Defining the plasma folate concentration associated with the red blood cell folate concentration threshold for optimal neural tube defects prevention: a population-based, randomized trial of folic acid supplementation

Association between gestational environmental chemical mixtures and folate exposures with autistic behaviors in a Canadian birth cohort

Background

Prenatal exposure to environmental chemicals may be associated with autism or autistic-like behaviors. Previous studies suggest that these associations are stronger when folic acid (FA) supplementation is lower.

Methods

We used data from the Maternal-Infant Research on Environmental Chemicals study, a Canadian pregnancy and birth cohort (2008-2011). We considered five separate chemical mixtures (measured during the first trimester of pregnancy): metals, organochlorine pesticides, per- and polyfluoroalkyl substances (PFAS), polychlorinated biphenyls (PCBs), and persistent organic pollutants (POPs; including organochlorine pesticides, PFAS, PCBs, and one polybrominated diphenyl ether congener). Autistic-like behaviors were documented in 601 3-4-year-old children with the social responsiveness scale-2 (SRS-2), where higher T-scores denote more behaviors. We used quantile g-computation to estimate the mixture-SRS-2 associations and assessed whether gestational FA supplementation and plasma total folate concentrations modified these associations.

Results

The PFAS mixture was associated with decreased SRS-2 T-scores (Ψ = -0.5; 95% confidence interval [CI] = -1.1, 0.1). The metal-SRS-2 associations were stronger in the positive direction among participants with high (>1,000 μg/d) FA supplementation (Ψ = 2.4; 95% CI = 0.8, 3.9) versus those with adequate (400-1,000 μg/d) supplementation (Ψ = -0.2; 95% CI = -1.1, 0.7) (p-interaction = 0.003). Plasma total folate concentrations similarly modified these associations (p-interaction = 0.01). The associations between the PFAS, PCB, and POP mixtures and SRS-2 T-scores were stronger in the positive direction among participants with low (<400 μg/d) versus adequate FA supplementation. This was not observed when assessing modification by plasma total folate concentrations.

Conclusion

Our results suggest that the metal mixture is more strongly associated with autistic-like behaviors among participants with higher folate exposure, and the PFAS, PCB, and POP mixtures are more strongly associated with autistic-like behaviors among participants with low FA supplementation.

Vitamin B12 status and metabolic health in women of reproductive age: Population-based biomarker survey

BACKGROUND AND AIMS

In clinical populations, vitamin B12 deficiency has been associated with adverse metabolic health (e.g., gestational diabetes). Population-level data among women of reproductive age could inform screening and interventions. The objective of this analysis was to examine the prevalence of adverse metabolic characteristics (elevated adiposity and central adiposity, hypertension, elevated glycated hemoglobin [HbA1c]) and associations of vitamin B12 status with metabolic characteristics in women as part of a population-based biomarker survey in Southern India.

METHODS

Participants (n = 980 women 15-40 y; not pregnant or lactating) were assessed for total vitamin B12, holotranscobalamin, methylmalonic acid, homocysteine, and HbA1c. Categorical anthropometry assessments and bioelectrical impedance analysis (e.g., whole body (WF%) and trunk (TF%) fat) were assessed among adults (≥18 y). Linear and binomial regressions were used to examine associations of vitamin B12 status with metabolic characteristics.

RESULTS

Overall, 25 % of participants had HbA1c ≥5.7 % (HbA1c ≥5.7-<6.5 %: 20.0 %; ≥6.5 %: 5.0 %), and 18.6 % had hypertension (Stage 1: 16.4 %; Stage 2: 2.2 %). Among adults, 23.4 % had body mass index of (BMI) 25.0-<30.0 kg/m2, 9.6 % had BMI ≥30.0 kg/m2, 13.4 % had elevated waist circumference (WC; >88.9 cm), and 20.8 % had elevated waist-hip ratio (WHR; ≥0.85 cm). Overall, higher vitamin B12 concentrations were associated with lower BMI and WC. Among adults, higher vitamin B12 concentrations were associated with lower WF% and TF%; and lower prevalence of overweight (BMI ≥25.0 kg/m2) and elevated WC, WHR, and WF%. Similarly, vitamin B12 <148 pmol/L was associated with higher BMI and WC overall and, among adults, higher WF% and TF%, and increased overweight (BMI ≥25.0 kg/m2; prevalence ratio: 1.31; 95 % confidence interval: 1.09-1.58), and elevated WC (>88.9 cm; 1.85 [1.32-2.60]), WHR (≥85.0; 1.38 [1.07-1.78]), WF% (>35 %; 1.29 [1.10-1.51]), and TF% (>35 %; 1.25 [1.06-1.49]).

CONCLUSIONS

The burden of adverse metabolic characteristics was substantial in this population of young, apparently healthy women. Among those with vitamin B12 <148 pmol/L there was increased central adiposity and overweight status. Evaluating vitamin B12 and metabolic outcomes prospectively could inform screening and interventions to improve women's health.

REGISTRATION NUMBER

NCT04048330.

Dendritic Molecular Baskets for Selective Binding of Toxic Methotrexate

We describe the preparation, assembly, recognition characteristics, and bioactivity of dendritic basket 612-. This novel cavitand has a deep aromatic pocket with three (S)-glutamic acid dendrons at the rim to amplify water solubility and prevent self-association. 1H NMR spectroscopy, calorimetry (ITC), and mass spectrometry (ESI-MS) measurements validate the formation of an inclusion complex between 612- and anticancer drug methotrexate (MTX2-) in water (Kd=9.2 μM). To identify the docking pose, a comparison of computed (DFT and MM) and experimental 1H NMR chemical shifts suggests that MTX2- folds inside 612- (π⋅⋅⋅π), forming HBs with the peptidic dendrons while anchoring (C-H⋅⋅⋅π) to the aromatic pocket through its N-methyl group. In consequence, 612- selectively binds MTX2- in competition with structurally similar folic acid and leucovorin (reversal poisoning agent). While the host is biocompatible (HEK293; IC50>150 μM) and produces inclusion complex [MTX⊂6]14- in cell media, it experiences limitation in pharmacokinetic sequestration of MTX2- as dihydrofolate reductase's affinity to the drug is suggested to prevail over that of 612-. Nonetheless, considering the basket's biocompatibility, tunability, and chemoselectivity, it stands as the leading candidate in the pursuit of an effective abiotic antidote for methotrexate poisoning.

Blood folate level needed for fully effective fortification in the prevention of neural tube defects

OBJECTIVE

Neural tube defects (NTDs) are a preventable folate deficiency disorder; increasing folic acid intake through food fortification increases serum and red blood cell folate and reduces the risk of an NTD pregnancy. There is controversy over the blood folate level needed to achieve the full preventive effect because of discrepant study conclusions.

METHODS

Results from two published studies were used to determine the relationship between serum folate and NTD risk which was compared with the observed result in a randomised trial of folic acid that increased serum folate from 5 ng/mL to 44 ng/mL among women who took a 4 mg daily periconceptional folic acid supplement.

RESULTS

Both studies showed a proportional (logarithmic) relationship between serum folate and NTD risk without evidence of a folate threshold above which there is no further NTD risk reduction. The suggestion of a threshold is due to the incorrect interpretation of the folate-NTD risk association when plotted on arithmetic scales, which conceals the proportional relationship between the two. Also, both studies accurately estimated the observed result from the randomised trial that achieved a median serum folate level of 44 ng/mL and an 83% preventive effect. This is much higher than has been achieved with current levels of folic acid fortification with serum folate between 10 and 16 ng/mL, resulting in an approximate 20% preventive effect.

CONCLUSION

To achieve fully effective fortification, median population serum folate levels need to be about 44 ng/mL, which would globally prevent about 250 000 NTD cases every year.

Evaluating the association of depressive symptoms on serum folate and erythrocyte folate levels based on the 2017-2020 NHANES database

Objective

To improve further the management of the nutritional status and dietary habits of depressed patients.

Methods

This study investigated the effect of different severity states of depressive symptoms on serum and erythrocyte folate levels using the Nutrition Examination Survey (NHANES) database from 2017 to 2020. We comprised a sample of 4,872 cases from NHANES database. We developed 3 linear regression models to assess the effect of depressive symptoms on erythrocyte folate and serum folate by collating and analyzing the data. The relationship between depression severity and erythrocyte folate as well as serum folate was also mutually validated by the results of multiple logistic regression. Finally, we made restricted cubic spline plots using the glm function of R.

Results

Depression remained negatively correlated with serum folate levels with a OR value of -0.02, 95% CI of -0.05 ~ -0.00. Moderate depression was negatively correlated with folate, with a OR value of -0.03, 95% CI of -0.05 ~ -0.00. When exploring the association between different degrees of depressive symptoms and erythrocyte folate, it was unexpectedly found that major depression was negatively associated with erythrocyte folate with a OR value of -0.18, 95% CI of -0.31 ~ -0.04 after adjusting for all covariates.

Conclusion

Depression is associated with folate levels. The risk of serum folate insufficiency or erythrocyte folate insufficiency is higher after a positive depression. For different degrees of depressive symptoms, serum folate levels were significantly lower than normal in patients with moderate depression, while erythrocyte folate levels were lower than normal in patients with major depression. Therefore, attention should be paid to the dietary habits and nutritional status of patients with depression or depressive symptoms when they are undergoing long-term antidepressant treatment. Folic acid supplementation is recommended for patients with moderate or severe depression or for depressed patients who have developed unhealthy eating habits.

A Randomized Crossover Trial of Acceptability of Quadruple-Fortified Salt in Women and their Households in Southern India

BACKGROUND

Double-fortified salt (DFS; iron, iodine) improved iron status in randomized trials and was incorporated into India's social safety net programs, suggesting opportunities to address other micronutrient deficiencies.

OBJECTIVES

To evaluate the acceptability of quadruple-fortified salt (QFS; iron, iodine, folic acid, and vitamin B12) in women and their households, using a randomized crossover trial design and triangle tests.

