Race-ethnicity differences in folic acid intake in women of childbearing age in the United States after folic acid fortification: findings from the National Health and Nutrition Examination Survey, 2001-2002

Bias analyses to investigate the impact of differential participation: Application to a birth defects case-control study

BACKGROUND

Certain associations observed in the National Birth Defects Prevention Study (NBDPS) contrasted with other research or were from areas with mixed findings, including no decrease in odds of spina bifida with periconceptional folic acid supplementation, moderately increased cleft palate odds with ondansetron use and reduced hypospadias odds with maternal smoking.

OBJECTIVES

To investigate the plausibility and extent of differential participation to produce effect estimates observed in NBDPS.

METHODS

We searched the literature for factors related to these exposures and participation and conducted deterministic quantitative bias analyses. We estimated case-control participation and expected exposure prevalence based on internal and external reports, respectively. For the folic acid-spina bifida and ondansetron-cleft palate analyses, we hypothesized the true odds ratio (OR) based on prior studies and quantified the degree of exposure over- (or under-) representation to produce the crude OR (cOR) in NBDPS. For the smoking-hypospadias analysis, we estimated the extent of selection bias needed to nullify the association as well as the maximum potential harmful OR.

RESULTS

Under our assumptions (participation, exposure prevalence, true OR), there was overrepresentation of folic acid use and underrepresentation of ondansetron use and smoking among participants. Folic acid-exposed spina bifida cases would need to have been ≥1.2× more likely to participate than exposed controls to yield the observed null cOR. Ondansetron-exposed cleft palate cases would need to have been 1.6× more likely to participate than exposed controls if the true OR is null. Smoking-exposed hypospadias cases would need to have been ≥1.2 times less likely to participate than exposed controls for the association to falsely appear protective (upper bound of selection bias adjusted smoking-hypospadias OR = 2.02).

CONCLUSIONS

Differential participation could partly explain certain associations observed in NBDPS, but questions remain about why. Potential impacts of other systematic errors (e.g. exposure misclassification) could be informed by additional research.

Multivitamin Use Among Hispanic Women of Reproductive Age in the United States, 2013-2022

Background: The U.S. Public Health Service and the Institute of Medicine recommend that all women capable of becoming pregnant consume 400 μg of folic acid daily to help prevent neural tube defects (NTDs). Hispanic women are at higher risk of having babies with NTDs than non-Hispanic White women. This study assessed multivitamin (MV) use, a main source of folic acid, among Hispanic women of reproductive age using a survey of solely U.S. Hispanic adults. Materials and Methods: MV use was assessed as part of Porter Novelli's Estilos survey, fielded annually through the largest online U.S. Hispanic panel, Offerwise's QueOpinas. During the study period of 2013-2022, 9,999 surveys were completed; selection was weighted to match the U.S. Census American Community Survey proportions. Log-binomial regression models were applied to estimate MV use trends by age groups, acculturation levels, and pregnancy intention. Results: Among 3,700 Hispanic women of reproductive age, overall no MV use increased from 39.3% in 2013 to 54.7% in 2022 (p for trend <0.0001), especially among Hispanic women aged 18-34 years and those classified as acculturated. Among women planning to get pregnant, daily MV use was 31.1% in 2013 compared with 18.7% in 2020-2022 (p = 0.04). Conclusions: Given the increase in no MV use among Hispanic women of reproductive age, targeted interventions may help reach at-risk groups for NTDs prevention.

Hispanic Women's Perceptions of Neural Tube Defects and Folic Acid Supplementation: A Qualitative Study

INTRODUCTION

In the United States, the prevalence of neural tube defects (NTDs) is higher among infants born to Hispanic women compared with those born to non-Hispanic women. The purpose of this study is to investigate perceptions of NTDs and the use of folic acid and folate as a preventive measure among Hispanic women.

METHODS

Purposive sampling was used to recruit Hispanic women from a prenatal clinic in a Northeastern metropolitan city. In-depth interviews were conducted by native Spanish-speaking researchers using a semistructured interview guide. Thematic analysis was used to develop themes related to a priori domains.

FINDINGS

The study sample consisted of 26 Hispanic women representing nine countries of origin. Four themes were revealed: dietary sources of folic acid, awareness of folic acid supplementation and fortification, preferences for receiving health information, and factors in decision-making concerning an NTD diagnosis.

CONCLUSIONS

This study highlights the importance of early and targeted educational interventions sensitive to the cultural needs of this population. Results suggest that current NTD health education efforts may not be sufficient to increase our participants' knowledge of NTD. Additionally, the disparity may be multimodal, potentially influenced by insufficient understanding of prenatal folic acid use and the role of religiosity in decision-making during pregnancy. If Hispanic women are more likely to continue pregnancies affected by NTDs, this factor could be a part of NTD disparities. Exploring factors beyond supplementation and fortification that might influence rates of NTDs at birth in the U.S. Hispanic population can help to inform prevention efforts.

Women Taking a Folic Acid Supplement in Countries with Mandatory Food Fortification Programs May Be Exceeding the Upper Tolerable Limit of Folic Acid: A Systematic Review

Background: In preconception and pregnancy, women are encouraged to take folic acid-based supplements over and above food intake. The upper tolerable limit of folic acid is 1000 mcg per day; however, this level was determined to avoid masking a vitamin B12 deficiency and not based on folic acid bioavailability and metabolism. This review’s aim is to assess the total all-source intake of folate in women of childbearing age and in pregnancy in high-income countries with folate food fortification programs. Methods: A systematic search was conducted in five databases to find studies published since 1998 that reported folate and folic acid intake in countries with a mandatory fortification policy. Results: Women of childbearing age do not receive sufficient folate intake from food sources alone even when consuming fortified food products; however, almost all women taking a folic acid-based supplement exceed the upper tolerable limit of folic acid intake. Conclusions: Folic acid supplement recommendations and the upper tolerable limit of 1000 mcg set by policy makers warrant careful review in light of potential adverse effects of exceeding the upper tolerable limit on folic acid absorption and metabolism, and subsequent impacts on women’s health during their childbearing years.

Disparities in Surgical Oncology: Management of Advanced Cancer

Significant variations in the patterns of care, incidence, and mortality rates of several common cancers have been noted. These disparities have been attributed to a complex interplay of factors, including genetic, environmental, and healthcare-related components. Within this review, primarily focusing on commonly occurring cancers (breast, lung, colorectal), we initially summarize the burden of these disparities with regard to incidence and screening patterns. We then explore the interaction between several proven genetic, epigenetic, and environmental influences that are known to contribute to these disparities.

Prevention of Neural Tube Defects in Europe: A Public Health Failure

Objective: Thirty years ago it was demonstrated that folic acid taken before pregnancy and in early pregnancy reduced the risk of a neural tube defect (NTD). Despite Public Health Initiatives across Europe recommending that women take 0.4 mg folic acid before becoming pregnant and during the first trimester, the prevalence of NTD pregnancies has not materially decreased in the EU since 1998, in contrast to the dramatic fall observed in the USA. This study aimed to estimate the number of NTD pregnancies that would have been prevented if flour had been fortified with folic acid in Europe from 1998 as it had been in the USA. Design and Setting: The number of NTD pregnancies from 1998 to 2017 that would have been prevented if folic acid fortification had been implemented in the 28 countries who were members of the European Union in 2019 was predicted was predicted using data on NTD prevalence from 35 EUROCAT congenital anomaly registries and literature searches for population serum folate levels and folic acid supplementation. Results: From 1998 to 2017 an estimated 95,213 NTD pregnancies occurred amongst 104 million births in the 28 countries in the EU, a prevalence of 0.92 per 1,000 births. The median serum folate level in Europe over this time period was estimated to be 14.1 μg/L. There is a lack of information about women taking folic acid supplements before becoming pregnant and during the first trimester of pregnancy, with one meta-analysis indicating that around 25% of women did so. An estimated 14,600 NTD pregnancies may have been prevented if the European countries had implemented fortification at the level adopted by the USA in 1998 and 25% of women took folic acid supplements. An estimated 19,500 NTD pregnancies would have been prevented if no women took folic acid supplements. Conclusions: This study suggests that failure to implement mandatory folic acid fortification in the 28 European countries has caused, and continues to cause, neural tube defects to occur in almost 1,000 pregnancies every year.

