Socioeconomic status and vitamin D deficiency among women of childbearing age: a population-based, case-control study in rural northern China

Vitamin D supplementation trials: Navigating the maze of unpredictable results

Vitamin D supplementation studies in various pleiotropic outcomes often yield conflicting results. This complexity arises from various factors, including individual differences (baseline Vitamin D levels, genetics, ethnicity, age, and gender). This review aims to clarify the complexities in Vitamin D supplementation research by examining various influencing factors, ultimately providing a comprehensive understanding to guide future studies and offer more accurate insights into the health impacts of Vitamin D supplementation. For this review, we searched PubMed, Google Scholar, and ScienceDirect, analyzing observational studies, meta-analyses, and randomized controlled trials to identify key factors influencing the efficacy of Vitamin D supplementation. By synthesizing findings from diverse research, we aimed to illuminate the nuances shaping the outcomes of these trials. In conclusion, the review suggests that several demographic and biological factors such as baseline 25(OH)D levels, age, ethnicity, genetics, body mass index, diet, sun exposure, medications, comorbid conditions, socioeconomic status, and self-supplementation all play significant roles in the outcomes of Vitamin D supplementation trials. In addition, the dose and duration of therapy, choice of daily versus bolus dosing, route of administration, and the role of free and bound forms of Vitamin D contribute to the complexity of trial results. Vitamin D's pleiotropic effects extend beyond calcium regulation, impacting various health aspects. Inadequate blood levels can confound trial outcomes, emphasizing the importance of reaching appropriate 25(OH)D thresholds. Study design, sample size, bias minimization, and methodology are critical in influencing trial outcomes and designing studies that account for baseline levels and compliance is crucial for meaningful and accurate results. Standardized assays and internationally agreed-upon cutoff levels are essential to mitigate variability in 25(OH)D measurements and improve result reliability.

Wahab N. Evaluating the Role of Vitamin D in Prediabetes Management, Insights from RCTs in the MENA Region: A Comprehensive Systematic Review

Background/Objectives: The association between vitamin D deficiency and prediabetes has been extensively investigated, yet the findings remain inconsistent, with limited data available on the MENA region. This systematic review aims to assess the relationship between vitamin D deficiency and prediabetes in the Middle East and North Africa (MENA) region, focusing specifically on randomized controlled trials (RCTs). Methods: A comprehensive literature search was performed across four databases, which were Ovid MEDLINE, Cochrane, Scopus, and PubMed. RCTs studies conducted on people with prediabetes aged 15 years and older who live in the MENA region, and receiving vitamin D supplementation were included in the study. Results: From 2194 studies identified from the literature search, only 51 studies were considered eligible for full-text review. Ultimately, seven articles were finalized for inclusion. The findings from these studies showed mixed results, where some studies indicated that vitamin D supplementation had no significant effect on these outcomes. The remaining reported improvements in insulin sensitivity and a reduced risk of progression to type 2 diabetes with vitamin D supplementation. Conclusions: This systematic review examines the complex and contradictory relationship between vitamin D deficiency and prediabetes in the MENA region. Due to the mixed pattern seen in the intervention of vitamin D to prevent the development of type 2 diabetes, further research is necessary to elucidate the underlying mechanisms and potential confounding factors specifically in population of the MENA region.

The status of serum 25(OH)D levels is related to breast cancer

AIM

Breast cancer is the second most common cancer among women and the leading cause of cancer-related mortality in this population. Numerous factors have been identified as either risk factors or protective factors for breast cancer. However, the role of Vitamin D (Vit. D) in breast cancer remains contentious, with conflicting findings in the literature. The present study aimed to compare serum Vit. D levels between women with and without breast cancer.

METHODS

This cross-sectional study included 40 women diagnosed with breast cancer, referred to the Mahdia Hamadan Radiotherapy Center in 2022. These participants were matched with 40 age- and Vit. D serum level-matched women without breast cancer. Serum Vit. D levels were measured using the ELISA method. Statistical analysis was performed using SPSS version 26, with a significance threshold set at a 95% confidence level.