METHODS

Women 18-49 y (n = 77) and their households were randomly assigned to receive QFS or DFS in a randomized crossover design over a 3-wk period (week 1: QFS/DFS, week 2: iodized salt, week 3: DFS/QFS). Each week, participants completed a 9-point hedonic questionnaire (1 = dislike extremely to 9 = like extremely) to evaluate 5 sensory domains (color, odor, taste, texture, and overall acceptability) of the intervention, and the remaining salt was weighed using a digital scale. Triangle tests were conducted among women to evaluate sensory discrimination of salt consumed in rice dishes prepared using standardized recipes. Mixed models were used to examine hedonic ratings and salt use; salt type, sequence, and period were included as fixed effects, and household was included as a random effect. Binomial tests were used to evaluate sensory discrimination of salt type in triangle tests.

RESULTS

Mean hedonic ratings for most of the 5 sensory domains were ≥7 (like moderately) and did not differ by salt type [overall acceptability mean (SD): QFS: 7.8 (0.7) compared with DFS: 7.7 (1.2); P = 0.68]. Household salt use (weighed) did not differ by salt type. During the 3-wk intervention period, weighed salt use and hedonic ratings significantly increased, indicating a period effect independent of salt type or sequence. In triangle tests, rice samples prepared with QFS, DFS, or iodized salt were not distinguishable.

CONCLUSIONS

Acceptability of QFS was high, based on individual hedonic ratings and weighed household salt use. Rice dishes prepared with DFS, QFS, and iodized salt were not distinguishable. Findings informed the design of a randomized trial of QFS in this population. This trial was registered at clinicaltrials.gov as NCT03853304 and CTRI/2024/04/066208.

Red blood cell folate and benign prostatic hyperplasia: results from the NHANES 2001-2008

BACKGROUND

Benign prostatic hyperplasia (BPH) affects 30% of men worldwide, folate is essential for life. However, few studies have investigated the relationship between folate levels and BPH. The present study aims to explore the relationship between red blood cell (RBC) folate, a better indicator of long-term folate intake, and BPH in United States (US) men.

METHODS

We used statistics from four cycles of the "National Health and Nutrition Examination Survey" (NHANES2001-2008), RBC folate data come from laboratory data and BPH date come from questionnaire data. A multivariate conditional logistic regression model and subgroup analysis were using to assess the association between RBC folate and BPH.

RESULTS

647 males from four survey cycles in the NHANES2001-2008, of which, 574 men (88.7%) had BPH. After adjusting for potential confounders, a considerable correlation was observed between RBC folate and BPH; With the first quintiles of RBC folate as the reference, multivariable-adjusted odds ratios (ORs) and confidence intervals (95% CIs) of the second, third, fourth, and the highest quintiles were 1.19 (0.58 ∼ 2.44), 1.39 (0.65 ∼ 2.97), 2.27 (0.96 ∼ 5.39), 2.26 (1.35 ∼ 3.76) and 5.37 (1.85 ∼ 15.59), respectively.

CONCLUSIONS

Individuals with high levels of RBC folate were associated with an increased risk of self-reported benign prostatic hyperplasia of US men.

Role of folic acid in regulating gut microbiota and short-chain fatty acids based on an in vitro fermentation model

Folic acid deficiency is common worldwide and is linked to an imbalance in gut microbiota. However, based on model animals used to study the utilization of folic acid by gut microbes, there are challenges of reproducibility and individual differences. In this study, an in vitro fecal slurry culture model of folic acid deficiency was established to investigate the effects of supplementation with 5-methyltetrahydrofolate (MTHF) and non-reduced folic acid (FA) on the modulation of gut microbiota. 16S rRNA sequencing results revealed that both FA (29.7%) and MTHF (27.9%) supplementation significantly reduced the relative abundance of Bacteroidetes compared with control case (34.3%). MTHF supplementation significantly improved the relative abundance of Firmicutes by 4.49%. Notably, compared with the control case, FA and MTHF supplementation promoted an increase in fecal levels of Lactobacillus, Bifidobacterium, and Pediococcus. Short-chain fatty acid (SCFA) analysis showed that folic acid supplementation decreased acetate levels and increased fermentative production of isobutyric acid. The in vitro fecal slurry culture model developed in this study can be utilized as a model of folic acid deficiency in humans to study the gut microbiota and demonstrate that exogenous folic acid affects the composition of the gut microbiota and the level of SCFAs. KEY POINTS: • Establishment of folic acid deficiency in an in vitro culture model. • Folic acid supplementation regulates intestinal microbes and SCFAs. • Connections between microbes and SCFAs after adding folic acid are built.

Association between serum folate and sleep duration in American adults: A cross-sectional analysis of the National Health and Nutrition Examination Survey 2005 to 2010

Folate is a vitamin that is exclusively derived from diet sources. Low folate levels are typically associated with cardiovascular disease, cognitive impairment, and cancer risk. However, few studies have examined the direct relationship between serum folate levels and sleep duration. Accordingly, we aimed to examine the relationship between serum folate levels and sleep duration. Using data from the National Health and Nutrition Examination Survey (NHANES), we examined the association between serum folate levels and sleep duration. We used laboratory data to obtain independent serum folate, and covariate data, including total cholesterol, high-density lipoprotein, blood glucose, and glycated hemoglobin; dependent variable sleep duration and covariate data including race, family income, marital status, education, and country of birth from questionnaire data; and other covariate data such as systolic blood pressure, diastolic blood pressure, waist circumference, and body mass index data from the measured data. Data was primarily analyzed using multiple regression analysis, stratified analysis with interactions, restricted cubic splines (RCS), and threshold effect analysis. A total of 14,072 participants over 19 years of age were enrolled, comprising 6923 (49.2%) males and 7149 (50.8%) females, with a median age of 48 years. The association between serum folate levels and sleep duration exhibited an inverted L-shaped curve (P = .033) in RCS. In the threshold analysis, for participants with serum folate of <32.208 nmol/L (β = 0.608, 95% CI: (0.275, 0.942), P < .001), the sleep duration was significantly increased by 0.608 minutes, with every 1 nmol/L in serum folate increased. At serum folate of ≥32.208 nmol/L, no significant association between serum folate and sleep duration was detected [β = 5.686, 95% CI: (-1.508, 12.88), P = .118]. Our findings revealed an inverted L-shaped relationship and saturation effects between serum folate levels and sleep duration in adults in the United States.

The unique presentation of the relationship between red blood cell folate and appendicular skeletal muscle mass: a cross-sectional study

The overconsumption of folic acid has been associated with deleterious health effects; however, the extant body of research on this matter remains controversial. The principal objective of our investigation was to scrutinize the correlation between red blood cell (RBC) folate levels and appendicular skeletal muscle mass (ASM) among adult individuals. A total of 4117 adults aged over 20 years were included. The weighted prevalence of low muscle mass status (LMMS) was 14.50%. The correlation between RBC folate and ASM showed an inverted U-shaped curve. When the RBC folate concentration is below 500 nmol/L, ASM increases with increasing RBC folate concentration. However, when the RBC folate level exceeds 500 nmol/L, ASM decreases with increased RBC folate level. After correcting multiple confounding factors, a positive correlation was found between RBC folate and LMMS (p < 0.001). Compared with the RBC folate first quartile, the multivariable-adjusted ORs and 95% CIs of the second quartile, third quartile, and highest quartile were 1.08(0.81-1.44), 1.06(0.79-1.43), and 1.96(1.47-2.61), respectively. Our research suggested that excessive levels of RBC folate may be associated with an increased risk of LMMS in adults. Thus, being more cautious when considering folic acid supplementation is recommended.

Folate and cobalamin status, indicators, modulators, interactions, and reference ranges from early pregnancy until birth: the Reus-Tarragona birth cohort study

BACKGROUND

Folate and cobalamin status, although essential for pregnancy, are not routinely monitored in prenatal care.

OBJECTIVES

To investigate folate and cobalamin status and determinants throughout pregnancy, in the absence of mandatory folic acid (FA) fortification.

METHODS

In a cohort study of 831 mothers recruited at <12 gestational weeks (GW), plasma folate, total homocysteine (tHcy), cobalamin, holotranscobalamin (holoTC), methylmalonic acid (MMA), red blood cell folate (RBCF), and the combined cobalamin status indicator (cB12) were determined at ≤12, 15, 24-27, 34 GW, labor and in the cord. Single nucleotide polymorphisms affecting folate and cobalamin status were determined. FA, cobalamin, micronutrient supplement use, and dietary folate and cobalamin intake (food frequency questionnaire) were recorded. Folate and cobalamin status predictors were assessed by multiple linear regression analysis.

RESULTS

Only 36.1% of the participants took FA preconceptionally and 47.4% and 7.3% had suboptimal RBCF (<906 nmol/L) and plasma cobalamin status (≤221 pmol/L), respectively, at ≤12 GW. RBCF determinants included planned pregnancy, FA supplementation, plasma cobalamin, and methylenetetrahydrofolate (MTHFR) 677C>T genotype. Cobalamin supplementation was positively associated with plasma cobalamin and early holoTC. Smoking and BMI were inversely associated with plasma cobalamin and early holoTC, but none were associated with MMA. Only participants with the MTHFR 677TT genotype, exceeding FA supplement recommendations, improved their folate status (interaction term: B (95% CI):0.15 (0.01, 0.29), P = 0.032). Smoking was inversely associated with plasma cobalamin status in participants with the methionine synthase reductase (MTRR) 524CC genotype only (interaction term:0.07 (0.01, 0.04), P = 0.014). Mothers with low early pregnancy cobalamin status and also those with bigger newborns, had lower cobalamin status at labor.

CONCLUSIONS

Suboptimal early pregnancy folate or cobalamin status affected 47.4% and 7.3% of the participants, respectively. The MTHFR 677TT genotype predicted folate status throughout pregnancy. Smoking and BMI were negatively associated with cobalamin status throughout pregnancy. Clinical Trial Registry number and website where it was obtained: NCT01778205. www.