A Description of Risk Factors for Non-alcoholic Fatty Liver Disease in the Southern Community Cohort Study: A Nested Case-Control Study

Background: Non-alcoholic fatty liver disease (NAFLD) is associated with obesity and hypercholesterolemia. In addition, total fat and folate intake have been associated with NAFLD.

Aims: We investigated risk factors for NAFLD among individuals of largely low socioeconomic status, and whether these associations differed by race.

Methods: A nested case-control study was conducted within the Southern Community Cohort Study. Through linkage of the cohort with Centers for Medicare and Medicaid Services, International Classification of Diseases, Ninth Revision, Clinical Modification codes were used to identify incident NAFLD cases. Controls were matched 4:1 to cases on enrollment age, sex, and race. A logistic regression was used to estimate odds ratios for the associations of NAFLD with covariates of interest.

Results: Neither total fat nor folate intake was significantly associated with NAFLD. Hypercholesterolemia (odds ratio 1.21) and body mass index (75th vs. 25th percentile) for blacks (odds ratio 1.96) and whites (odds ratio 2.33) were associated with an increased risk of non-alcoholic fatty liver disease. No significant interaction with race for any of the studied variables was noted.

Conclusions: Both hypercholesterolemia and increasing body mass index, but not total fat and folate intake, were risk factors for NAFLD in the Southern Community Cohort Study.

Comparison of Dietary Micronutrient Intakes by Body Weight Status among Mexican-American and Non-Hispanic Black Women Aged 19-39 Years: An Analysis of NHANES 2003-2014

The objective of the current study was to examine micronutrient intake from foods in women of childbearing age and to better understand potential nutritional problems varied by body weight status in minority women. A sample of women aged 19-39 years from the National Health and Nutrition Examination Surveys (NHANES) 2003-2014 was analyzed. Dietary intakes of 13 micronutrients were estimated using the National Cancer Institute method. Mexican-American and non-Hispanic Black women were categorized into normal/under-weight, overweight, or obese groups according to their body mass index (BMI). Mexican-American and non-Hispanic Black women had lower dietary intakes for vitamins A, B2, B6, B12, and D, folate, calcium, and magnesium than non-Hispanic Whites. Among Mexican-Americans, obese women had the lowest dietary intake of vitamins A, B2, C and D. Obese non-Hispanic Black women had significantly lower dietary intakes of iron and zinc than their normal/under-weight counterparts. Comparable percentages (>30%) of Mexican-American and non-Hispanic Black women had dietary intake less than the Estimated Average Requirements (EARs) for several key nutrients including vitamin A, C and D, folate, calcium and magnesium, and the percentages varied by body weight status. These results indicate micronutrient inadequacies persist among and within racial/ethnic and body weight groups.

Ethnic Differences in Dietary Management of Gestational Diabetes Mellitus: A Mixed Methods Study Comparing Ethnic Chinese Immigrants and Australian Women

BACKGROUND

Dietary modification is the primary intervention strategy for management of gestational diabetes mellitus (GDM), which usually occurs in the third trimester of pregnancy when women have extra nutritional needs. There is a high migration rate of ethnic Chinese people to Western countries, and those women present a high-risk group for GDM. Little is known about diet, dietary self-management, and nutritional supplementation use among ethnic Chinese migrant women with GDM compared with members of the host population with GDM.

OBJECTIVE

This study aimed to compare the perceptions and experiences of dietary self-management and nutritional needs of ethnic Chinese migrants with those of Australian-born white women with GDM in Australia.

DESIGN

A predominantly qualitative mixed methods approach with a quantitative component was used. Data collection involved in-depth, semistructured interviews, and 3-day 24-hour recall diaries collected concurrently. Data analysis and management relied on NVivo (QSR International Pty Ltd), FoodWorks (FoodWorks Professional 2017, Xyris Software), and SPSS (SPSS Inc). Pearson χ² test, independent-samples t test, and Mann-Whitney U test were used to compare nutrient intakes between groups. The Pearson correlation was used to determine the relationship between dietary patterns and nutrient intake.

PARTICIPANTS

A total of 44 ethnic Chinese and 39 Australian-born white participants with GDM were recruited from two large Australian maternity services located in tertiary hospitals.

RESULTS

Ethnic differences in satisfaction with GDM education influenced GDM self-management. Ethnic Chinese women with GDM perceived dietary advice received from health professionals to be lacking in cultural relevance and detail and responded by restricting their dietary intake and relying on nutritional supplementation. The perceived benefits of specific supplements produced ethnic differences in the patterns of supplement use. Cultural dietary patterns influenced dietary adequacy in pregnancy.

CONCLUSIONS

This study suggests the need for provision of more concrete, prescriptive, and culturally relevant dietary and supplementation advice for ethnic Chinese women with GDM.

Factors Influencing Low Prevalence of Neurodevelopmental Disabilities Among US Hispanic/Latino Children

OBJECTIVES

Hispanic/Latino (H/L) children have lower prevalence of neurodevelopmental disabilities (NDD) than other groups. The explanations for this are complex, but may be related to nativity, language barriers, and lack of access to and utilization of healthcare. Previous research focused on how these factors affect children with NDD, but little research has jointly examined whether these factors predict NDD. This study examines whether social and environmental factors explain low prevalence of NDD in this population.

METHODS

This study uses nationally representative Integrated Public Use Microdata Series National Health Interview Survey data (N = 200,622) and multivariate logistic regression analysis to compare NDD prevalence in white and H/L children (average age of 10.2), and examines whether nativity, healthcare access, healthcare utilization, and language barriers explain this disability disparity.

RESULTS

Findings reveal that the H/L NDD disparity is not explained by differences in access to or utilization of healthcare, or as a result of language differences that may create barriers to NDD diagnosis. While H/L children whose sampled adult was born in the USA have lower rates of NDD than whites, H/Ls whose sampled adult were not born in the USA have even lower probability of NDD than H/Ls who were born in the USA.

CONCLUSIONS

These findings may be a result of cultural differences in knowledge or understanding of what constitutes a disability or the result of differential treatment within the healthcare system among H/Ls. The findings underscore the importance of accessible and culturally appropriate health and clinical care interventions among H/L communities.

Trends in Multivitamin Use Among Women of Reproductive Age: United States, 2006-2016

BACKGROUND

Women of reproductive age can consume 0.4 milligrams of folic acid daily to reduce the risk of a neural tube defect (NTD)-affected pregnancy. Multivitamins (MVs) are one source of folic acid.

MATERIALS AND METHODS

Using HealthStyles survey data (n = 9268), we assessed change in prevalence of MV use during 2006-2016 among women by age (18-24, 25-34, and 35-44 years), race/ethnicity (non-Hispanic [NH] white, NH black, Hispanic), and pregnancy status (trying to get pregnant, not pregnant nor trying to get pregnant, and pregnant) using log-binomial regression.

