the disproportionately high colorectal cancer incidence among African Americans.

The Healthy Taiwanese Eating Approach is inversely associated with all-cause and cause-specific mortality: A prospective study on the Nutrition and Health Survey in Taiwan, 1993-1996

Background

Few longitudinal studies have investigated the association between foods/dietary pattern and mortality risk in the Asian population. We investigated the prospective association between foods/dietary pattern and risk of death among ethnic Chinese adults in Taiwan.

Methods

The study population included 2475 young and middle-aged adults (aged 18–65 years at baseline) who completed the questionnaires and physical examinations in the Nutrition and Health Survey in Taiwan from 1993 to 1996. A food frequency questionnaire was administered to assess food consumption habits in a face-to-face interview. With survey data linked to the Taiwanese Death Registry, Cox proportional hazard model was used to identify the foods associated with all-cause mortality(followed until 2012), which were then tallied to calculate a dietary pattern score called Taiwanese Eating Approach(TEA) score. The TEA scores were then associated with various kinds of mortality outcomes. In addition, data from 431 elders (aged≥65 yrs) with 288 death endpoints were used to conduct a sensitivity analysis.

Results

A total of 385(15.6%) participants died (111 cardiovascular related deaths and 122 cancer related deaths) during the 17.8-year follow-up period(41274 person-years). Twelve foods (9 inverse [vegetables/fish/milk/tea](+1) and 3 positive[fatty meats/fermented vegetables/sweet drinks](-1)) were significantly associated with all-cause mortality risk. All adults were grouped by their cumulative food score into three diet groups: poor diet(29.3% of all subjects), average diet(44.0%), and healthy diet(26.70%). The better the diet, the lower the total, cardiovascular, and other cause mortality outcomes (trend-p < .001). The hazard ratio for the healthy diet was 0.64 (95% confidence interval:0.47–0.87) for total mortality, and 0.52(0.28–0.95) for cardiovascular death, compared with the poor diet in the multivariable models. This phenomenon was also seen in older adults for all-cause, cancer, and other cause mortalities.

Conclusion

Consuming a healthy Taiwanese Eating Approach (TEA) diet is negatively associated with all-cause, cardiovascular, and other-cause mortalities in Taiwan.

Does the High Prevalence of Vitamin D Deficiency in African Americans Contribute to Health Disparities?

African Americans have higher incidence of, and mortality from, many health-related problems than European Americans. They also have a 15 to 20-fold higher prevalence of severe vitamin D deficiency. Here we summarize evidence that: (i) this health disparity is partly due to insufficient vitamin D production, caused by melanin in the skin blocking the UVB solar radiation necessary for its synthesis; (ii) the vitamin D insufficiency is exacerbated at high latitudes because of the combination of dark skin color with lower UVB radiation levels; and (iii) the health of individuals with dark skin can be markedly improved by correcting deficiency and achieving an optimal vitamin D status, as could be obtained by supplementation and/or fortification. Moderate-to-strong evidence exists that high 25-hydroxyvitamin D levels and/or vitamin D supplementation reduces risk for many adverse health outcomes including all-cause mortality rate, adverse pregnancy and birth outcomes, cancer, diabetes mellitus, Alzheimer's disease and dementia, multiple sclerosis, acute respiratory tract infections, COVID-19, asthma exacerbations, rickets, and osteomalacia. We suggest that people with low vitamin D status, which would include most people with dark skin living at high latitudes, along with their health care provider, consider taking vitamin D3 supplements to raise serum 25-hydroxyvitamin D levels to 30 ng/mL (75 nmol/L) or possibly higher.

A prospective study of yogurt and other dairy consumption in relation to incidence of type 2 diabetes among black women in the USA

BACKGROUND

Yogurt consumption and low-fat dairy consumption have been associated with reduced incidence of type 2 diabetes (T2D) in some studies.

OBJECTIVE

We assessed the relation of yogurt and other dairy consumption to incidence of T2D in black women, a population group with a disproportionately high incidence of T2D.

METHODS

The Black Women's Health Study has followed 59,000 US black women since 1995 through biennial questionnaires which update health information. Each questionnaire inquired about doctor-diagnosed diabetes in the previous 2 y. FFQs completed by participants in 1995 and 2001 provided information on yogurt and other dietary intake. HRs with 95% CIs for yogurt (nonfrozen or frozen) and other dairy consumption in relation to incident T2D (n = 8061 cases) were estimated with Cox proportional hazards regression, controlling for risk factors for T2D.

RESULTS

The HR for consumption of ≥1 serving of yogurt/d relative to <1 serving/mo was 0.99 (95% CI: 0.87, 1.13, P trend = 0.65) after control for dietary and nondietary risk factors for T2D. The multivariable HR was 0.97 (95% CI: 0.75, 1.27; P trend = 0.74) for 2 or more servings/d of low-fat dairy other than yogurt relative to <1 serving/mo and 1.06 (95% CI: 0.91, 1.25, P trend = 0.36) for 2 or more servings/d of regular dairy relative to <1 serving/mo.