CLINICALTRIALS

gov.

Improvement of serum folate status in the US women of reproductive age with fortified iodised salt with folic acid (FISFA study)

OBJECTIVE

Mandatory folic acid fortification of enriched grains has reduced neural tube defect prevalence in several countries. We examined salt as an additional vehicle for folic acid fortification. The primary objective was to examine the change in serum folate concentration after 1 month of consumption of fortified iodised salt with folic acid (FISFA) among women of reproductive age. The secondary objectives were to examine (1) the feasibility of implementing FISFA intervention and (2) the acceptability of FISFA.

DESIGN

We conducted a pre–post intervention study (January–April 2023). Participants received a FISFA saltshaker with the study salt (1 g of sodium chloride salt fortified with 100 mcg of folic acid) to use instead of regular table salt for 1 month. Serum folate was measured using the Elecsys Folate-III immunoassay method at baseline and 1-month endpoint. Change in serum folate was assessed using a two-tailed Wilcoxon signed rank test for paired samples.

SETTING

Metropolitan city, Southern USA.

PARTICIPANTS

Non-pregnant, 18–40-year-old women who lived alone/with a partner.

RESULTS

Thirty-two eligible women consented to participate, including eleven non-Hispanic-White, eleven non-Hispanic-Black and ten Hispanic. Post-intervention, there was a significant increase in median serum folate concentration of 1·40 nmol/l (IQR 0·74–2·05; P < 0·001) from 24·08 nmol/l to 25·96 nmol/l in an analytical sample of n 29. An increase was seen in 28/29 (93 %) participants. Feasibility: 100 % study consent and compliance. FISFA acceptability: 25 d average use; 1·28 g average daily intake; 96·7 % and 90 % reported taste and colour of FISFA as highly acceptable, respectively.

CONCLUSIONS

FISFA is an effective approach to increasing serum folate concentrations among women of reproductive age. Findings should be replicated in a larger study.

Association between RBC folate and diabetic nephropathy in Type2 diabetes mellitus patients: a cross-sectional study

Folates play a crucial role as cofactors in metabolic pathways, influencing biological methylation and nucleotide synthesis, which has a significant impact on overall health and disease susceptibility. Diabetic nephropathy (DN) is a prevalent and severe complication of diabetes mellitus (DM). The correlation between RBC folate and DN remains unclear currently. This study aims to assess whether RBC folate is associated with DN. Based on data from the NHANES (2011-2018), we conducted a cross-sectional study involving 3070 adults with type 2 DM (T2DM). Demographic factors, levels of folate and vitamin B12, dietary folate intakes, and relevant laboratory data were obtained from all participants. Logistic regression, fitting smooth curves, interaction effects were utilized to support the research objectives. Regression analyses demonstrated a positive relation between RBC folate and DN. (P < 0.001). A positive association between levels of RBC folate and the risk of DN was observed after full adjustment for all the confounding variables (odds ratio: 1.38, 95% confidence interval: 1.27-1.49, P < 0.001). Similar patterns of association were observed for subgroup analysis (all P values for interaction > 0.05). In addition, curve fitting after adjusting for all the confounding variables demonstrated that there was a linear relationship between RBC folate and DN (P for non-linearity = 0.147). Increased RBC folate levels were linked to a higher risk of DN in type 2 diabetes. RBC folate should be considered as a crucial indicator for folate status in DN.

Combined Exposure to Folate and Lead during Pregnancy and Autistic-Like Behaviors among Canadian Children from the MIREC Pregnancy and Birth Cohort

BACKGROUND

Folic acid (FA) supplementation may attenuate the associations between gestational exposure to certain chemicals and autism or autistic-like behaviors, but to our knowledge, this has not been assessed for lead.

OBJECTIVES

We examined whether the relationship between gestational blood-lead levels (BLLs) and autistic-like behaviors was modified by gestational plasma total folate concentrations, FA supplementation, and maternal methylenetetrahydrofolate reductase (MTHFR) 677C>T genotype.

METHODS

We used data from the Maternal-Infant Research on Environmental Chemicals study (2008-2011), a Canadian pregnancy and birth cohort study. Childhood autistic-like behaviors were documented in 601 children 3-4 y of age with the Social Responsiveness Scale-2 (SRS-2), where higher scores denote more autistic-like behaviors. We measured BLLs and plasma total folate concentrations during the first and third trimesters of pregnancy. We also estimated gestational FA supplementation via surveys and genotyped the maternal MTHFR 677C>T single nucleotide polymorphism (SNP). We estimated the confounder-adjusted associations between log 2 -transformed BLLs and SRS-2 scores by two indicators of folate exposure and maternal MTHFR 677C>T genotype using linear regression.

RESULTS

Third-trimester BLLs were associated with increased SRS-2 scores [β a d j = 3.3 ; 95% confidence interval (CI): 1.1, 5.5] among participants with low (< 10 th percentile), third-trimester, plasma total folate concentrations, but BLL-SRS-2 associations were null (β a d j = - 0.3 ; 95% CI: - 1.2 , 0.5) among those in the middle category (≥ 10 th and < 80 th percentiles) (p-interaction < 0.001 ). FA supplementation also attenuated these associations. Both folate indicators modified first-trimester BLL-SRS-2 associations, but to a lesser extent. Third-trimester BLL-SRS-2 associations were slightly stronger among participants who were homozygous for the T (minor) allele of the MTHFR 677C>T SNP (β a d j = 0.9 ; 95% CI: - 1.2 , 3.1) than those without the T allele (β a d j = - 0.3 ; 95% CI: - 1.3 , 0.7), but the difference was not statistically significant (p -interaction = 0.28 ).

DISCUSSION

Folate may modify the associations between gestational lead exposure and childhood autistic-like behaviors, suggesting that it mitigates the neurotoxic effects of prenatal lead exposure. https://doi.org/10.1289/EHP14479.

Evaluating Access to Health Care in Mothers and Caregivers of Children under Five Years of Age in Rural Communities of Yucatán, Mexico

Populations in rural communities have more limited access to health care and attention than urban populations. The present study aimed to evaluate barriers to access to health care in mothers and caregivers of children under five years of age, twelve months after an educational intervention. The study was carried out from February to September 2022, and 472 mothers from eight communities in the state of Yucatán, in the southeast of the United Mexican States, participated. A comparative analysis was carried out on help-seeking times, obstacles to reaching it, and illnesses in children. The results revealed that the main barriers to access to care were long times to decide to seek help, lack of financial resources to pay for the transfer to another health unit, lack of someone to accompany the mother or caregiver when the child needed be transferred, and lack of transportation for the transfer. Disease knowledge remained at different levels in the eight communities; the significant differences occurred in four communities, one specifically for heart defects. It was concluded that, in the rural populations studied, there are barriers to access to health care which have to do with neglected social determinants, such as those related to conditions of gender, income, social support network, and the health system. Access to health care must be universal, so public health interventions should be aimed at reducing the barriers that prevent the population from demanding and using services in a timely manner.

Folate and Vitamin B12 Status in Women of Reproductive Age in Rural Haryana, India: Estimating Population-Based Prevalence for Neural Tube Defects

BACKGROUND

Folate and vitamin B12 deficiencies in pregnant women are associated with increased risk for adverse maternal and infant health outcomes, including neural tube defects (NTDs).

METHODS

A population-based cross-sectional survey was conducted in two rural areas in Ambala District, Haryana, India in 2017 to assess baseline folate and vitamin B12 status among women of reproductive age (WRA) and predict the prevalence of NTDs. We calculated the prevalence of folate and vitamin B12 deficiency and insufficiency by demographic characteristics among 775 non-pregnant, non-lactating WRA (18-49 years). Using red blood cell (RBC) folate distributions and an established Bayesian model, we predicted NTD prevalence. All analyses were conducted using SAS-callable SUDAAN Version 11.0.4 to account for complex survey design.

RESULTS

Among WRA, 10.1% (95% CI: 7.9, 12.7) and 9.3% (95% CI: 7.4, 11.6) had serum (<7 nmol/L) and RBC folate (<305 nmol/L) deficiency, respectively. The prevalence of RBC folate insufficiency (<748 nmol/L) was 78.3% (95% CI: 75.0, 81.3) and the predicted NTD prevalence was 21.0 (95% uncertainly interval: 16.9, 25.9) per 10,000 live births. Prevalences of vitamin B12 deficiency (<200 pg/mL) and marginal deficiency (≥200 pg/mL and ≤300 pg/mL) were 57.7% (95% CI: 53.9, 61.4) and 23.5% (95% CI: 20.4, 26.9), respectively.

CONCLUSIONS

The magnitude of folate insufficiency and vitamin B12 deficiency in this Northern Indian population is a substantial public health concern. The findings from the survey help establish the baseline against which results from future post-fortification surveys can be compared.

Gestational exposure to organochlorine compounds and metals and infant birth weight: effect modification by maternal hardships

BACKGROUND

Gestational exposure to toxic environmental chemicals and maternal social hardships are individually associated with impaired fetal growth, but it is unclear whether the effects of environmental chemical exposure on infant birth weight are modified by maternal hardships.

METHODS

We used data from the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, a pan-Canadian cohort of 1982 pregnant females enrolled between 2008 and 2011. We quantified eleven environmental chemical concentrations from two chemical classes - six organochlorine compounds (OCs) and five metals - that were detected in ≥ 70% of blood samples collected during the first trimester. We examined fetal growth using birth weight adjusted for gestational age and assessed nine maternal hardships by questionnaire. Each maternal hardship variable was dichotomized to indicate whether the females experienced the hardship. In our analysis, we used elastic net to select the environmental chemicals, maternal hardships, and 2-way interactions between maternal hardships and environmental chemicals that were most predictive of birth weight. Next, we obtained effect estimates using multiple linear regression, and plotted the relationships by hardship status for visual interpretation.