RESULTS

Daily MV consumption decreased overall from 32.7% to 23.6% during 2006-2016 for women aged 18-44 years (p for trend <0.001). Age-specific decreases were seen in women aged 25-34 years (2006: 34.1%; 2016: 23.7%; p < 0.001) and 35-44 years (2006: 37.3%; 2016: 27.1%; p < 0.001). Decreases in daily MV intake were found among NH whites (2006: 35.4%; 2016: 24.9%; p < 0.001) and Hispanics (2006: 30.6%; 2016: 22.1%; p < 0.001), but remained unchanged among NH blacks (2006: 23.7%; 2016: 21.8%; p = 0.87). Daily MV intake remained unchanged for women trying to get pregnant (2006: 40.2%; 2012: 38.3%; p = 0.19), decreased for women not pregnant nor trying to get pregnant (2006: 31.3%; 2012: 21.3%; p < 0.001), and fluctuated for pregnant women (2006: 53.8%; 2012: 71.0%; p = 0.21). Prevalence of no MV consumption increased significantly across all age and race/ethnicity groups.

CONCLUSIONS

Overall MV intake decreased for the past decade and varied by age, race/ethnicity, and pregnancy status. Innovative messaging and targeted interventions for increasing folic acid intake are needed to reduce NTDs.

Maternal postpartum plasma folate status and preterm birth in a high-risk US population

OBJECTIVE

While maternal folate deficiency has been linked to poor pregnancy outcomes such as neural tube defects, anaemia and low birth weight, the relationship between folate and preterm birth (PTB) in the context of the US post-folic acid fortification era is inconclusive. We sought to explore the relationship between maternal folate status and PTB and its subtypes, i.e. spontaneous and medically indicated PTB.

DESIGN

Observational study.

SETTING

Boston Birth Cohort, a predominantly urban, low-income, race/ethnic minority population at a high risk for PTB.ParticipantsMother-infant dyads (n 7675) enrolled in the Boston Birth Cohort. A sub-sample (n 2313) of these dyads had maternal plasma folate samples collected 24-72 h after delivery.

RESULTS

Unadjusted and adjusted logistic regressions revealed an inverse relationship between the frequency of multivitamin supplement intake and PTB. Compared with less frequent use, multivitamin supplement intake 3-5 times/week (adjusted OR (aOR) = 0·78; 95 % CI 0·64, 0·96) or &gt;5 times/week (aOR = 0·77; 95 % CI 0·64, 0·93) throughout pregnancy was associated with reduced risk of PTB. Consistently, higher plasma folate levels (highest v. lowest quartile) were associated with lower risk of PTB (aOR = 0·74; 95 % CI 0·56, 0·97). The above associations were similar among spontaneous and medically indicated PTB.

CONCLUSIONS

If confirmed by future studies, our findings raise the possibility that optimizing maternal folate levels across pregnancy may help to reduce the risk of PTB among the most vulnerable US population in the post-folic acid fortification era.

Red blood cell folate levels in Canadian Inuit women of childbearing years: influence of food security, body mass index, smoking, education, and vitamin use

Background

The benefits of folic acid for prevention of congenital anomalies are well known. For the Inuit of Canada, where vitamin use is low and access to folate-rich foods limited, fortification is likely a major source of intake. We sought to determine whether red blood cell folate (RBCF) levels of Inuit women reached accepted target levels.

Methods

The Inuit Health Survey, 2007–2008, included evaluation of RBCF levels among 249 randomly selected non-pregnant women of reproductive age. Using descriptive statistics and linear regression analyses, RBCF levels were assessed and compared across several socio-demographic variables to evaluate the characteristics associated with RBCF status.

Results

Mean (SD) RBCF levels of 935.5 nmol/L (± 192) reached proposed target levels (> 906 nmol/L); however, 47% of women had lower than target levels. In bivariate analysis, non-smoking, higher education, higher income, food security, increased body mass index, and vitamin use were each significantly associated with higher RBCF. Increased levels of smoking had a negative association with RBCF levels (− 5.8 nmol/L per cigarette smoked per day (p = 0.001)). A total of 6.8% of women reported taking vitamin supplements, resulting in a 226 nmol/L higher RBCF level on average compared to non-users (p < 0.001).

Conclusion

While mean levels of folate reached target levels, this was largely driven by the small number of women taking vitamin supplements. Our results suggest that folate status is often too low in Inuit women of childbearing years. Initiatives to improve food security, culturally relevant education on folate-rich traditional foods, vitamin supplements, and smoking cessation/reduction programs may benefit Inuit women and improve birth outcomes.

Race and ethnicity and preconception folic acid supplement use among pregnant women in Georgia, PRAMS 2009 to 2011

BACKGROUND

The United States Public Health Service recommends that all women of reproductive age consume 400 μg of folic acid daily to prevent major neural tube defects. Hispanics have the highest prevalence of neural tube defects compared with other race/ethnic groups. We studied prevalence of preconception folic acid supplement use, and its association with race/ethnicity among pregnant women in Georgia.

METHODS

Using state-wide population-based data from 2009 to 2011 Georgia Pregnancy Risk Assessment Monitoring System, we examined the prevalence of preconception folic acid supplement use among pregnant women aged 18 to 45 years. We conducted multivariable logistic regression and estimated adjusted odds ratios and 95% confidence intervals to examine the association between race/ethnicity and supplemental folic acid use among study participants.

RESULTS

Overall, 25% of all participants reported taking folic acid supplements daily before conception. Only 21% of Hispanic women reported preconception folic acid supplement use. Hispanic women were twice as likely to not take folic acid supplements (adjusted odds ratio = 2.15; 95% confidence interval, 1.35-3.40) compared with non-Hispanic whites, after controlling for maternal age, parity, pregnancy intention, knowledge that folic acid prevents birth defects, and preconception smoking and exercise.

CONCLUSION

Hispanics are a growing population in the United States with an expected 14 million women of child-bearing age by 2020, and the prevalence of preconception folic acid supplement use is low in this group with a high risk of neural tube defects. Promotion of voluntarily fortified corn masa flour can lower neural tube defects in Hispanics. Mandatory corn masa fortification will be a more effective public health policy.Birth Defects Research 109:38-48, 2017. © 2016 Wiley Periodicals, Inc.

Discussing Appropriate Medication Use and Multivitamin Intake with a Healthcare Provider: An Examination of Two Elements of Preconception Care Among Latinas

BACKGROUND

Counseling for appropriate medication use and folic acid consumption are elements of preconception care critical for improving pregnancy outcomes. Hispanic women receive less preconception care than women of other race/ethnic groups. The objective of this analysis is to describe differences in these two elements of preconception care among Hispanic subsegments.

MATERIALS AND METHODS

Porter Novelli's 2013 Estilos survey was sent to 2,609 U.S. Hispanic adults of the Offerwise QueOpinas Panel. Surveys were completed by 1,000 individuals (calculated response rate 42%), and results were weighted to the 2012 U.S. Census Hispanic proportions for sex, age, income, household size, education, region, country of origin, and acculturation. Responses were analyzed with weighted descriptive statistics, linear regression, and Rao-Scott chi-square tests.

RESULTS

Of the 499 female respondents, 248 had a child under the age of 18 years and were asked about healthcare provider discussions concerning medication use before or during their last pregnancy. Timing of discussions varied by maternal age, marital status, income, youngest child's country of birth, and acculturation. Discussions before pregnancy were reported by 47% of the female respondents; high acculturated women more often reported never having such discussions. Among female respondents, 320 were of reproductive age, and 27% of those reported daily multivitamin use. Multivitamin use varied by pregnancy intention and youngest child's country of birth, but did not vary significantly by acculturation.

CONCLUSIONS

Differences in discussions concerning medication use in pregnancy and multivitamin use exist among Hispanic subsegments based on pregnancy intention, marital status, income, youngest child's country of birth, and level of acculturation.