RESULTS

The mean ± standard deviation of serum Vit. D levels in women with and without breast cancer were 31.9 ± 28.27 ng/mL and 37.98 ± 15.89 ng/mL, respectively (P = 0.024). The prevalence of Vit. D insufficiency was 50% in the breast cancer group and 27.5% in the control group, while 50% of the breast cancer group and 72.5% of the control group had sufficient Vit. D levels (P = 0.008). In women with breast cancer, lower Vit. D levels were significantly associated with lower educational (P < 0.001), economic (P < 0.001), and social status (P < 0.001). A weak positive correlation was observed between serum Vit. D levels and patient age (r = 0.162, P = 0.152).

CONCLUSION

The significant difference in serum Vit. D levels between women with and without breast cancer suggests that Vit. D deficiency may be associated with breast cancer risk. These findings support the hypothesis that improving Vit. D status in women could potentially reduce the incidence of breast cancer.

Vitamin D Status in Roma Mothers and Newborns: Socioeconomic Factors and Impact on Neonatal Outcome

BACKGROUND

The Roma are a socioeconomically disadvantaged, marginalized community with reduced access to education, social services, and healthcare. Despite the known health risks they are exposed to, we have limited data about a wide range of health outcomes in this population, including vitamin D deficiency. The aim of this study was to investigate prevalence of vitamin D deficiency and its impact on the anthropometric outcomes of newborns in a group of Roma mothers and their infants in Romania.

METHODS

In total, 131 Roma women and 131 newborns were included in the study. Vitamin D levels in both mothers and newborns, as well as the birth weight, length, and head circumference of newborns, were recorded at birth. We also assessed socioeconomic factors, including education, employment status, income, and living conditions, as well as factors that influence vitamin D status, including sun exposure, use of sunscreen, fish consumption, and skin type.

RESULTS

All mothers and almost all newborns had vitamin D insufficiency or deficiency, with 25-hydroxivitamin D levels below 30 ng/mL. Maternal vitamin D status was significantly correlated with neonatal vitamin D levels (p < 0.01) but not with anthropometric outcomes such as birth weight (p = 0.57), birth length (p = 0.53), or head circumference (p = 0.96). Most study participants had a low socioeconomic status, reporting severe deficiencies in education, employment status, household income, and living conditions.

CONCLUSIONS

Vitamin D deficiency is a significant public health issue among Roma women and their newborns, which may be compounded by the socioeconomic challenges of this vulnerable population.

Prevalence of Vitamin D Deficiency in Orthopedic Trauma Patients: A Cross-Sectional Survey From a Tertiary Care Trauma Center

Background Vitamin D deficiency is prevalent globally, with potential consequences for bone health and trauma outcomes. This study aimed to assess the prevalence of vitamin D deficiency in orthopedic trauma patients and investigate its correlation with various demographic and injury-related factors. Methodology A cross-sectional investigation was undertaken at a tertiary care center. An evaluation of serum 25-hydroxyvitamin D3 levels was conducted on 124 individuals, aged 20 to 70 years, who were hospitalized with orthopedic injuries. Demographic information, the injury method, the bone involvement pattern, and socioeconomic status were documented. Statistical analysis was employed to evaluate the correlations between vitamin levels D and these variables. Results The overall prevalence of vitamin D deficiency was 54 (43.6%) cases, with nine (7.3%) cases exhibiting severe deficiency and 45 (36.3%) cases exhibiting moderate deficiency. Higher rates of deficiency were associated with lower socioeconomic status (p = 0.044) and low-velocity trauma (p = 0.037). No significant association was found with age, sex, or residence. Interestingly, patients with multiple fractures were more prone to deficiency compared to those with single fractures. Conclusions This survey revealed a significant vitamin D deficiency among orthopedic trauma patients. Factors such as socioeconomic status and the nature of the injury emerged as significant risk factors. While conducting routine vitamin D assessments might pose challenges in developing nations, consistent supplementation could prove advantageous in enhancing fracture healing and overall health outcomes among this demographic. There is a call for future research to delve deeper into the role of vitamin D in trauma management and refine supplementation strategies.