RESULTS

Elastic net selected trans-nonachlor, lead, low educational status, racially minoritized background, and low supplemental folic acid intake. All were inversely associated with birth weight. Elastic net also selected interaction terms. Among those with increasing environmental chemical exposures and reported hardships, we observed stronger negative associations and a few positive associations. For example, every two-fold increase in lead concentrations was more strongly associated with reduced infant birth weight among participants with low educational status (β = -100 g (g); 95% confidence interval (CI): -215, 16), than those with higher educational status (β = -34 g; 95% CI: -63, -3). In contrast, every two-fold increase in mercury concentrations was associated with slightly higher birth weight among participants with low educational status (β = 23 g; 95% CI: -25, 71) compared to those with higher educational status (β = -9 g; 95% CI: -24, 6).

CONCLUSIONS

Our findings suggest that maternal hardships can modify the associations of gestational exposure to some OCs and metals with infant birth weight.

Maternal Smoking during Pregnancy and its effects on Neural Tube Defects

Objectives

Maternal smoking is a potent teratogen among congenital malformations, however its role in the development of Neural Tube Defects (NTDs) is still unclear. In this systematic review, we intend to further investigate the interaction of smoking during pregnancy and the incidence of NTDs.

Materials & Methods

This article was written according to PRISMA criteria from February 2015 and August 2022. After examining the four stages of PRISMA criteria, we selected clinical articles. These articles were selected from PubMed, Scopus and Google scholar (for results follow-up) databases. We gathered NTDs effect and types, smoking type and habit of parents, from neonates.

Results

Eventually, 8 articles were included by two separated authors, Smoking was associated with an increase NTDs in the population of pregnant mothers and also among children whose fathers smoked. The main side effects that were considered to be the cause of NTDs besides smoking were alcohol and BMI (18.5-24.9). Smoking also affects the level of folic acid as a substance with an essential role that affects the closure of the neural tube. folic acid available to infants changing along with the level of other blood elements such as zinc, that necessary prevent for NTDs condition.

Conclusion

Parental smoking can be considered as one of the strong teratogens in the occurrence of NTDs. Smoking, whether active or passive by the mother, or by the father, is associated with the occurrence of NTDs, In order to reduce the prevalence this disorder, we advise pregnant mothers and neonate's fathers to quit smoking.

Defining Optimal Cobalamin Status for Neonates and Infants

BACKGROUND

An optimal cobalamin status is necessary for normal neurodevelopment.

OBJECTIVE

To give a description of the epidemiology, pathophysiology and diagnostic challenges related to cobalamin insufficiency in neonates and infants in order to prevent its occurence.

RESULTS

Inadequate cobalamin status is prevalent among neonates and young infants, due to a high prevalence of maternal cobalamin deficiency, exclusive breastfeeding for extended periods and late introduction of animal food. Cobalamin insufficiency is associated with delayed neurodevelopment and subtle clinical symptoms like feeding difficulties, regurgitations and constipation in young infants. Early diagnosis and treatment of impaired cobalamin status is important to prevent neurologic damage.

CONCLUSION

Clinical suspicion of cobalamin insufficiency in infants should infer immediate biochemical testing and a plasma total homocysteine > 5.0 µmol/L indicate cobalamin insufficiency in need of intramuscular treatment with hydroxycobalamin, followed by introduction of animal food after 4 months of age.

Maternal non-compliance with recommended folic acid supplement use alters global DNA methylation in cord blood of newborns: A cohort study

BACKGROUND & AIMS

Prenatal folate exposure may alter epigenetic marks in the offspring. We aimed to evaluate associations between prenatal exposure to folic acid (FA) in preconception and in utero with cord blood DNA methylation in long interspersed nuclear element 1 (LINE-1) and Alu short interspersed nuclear elements (SINEs) as markers of global DNA methylation levels.

METHODS

Data come from 325 mother-child pairs participating in the Nutrition in Early Life and Asthma (NELA) birth cohort (2015-2018). Pregnant women were asked about supplement use, including brand name and dose, one month before pregnancy (preconception) and through the trimesters of pregnancy. Maternal dietary folate intake was assessed using a validated food frequency questionnaire with additional questions for FA supplement use. Folate serum levels were measured in mothers at 24 weeks of gestation and in cord blood of newborns. DNA methylation was quantitatively assessed by bisulfite pyrosequencing on 5 LINE-1 and 3 Alu different elements. Associations were estimated using multivariable linear regression models.

RESULTS

A reduction in methylation levels of LINE-1 in newborns was associated with the use of FA supplements below the recommended doses (<400 ug/day) during preconception (-0.50; 95% CI: -0.91, -0.09; P = 0.016), and from preconception up to 12 weeks of gestation (-0.48; 95% CI: -0.88, -0.08; P = 0.018). Maternal use of FA supplements above the tolerable upper intake level of 1000 ug/day from preconception until 12 weeks of gestation was also related to lower methylation in LINE-1 at birth (-0.77; 95% CI: -1.52, -0.02; P = 0.044). Neither FA supplement use after 12 weeks of gestation nor maternal total folate intake (diet plus supplements) were associated with global DNA methylation levels at birth.

CONCLUSIONS

Maternal non-compliance with the use of FA supplement recommendations from preconception up to 12 weeks of gestation reduces offspring global DNA methylation levels at birth.

Folate - a scoping review for Nordic Nutrition Recommendations 2023

Folate is an essential micronutrient for normal development and metabolic function, and folate deficiency is associated with an increased risk of cancer, cardiovascular disease, mental dysfuntion and negative pregnancy outcomes. When estimating folate requirements, one must consider different bioavailability and functionality between synthetic folic acid and dietary folate, together with increased needs of folate in women of fertile age, pregnant and lactating women, preterm and small for gestational age weight infants and individuals who are homozygote for the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene polymorphism. In order to achieve an adequate metabolic status based on the metabolic marker total homocysteine, and not merely the absence of clinical signs of folate deficiency, the recommended intake of folate differs according to age, pregnancy and lactation. According to the World Health Organization, a decision limit for folate deficiency in adults is serum folate level below 10 nmol/L, and in women of fertile age a red blood cell folate level below 906 nmol/L in order to prevent neural tube defects. Qualified systematic reviews along with identified relevant literature have been used for this scoping review prepared for the Nordic Nutrition Recommendations 2023.

Before Is Better: Innovative Multidisciplinary Preconception Care in Different Clinical Contexts

CONTEXT

Implementation of pre-conception care units is still very limited in Italy. Nowadays, the population's awareness of the reproductive risks that can be reduced or prevented is very low. Purpose and main findings: We presented a new personalized multidisciplinary model of preconception care aimed at identifying and possibly reducing adverse reproductive events. We analyzed three cohorts of population: couples from the general population, infertile or subfertile couples, and couples with a previous history of adverse reproductive events. The proposal involves a deep investigation regarding family history, the personal histories of both partners, and reproductive history.

PRINCIPAL CONCLUSIONS

Preconception care is still neglected in Italy and under-evaluated by clinicians involved in natural or in vitro reproduction. Adequate preconception counseling will improve maternal and fetal obstetrical outcomes.

Nonlinear Relationship Between Maternal and Cord Blood Vitamin B12 and Folate from a Chinese Population-Based Study

Purpose

There remains a data gap on vitamin B12 and folate level in maternal and child populations. This study aimed to assess the status of vitamin B12 and folate in maternal serum (MS) and umbilical cord serum (UCS).

Materials and Methods

This was a planned secondary analysis of a case-control study. A total of 858 pregnant women during late pregnancy and their newborns in the hospitals of China were included. Maternal peripheral venous blood and neonatal umbilical cord blood were collected to determine serum vitamin B12 and folate concentration. Relationship of vitamin B12 or folate concentration between MS and UCS was assessed by a quantile regression model and the non-linear relationship between them was examined.

Results

Nutritional status of serum folate was better than that of vitamin B12. Prevalence of deficiency in MS vitamin B12 and folate was 73.4% and 14.2%, respectively and these figures were about 17.8% and 0.1% in UCS. Both vitamin B12 and folate levels in UCS were significantly higher than those in MS (vitamin B12: 321.0 pg/mL vs 158.3 pg/mL, folate: 16.5 ng/mL vs 7.0 ng/mL, P <0.001). The median UCS-MS ratio of vitamin B12 and folate was 2.0 (95% CI: 1.94-2.06) and 2.4 (95% CI: 2.30-2.53), respectively. The levels of folate and vitamin B12 in UCS increased nonlinearly with their increase in MS which presented an inverted U-shaped curve.

Conclusion

Deficiency in vitamin B12 and folate in the women during late pregnancy in China is prevalent. Nutritional status of the two vitamins in umbilical cord serum is correlated nonlinearly with that in maternal serum. Folic acid supplementation may be accompanied with vitamin B12 to improve status of vitamin B12 and folate during pregnancy.

Initiation and duration of folic acid supplementation in preventing congenital malformations

BACKGROUND

Folic acid (FA) supplementation is associated with a lower risk of the neural tube and heart defects and is recommended for women of childbearing age. Although there are detailed recommendations, differences in the initiation time and duration of FA supplementation remain poorly studied.

METHODS

A multicentre prospective study of 17,713 women was conducted. The incidence of congenital malformations in women taking a recommended dosage (e.g. 0.4 or 0.8 mg/day) of FA was compared with that in women without supplementation. The predicted probability of malformations by the initiation time and duration of FA use was estimated to determine optimal options.