Adding folic acid to corn Masa flour: Partnering to improve pregnancy outcomes and reduce health disparities

Although strides have been made in preventing neural tube defects (NTDs), Hispanic women remain more likely to have a baby born with an NTD and less likely to know the benefits of, or consume, folic acid than women of other race/ethnic groups. In 1998, the U.S. Food and Drug Administration (FDA) mandated that all enriched cereal grain products be fortified with folic acid; however, corn masa flour (CMF), used to make many corn products that are a diet staple of many Hispanic groups, was not included under this regulation. In 2006, a Working Group began a collaboration to address this disparity by pursuing a petition to FDA to allow folic acid to be added voluntarily to CMF. The petition process was a monumental effort that required collaboration and commitment by partners representing the affected population, manufacturers, scientists, and others. The petition was approved in 2016 and folic acid is now added to CMF products, with expected results of more women achieving the recommended daily folic acid intake, more infants born per year without an NTD, and millions of dollars in direct medical expenditures averted. This 10-year public-private partnership brought together diverse groups that traditionally have different goals. The Working Group continues to work toward ensuring that fortified CMF products are available to the consumer, with the end goal of achieving a reduction in NTD-affected pregnancies.

Folic acid supplement use and the risk of gestational hypertension and preeclampsia

BACKGROUND

Hypertensive disorders of pregnancy are among the leading causes of maternal morbidity and mortality. Studies suggest that the use of folic acid may lower the risk of hypertensive disorders in pregnant women.

AIM

The aim of this study was to assess the effects of timing and duration of folic acid-containing supplement use on the risk for gestational hypertension and preeclampsia.

METHODS

Exposures and outcomes data were obtained through interviews and review of participant's medical records from the MotherToBaby cohort studies across the United States and Canada. Demographics, medical history, lifestyle factors, substance use, and fetal sex were assessed as potential confounders. Unadjusted and adjusted risks for gestational hypertension and preeclampsia were examined using odds ratios and 95% confidence intervals.

FINDINGS

3247 women were included in the study. Compared to non-supplement use, early and late supplement use were not significantly associated with the development of gestational hypertension or preeclampsia. The odds of developing gestational hypertension and preeclampsia were significantly reduced as the duration of folic acid-containing supplement use increased.

CONCLUSION

Findings from this study suggest that the use of folic acid-containing supplements may mitigate the risk for gestational hypertension and preeclampsia.

Folic Acid Education for Hispanic Women: The Promotora de Salud Model

BACKGROUND

Although rates of neural tube defects (NTDs) have declined in the United States since fortification, disparities still exist with Hispanic women having the highest risk of giving birth to a baby with a NTD. The Promotora de Salud model using community lay health workers has been shown to be an effective tool for reaching Hispanics for a variety of health topics; however, literature on its effectiveness in folic acid interventions is limited.

MATERIALS AND METHODS

An intervention using the Promotora de Salud model was implemented in four U.S. counties with large populations of Hispanic women. The study comprised the following: (1) a written pretest survey to establish baseline levels of folic acid awareness, knowledge, and consumption; (2) a small group education intervention along with a 90-day supply of multivitamins; and (3) a postintervention (posttest) assessment conducted 4 months following the intervention.

RESULTS

Statistically significant differences in pre- and posttests were observed for general awareness about folic acid and vitamins and specific knowledge about the benefits of folic acid. Statistically significant changes were also seen in vitamin consumption and multivitamin consumption. Folic acid supplement consumption increased dramatically by the end of the study.

CONCLUSIONS

The Promotora de Salud model relies on interpersonal connections forged between promotoras and the communities they serve to help drive positive health behaviors. The findings underscore the positive impact that these interpersonal connections can have on increasing awareness, knowledge, and consumption of folic acid. Utilizing the Promotora de Salud model to reach targeted populations might help organizations successfully implement their programs in a culturally appropriate manner.

Establishing Safe and Potentially Efficacious Fortification Contents for Folic Acid and Vitamin B12

Determining the micronutrient contents in fortified foods depends not only on the health goal (additional intake to complement the diet), but also on ensuring that fortification does not raise micronutrient intakes beyond the Tolerable Upper Intake Level (UL), i.e., the safe limit. Technological incompatibility and cost may also restrict the fortification contents. For folic acid, the limiting factor is safety, while for vitamin B12, it is cost. However, adequate fortification contents that are both safe and efficacious can be estimated for both nutrients. In order to obtain the maximum benefit from the fortification programs, three different formulas responding to three categories of consumption, as specified by the median and 95th percentile of consumption, are proposed.

The model presented is based on the estimation of a Feasible Fortification Level (FFL), which then is used to determine the average, minimum, and maximum contents of the nutrients during production, taking into consideration the acceptable variation of the fortification process. Finally, the regulatory parameters, which support standards and enforcement, are calculated by reducing the proportion of the nutrient that is degraded during the usual marketing process of the fortified food. It is expected that this model will establish a common standard for food fortification, and improve the reliability and enforcement procedures of these programs.

The model was applied to flours as vehicles for folic acid in the United States, Guatemala, and Chile. Analysis of the data revealed that, with the exception of Chile, where wheat flour consumption is very high and probably within a narrow range, supplementation with folic acid is still needed to cover individuals at the low end of consumption. This is especially true when the difference in flour consumption is too wide, as in the case of Guatemala, where the proportional difference between consumption at the 95th percentile of the nonpoor group is as high as 100 times the consumption at the 5th percentile of the extremely poor group. Adoption of fortification content for staple foods near the safe limit brings together the need of restricting the voluntary addition of the specific nutrient to other foods and to dietary supplements.

Prevention of neural tube defects in the UK: a missed opportunity

OBJECTIVE

In 1991, the Medical Research Council (MRC) Vitamin Study demonstrated that folic acid taken before pregnancy and in early pregnancy reduced the risk of a neural tube defect (NTD). We aimed to estimate the number of NTD pregnancies that would have been prevented if flour had been fortified with folic acid in the UK from 1998 as it had been in the USA.

DESIGN

Estimates of NTD prevalence, the preventive effect of folic acid and the proportion of women taking folic acid supplements before pregnancy were used to predict the number of NTD pregnancies that would have been prevented if folic acid fortification had been implemented.

SETTING

Eight congenital anomaly registers in England and Wales.

MAIN OUTCOME MEASURES

The prevalence of pregnancies with an NTD in the UK and the number of these pregnancies that would have been prevented if folic acid fortification had been implemented.

RESULTS

From 1991 to 2012, the prevalence of NTD pregnancies was 1.28 (95% CI 1.24 to 1.31) per 1000 total births (19% live births, 81% terminations and 0.5% stillbirths and fetal deaths ≥20 weeks' gestation). If the USA levels of folic acid fortification from 1998 onwards had been adopted in the UK, an estimated 2014 fewer NTD pregnancies would have occurred.

CONCLUSIONS

Failure to implement folic acid fortification in the UK has caused, and continues to cause, avoidable terminations of pregnancy, stillbirths, neonatal deaths and permanent serious disability in surviving children.

Maternal prenatal intake of one-carbon metabolism nutrients and risk of childhood leukemia

PURPOSE

Folate, vitamins B12 and B6, riboflavin, and methionine are critical nutrients for the one-carbon metabolism cycle involved in DNA synthesis and epigenetic processes. We examined the association between maternal intake of these nutrients before pregnancy and risk of childhood acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) in a matched case-control study.

METHODS

Maternal dietary intake and vitamin supplement use in the year before pregnancy was assessed by food frequency questionnaire for 681 ALL cases, 103 AML cases, and 1076 controls. Principal component analysis was used to construct a variable representing combined nutrient intake, and conditional logistic regression estimated the odds ratio (OR) and 95% confidence interval (CI) for the association of ALL and AML with the principal component and each nutrient.

RESULTS

Higher maternal intake of one-carbon metabolism nutrients from food and supplements combined was associated with reduced risk of ALL (OR for one-unit change in the principal component = 0.91, CI 0.84-0.99) and possibly AML (OR for the principal component = 0.83, CI 0.66-1.04). When analyzed separately, intake of supplements high in these nutrients was associated with a reduced risk of ALL in children of Hispanic women only.