CONCLUSION

Results from this study do not support an inverse association of yogurt consumption or other dairy consumption with T2D risk in black women.

Intake of vitamin D and calcium, sun exposure, and risk of breast cancer subtypes among black women

BACKGROUND

The randomized placebo-controlled Vitamin D and Omega-3 Trial suggested a possible benefit of vitamin D on cancer incidence among black individuals. However, data are limited regarding the impact of vitamin D on breast cancer subtypes among African-American/black women, who tend to develop more aggressive forms of breast cancer.

OBJECTIVES

We hypothesize that more vitamin D exposure (through diet, supplements, and sunlight) and higher intake of calcium are associated with decreased risk of estrogen receptor (ER)+ and ER- breast cancer, and of triple-negative breast cancer (TNBC) among black women.

METHODS

This study was conducted among 1724 black cases and 1233 controls in the Women's Circle of Health Study (WCHS) and WCHS2. Polytomous logistic regressions were used to estimate ORs and 95% CIs of ER+ and ER- breast cancer; logistic regressions were used for TNBC. The ORs from each study were pooled using an inverse-variance-weighted random-effects model.

RESULTS

Dietary vitamin D and calcium intake were not associated with risk of breast cancer subtypes in the pooled analysis. For supplemental vitamin D, we observed possible inverse associations between intake of ≤800 IU/d (compared with nonuse) and risk of several subtypes, with effects that appeared strongest for TNBC (OR: 0.58; 95% CI: 0.35, 0.94); no association was found for >800 IU/d. More daylight hours spent outdoors in a year was associated with lower risk of ER+, ER-, and TNBC (e.g., highest compared with lowest quartile: TNBC OR: 0.53; 95% CI: 0.31, 0.91; P-trend = 0.02).

CONCLUSIONS

Moderate supplemental vitamin D intake was associated with decreased risk of TNBC, and increased sun exposure was associated with reduced risk of ER+, ER-, and TNBC among black women.

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

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

Repurposing vitamin D for treatment of human malignancies via targeting tumor microenvironment

Tumor cells along with a small proportion of cancer stem cells exist in a stromal microenvironment consisting of vasculature, cancer-associated fibroblasts, immune cells and extracellular components. Recent epidemiological and clinical studies strongly support that vitamin D supplementation is associated with reduced cancer risk and favorable prognosis. Experimental results suggest that vitamin D not only suppresses cancer cells, but also regulates tumor microenvironment to facilitate tumor repression. In this review, we have outlined the current knowledge on epidemiological studies and clinical trials of vitamin D. Notably, we summarized and discussed the anticancer action of vitamin D in cancer cells, cancer stem cells and stroma cells in tumor microenvironment, providing a better understanding of the role of vitamin D in cancer. We presently re-propose vitamin D to be a novel and economical anticancer agent.

Molecular evidence of role of vitamin D deficiency in various extraskeletal diseases

BACKGROUND

Role of vitamin D is not only limited to skeletal system but various other systems of the body, such as immune system, endocrine system, and cardiopulmonary system.

MATERIALS AND METHODS

It is supported by the confirmations of systems-wide expression of vitamin D receptor (VDR), endocrinal effect of calcitriol, and its role in immune responses.

RESULTS

Expression of VDR in various systems, immunoregulatory and hormonal response of vitamin D and deficiency of vitamin D may establish various pathologies in the body.

CONCLUSION

This review provides molecular evidence of relation of vitamin D with extra skeletal.

Association of Degree of European Genetic Ancestry With Serum Vitamin D Levels in African Americans

Circulating levels of vitamin D are generally lower in African Americans than in US whites, and 1 prior analysis carried out in a small number of African Americans suggested that, within this population, vitamin D levels may be related to the degree of genetic admixture. We assessed the association between percentage of European ancestry and serum vitamin D level (assessed in 2013-2015) among 2,183 African-American women from the Black Women's Health Study whose DNA had been genotyped for ancestry-informative markers. ADMIXMAP software was used to estimate the percentage of European ancestry versus African ancestry in each individual. In linear regression analyses with adjustment for genotype batch, age, body mass index, supplemental vitamin D use, ultraviolet B radiation flux in the participant's state of residence, and season of blood draw, each 10% increase in European ancestry was associated with a 0.67-ng/mL increase in serum vitamin D concentration (95% confidence interval: 0.17, 1.17). The association was statistically significant only among women who were not taking vitamin D supplements (for each 10% increase in European ancestry, β = 0.86, 95% confidence interval: 0.14, 1.57). Among African Americans, use of vitamin D supplements may help to reduce vitamin D deficiency associated with genetic ancestry.