RESULTS

Periconceptional FA supplementation was associated with a lower and insignificant risk of congenital malformations (1.59% vs. 2.37%; odds ratio [OR] 0.69; 95% confidence interval [CI]: 0.44-1.08), heart defects (3.8 vs. 8.0 per 1000 infants; OR, 0.47; 0.21-1.02), and neural tube defects (7.0 vs. 11.5 per 10,000 infants; OR, 0.64; 0.08-5.15). FA use after pregnancy provided greater protection against total malformations. Statistically significant associations were found in women who initiated FA supplementation in the first month of gestation (OR, 0.55; 95% CI: 0.33-0.91) and in those who supplemented for 1 to 2 months (OR, 0.59; 95% CI: 0.36-0.98). Similar results were found for heart defects. The optimal initiation time was 1.5 (optimal range: 1.1 to 1.9) months before pregnancy and a duration of 4.0 (3.7 to 4.4) months was reasonable to achieve the lowest risk of congenital malformations. Heart defect prevention required an earlier initiation (2.2 vs. 1.1 months before pregnancy) and a longer duration (4.7 vs. 3.7 months) than the prevention of other malformations.

CONCLUSIONS

The timely initiation of FA supplementation for gestation was associated with a decreased risk of congenital malformations, which was mainly attributed to its protection against heart defects. The initiation of FA supplementation 1.5 months before conception with a duration of 4 months is the preferred option for congenital malformation prevention.

TRIAL REGISTRATION

Chictr.org.cn identifier: ChiCTR-SOC-17010976.

Neural tube defects: a review of global prevalence, causes, and primary prevention

Neural tube defects (NTDs) are common birth defects and contribute to life-long disabilities, high medical care costs, and perinatal and child mortality. This review is a primer on prevalence, causes, and evidence-based prevention strategies for NTDs. The estimated average global prevalence of NTDs is two cases per 1000 births, amounting to approximately 214,000-322,000 affected pregnancies worldwide annually. Prevalence and associated adverse outcomes are disproportionately high in developing countries. NTDs have multiple risk factors including genetic and non-genetic (i.e., maternal nutritional status, pre-pregnancy diabetes, early pregnancy exposure to valproic acid (anti-epileptic medication), and a previous pregnancy affected by a NTD) factors. Maternal folate insufficiency before and during early pregnancy is the most common risk factor and is preventable. Folic acid (vitamin B9) is required for formation of the neural tube early in pregnancy, around 28 days after conception, when most women are unaware of their pregnancies. Current guidelines recommend that all women planning or capable of pregnancy take a daily supplement containing 400-800 μg of folic acid. Mandatory folic acid fortification of staple foods (e.g., wheat flour, maize flour, rice) is safe, economical, and the effective intervention for primary prevention of NTDs. Currently, about 60 countries are implementing mandatory folic acid fortification of staple foods, preventing just a quarter of all preventable NTD cases worldwide. There is an urgent need for active champions, including neurosurgeons and other healthcare providers, to generate political will and promote effective mandatory food fortification with folic acid, and reach equitable primary prevention of NTDs in all countries.

Global strategies for the prevention of neural tube defects through the improvement of folate status in women of reproductive age

INTRODUCTION

Neural tube defects represent a global public health problem, mainly in countries where effective prevention strategies are not yet in place. The global prevalence of neural tube defects is estimated at 18.6/10,000 (uncertainty interval: 15.3-23.0) live births, where ~ 75% of cases result in under-five mortality. Most of the mortality burden is in low- and middle-income countries. The main risk factor for this condition is insufficient folate levels in women of reproductive age.

METHODS

This paper reviews the extent of the problem, including the most recent global information on folate status in women of reproductive age and the most recent estimates of the prevalence of neural tube defects. Additionally, we provide an overview of the available interventions worldwide to reduce the risk of neural tube defects by improving folate status in the population, including dietary diversification, supplementation, education, and fortification.

RESULTS

Large-scale food fortification with folic acid is the most successful and effective intervention to reduce the prevalence of neural tube defects and associated infant mortality. This strategy requires the coordination of several sectors, including governments, the food industry, health services providers, the education sector, and entities that monitor the quality of the service processes. It also requires technical knowledge and political will. An international collaboration between governmental and non-governmental organizations is essential to succeed in saving thousands of children from a disabling but preventable condition.

DISCUSSION

We propose a logical model for building a national-level strategic plan for mandatory LSFF with folic acid and explain the actions needed for promoting sustainable system-level change.

Multivitamin/Multimineral Supplementation Prevents or Reverses Decline in Vitamin Biomarkers and Cellular Energy Metabolism in Healthy Older Men: A Randomized, Double-Blind, Placebo-Controlled Study

Despite the reported prevalence of micronutrient deficiencies in older adults, it is not yet established whether multivitamin/multimineral (MV/MM) supplements improve blood micronutrient status in individuals over the age of 65. Therefore, a cohort of 35 healthy men (>67 years) was recruited for an MV/MM supplementation trial. The primary endpoint was, as an indicator of micronutrient status, changes in blood micronutrient biomarkers from baseline to at least six months of supplementation with MV/MM or placebo. The secondary endpoint was basal O2 consumption in monocytes as an indicator of cellular metabolism. MV/MM supplementation improved blood concentrations of pyridoxal phosphate, calcifediol, α-tocopherol, and β-carotene concentrations throughout the cohort. By contrast, those in the placebo group generally showed declines in blood vitamin concentrations and an increased prevalence of suboptimal vitamin status during the study period. On the other hand, MV/MM supplementation did not significantly affect blood mineral concentrations, i.e., calcium, copper, iron, magnesium, and zinc. Interestingly, MV/MM supplementation prevented the decline in monocyte O2 consumption rate. Overall, MV/MM use improves or prevents declines in vitamin, but not mineral, status and limits declines in cellular O2 consumption, which may have important implications for metabolism and immune health in healthy older men.

Association of Early Pregnancy Perfluoroalkyl and Polyfluoroalkyl Substance Exposure With Birth Outcomes

Importance

Prenatal perfluoroalkyl and polyfluoroalkyl substances (PFAS) have been linked to adverse birth outcomes. Previous research showed that higher folate concentrations are associated with lower blood PFAS concentrations in adolescents and adults. Further studies are needed to explore whether prenatal folate status mitigates PFAS-related adverse birth outcomes.

Objective

To examine whether prenatal folate status modifies the negative associations between pregnancy PFAS concentrations, birth weight, and gestational age previously observed in a US cohort.

Design, Setting, and Participants

In a prospective design, a prebirth cohort of mothers or pregnant women was recruited between April 1999 and November 2002, in Project Viva, a study conducted in eastern Massachusetts. Statistical analyses were performed from May 24 and October 25, 2022.

Exposure

Plasma concentrations of 6 PFAS compounds were measured in early pregnancy (median gestational week, 9.6). Folate status was assessed through a food frequency questionnaire and measured in plasma samples collected in early pregnancy.

Main Outcomes and Measures

Birth weight and gestational age, abstracted from delivery records; birth weight z score, standardized by gestational age and infant sex; low birth weight, defined as birth weight less than 2500 g; and preterm birth, defined as birth at less than 37 completed gestational weeks.

Results

The cohort included a total of 1400 mother-singleton pairs. The mean (SD) age of the mothers was 32.21 (4.89) years. Most of the mothers were White (73.2%) and had a college degree or higher (69.1%). Early pregnancy plasma perfluorooctanoic acid concentration was associated with lower birth weight and birth weight z score only among mothers whose dietary folate intake (birth weight: β, -89.13 g; 95% CI, -166.84 to -11.42 g; birth weight z score: -0.13; 95% CI, -0.26 to -0.003) or plasma folate concentration (birth weight: -87.03 g; 95% CI, -180.11 to 6.05 g; birth weight z score: -0.14; 95% CI, -0.30 to 0.02) were below the 25th percentile (dietary: 660 μg/d, plasma: 14 ng/mL). No associations were found among mothers in the higher folate level groups, although the tests for heterogeneity did not reject the null. Associations between plasma perfluorooctane sulfonic acid and perfluorononanoate (PFNA) concentrations and lower birth weight, and between PFNA and earlier gestational age were noted only among mothers whose prenatal dietary folate intake or plasma folate concentration was in the lowest quartile range. No associations were found among mothers in higher folate status quartile groups.

Conclusions and Relevance

In this large, US prebirth cohort, early pregnancy exposure to select PFAS compounds was associated with adverse birth outcomes only among mothers below the 25th percentile of prenatal dietary or plasma folate levels.

Estimating the serum folate concentration that corresponds to the red blood cell folate concentration threshold associated with optimal neural tube defects prevention: A population-based biomarker survey in Southern India

BACKGROUND

RBC folate concentrations are monitored at the population level, with a recommended threshold for optimal neural tube defect (NTD) prevention. A corresponding threshold for serum folate has not been established.

OBJECTIVES

This study aimed to estimate the serum folate insufficiency threshold corresponding to the RBC folate threshold for NTD prevention and examine how this threshold is modified by vitamin B12 status.

METHODS

Participants were women (15-40 y; not pregnant or lactating; n = 977) from a population-based biomarker survey in Southern India. RBC folate and serum folate were measured via microbiologic assay. RBC folate deficiency (<305 nmol/L) and insufficiency (<748 nmol/L), serum vitamin B12 deficiency (<148 pmol/L) and vitamin B12 insufficiency (<221 pmol/L), elevated plasma MMA (>0.26 μmol/L), elevated plasma homocysteine (>10.0 μmol/L), and elevated HbA1c (≥6.5%) were evaluated. Bayesian linear models were used to estimate unadjusted and adjusted thresholds.

RESULTS

Compared with adequate vitamin B12 status, the estimated serum folate threshold was higher in participants with serum vitamin B12 deficiency (72.5 vs. 28.1 nmol/L) or vitamin B12 insufficiency (48.7 vs. 24.3 nmol/L) and elevated MMA (55.6 vs. 25.9 nmol/L). The threshold was lower in participants with elevated HbA1c (HbA1c ≥6.5% vs. <6.5%; 21.0 vs. 40.5 nmol/L).