CONCLUSIONS

In conclusion, these data suggest that higher maternal intake of one-carbon metabolism nutrients may reduce risk of childhood leukemia.

Folic Acid Intake and Neural Tube Defects: Two Egyptian Centers Experience

Neural tube defects (NTDs) are a group of congenital malformations with worldwide distribution and complex etiopathogenesis. Folic acid plays a pivotal role in their prevention. We aimed to identify the protective effect of folic acid intake against NTDs and its dependence on different socioeconomic and environmental factors in a cohort of mothers in Egypt. A cross-sectional study was carried over a period of 12 months on mothers who gave birth to babies with NTDs (group 1) and a control group with healthy offsprings (group 2). Both groups completed 2 questionnaires: food frequency questionnaire targeting the daily folate intake, and socioeconomic status and medical history questionnaire. Both groups of mothers received folate <800 μg/day, recommended for pregnant women. A strong association was detected between NTDs and urban residency with medium educated mothers, with negative consanguinity, who had folate intake < 400 μg daily, and who had their food long cooked. Each of these factors separately had a limited impact to cause NTDs, but when present together they did augment each other. Interestingly enough is the role of fava bean, cauliflower, spinach, and mango in predisposing of NTDs in the presence of the above-mentioned factors. The protective effect of folic acid intake against NTDs may depend on the synergism of different socioeconomic and environmental factors (which differ from country to another). In Egypt, females especially the medium-educated who live in urban areas should be well-informed with the value of folate intake in the periconceptional period.

Tree nut consumption is associated with better nutrient adequacy and diet quality in adults: National Health and Nutrition Examination Survey 2005-2010

Nutrient adequacy of tree nut consumers has not been examined. The National Health and Nutrition Examination Survey 2005–2010 data were used to assess the association of tree nut consumption by adults 19+ years (n = 14,386) with nutrient adequacy and diet quality. Covariate adjusted usual intake was determined using two 24-h dietary recalls and the National Cancer Institute method. Percentages of the consumption groups below the Estimated Average Requirement (EAR) or above the Adequate Intake (AI) were determined. Diet quality was determined using the Healthy Eating Index-2005 (HEI) score. Usual intake data showed consumers of tree nuts had a lower percentage (p < 0.0001) of the population below the EAR for vitamins A (22 ± 5 vs. 49 ± 1), E (38 ± 4 vs. 94 ± 0.4) and C (17 ± 4 vs. 44 ± 1); folate (2.5 ± 1.5 vs. 12 ± 0.6); calcium (26 ± 3 vs. 44 ± 1); iron (3 ± 0.6 vs. 9 ± 0.4); magnesium (8 ± 1 vs. 60 ± 1); and zinc (1.5 ± 1 vs. 13 ± 1). Tree nut consumers had a higher percentage (p < 0.0001) of the population above the AI for fiber (33 ± 3 vs. 4 ± 0.3) and potassium (12 ± 3 mg vs. 2 ± 0.2 mg). HEI-2005 total score was higher (p < 0.0001) in tree nut consumers (61 ± 0.7 vs. 52 ± 0.3) than non-consumers. Health professionals should encourage the use of tree nuts as part of a dietary approach to healthy eating.

Contemporary issues surrounding folic Acid fortification initiatives

The impact of folate on health and disease, particularly pregnancy complications and congenital malformations, has been extensively studied. Mandatory folic acid fortification therefore has been implemented in multiple countries, resulting in a reduction in the occurrence of neural tube defects. However, emerging evidence suggests increased folate intake may also be associated with unexpected adverse effects. This literature review focuses on contemporary issues of concern, and possible underlying mechanisms as well as giving consideration the future direction of mandatory folic acid fortification. Folate fortification has been associated with the presence of unmetabolized folic acid (PteGlu) in blood, masking of vitamin B12 deficiency, increased dosage for anti-cancer medication, photo-catalysis of PteGlu leading to potential genotoxicity, and a role in the pathoaetiology of colorectal cancer. Increased folate intake has also been associated with twin birth and insulin resistance in offspring, and altered epigenetic mechanisms of inheritance. Although limited data exists to elucidate potential mechanisms underlying these issues, elevated blood folate level due to the excess use of PteGlu without consideration of an individual's specific phenotypic traits (e.g. genetic background and undiagnosed disease) may be relevant. Additionally, the accumulation of unmetabolized PteGlu may lead to inhibition of dihydrofolate reductase and other enzymes. Concerns notwithstanding, folic acid fortification has achieved enormous advances in public health. It therefore seems prudent to target and carefully monitor high risk groups, and to conduct well focused further research to better understand and to minimize any risk of mandatory folic acid fortification.

Autism spectrum disorders and race, ethnicity, and nativity: a population-based study

OBJECTIVE

Our understanding of the influence of maternal race/ethnicity and nativity and childhood autistic disorder (AD) in African Americans/blacks, Asians, and Hispanics in the United States is limited. Phenotypic differences in the presentation of childhood AD in minority groups may indicate etiologic heterogeneity or different thresholds for diagnosis. We investigated whether the risk of developing AD and AD phenotypes differed according to maternal race/ethnicity and nativity.

METHODS

Children born in Los Angeles County with a primary AD diagnosis at ages 3 to 5 years during 1998-2009 were identified and linked to 1995-2006 California birth certificates (7540 children with AD from a cohort of 1,626,354 births). We identified a subgroup of children with AD and a secondary diagnosis of mental retardation and investigated heterogeneity in language and behavior.

RESULTS

We found increased risks of being diagnosed with AD overall and specifically with comorbid mental retardation in children of foreign-born mothers who were black, Central/South American, Filipino, and Vietnamese, as well as among US-born Hispanic and African American/black mothers, compared with US-born whites. Children of US African American/black and foreign-born black, foreign-born Central/South American, and US-born Hispanic mothers were at higher risk of exhibiting an AD phenotype with both severe emotional outbursts and impaired expressive language than children of US-born whites.

CONCLUSIONS

Maternal race/ethnicity and nativity are associated with offspring's AD diagnosis and severity. Future studies need to examine factors related to nativity and migration that may play a role in the etiology as well as identification and diagnosis of AD in children.

Effect of increasing voluntary folic acid food fortification on dietary folate intakes and adequacy of reproductive-age women in New Zealand

OBJECTIVE

Mandatory folic acid fortification of breads in New Zealand was put on hold in 2009. At this time, bread manufacturers were requested to adopt greater voluntary fortification and agreed to add folic acid to approximately one-third of their bread range. We sought to evaluate the impact of increased voluntary fortification of bread and the proposed mandatory fortification programme on folate intake adequacy of reproductive-age women.

DESIGN

Cross-sectional study conducted in 2008. Dietary data were collected using 3 d weighed food records and usual folate intakes were generated by modifying the food composition table as follows: (i) voluntary fortification of bread as of 2008 (six breads); (ii) increased voluntary fortification of bread as of 2011 (thirty-four breads); and (iii) mandatory fortification of all breads. The prevalence of inadequate folate intake was calculated for all three scenarios using the Estimated Average Requirement (320 μg dietary folate equivalents/d) cut-point method.

SETTING

New Zealand.

SUBJECTS

Healthy non-pregnant women (n 125) aged 18-40 years.

RESULTS

Usual folate intake in 2008 was 362 μg dietary folate equivalents/d. Increased voluntary bread fortification led to a marginal increase in folate intakes (394 μg dietary folate equivalents/d) and a decline in inadequacy from 37 % to 29 %. Mandatory fortification resulted in an increase of 89 μg folic acid/d, which substantially shifted both the proportion of women with folic acid intakes above 100 μg/d and the distribution of overall folate intakes, producing a marked reduction in inadequacy to 5 %.