Serum 25 hydroxycholecalciferol in periodontitis patients with type 2 diabetes mellitus - A socioeconomic and clinicobiochemical study in Chhattisgarh

Background

Very few studies have examined the impact of the concurrent presence of periodontitis (PD) and type 2 diabetes mellitus (T2DM) on serum Vitamin D levels, particularly in developing nations like India, and needs further investigation.

Aim

This study aims to assess the relationship between serum Vitamin D values and PD in T2DM patients and to study the correlation between socioeconomic and demographic variables that influence the serum Vitamin D levels and the extent of PD in patients with T2DM.

Materials and Methods

This was a cross-sectional, hospital-based research. Medical, dental, and diet histories were obtained from the participants, and their socioeconomic status (SES) was determined. Clinical parameters - plaque index (PI), gingival index (GI), sites with gingival bleeding, probing pocket depth (PPD), and clinical attachment level (CAL) were compared among three groups -patients with generalized Stage III Grade B PD with T2DM (n=35), patients with generalized stage III Grade B PD (n=35) and healthy controls (n=35) and the clinical parameters - plaque index(PI), gingival index(GI), sites with gingival bleeding, probing pocket depth(PPD), and clinical attachment level(CAL) were measured. Biochemical tests included the evaluation of serum 25-hydroxyvitamin D (25[OH] D) and hemoglobin A1C (HbA1c) levels.

Statistical Analysis

Periodontal and biochemical parameters were compared using a one-way analysis of variance across the three groups. The association between clinical parameters, SES, and 25(OH)D was examined using Pearson's correlation coefficient test and linear regression analysis.

Results

The serum 25(OH)D levels were lowest in the subjects with generalized Stage III Grade B PD with T2DM (13.54 ± 3.31 ng/mL). Furthermore, there was a significant (P < 0.01) negative correlation between serum 25(OH)D and periodontal parameters, PI (-0.442), PPD (-0.474), CAL (-0.459), sites with gingival bleeding (-0.354), and GI (-0.346) among the groups. The regression analyses showed that an increase in periodontal parameters (PI, GI, PPD, and CAL) and a higher HbA1c was linked to a lower 25(OH)D. However, the periodontal parameters and 25(OH)D levels showed no correlation with socioeconomic and demographic parameters in the study.

Conclusion

Serum Vitamin D values are negatively influenced by the synergistic effect of PD and T2DM or by the presence of PD alone. However, the association of SES on serum Vitamin D values in individuals with PD and T2DM or PD alone could not be demonstrated.

Retrospective Analysis of Vitamin D Deficiency in an Adult Population of Arad County, Western Romania (2019-2022)

Vitamin D, a steroid hormone synthesized primarily in the skin upon exposure to ultraviolet light, is widely deficient across global populations. This study aimed to fill the data gap in Western Romania by measuring 25-hydroxy-vitamin D levels in a cohort of 7141 from Arad County. It was observed that women, younger adults (18-29 years), and older adults (70-79 years) had notably lower vitamin D levels compared to the average population. Additionally, there was a rise in vitamin D levels over the four-year span of 2018-2022, coinciding with the COVID-19 pandemic. Our research provides fresh data on those most susceptible to vitamin D deficiency and lays the groundwork for educational campaigns on vitamin D supplementation benefits.

Trends of serum 25(OH) vitamin D and association with cardiovascular disease and all-cause mortality: from NHANES survey cycles 2001-2018

Background

The focus of this survey is on survey data for adults aged 20 and above, covering nine survey cycles from 2001 to 2018. Additionally, the present study explored the correlation between vitamin D concentrations and both cardiovascular disease (CVD) and all-cause mortality.

Objective

The objectives of this study were to evaluate the trend of changes in the serum 25(OH)D concentration changes in US adults during the survey period, the prevalence of vitamin D deficiency, and the current status of vitamin D dietary intake and supplementation.

Methods

In-home health interviews were performed using meticulously designed questionnaires that gathered information on demographic details, socioeconomic conditions, dietary patterns, and overall health status. Health assessments were conducted in specially designed mobile centers.