CONCLUSIONS

The estimated serum folate threshold for optimal NTD prevention was similar to previous reports (24.3 vs. 25.6 nmol/L) among participants with sufficient vitamin B12 status. However, this threshold was more than 2-fold higher in participants with vitamin B12 deficiency and substantially higher across all indicators of insufficient vitamin B12 status (<221 pmol/L, elevated MMA, combined B12, impaired vitamin B12 status), and lower in participants with elevated HbA1c. Findings suggest a serum folate threshold for NTD prevention may be possible in some settings; however, it may not be appropriate in populations with high prevalence of vitamin B12 insufficiency. Am J Clin Nutr 2023;xx:xx-xx. This trial was registered at https://clinicaltrials.gov as NCT04048330.

Effect of epigenetic activating of Dlk1-Dio3 imprinted cluster on miR-370 expression due to folate deficiency during nerve development

Proper Dlk1-Dio3 imprinting plays a critical role in embryogenesis, and folic acid deficiency may affect the imprinting of this locus through epigenetic regulation. However, whether and how folic acid directly impacts the imprinting status of Dlk1-Dio3 to affect neural development remain unclear. Here, we found decreased IG-DMR (intergenic -differentially methylated regions) methylation in the folate-deficient encephalocele in humans, suggesting that abnormal Dlk1-Dio3 imprinting status is related to neural tube defects (NTDs) caused by folate deficiency. Similar results were obtained with folate-deficient embryonic stem cells. By miRNA chip analysis, folic acid deficiency led to changes in multiple miRNAs, including the upregulation of 15 miRNAs located in the Dlk1-Dio3 locus. Real-time PCR confirmed that seven of these miRNAs were upregulated, especially miR-370. In contrast to normal embryonic development, in which expression of miR-370 is highest at E9.5, the abnormally high and sustained expression of miRNA-370 in folate-deficient E13.5 embryos may contribute to NTDs. In addition, we found that DNMT3A (de novo DNA methyltransferases 3A) is a direct target gene of miR-370 in neural cells, and DNMT3A participates in the role of miR-370 in inhibiting cell migration. Finally, in the folate-deficient mouse model, Dlk1-Dio3 epigenetic activation was found in fetal brain tissue, along with the upregulation of miR-370 and the downregulation of DNMT3A. Collectively, our findings demonstrate a pivotal role of folate in the epigenetic regulation of Dlk1-Dio3 imprinting during neurogenesis, revealing an elegant mechanism for the activation of Dlk1-Dio3 locus miRNAs in folic acid deficiency.

A Randomized Trial of Quadruple-Fortified Salt for Anemia and Birth Defects Prevention in Southern India: Protocol Design and Methods

Background

Women of reproductive age are at an increased risk of anemia and micronutrient deficiencies. Evidence supports the role of periconceptional nutrition in the development of neural tube defects (NTDs) and other pregnancy complications. Vitamin B12 deficiency is a risk factor for NTDs and may modify folate biomarkers that predict NTD risk at the population level. There is an interest in mandatory fortification with vitamin B12 and folic acid for anemia and birth defect prevention. However, there are limited population-representative data needed to inform policy and guidelines.

Objectives

This randomized trial will be conducted to evaluate the efficacy of quadruple-fortified salt (QFS; iron, iodine, folic acid, vitamin B12) in 1,000 households in Southern India.

Methods

Women 18 to 49 y who are not pregnant or lactating and reside within the catchment area of our community-based research site in Southern India will be screened and invited to participate in the trial. After informed consent, women and their households will be randomized to receive one of the following 4 interventions: 1) double-fortified salt (DFS; iron, iodine), 2) DFS + folic acid (iron, iodine, folic acid), 3) DFS + vitamin B12 (iron, iodine, vitamin B12), or 4) DFS + folic acid and vitamin B12 (QFS; iron, iodine, folic acid, vitamin B12) for 12 mo. Structured interviews will be conducted by trained nurse enumerators to collect sociodemographic, anthropometric, dietary, health, and reproductive history data. Biological samples will be collected at baseline, midpoint, and endpoint. Whole blood will be analyzed for hemoglobin using Coulter Counter. Total vitamin B12 will be measured by chemiluminescence; red blood cell folate and serum folate will be evaluated using the World Health Organization-recommended microbiologic assay.

Conclusions

The results of this randomized trial will help to evaluate the efficacy of QFS to prevent anemia and micronutrient deficiencies. Clinical trial registration numbers: NCT03853304 and Clinical Trial Registry of India REF/2019/03/024479.

Registration number

NCT03853304 and REF/2019/03/024479.

Higher Than Recommended Folic Acid Intakes is Associated with High Folate Status Throughout Pregnancy in a Prospective French-Canadian Cohort

BACKGROUND

Folate and vitamin B12 status during pregnancy are important for maternal and neonatal health. Maternal intake and prepregnancy body mass index (ppBMI) can influence biomarker status.

OBJECTIVES

This study aimed to, throughout pregnancy; 1) assess folate and B12 status including serum total folate, plasma total vitamin B12, and homocysteine (tHcy); 2) examine how these biomarkers are associated with intakes of folate and B12 and with ppBMI; and 3) determine predictors of serum total folate and plasma total vitamin B12.

METHODS

In each trimester (T1, T2, and T3), food and supplement intakes of 79 French-Canadian pregnant individuals were assessed by 3 dietary recalls (R24W) and a supplement use questionnaire. Fasting blood samples were collected. Serum total folate and plasma total vitamin B12 and tHcy were assessed by immunoassay (Siemens ADVIA Centaur XP).

RESULTS

Participants were 32.1 ± 3.7 y and had a mean ppBMI of 25.7 ± 5.8 kg/m². Serum total folate concentrations were high (>45.3 nmol/L, T1: 75.4 ± 55.1, T2: 69.1 ± 44.8, T3: 72.1 ± 52.1, P = 0.48). Mean plasma total vitamin B12 concentrations were >220 pmol/L (T1: 428 ± 175, T2: 321 ± 116, T3: 336 ± 128, P < 0.0001). Mean tHcy concentrations were <11 μmol/L across trimesters. Most participants (79.6%-86.1%) had a total folic acid intake above the Tolerable Upper Intake Level (UL, >1000 μg/d). Supplement use accounted for 71.9%-76.1% and 35.3%-41.8% of total folic acid and vitamin B12 intakes, respectively. The ppBMI was not correlated with serum total folate (P > 0.1) but was weakly correlated with and predicted lower plasma total vitamin B12 in T3 (r = -0.23, P = 0.04; r² = 0.08, standardized beta [sβ] = -0.24, P = 0.01). Higher folic acid intakes from supplements predicted higher serum total folate (T1: r² = 0.05, sβ = 0.15, P = 0.04, T2: r² = 0.28, sβ = 0.56, P = 0.01, T3: r² = 0.19, sβ = 0.44, P < 0.0001).

CONCLUSIONS

Most pregnant individuals had elevated serum total folate concentrations, reflecting total folic acid intakes above the UL driven by supplement use. Vitamin B12 concentrations were generally adequate and differed by ppBMI and pregnancy stage.

Association between cooking fuel and folate insufficiency among pregnant women in Northern China

This study explored whether using a coal or biomass stove for cooking was associated with a greater risk of red blood cell (RBC) folate insufficiency among pregnant women compared to using clean energy. A researcher-designed questionnaire was used to collect information on exposure-related factors and confounding factors. RBC folate concentrations were examined by microbiological assay. Binary logistic regression analysis was used to identify factors related to RBC folate insufficiency. The use of coal or firewood for cooking was associated with an increased risk of RBC folate insufficiency (<906 nmol/L) compared to gas. In subgroup analyses, associations between the use of polluting cooking fuels and folate insufficiency were positive for both urban and rural residents and statistically significant for rural women. Efforts to promote the use of clean energy and proper ventilation, especially in rural areas, are recommended to improve the health of pregnant women and their offspring.

Associations between folic acid supplement use and folate status biomarkers in the first and third trimesters of pregnancy in the Maternal-Infant Research on Environmental Chemicals (MIREC) Pregnancy Cohort Study

BACKGROUND

Achieving optimal folate status during early gestation reduces the risk of neural tube defects (NTDs). While inadequate folate intake remains a concern, it is becoming increasingly common for individuals to consume higher than recommended doses of folic acid (FA) with minimal additional benefit.

OBJECTIVE

Here, we sought to investigate the determinants, including FA supplement dose and use, of plasma total and individual folate vitamer concentrations in the first and third trimesters of pregnancy.

METHODS

Using data from the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, a cohort exposed to mandatory FA fortification, we measured plasma total folate and individual folate vitamer [5-methyltetrahydrofolate (5-methylTHF), unmetabolized FA (UMFA), and non-methyl folates (sum of THF, 5-formylTHF, 5,10-methenyl-THF)] concentrations in the first and third trimesters (n = 1,893). Using linear mixed models, we estimated associations between plasma folate concentrations, total daily supplemental FA intake, plasma vitamin B-12 concentrations, and multiple demographic, maternal, and reproductive factors.

RESULTS

Almost 95% of MIREC study participants met or exceeded the recommended daily supplemental FA intake from supplements (≥400 μg/d), with approximately 25% consuming more than the Tolerable Upper Intake Level (>1000 μg/d). Over 99% of MIREC participants had a plasma total folate status indicative of maximal NTD risk reduction (25.5 nmol/L) regardless of FA supplement dose. UMFA was detected in almost all participants, with higher concentrations associated with higher FA doses. Determinants of adequate FA supplement intake and folate status associated with reduced NTD risk included indicators of higher socioeconomic position, higher maternal age, nulliparity, and lower prepregnancy BMI.

CONCLUSIONS

In the context of mandatory FA fortification, our data indicate that higher-than-recommended FA doses are unwarranted, with the exception of individuals at higher risk for NTDs. Ideally, prenatal supplements would contain 400 rather than 1000 µg FA, thereby enabling the consumption of optimal and safe FA doses.