CONCLUSIONS

Increased voluntary bread fortification efforts are far inferior to mandatory fortification as a reliable public health intervention.

Preconceptional folic acid-containing supplement use in the National Birth Defects Prevention Study

BACKGROUND

Despite public health campaigns encouraging women to take a daily folic acid supplement, the proportion of reproductive age women, in the United States, who comply with this recommendation is less than optimal. The objective of this analysis was to identify predictors of preconceptional folic acid-containing supplement use to define subgroups of women who may benefit from targeted folic acid campaigns.

METHODS

This study included 6570 mothers of live born infants from the control population of National Birth Defects Prevention Study (1997-2005). Logistic regression analyses were used to identify predictors of preconceptional folic acid supplementation. A classification and regression tree (CART) analysis was used to define subgroups of women with different patterns of preconceptional folic acid supplementation.

RESULTS

Race/ethnicity, education, age at delivery, nativity, employment, income, number of dependents, smoking, and birth control use were significantly associated with preconceptional folic acid-containing supplement use. Based on a CART analysis, education, race/ethnicity, and age were the most distinguishing factors between women with different preconceptional supplementation patterns. Non-white women with <4 years of a college education were the least likely to use folic acid-containing supplements (11%). However, even in the most compliant subgroup (women with ≥4 years of college), only 60% of women supplemented with folic acid.

CONCLUSION

These results demonstrate the need for continued efforts to increase folic acid supplementation among all reproductive aged women. However, the success of such efforts may be improved if maternal characteristics such as education, race/ethnicity, and age, are considered in the development of future interventions.

Promotora de salud: promoting folic acid use among Hispanic women

BACKGROUND

The U.S. Public Health Service recommends that all women in the United States capable of becoming pregnant consume 400 μg of folic acid daily to reduce their risk of having a pregnancy affected by a neural tube defect (NTD). However, disparities exist in the consumption of folic acid, with Hispanic women having lower rates of folic acid consumption than non-Hispanic white women.

METHODS

A community-based feasibility study was designed to assess the utility of the promotora de salud model to promote consumption of multivitamins containing folic acid for the prevention of NTDs among Spanish-speaking Hispanic women in North Carolina. The study consisted of an educational intervention given by a promotora (a lay, community health worker), with data collection occurring at baseline and four months post-intervention to measure changes in knowledge and behavior. Overall, 52% (n=303) of participants completed all components of the study.

RESULTS

Self-reported daily multivitamin consumption increased from 24% at baseline to 71% four months post-intervention. During the same time frame, awareness of folic acid increased from 78% to 98% and knowledge of the role of folic acid in the prevention of birth defects increased from 82% to 92%.

CONCLUSIONS

The results of this study indicate that the promotora de salud model may be effective in reaching a subpopulation of women with the folic acid message. Additional studies with larger population sizes are warranted to validate these findings.

Fortification of corn masa flour with folic acid in the United States: an overview of the evidence

Corn masa flour, used to make products such as corn tortillas, is a staple food for Hispanic populations residing in the United States, particularly among Mexican Americans and Central Americans. Research has indicated that Hispanic women in the United States continue to be at a higher risk of having a neural tube defect-affected pregnancy than women of other races/ethnicities, even after the introduction of folic acid fortification of cereal grain products labeled as "enriched." Corn masa flour has, therefore, been suggested as a potential food vehicle for folic acid in the United States. This paper explores the potential impact that folic acid fortification of corn masa flour could have on the Hispanic population in the United States.

Knowledge and periconceptional use of folic acid for the prevention of neural tube defects in ethnic communities in the United Kingdom: systematic review and meta-analysis

BACKGROUND: It is widely accepted that periconceptional supplementation with folic acid can prevent a significant proportion of neural tube defects (NTDs). The present study evaluated how folic acid knowledge and periconceptional use for NTD prevention varies by ethnicity in the United Kingdom (U.K.).

METHODS: A literature search was conducted to identify studies that included assessment of folic acid knowledge or use in U.K. women of different ethnicities. Only research and referenced sources published after 1991, the year of the landmark Medical Research Council’s Vitamin Study, were included. A meta-analysis was performed of studies that assessed preconceptional folic acid use in Caucasians and non-Caucasians.

RESULTS: Five studies met the inclusion criteria for assessment of knowledge and/or use of folic acid supplements in U.K. women including non-Caucasians. The available evidence indicates that South Asians specifically have less knowledge and lower periconceptional use of folic acid than Caucasians; one study found that West Indian and African women also had lower folic acid uptake. A synthesis of results from three of the studies, in a meta-analysis, shows that Caucasians are almost three times more likely to take folic acid before conception than non-Caucasians.

CONCLUSION: From the limited evidence available, U.K. women of non-Caucasian ethnicity appear to have less knowledge and a lower uptake of folic acid supplementation than Caucasians during the periconceptional period. Implementing targeted, innovative education campaigns together with a mandatory fortification policy, including the fortification of ethnic minority foods, will be required for maximum prevention of folic acid–preventable NTDs across different ethnic groups. Birth Defects Research (Part A) 97:444–451, 2013. © 2013 Wiley Periodicals, Inc.

Do in utero events contribute to current health disparities in reproductive medicine?

Health disparities exist in reproductive medicine as discussed in detail in the subsequent articles of this issue; however, in most cases, the exact cause of these differences is unknown. Some of these disparities can be linked to environmental exposures such as alcohol and other hazardous toxic exposures (polycarbonate, pesticides, nicotine) in adults. In addition, low socioeconomic status, behavioral risk factors, and lack of education have been linked to poor obstetric and reproductive outcomes in minority groups. Aside from these various environmental exposures later in life, there is evidence that adverse events in utero could contribute to poor reproductive outcome in specific minority groups. We will focus on the developmental origins of health and disease as a possible causal mechanism for health disparities in reproductive diseases, as this perspective may suggest tractable solutions of how to address and eliminate these health disparities.

Determinants of neural tube defect (NTD)-protective circulating concentrations of folate in women of child-bearing age in the US post-folic acid fortification era

We evaluated folate status of child-bearing age women diagnosed with abnormal pap smear in the US post-folic acid (FA) fortification era and assessed the determinants of NTD-protective and supra-physiologic (SP) concentrations of folate. The distribution of 843 women according to NTD-protective concentrations of RBC folate, plasma folate and SP concentrations of plasma folate were tested in relation to demographic and life-style factors. Logistic regression models specified NTD-protective concentrations of RBC and plasma folate or SP concentrations of plasma folate as dependent variables and demographic and life-style factors as independent predictors of interest. More than 82% reached NTD-protective concentrations of RBC and plasma folate and ~30% reached SP concentrations of plasma folate. FA supplement use was associated with having SP concentrations of plasma folate rather than NTD-protective concentrations of folate. African American (AA) women and smokers were significantly less likely to achieve NTD-protective concentrations of RBC and plasma folate. A large majority of women reached NTD-protective concentrations of folate with the current level of FA fortification without using supplementary FA. Therefore, the remaining disparities in AA women and in smokers should be addressed by targeted individual improvements in folate intake.

The role of folic acid in fetal programming of birth phenotypes and early human development: a biopsychosocial perspective

Preterm birth, low birthweight, intrauterine growth retardation and small for gestational age are birth phenotypes that significantly contribute to life-long morbidity and mortality. This review examines the epidemiologic and biologic evidence of folic acid (FA) as a potential population-based intervention to curtail some adverse birth phenotypic expressions, and by extension, their later physical and neurodevelopmental consequences. We outlined a feto-placental adaptation categorization taking into account how prenatal insults may be encoded in fetal development, the adaptive success of the feto-placental response, and subsequent expression in the health of the fetus. Although there are plausible biological pathways that can be implicated, we found that the epidemiological evidence on the role of perinatal FA nutriture and fetal programming of adverse birth phenotypes is still inconclusive. Because biologic and epidemiological considerations alone do not suffice in deciphering the utility of FA in averting adverse birth phenotypes, we proposed a biopsychosocial model that takes into account multi-layered psychosocial contexts for improving subsequent research studies in this area.