Results

Survey data from 2001 to 2018 revealed a rise in serum 25(OH)D levels, from a weighted mean (95% CI) of 65.6 (63.8-67.4) nmol/L during 2001-2002 to 73.5 (70.4-76.5) nmol/L during 2017-2018, among US adults, while overall vitamin D deficiency rates remained stable (p = 0.152). Notably, in adults aged 20-39, 25(OH)D levels decreased (p = 0.002 for trend), and 25(OH)D deficiency increased (p = 0.003 for trend), especially among those with low incomes (deficiency >30%). Upon multivariable adjustment, an L-shaped relationship was found between serum 25(OH)D concentrations and both CVD and all-cause mortality (p < 0.001 for nonlinearity), as corroborated by sensitivity analyses.

Conclusion

From 2001 to 2018, US adults experienced a significant increase in their serum 25(OH) D concentration. However, subgroups of individuals, including young adults and individuals with lower socioeconomic status, exhibited a heightened risk of 25(OH)D deficiency. Furthermore, an L-shaped relationship was found between 25(OH)D concentration and both all-cause and CVD mortality among US adults.

The Impact of Vitamin D Deficiency on Infants' Health

Vitamin D is an essential nutrient that plays a vital role in bone health and musculoskeletal development. The aim of this narrative review is to present up-to-date information about the impact of vitamin D deficiency (VDD) on the health status of infants in their first year of life. Vitamin D is indispensable for skeletal growth and bone health, and emerging research suggests that it may also have significant roles in maternal and fetal health. VDD affects a large proportion of infants according to current guidelines. However, its prevalence varies depending on geographic location, skin pigmentation, and the time of year. Based on current guidelines for normal vitamin D levels and recommended daily intake, studies suggest that VDD is a global health issue with potentially significant implications for those at risk, especially infants. Our understanding of the role of vitamin D has improved significantly in the last few decades. Systematic reviews and meta-analyses investigating the effect of vitamin D on preterm birth, low birth weight, anthropometric parameters, and health outcomes such as infectious diseases in infants, have found conflicting or inconsistent results. It is important to encourage further research to fill in these knowledge gaps and develop national or global strategies that ease the burden of VDD, especially in groups at risk.

Socioeconomic Status Affects Postoperative Time to Union in Pediatric Patients with a Surgically Treated Fracture

Fractures account for 10% to 25% of all pediatric injuries, and surgical treatment is common. In such cases, postoperative healing can be affected by a number of factors, including those related to socioeconomic status (SES). The purpose of this study was to investigate the relationship between time to fracture union and SES, which was measured with use of the median household income (MHI) and Child Opportunity Index (COI).

Methods

A retrospective review was conducted of pediatric patients with a long-bone fracture that had been surgically treated at a Level-I pediatric trauma center between January 2010 and June 2020. Demographic and relevant medical data were collected. Patients were sorted into union and nonunion groups. The ZIP code of each patient was collected and the MHI and COI of that ZIP code were identified. Income brackets were created in increments of $10,000 ranging from $20,000 to $100,000, with an additional category of >$100,000, and patients were sorted into these groups according to MHI. Comparisons among the income groups and among the union status groups were conducted for each of the collected variables. A multiple regression analysis was utilized to determine the independent effect of each variable on time to union.

Results

A total of 395 patients were included in the final sample, of whom 51% identified as Hispanic. Patients in the union group had a higher mean COI and MHI. Nonunion occurred in only 8 patients. Patients who achieved fracture union in ≤4 months had a significantly higher mean COI and MHI. When controlling for other demographic variables, the time to union increased by a mean of 9.6 days for every $10,000 decrease in MHI and increased by a mean of 6.8 days for every 10-unit decrease in the COI.

Conclusions

The present study is the first, to our knowledge, to investigate the relationship between SES and time to fracture union in pediatric patients. When controlling for other demographic factors, we found a significant relationship between SES and time to union in pediatric patients with a surgically treated fracture. Further investigations of the relationship between SES and time to union in pediatric patients are needed to determine potential mechanisms for this relationship.