The silent tragic reality of Hidden Hunger, anaemia, and neural-tube defects (NTDs) in India

Hidden Hunger arising from nutritional iron-, folate-, and vitamin-B₁₂-deficiencies is exceedingly common in India and has profound negative impacts on anaemia, on pregnancy, and on embryonic-foetal neurodevelopment in utero, which predisposes to NTDs and psychological-psychiatric manifestations in childhood. Whereas younger-to-middle-aged Indians fail to perform at maximum potential, the elderly are at risk for calamitous neurologic events. However, these micronutrient-deficiencies are eminently correctable through food-fortification. Therefore, the Indian Government can no longer afford the luxury of inaction by either denying or downplaying the gravity of this problem. What is critically needed from India's leaders is an urgent, clear-eyed reappraisal and act of anagnorisis-(an often startling self-recognition and discovery of a profoundly serious error and tragic flaw)-in failing to confront this problem for decades. Only when closely followed by a metanoia-(a transformative change of heart that triggers remedial action)-can they help India avoid a catastrophic tryst with destiny.

Low erythrocyte folate levels and increased risk of invasive cervical cancer in Chinese women

AIM

To investigate the relationship between erythrocyte folate levels and cervical lesions.

METHODS

Using a case-control method, patients with cervical lesions from September 2021 to February 2022 in the Department of Obstetrics and Gynecology, Jiangnan University Hospital were selected as study subjects. After cervical biopsy, 40 cases of cervical intraepithelial neoplasia (CIN) CIN3 and 65 cases of cervical cancer as case group. The normal population of 120 cases attending the same period served as the control group. A competitive model was used to establish a chemiluminescence immunoassay (CLIA) for human erythrocyte folate. Erythrocyte folate levels of 225 subjects were determined.

RESULTS

Serum folate levels were 7.82 ± 3.13, 8.04 ± 3.58, and 7.58 ± 4.30 ng/ml in the control, CIN3, and cervical cancer groups, with no statistically significant differences (p = 0.959). Erythrocyte folate levels were 307.27 ± 122.95, 306.52 ± 189.77, and 285.42 ± 125.74 ng/ml, respectively, with statistically significant differences (p = 0.03).

CONCLUSIONS

In a population of middle-aged Chinese women, the lower the erythrocyte folate value, the greater the risk of cervical cancer. In addition, serum folate levels were not associated with cervical lesions.

Folic Acid and the Prevention of Birth Defects: 30 Years of Opportunity and Controversies

For three decades, the US Public Health Service has recommended that all persons capable of becoming pregnant consume 400 μg/day of folic acid (FA) to prevent neural tube defects (NTDs). The neural tube forms by 28 days after conception. Fortification can be an effective NTD prevention strategy in populations with limited access to folic acid foods and/or supplements. This review describes the status of mandatory FA fortification among countries that fortify (n = 71) and the research describing the impact of those programs on NTD rates (up to 78% reduction), blood folate concentrations [red blood cell folate concentrations increased ∼1.47-fold (95% CI, 1.27, 1.70) following fortification], and other health outcomes. Across settings, high-quality studies such as those with randomized exposures (e.g., randomized controlled trials, Mendelian randomization studies) are needed to elucidate interactions of FA with vitamin B12 as well as expanded biomarker testing.

Preventing birth defects, saving lives, and promoting health equity: an urgent call to action for universal mandatory food fortification with folic acid

July 20, 2021 marked the 30th anniversary of the publication of the landmark trial by the British Medical Research Council showing unequivocally that maternal intake of folic acid (vitamin B9) starting before pregnancy prevents most cases of infant spina bifida and anencephaly-two major neural tube defects that are severe, disabling, and often fatal. Mandatory food fortification with folic acid is a safe, cost-effective, and sustainable intervention to prevent spina bifida and anencephaly. Yet few countries implement fortification with folic acid; only a quarter of all preventable spina bifida and anencephaly cases worldwide are currently avoided by food fortification. We summarise scientific evidence supporting immediate, mandatory fortification with folic acid to prevent the development of spina bifida and anencephaly. We make an urgent call to action for the World Health Assembly to pass a resolution for universal mandatory folic acid fortification. Such a resolution could accelerate the slow pace of spina bifida and anencephaly prevention globally, and will assist countries to reach their 2030 Sustainable Development Goals on child mortality and health equity. The cost of inaction is profound, and disproportionately impacts susceptible populations in low-income and middle-income countries.

Guideline No. 427: Folic Acid and Multivitamin Supplementation for Prevention of Folic Acid-Sensitive Congenital Anomalies

OBJECTIVE

To provide updated guidance on pre-conception folic acid and multivitamin supplementation for primary and secondary (recurrence) prevention of neural tube defects and other folate-sensitive congenital anomalies.

TARGET POPULATION

Women aged 12-45 years who could become pregnant should be aware of the risk of serious birth defects without adequate pre-conception and first-trimester folic acid supplementation.

OPTIONS

Optimizing folic acid supplementation is complex and depends on factors including dosage; type of supplement; bioavailability of folate from food, timing of initiating supplementation; and metabolic and genetic factors. For all women who could become pregnant, a low daily dosage of folic acid is recommended before conception and throughout pregnancy and breastfeeding. High-dosage folic acid supplementation is recommended only for women who can become pregnant and have had a previous pregnancy affected by a neural tube defect or other folate-sensitive congenital anomaly. Directed personalized approaches could be considered and adopted for women who can become pregnant and have complex risks (genetic, medical, or surgical risk factors), using new knowledge of co-factor metabolism and synergy, as well as red blood cell or serum folate testing. Such approaches would require changes to current provincial health care maternal serum folate screening/testing.

OUTCOMES

New approaches to oral folic acid supplementation, including triage tools, need to be considered to optimize the benefits of decreasing risk of neural tube defects and folate-sensitive congenital anomalies.

BENEFITS, HARMS, AND COSTS

Oral folic acid supplementation, or dietary folate intake combined with a multivitamin/micronutrient supplement, is associated with lower rates of neural tube defects, other folate-sensitive birth defects, and obstetrical complications. The costs are those attributable to daily vitamin supplementation and a healthy, folate-rich diet.

EVIDENCE

A literature search was designed and carried in PubMed and the Cochrane Library databases from 1990 to 2021 using following MeSH terms and keywords (and variants): folic acid supplementation; folate food fortification; primary neural tube defect prevention; prevention of recurrence of neural tube defects; folate-sensitive birth defects; folate supplementation benefit; folate supplementation risk; folate pregnant woman physiology; pregnant woman RBC folate level; pregnant woman serum folate levels; folate and epilepsy; folate and obesity. This guideline was based upon expert guidelines or opinions, systematic reviews, randomized controlled clinical trials, and observational case-control studies and case series retrieved, published in English from 1990 to 2021.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and weak recommendations).

INTENDED AUDIENCE

Maternity health care providers (physicians, midwives, nurses) and other providers of pregnancy-related wellness and health counselling.

SUMMARY STATEMENTS

RECOMMENDATIONS.

Directive clinique no427 : Suppléments d'acide folique et multivitamines en prévention des anomalies congénitales sensibles à l'acide folique

OBJECTIF

Offrir des recommandations à jour sur l'utilisation de multivitamines et de suppléments d'acide folique avant la conception pour la prévention primaire et secondaire (récidive) des anomalies du tube neural et des autres anomalies congénitales sensibles à l'acide folique.

POPULATION CIBLE

Les femmes de 12 à 45 ans qui pourraient devenir enceintes doivent être informées des risques importants d'anomalies congénitales en l'absence d'une supplémentation adéquate en acide folique avant la conception et pendant le premier trimestre.

OPTIONS

La supplémentation optimale en acide folique est complexe et repose sur divers facteurs tels que la dose, le type de suppléments, la biodisponibilité du folate dans l'alimentation, le moment du début de la supplémentation ainsi que sur les facteurs métaboliques et génétiques. Pour toutes les femmes qui peuvent devenir enceintes, une faible dose quotidienne d'acide folique est recommandée avant la conception et pendant la grossesse et l'allaitement. La supplémentation à forte dose d'acide folique est recommandée uniquement chez les femmes qui peuvent devenir enceintes et qui ont un antécédent de grossesse avec anomalie du tube neural ou toute autre anomalie congénitale sensible à l'acide folique. Il est possible d'envisager et d'adopter une approche personnalisée chez les femmes qui peuvent devenir enceintes et qui présentent des risques complexes (facteurs de risque génétiques, médicaux ou chirurgicaux) en se fondant sur les nouvelles connaissances en matière de métabolisme et synergie des cofacteurs et sur l'analyse du taux sérique et érythrocytaire d'acide folique. Ce genre d'approche exige une modification des protocoles provinciaux actuels de santé publique concernant le dépistage et l'analyse du taux sérique maternel d'acide folique. RéSULTATS: Les nouvelles stratégies de supplémentation en acide folique par voie orale, y compris dans les outils de triage, doivent être prises en compte pour diminuer de façon optimale le risque d'anomalies du tube neural et d'anomalies congénitales sensibles à l'acide folique. BéNéFICES, RISQUES ET COûTS: On observe une diminution du taux d'anomalies du tube neural, des autres anomalies congénitales sensibles à l'acide folique et des complications obstétricales chez les femmes qui prennent des suppléments oraux d'acide folique ou qui complémentent leur apport alimentaire en folate au moyen de multivitamines ou de suppléments de micronutriments. Les coûts relatifs sont liés à la prise quotidienne de suppléments vitaminiques et à l'adoption d'un régime alimentaire sain et riche en folate. DONNéES PROBANTES: Une recherche a été effectuée dans les bases de données PubMed et Cochrane Library pour trouver des articles publiés entre 1990 et 2021, en utilisant les termes MeSH et mots-clés (et leurs variantes) suivants : folate food fortification; primary neural tube defect prevention; prevention of recurrence of neural tube defects; folate-sensitive birth defects; folate supplementation benefit; folate supplementation risk; folate pregnant woman physiology; pregnant woman RBC folate level; pregnant woman serum folate levels; folate and epilepsy; folate and obesity. Cette directive clinique repose sur des lignes directrices et opinions de spécialistes, des revues systématiques, des essais cliniques randomisés et des études observationnelles de cas-témoin et de séries de cas qui ont été publiés en anglais entre 1990 et 2021. MéTHODES DE VALIDATION: Les auteurs ont évalué la qualité des données probantes et la force des recommandations en utilisant le cadre méthodologique GRADE (Grading of Recommendations, Assessment, Development, and Evaluation). Voir l'annexe A en ligne (tableau A1 pour les définitions et tableau A2 pour l'interprétation des recommandations fortes et faibles). PROFESSIONNELS CONCERNéS: Fournisseurs de soins de maternité (médecins, sages-femmes et infirmières) et autres fournisseurs d'accompagnement en santé et bien-être lié à la grossesse. DÉCLARATIONS SOMMAIRES: RECOMMANDATIONS.