Methyl donor supplementation blocks the adverse effects of maternal high fat diet on offspring physiology

Maternal consumption of a high fat diet during pregnancy increases the offspring risk for obesity. Using a mouse model, we have previously shown that maternal consumption of a high fat (60%) diet leads to global and gene specific decreases in DNA methylation in the brain of the offspring. The present experiments were designed to attempt to reverse this DNA hypomethylation through supplementation of the maternal diet with methyl donors, and to determine whether methyl donor supplementation could block or attenuate phenotypes associated with maternal consumption of a HF diet. Metabolic and behavioral (fat preference) outcomes were assessed in male and female adult offspring. Expression of the mu-opioid receptor and dopamine transporter mRNA, as well as global DNA methylation were measured in the brain. Supplementation of the maternal diet with methyl donors attenuated the development of some of the adverse effects seen in offspring from dams fed a high fat diet; including weight gain, increased fat preference (males), changes in CNS gene expression and global hypomethylation in the prefrontal cortex. Notable sex differences were observed. These findings identify the importance of balanced methylation status during pregnancy, particularly in the context of a maternal high fat diet, for optimal offspring outcome.

Dietary supplement use and folate status during pregnancy in the United States

Adequate folate and iron intake during pregnancy is critical for maternal and fetal health. No previous studies to our knowledge have reported dietary supplement use and folate status among pregnant women sampled in NHANES, a nationally representative, cross-sectional survey. We analyzed data on 1296 pregnant women who participated in NHANES from 1999 to 2006 to characterize overall supplement use, iron and folic acid use, and RBC folate status. The majority of pregnant women (77%) reported use of a supplement in the previous 30 d, most frequently a multivitamin/-mineral containing folic acid (mean 817 μg/d) and iron (48 mg/d). Approximately 55-60% of women in their first trimester reported taking a folic acid- or iron-containing supplement compared with 76-78% in their second trimester and 89% in their third trimester. RBC folate was lowest in the first trimester and differed by supplement use across all trimesters. Median RBC folate was 1628 nmol/L among users and 1041 nmol/L among nonusers. Among all pregnant women, median RBC folate increased with trimester (1256 nmol/L in the first, 1527 nmol/L in the second, and 1773 nmol/L in the third). Given the role of folic acid in the prevention of neural tube defects, it is notable that supplement use and median RBC folate was lowest in the first trimester of pregnancy, with 55% of women taking a supplement containing folic acid. Future research is needed to determine the reasons for low compliance with supplement recommendations, particularly folic acid, in early pregnancy.

Preconception folic acid supplementation and risk for chromosome 21 nondisjunction: a report from the National Down Syndrome Project

Both a lack of maternal folic acid supplementation and the presence of genetic variants that reduce enzyme activity in folate pathway genes have been linked to meiotic nondisjunction of chromosome 21; however, the findings in this area of research have been inconsistent. To better understand these inconsistencies, we asked whether maternal use of a folic acid-containing supplement before conception reduces risk for chromosome 21 nondisjunction. Using questionnaire data from the National Down Syndrome Project, a population-based case-control study, we compared the use of folic acid-containing supplements among mothers of infants with full trisomy 21 due to maternal nondisjunction (n = 702) and mothers of infants born with no major birth defects (n = 983). Using logistic regression, adjusting for maternal age, race/ethnicity, and infant age at maternal interview, we found no evidence of an association between lack of folic acid supplementation and maternal nondisjunction among all case mothers (OR = 1.16; 95% CI: 0.90-1.48). In analyses stratified by meiotic stage and maternal age (<35 or ≥35 years), we found an association among older mothers experiencing meiosis II nondisjunction errors (OR = 2.00; 95% CI: 1.08-3.71). These data suggest that lack of folic acid supplementation may be associated specifically with MII errors in the aging oocyte. If confirmed, these results could account for inconsistencies among previous studies, as each study sample may vary by maternal age structure and proportion of meiotic errors.

Modeling fortification of corn masa flour with folic acid: the potential impact on exceeding the tolerable upper intake level for folic acid, NHANES 2001-2008

Background

The Institute of Medicine set a tolerable upper intake level (UL) for usual daily total folic acid intake (1,000 µg). Less than 3% of US adults currently exceed the UL.

Objective

The objective of this study was to determine if folic acid fortification of corn masa flour would increase the percentage of the US population who exceed the UL.

Design

We used dietary intake data from NHANES 2001–2008 to estimate the percentage of adults and children who would exceed the UL if corn masa flour were fortified at 140 µg of folic acid/100 g.

Results

In 2001–2008, 2.5% of the US adult population (aged≥19 years) exceeded the UL, which could increase to 2.6% if fortification of corn masa flour occurred. With corn masa flour fortification, percentage point increases were small and not statistically significant for US adults exceeding the UL regardless of supplement use, sex, race/ethnicity, or age. Children aged 1–8 years, specifically supplement users, were the most likely to exceed their age-specific UL. With fortification of corn masa flour, there were no statistically significant increases in the percentage of US children who were exceeding their age-specific UL, and the percentage point increases were small.

Conclusions

Our results suggest that fortification of corn masa flour would not significantly increase the percentage of individuals who would exceed the UL. Supplement use was the main factor related to exceeding the UL with or without fortification of corn masa flour and within all strata of sex, race/ethnicity, and age group.

Modelling fortification of corn masa flour with folic acid and the potential impact on Mexican-American women with lower acculturation

OBJECTIVE

Hispanics with lower acculturation may be at higher risk for neural tube defects compared with those with higher acculturation due to lower total folic acid intake or other undetermined factors. Modelling has indicated that fortification of corn masa flour with folic acid could selectively target Mexican Americans more than other race/ethnicities. We assessed whether fortification of corn masa flour with folic acid could selectively increase folic acid intake among Mexican-American women with lower acculturation, as indicated by specific factors (language preference, country of origin, time living in the USA).

DESIGN

We used dietary intake and dietary supplement data from the National Health and Nutrition Examination Survey 2001-2008, to estimate the amount of additional total folic acid that could be consumed if products considered to contain corn masa flour were fortified at 140 μg of folic acid per 100 g of corn masa flour.

SETTING

USA.

SUBJECTS

Non-pregnant women aged 15-44 years (n 5369).

RESULTS

Mexican-American women who reported speaking Spanish had a relative percentage change in usual daily total folic acid intake of 30·5 (95 % CI 27·8, 33·4) %, compared with 8·3 (95 % CI 7·3, 9·4) % for Mexican-American women who reported speaking English. We observed similar results for other acculturation factors. An increase of 6·0 percentage points in the number of Mexican-American women who would achieve the recommended intake of ≥400 μg folic acid/d occurred with fortification of corn masa flour; compared with increases of 1·1 percentage points for non-Hispanic whites and 1·3 percentage points for non-Hispanic blacks. An even greater percentage point increase was observed among Mexican-American women who reported speaking Spanish (8·2).

CONCLUSIONS

Fortification of corn masa flour could selectively increase total folic acid intake among Mexican-American women, especially targeting Mexican-American women with lower acculturation, and result in a decrease in the number of pregnancies affected by neural tube defects.

Maternal periconceptional folic acid intake and risk of autism spectrum disorders and developmental delay in the CHARGE (CHildhood Autism Risks from Genetics and Environment) case-control study

BACKGROUND

Periconceptional folate is essential for proper neurodevelopment.