Sex consideration in diet-biomarker-related indices: a systematic review

OBJECTIVE

An index of biomarkers derived from dietary factors (diet-biomarker-related index) identifies foods and nutrients that encompass physiological potentials and provides scientific evidence for dietary patterns that increase the risk of disease associated with specific biomarkers. Although men and women have different dietary patterns and physiological characteristics, sex is not often considered when investigators develop a diet-biomarker-related index. We aimed to review whether epidemiological studies developed diet-biomarker-related indices in a sex-specific way.

DESIGN

We systematically searched for epidemiological studies that developed diet-biomarker-related indices, including (i) biomarker prediction indices that include dietary factors as explanatory variables and (ii) dietary patterns to explain biomarker variations, in the PubMed and EMBASE databases. We qualitatively reviewed the sex consideration in index development.

RESULTS

We identified seventy-nine studies that developed a diet-biomarker-related index. We found that fifty-four studies included both men and women. Of these fifty-four studies, twenty-nine (53·7 %) did not consider sex, eleven (20·3 %) included sex in the development model, seven (13·0 %) considered sex but did not include sex in the development model, and seven (13·0 %) derived a diet-biomarker-related index for men and women separately. A list of selected dietary factors that explained levels of biomarkers generally differed by sex in the studies that developed a diet-biomarker-related index in a sex-specific way.

CONCLUSIONS

Most studies that included both men and women did not develop the diet-biomarker-related index in a sex-specific way. Further research is needed to identify whether a sex-specific diet-biomarker-related index is more predictive of the disease of interest than an index without sex consideration.

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

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

Determinants of Plasma 25-Hydroxyvitamin D Concentrations among Breast Cancer Survivors in Korea

We identified demographic, lifestyle, and clinical factors associated with vitamin D status among breast cancer survivors. The vitamin D prediction model may be a useful surrogate of circulating 25-hydroxvitamin D (25(OH)D) concentrations when this measure was not available. We included a total of 216 Korean breast cancer survivors aged 21–79 years who had been diagnosed with stage I to III primary breast cancer and had breast cancer surgery at least 6 months before enrolment. We used linear and logistic regressions to identify determinants for the plasma 25(OH)D concentrations and vitamin D insufficiency (plasma 25(OH)D concentration < 50 nmol/L). We observed that 48.85% of breast cancer survivors had a plasma 25(OH)D concentration less than 50 nmol/L. We identified the following determinants for plasma 25(OH)D concentrations: time since diagnosis (β = −0.005 for 1 month increment), supplementary vitamin D intake (β = 0.06 for 10 μg/day increment), season of the blood draw (β = 0.35 for summer; β = 0.32 for fall; β = 0.26 for winter vs. spring), smoking status (β = 0.28 for former vs. never), use of any supplement (β = −0.35 for non-use vs. use), and the parity number (β = −0.30 for three or more vs. one) were associated with the plasma 25(OH)D concentrations. In addition to the aforementioned variables, body mass index (BMI) was associated with the prevalence of vitamin D insufficiency. We identified the determinants for the plasma 25(OH)D concentrations among Korean breast cancer survivors. Future studies are needed to investigate the role of vitamin D in the progression of breast cancer among Korean breast cancer survivors.

Association of Vitamin D3 Level with Breast Cancer Risk and Prognosis in African-American and Hispanic Women

Background: This study investigated the association of vitamin D3 levels with breast cancer risk and progression in African-Americans and Hispanics. Methods: A total of 237 African-American (Cases = 119, Control = 118) and 423 Hispanic women (Cases = 124, Control = 299) were recruited in the study. Blood samples were collected at the time of breast cancer screening and prior to cancer treatment for 4 weeks on average for the cases. The serum 25-hydroxyvitamin D (25(OH)D3) was measured at a Quest-Diagnostics facility. Results: The results showed that 69.2% of African-Americans and 37.8% of Hispanics had 25(OH)D3 levels below 20 ng/mL. The 25(OH)D3 level below 20 ng/mL was significantly associated with breast cancer in both African-Americans (OR = 2.5, 95% CI = 1.3-4.8) and Hispanics (OR = 1.9, 95% CI = 1.1-3.0). However, the predicted probabilities of breast cancer in African-Americans were significantly higher than in Hispanics (p < 0.001). The 25(OH)D3 below 20 ng/mL was significantly associated with triple negative breast cancer (TNBC) in African-Americans (OR = 5.4, p = 0.02, 95% CI = 1.4-15), but not in Hispanics in our cohort of participants. Levels of 25(OH)D3 below 26 ng/mL predicts a decrease in disease-free survival, but it was not an independent predictor. Conclusions: Our data shows an association between 25(OH)D3 levels and the risk of breast cancer. Further studies on the relationship between 25(OH)D3 level and breast cancer risk are warranted.