Level of Evidence

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Geographic and urban-rural disparities in dietary energy and macronutrient composition among women of childbearing age: findings from the China health and nutrition survey,1991-2015

BACKGROUND

Understanding nutritional status among women of childbearing age (WCA) is of increasing concern, as nutrient intakes may affect the health of WCA and well-being of their offspring. This study aimed to investigate secular trends of dietary energy and macronutrients intakes and access longitudinally the urban-rural and geographic disparities among Chinese WCA.

METHODS

A total of 10,219 participants were involved in three rounds of the Chinese Health and Nutrition Survey (CHNS:1991, 2004, and 2015). Average macronutrients intakes were compared against the Chinese Dietary Reference Intakes Standard (DRIs) to better assess adequacy. Mixed effect models were used to estimate the secular trends of dietary intake.

RESULTS

A total of 10,219 participants were involved. Dietary fat, the percentage of energy (%E) from fat, and the proportion with more than 30% of energy from fat and less than 50% from carbohydrates increased notably over time (p < 0.001). In 2015, urban western WCA had the most dietary fat (89.5 g/d), %E from fat (41.4%), with the highest proportion of energy from fat (81.7%) and carbohydrate (72.1%) out the range of DRIs. From 1991 to 2015, the average urban-rural differences in dietary fat decreased from 15.7 g/d to 3.2 g/d among eastern WCA. However, it increased to 16.4 g/d and 6.3 g/d among central and western WCA, respectively.

CONCLUSION

WCA was experiencing a rapid transformation to a high-fat diet. Temporal variation with obvious urban-rural and geographic disparities in dietary. energy and macronutrient composition persistently existed among Chinese WCA.These findings have implications of future public strategies to strengthen the nutrition propaganda and education of balanced diet for WCA to help them to improve their nutritional status, especially for those living in western China.

Interaction of Passive Smoking and Diet Habits on Vitamin D Deficiency among Women of Reproductive Age in Rural Central China

Objective: Maternal dietary undernutrition is known to be associated with the risk of vitamin D (VD) deficiency. However, whether the risk of VD deficiency in women of reproductive age is influenced by the interaction between passive smoking and inadequate nutrition remains unknown. The aim of this study is to explore the interaction between passive smoking and dietary undernutrition on the risk of VD deficiency. Methods: A population-based case−control study including 1151 non-pregnant women of reproductive age between 18 and 40 years old was conducted in Henan Province, China from 2009 to 2010. Blood samples and information on exposure factors were collected. The prevalence of VD deficiency was estimated based on a result of serum 25-hydroxyvitamin D [25(OH)D] < 26.0 ng/mL. A multivariate logistic regression analysis was performed to explore the risk of VD deficiency. Results: The prevalence of VD deficiency was 61.5%. After adjusting for potential confounding factors, the interactions between passive smoking and no nutritional supplementation, passive smoking and insufficient egg intake, and passive smoking and insufficient milk dairy products intake were associated with the risk of VD deficiency, and the adjusted ORs were 3.40 (95% CI 2.26−5.13), 2.87 (95% CI 2.20−4.10), and 2.18 (95% CI 1.33−3.58), respectively. The interaction coefficients were calculated to be 2.35, 2.79, and 1.70, respectively, indicating there were significant interaction effects, as all of the coefficients were higher than 1. Conclusions: Our findings present that the risk of VD deficiency was potentially influenced by interactions between passive smoking and inadequate nutrition. Passive smoking might strengthen the effect of inadequate nutrition on the risk of VD deficiency among rural women of reproductive age. More attention should be paid to the health education and nutritional status improvement of women of reproductive age, especially in rural areas of developing countries.