OBJECTIVE

Maternal folic acid intake was examined in relation to the risk of autism spectrum disorder (ASD) and developmental delay (DD).

DESIGN

Families enrolled in the CHARGE (CHildhood Autism Risks from Genetics and Environment) Study from 2003 to 2009 were included if their child had a diagnosis of ASD (n = 429), DD (n = 130), or typical development (TD; n = 278) confirmed at the University of California Davis Medical Investigation of Neurodevelopmental Disorders Institute by using standardized clinical assessments. Average daily folic acid was quantified for each mother on the basis of dose, brands, and intake frequency of vitamins, supplements, and breakfast cereals reported through structured telephone interviews.

RESULTS

Mean (±SEM) folic acid intake was significantly greater for mothers of TD children than for mothers of children with ASD in the first month of pregnancy (P1; 779.0 ± 36.1 and 655.0 ± 28.7 μg, respectively; P < 0.01). A mean daily folic acid intake of ≥600 μg (compared with <600 μg) during P1 was associated with reduced ASD risk (adjusted OR: 0.62; 95% CI: 0.42, 0.92; P = 0.02), and risk estimates decreased with increased folic acid (P-trend = 0.001). The association between folic acid and reduced ASD risk was strongest for mothers and children with MTHFR 677 C>T variant genotypes. A trend toward an association between lower maternal folic acid intake during the 3 mo before pregnancy and DD was observed, but not after adjustment for confounders.

CONCLUSIONS

Periconceptional folic acid may reduce ASD risk in those with inefficient folate metabolism. The replication of these findings and investigations of mechanisms involved are warranted.

Maternal micronutrient status and preterm versus term birth for black and white US women

OBJECTIVE

Micronutrient deficiencies are hypothesized to play a role in spontaneous preterm birth (PTB; <37 weeks of gestation) and possibly the racial disparity in rates of PTB between black and white women. Yet relatively few studies have addressed the role of micronutrient deficiencies in spontaneous PTB among black and white women in the United States. The purpose of this study was to investigate whether 25-hydroxy vitamin D (25-OH-D), folate, and omega-6/omega-3 fatty acid status are associated with spontaneous PTB among black and white women in the United States.

METHODS

Biospecimens and medical record data for this study were derived from a subsample of the 1547 women enrolled into the Nashville Birth Cohort during 2003-2006. We randomly selected 80 nulliparous and primiparous women for whom stored plasma samples from the delivery admission were available and analyzed the stored plasma for 25-OH-D, folate, and total omega-6/omega-3 fatty acids. We used multivariate logistic regression to assess the odds of spontaneous PTB among women with 25-OH-D <20 ng/mL, folate <5 ug/L, and omega-6/omega-3 >15.

RESULTS

An omega-6/omega-3 ratio >15 was significantly associated with spontaneous PTB for white (adjusted odds ratio [aOR] 4.25, 95% confidence interval [CI] 1.25-14.49) but not black women (aOR 1.90, 95% CI: 0.69-5.40), whereas no significant relationships were observed for folate and 25-OH-D status and PTB for black or white women.

CONCLUSION

Maternal plasma total omega-6/omega-3 fatty acid ratio >15 at delivery was significantly associated with spontaneous PTB for white, but not black, women.

Assessing vitamin status in large population surveys by measuring biomarkers and dietary intake - two case studies: folate and vitamin D

The National Health and Nutrition Examination Survey (NHANES) provides the most comprehensive assessment of the health and nutrition status of the US population. Up-to-date reference intervals on biomarkers and dietary intake inform the scientific and public health policy communities on current status and trends over time.

The main purpose of dietary assessment methods such as the food-frequency questionnaire, food record (or diary), and 24-hr dietary recall is to estimate intake of nutrients and, together with supplement usage information, describe total intake of various foods or nutrients. As with all self-reporting methods, these tools are challenging to use and interpret. Yet, they are needed to establish dietary reference intake recommendations and to evaluate what proportion of the population meets these recommendations. While biomarkers are generally expensive and, to some degree, invasive, there is no question as to their ability to assess nutrition status. In some cases biomarkers can also be used to assess intake or function, although rarely can one biomarker fulfill all these purposes. For example, serum folate is a good indicator of folate intake, red blood cell (RBC) folate is a good status indicator, and plasma total homocysteine is a good functional indicator of one-carbon metabolism.

Using folate and vitamin D – two vitamins that are currently hotly debated in the public health arena – as two case studies, we discuss the complexities of using biomarkers and total intake information to assess nutrition status. These two examples also show how biomarkers and intake provide different information and how both are needed to evaluate and set public health policy. We also provide guidance on general requirements for using nutrition biomarkers and food and supplement intake information in longitudinal, population-based surveys.

Periconceptional bread intakes indicate New Zealand's proposed mandatory folic acid fortification program may be outdated: results from a postpartum survey

Background

In September 2009, a folic acid fortification mandate (135 μg/100 g bread) was to be implemented in New Zealand. However, due to political and manufacturer objection, fortification was deferred until May 2012. Based on estimates of bread consumption derived from a 1997 nationally representative survey, this program was intended to deliver a mean additional intake of 140 μg folic acid/d to women of childbearing age. Little is known about current bread consumption patterns in this target group. The aim of this study was to assess bread consumption among women prior to and during pregnancy with the intent to estimate periconceptional folic acid intakes that would be derived from bread if mandatory fortification were implemented as currently proposed.

Methods

A retrospective survey of 723 postpartum women in hospitals and birthing centres across New Zealand was conducted using a self-administered questionnaire on bread intake prior to and during pregnancy and maternal socio-demographic and obstetric characteristics.

Results

Median bread intake before conception (2 slices/d) was below that of previous data upon which the current fortification proposal was modeled (3-4 slices/d). If mandatory fortification is implemented as proposed, only 31% (95% CI = 24%-37%) of childbearing-age women would attain an additional folic acid intake of ≥ 140 μg/d, with a mean of 119 μg/d (95% CI = 107 μg/d-130 μg/d). Based on these data, a fortification level of 160 μg/100 g bread is required to achieve the targeted mean of 140 μg folic acid/d. Nonetheless, under the current proposal additional folic acid intakes would be greatest among the least advantaged segments of the target population: Pacific and indigenous Māori ethnic groups; those with increased parity, lower income and education; younger and single mothers; and women with unplanned pregnancies. Subgroups predicted to derive less than adequate folic acid intakes from the proposed policy were women of Asian descent and those with a postgraduate education.

Conclusions

This study provides insight on the ability of a fortification policy to benefit the groups at highest risk of poor folate intakes in a population. However, bread consumption among the target group of childbearing women appears to have declined since the data used in previous dietary modeling were collected. Thus, it seems prudent to re-model dietary folic acid intakes based on more recent national survey data prior to the implementation of a mandatory folic acid fortification policy.

Maternal one-carbon nutrient intake and cancer risk in offspring

Dietary intake of one-carbon nutrients, particularly folate, vitamin B(2) (riboflavin), vitamin B(6) , vitamin B(12) , and choline have been linked to the risk of cancers of the colon and breast in both human and animal studies. More recently, experimental and epidemiological data have emerged to suggest that maternal intake of these nutrients during gestation may also have an impact on the risk of cancer in offspring later in life. Given the plasticity of DNA methylation in the developing embryo and the established role of one-carbon metabolism in supporting biological methylation reactions, it is plausible that alterations in maternal one-carbon nutrient availability might induce subtle epigenetic changes in the developing embryo and fetus that persist into later life, altering the risk of tumorigenesis throughout the lifespan. This review summarizes the current literature on maternal one-carbon nutrient intake and offspring cancer risk, with an emphasis on cancers of the colon and breast, and discusses specific epigenetic modifications that may play a role in their pathogenesis.