Prevalence of Vitamin D and Calcium Deficiency and Insufficiency in Women of Childbearing Age and Associated Risk Factors: A Systematic Review and Meta-Analysis

Vitamin D deficiency and insufficiency as well as low serum calcium levels can trigger negative health outcomes in women of childbearing age. Therefore, we aimed to estimate the prevalence of serum vitamin D and calcium deficiencies and insufficiencies and associated risk factors in Brazilian women of childbearing age and to assess whether there are differences in prevalence according to regions of the country and the presence or absence of pregnancy. The systematic literature review was performed using the following databases: PubMed, LILACS, Embase, Scopus, and Web of Science. Cross-sectional, cohort, and intervention studies were included. Among pregnant women, the prevalence of vitamin D deficiency ranged from 0% to 27% and of vitamin D insufficiency from 33.9% to 70.4%. Among non-pregnant women, the prevalence of vitamin D deficiency ranged from 0% to 41.7% and of vitamin D insufficiency from 38.5% to 69.3%. We found a high prevalence of vitamin D deficiency and insufficiency in women of childbearing age, with insufficiency affecting more than half of these women. The highest prevalence of vitamin D deficiency and insufficiency was observed in the South region. It was not possible to assess the prevalence and factors associated with calcium deficiency.

Prevalence, trend, and predictor analyses of vitamin D deficiency in the US population, 2001-2018

Background

The National Health and Nutrition Examination Surveys (NHANES) collect and release data to the public every 2 years. The latest NHANES study on the vitamin D status of Americans was based on data from 2001 to 2014, and the latest data (2015–2016 and 2017–2018) have not been studied yet. Thus, we extracted all the available data from NHANES (2001–2018), aiming to analyze the prevalence and trends of vitamin D deficiency (VDD) in the US population to bridge the research gap.

Methods

According to previous studies and nutritional guidelines for vitamin D, severe VDD was defined as serum 25(OH)D levels of <25 nmol/L, moderate deficiency as 25–50 nmol/L, insufficiency as 50–75 nmol/L, and sufficiency as >75 nmol/L. We comprehensively estimated the prevalence of serum 25(OH)D levels of <25, 25–50, 50–75, and >75 nmol/L in Americans and described trends in vitamin D status from 2001 to 2018. Weighted multivariate linear regression models were used to explore the predictors of VDD. All analyses and the data were adjusted for the complex sampling design of NHANES using Mobile Examination Center (MEC) weights.

Results

Based on the most recent data of 71,685 participants, our study showed that the weighted prevalence of severe and moderate VDD was 2.6% and 22.0%, and the prevalence of vitamin D insufficiency (VDI) and sufficiency was 40.9% and 34.5%. The prevalence of severe and moderate VDD was higher in women, non-Hispanic black Americans, people aged 20–29 years, and during the season of winter. From 2001 to 2018, we found a slight linear decrease in the prevalence of moderate VDD (coefficient = −0.847; P = 0.009) and VDI (coefficient = −0.810; P = 0.014). We also found a slight linear increase in vitamin D sufficient (coefficient = 1.693; P = 0.004). However, no trend change was observed in severe VDD (coefficient = −0.037; P = 0.698). Age, sex, ethnicity, season, sun-protective behaviors, lower BMI, lower socioeconomic status (SES), drinking, and lower milk consumption were predictors of severe VDD.

Conclusion

Vitamin D deficiency is still prevalent in the United States, especially in non-Hispanic black Americans, women, individuals aged 20–29, and during winter. Therefore, individuals, healthcare providers, and policymakers should take public health measures to develop and implement prevention strategies to deal with VDD.

Maternal Passive Smoking, Vitamin D Deficiency and Risk of Spontaneous Abortion

Background: Maternal passive smoking and vitamin D deficiency might elevate risk of spontaneous abortion. The study aimed to investigate the association of co-exposure to passive smoking and vitamin D deficiency with the risk of spontaneous abortion. Methods: A population-based case-control study was performed among non-smoking women in Henan Province, China, with 293 spontaneous abortion cases and 496 liveborn controls with term, normal birthweight. Results: Compared to women without exposure to passive smoking nor vitamin D deficiency, women with deficient vitamin D alone and women with exposure to passive smoking alone had increased risk of spontaneous abortion (OR = 1.76, 95%CI: 1.08~2.89; OR = 1.73, 95%CI: 1.11~2.69, respectively). The risk of spontaneous abortion was even higher for those with co-exposure to passive smoking and vitamin D deficiency (OR = 2.50, 95%CI: 1.63~3.84). A dose-response relationship was found of an incremental risk of spontaneous abortion with rising numbers of exposures to passive smoking and vitamin D deficiency (p < 0.001). Conclusion: Co-exposure to passive smoking and vitamin D deficiency was associated with an elevated risk of spontaneous abortion, and the risk of spontaneous abortion rose with rising numbers of exposures. Intervention programs need to specifically target the vulnerable groups of pregnant women with both malnutrition and unfavorable environmental exposure.

Dietary and serum vitamin D and preeclampsia risk in Chinese pregnant women: a matched case-control study

The effect of vitamin D (VD) on the risk of preeclampsia (PE) is uncertain. Few of previous studies focused on the relationship between dietary VD intake and PE risk. Therefore, we conducted this 1:1 matched case-control study to explore the association of dietary VD intake and serum VD concentrations with PE risk in Chinese pregnant women. A total of 440 pairs of participants were recruited during March 2016 to June 2019. Dietary information was obtained using a seventy-eight-item semi-quantitative FFQ. Serum concentrations of 25(OH)D₂ and 25(OH)D₃ were measured by liquid chromatography-tandem MS. Multivariate conditional logistic regression was used to estimate OR and 95 % CI. Restricted cubic splines (RCS) were plotted to evaluate the dose-response relationship of dietary VD intake and serum VD concentrations with PE risk. Compared with the lowest quartile, the OR of the highest quartile were 0·45 (95 % CI 0·29, 0·71, P_trend = 0·001) for VD dietary intake and 0·26 (95 % CI 0·11, 0·60, P_trend = 0·003) for serum levels after adjusting for confounders. In addition, the RCS analysis suggested a reverse J-shaped relationship between dietary VD intake and PE risk (P-nonlinearity = 0·02). A similar association was also found between serum concentrations of total 25(OH)D and PE risk (P-nonlinearity = 0·02). In conclusion, this study provides evidence that higher dietary intake and serum levels of VD are associated with the lower risk of PE in Chinese pregnant women.

What Prompted the Adoption of Self-Protective Behaviors in Response to COVID-19? Evidence From Women Living in the Rural Areas of Western China

Background

Self-protective behaviors, such as handwashing and mask-wearing, are effective to reduce the spread of coronavirus disease (COVID-19), but few studies have focused on women living in rural areas who bear the brunt of the impacts of the pandemic due to their economic and social vulnerabilities. This study explores what prompted the adoption of self-protective behaviors in response to COVID-19 among women living in rural areas of western China.

Methods

The study sample consisted of 1,524 women from 116 townships across 10 counties in rural western China. We collected data in May and August 2020 on women's socioeconomic characteristics, exposure to COVID-19-related information, psychological response to COVID-19, and adoption of self-protective behaviors. Structural equation modeling (SEM) analyses were conducted to analyze the relations among the variables.

Results

During the lockdown, 1,221 (80.12%) of the 1,524 women in the study sample reported wearing a mask every time when they went outside and 1,021 (66.99%) reported handwashing with soap every time after they came home. Perceived efficacy had the strongest association with self-protective behaviors (β = 0.38; p < 0.001). Receiving public health guidance (β = 0.18; p < 0.001) was indirectly associated with more self-protective behaviors via greater perceived efficacy. Higher socioeconomic status was also directly associated with increased adoption of self-protective behaviors (β = 0.24; p < 0.001). Other variables, such as receiving surveillance and risk information, communication channels, perceived risks, and fear, were indirectly associated with the adoption of self-protective behaviors with smaller effect sizes (all β were lower than 0.10).

Conclusions

Not all women were able to adopt self-protective behaviors, such as mask-wearing and handwashing, during the COVID-19 pandemic in western China. To further encourage behavioral changes in response to public health crises, the government should develop clear and actionable guidelines and adopt targeted health communication strategies to reach the most disadvantaged groups of society. These findings may inform tailored responses to COVID-19 in other low- and middle-income countries.

Interactive Effects of Maternal Vitamin D Status and Socio-Economic Status on the Risk of Spontaneous Abortion: Evidence from Henan Province, China

Background: Maternal vitamin D deficiency might generate adverse reproductive outcomes, and socio-economic inequalities in micronutrient-related diseases have often been found. This study aimed to explore the interactive effects of maternal vitamin D status and socio-economic status (SES) on risk of spontaneous abortion. Methods: A population-based case–control study was conducted including 293 women with spontaneous abortion and 498 control women in December 2009 and January, 2010 in Henan Province, China. Information on pregnancy outcomes, maternal demographic, lifestyle and exposure factors and blood samples were collected at the same time. Vitamin D deficiency was defined as 25(OH)D < 20 ng/mL. SES index was constructed with principal component analysis by aggregating women’s and their husbands’ education level and occupation, and household income and expenditure. Interactive effects were assessed on a multiplicative scale with ratio of the odds ratio (ROR). Results: Compared to those with high SES and vitamin D sufficiency, women with vitamin D deficiency and low SES index had an increased risk of spontaneous abortion (aOR: 1.99; 95% CI: 1.23–3.23). The ROR was 2.06 (95% CI: 1.04–4.10), indicating a significant positive multiplicative interaction. Conclusions: Maternal low SES may strengthen the effect of vitamin D deficiency exposure on spontaneous abortion risk in this Chinese population.

Influence of maternal socioeconomic deprivation and living environment on newborn bloodspot 25-hydroxyvitamin D levels

Objectives

Vitamin D deficiency in neonates can have life-threatening consequences, hence the knowledge of risk factors is essential. This study aimed to explore the effect of maternal socioeconomic status (SES) on newborn 25-hydroxyvitamin D (25OHD) concentrations.

Design

Over two 1-week periods (winter and summer of 2019), 3000 newborn heel prick dried blood spots (DBS) and additional data of newborns, from a regional newborn screening laboratory (52° N) in the West Midlands, UK, were gathered. Post code was replaced with lower layer super output area (LSOA). Index of Multiple Deprivation (IMD) quintiles for the corresponding LSOA was used to assess SES [quintile one (Q1): most deprived 20%, quintile five (Q5): least deprived 20%]. Each of the seven domains of deprivation were examined (income, employment, education, health, barriers to housing and services, crime and living environment). 25OHD was measured on 6mm sub-punch from DBS using quantitative liquid chromatography tandem mass spectrometry and equivalent plasma values were derived.

Results

In total 2999 (1500 summer-born, 1499 winter-born) newborn DBS (1580 males) were analysed. Summer-born newborns had significantly higher 25OHD (IQR) concentrations [49.2 (34.3; 64.8) nmol/l] than winter-born newborns [29.1 (19.8; 40.6) nmol/l, p<0.001].25OHD levels varied significantly between the different IMD quintiles in the whole (p<0.001) and summer-born cohort (p<0.001), but not in the winter-born cohort (p=0.26), whereby Q1 had the lowest 25OHD concentrations. Among the domains of deprivation, living environment had a significant influence on 25OHD levels (β=0.07, p=0.002). In this subdomain, 25OHD levels varied significantly between quintiles in the whole (p<0.001) and summer-born cohort (mean 25OHD Q1 46.45 nmol/l, Q5 54.54 nmol/l; p<0.001) but not in the winter-born cohort (mean 25OHD Q1 31.57 nmol/l, Q5 31.72 nmol/l; p=0.16). In a regression model, living environment was still significant (p=0.018), albeit less than season of birth and ethnicity.

Conclusion

Among the seven domains of deprivation, maternal living environment had the greatest effect on newborn 25OHD levels. Whilst improved living environment positively influenced vitamin D status in the summer-born babies, winter-born had low 25OHD levels irrespective of the environment. Strategies such as enhanced supplementation and food fortification with vitamin D should be considered to overcome the non-modifiable main risk factors for vitamin D deficiency.