Reduced Kidney Function Is Associated with Increasing Red Blood Cell Folate Concentration and Changes in Folate Form Distributions (NHANES 2011-2018)

Background: Current studies examining the effects of high concentrations of red blood cell (RBC) or serum folates assume that high folate concentrations are an indicator of high folic acid intakes, often ignoring the contributions of other homeostatic and biological processes, such as kidney function. Objective: The current study examined the relative contributions of declining kidney function, as measured by the risk of chronic kidney disease (CKD), and usual total folic acid intake on the concentrations of RBC folate and serum folate (total as well as individual folate forms). Design: Cross-sectional data from the National Health and Nutrition Examination Survey (NHANES) collected in 2-year cycles were combined from 2011 to 2018. A total of 18,127 participants aged ≥16 years with available folate measures, kidney biomarker data (operationalized as a categorical CKD risk variable describing the risk of progression), and reliable dietary recall data were analyzed. Results: RBC folate concentrations increased as CKD risk increased: low risk, 1089 (95% CI: 1069, 1110) nmol/L; moderate risk, 1189 (95% CI: 1158, 1220) nmol/L; high risk, 1488 (95% CI: 1419, 1561) nmol/L; and highest risk, 1443 (95% CI: 1302, 1598) nmol/L (p < 0.0001). Similarly, serum total folate concentrations increased as CKD risk increased: low risk: 37.1 (95% CI: 26.3, 38.0) nmol/L; moderate risk: 40.2 (95% CI: 38.8, 41.7) nmol/L; high risk: 48.0 (95% CI: 44.3, 52.1) nmol/L; the highest Risk: 42.8 (95% CI: 37.8, 48.4) nmol/L (p < 0.0001). The modeled usual intake of folic acid showed no difference among CKD risk groups, with a population median of 225 (interquartile range: 108−390) µg/day. Conclusion: Both RBC and serum folate concentrations increased with declining kidney function without increased folic acid intake. When analyzing associations between folate concentrations and disease outcomes, researchers may want to consider the confounding role of kidney function.

Associations of Serum and Red Blood Cell Folate With All-Cause and Cardiovascular Mortality Among Hypertensive Patients With Elevated Homocysteine

Objectives

This study aims to explore the associations between serum and red blood cell (RBC) folate as indicators of short- and long-term folate status, respectively, and all-cause as well as CVD mortality among hypertensive patients with elevated homocysteine.

Methods

A prospective cohort study of the National Health and Nutrition Examination Survey (1999–2006) and 2015 Linked Mortality File was performed. All-cause and CVD mortality risk estimated using Cox proportional hazards models with adjusting for multiple potential covariates.

Results

A total of 1,753 hypertensive patients with elevated homocysteine [mean (SD) age, 68.5 (13.1)] were included in the analysis. During a median follow-up of 10.0 years, a total of 899 all-cause and 257 CVD deaths occurred. Compared the highest with the lowest quartile of RBC folate, the multivariable adjusted hazard ratios and 95% confidence intervals for all-cause and CVD death were 1.13 (0.92–1.39) and 1.47 (1.01–2.16) respectively. There was a significant and positive trend between RBC folate and the risk of CVD death (p for trend = 0.0196). No significant association was found between serum folate and mortality risk among the study sample.

Conclusions

High level of RBC folate is associated with an increased risk of cardiovascular mortality among hypertensive patients with elevated homocysteine while serum folate has no such effects.

Effects of maternal folate and vitamin B12 on gestational diabetes mellitus: a dose-response meta-analysis of observational studies

To comprehensively estimate the association of gestational diabetes mellitus (GDM) risk with maternal red blood cell (RBC) folate, plasma/serum folate, dose and duration of folic acid supplement (FAS) intake and vitamin B12 separately. PubMed, Web of science, CNKI, and Wanfang Databases were searched through March 26, 2021. We synthesized data using random-effects model meta-analysis in Stata 12.0. Sensitivity, subgroup and dose-response analyses were also performed. The certainty of evidence was evaluated using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE). Twenty six datasets from thirteen eligible observational studies were included in the study. We found a significant increase of GDM risk with the highest versus lowest category of RBC folate (OR = 1.96, 95% CI: 1.48-2.61, I2 = 0.0%, moderate-certainty evidence) and plasma/serum folate (OR = 1.23, 1.02-1.48, I2 = 57.8%, low-certainty evidence). The dose-response analysis revealed that each 200 ng/ml increase in RBC folate was significantly associated with 8% higher GDM risk. No significant association between dose of FAS intake and GDM risk was found with very low cetainty. Meanwhile, longer duration (≥3 months) of FAS conferred 56% significant higher GDM risk (OR = 1.56, 1.02-2.39, very low certainty evidence). No significant association of GDM risk with highest plasma/serum B12 was observed compared to lowest B12 (OR = 0.77, 0.58-1.02, very low-certainty evidence). Moderate-certainty evidence suggests that higher RBC folate appears to significantly increase GDM risk. Higher plasma/serum folate may increase GDM risk but with low certainty. Further well-designed trials or prospective studies are needed.

Prenatal Folate and Choline Levels and Brain and Cognitive Development in Children: A Critical Narrative Review

Women’s nutritional status during pregnancy can have long-term effects on children’s brains and cognitive development. Folate and choline are methyl-donor nutrients and are important for closure of the neural tube during fetal development. They have also been associated with brain and cognitive development in children. Animal studies have observed that prenatal folate and choline supplementation is associated with better cognitive outcomes in offspring and that these nutrients may have interactive effects on brain development. Although some human studies have reported associations between maternal folate and choline levels and child cognitive outcomes, results are not consistent, and no human studies have investigated the potential interactive effects of folate and choline. This lack of consistency could be due to differences in the methods used to assess folate and choline levels, the gestational trimester at which they were measured, and lack of consideration of potential confounding variables. This narrative review discusses and critically reviews current research examining the associations between maternal levels of folate and choline during pregnancy and brain and cognitive development in children. Directions for future research that will increase our understanding of the effects of these nutrients on children’s neurodevelopment are discussed.

Managing folate deficiency implies filling the gap between laboratory and clinical assessment

The characterization of folate status in subjects at risk of deficiency and with altered vitamin homeostasis is crucial to endorse preventive intervention health policies, especially in developed countries. Several physiological changes (i.e. pregnancy), clinical situations and diseases have been associated to increased requirement, impaired intake and absorption of folate. However clinical practice guidelines (CPG) endorse folic acid supplementation generally discarding the use of its determination in serum to assess the risk of deficiency and/or its concentration at baseline. Poor confidence on the diagnostic accuracy of serum folate assays still persists in the current CPGs although recent standardization efforts have greatly improved inter-method variability and precision. In this review we critically appraise the methodological issues concerning laboratory folate determination and the evidence on the potential adverse effects of folic acid exposure. The final aim is to build a sound background to promote serum folate-based cost-effective health care policies by optimizing folic acid supplementation in subjects at risk of deficiency and with altered folate homeostasis. Our first result was to adjust in relation to current serum folate assays the thresholds reported by CPGs as index of folate status, defined on the association with metabolic and hematologic indicators. We identify a statistically significant difference between the estimated thresholds and accordingly show that the assessment of folate status actually changes in relation to the assay employed. The use of the method-dependent thresholds here reported may pragmatically endorse the stewardship of folic acid supplementation in clinical practice and increase the cost-effectiveness of health care policies.

Maternal folic acid and multivitamin supplementation: International clinical evidence with considerations for the prevention of folate-sensitive birth defects

More evidence is available for maternal intake, absorption, distribution, tissue specific concentrations, and pregnancy outcomes with folic acid (fortification/supplementation) during preconception - first trimester. This Quality Improvement prevention review used expert guidelines/opinions, systematic reviews, randomized control trials/controlled clinical trials, and observational case control/case series studies, published in English, from 1990 to August 2021. Optimization for an oral maternal folic acid supplementation is difficult because it relies on folic acid dose, type of folate supplement, bio-availability of the folate from foods, timing of supplementation initiation, maternal metabolism/genetic factors, and many other factors. There is continued use of high dose pre-food fortification 'RCT evidenced-based' folic acid supplementation for NTD recurrence pregnancy prevention. Innovation requires preconception and pregnancy use of 'carbon one nutrient' supplements (folic acid, vitamin B12, B6, choline), using the appropriate evidence, need to be considered. The consideration and adoption of directed personalized approaches for maternal complex risk could use serum folate testing for supplementation dosing choice. Routine daily folic acid dosing for low-risk women should consider a multivitamin with 0.4 mg of folic acid starting 3 months prior to conception until completion of breastfeeding. Routine folic acid dosing or preconception measurement of maternal serum folate (after 4-6 weeks of folate supplementation) could be considered for maternal complex risk group with genetic/medical/surgical co-morbidities. These new approaches for folic acid oral supplementation are required to optimize benefit (decreasing folate sensitive congenital anomalies; childhood morbidity) and minimizing potential maternal and childhood risk.

B vitamin blood concentrations and one-carbon metabolism polymorphisms in a sample of Italian women and men attending a unit of transfusion medicine: a cross-sectional study

PURPOSE

To define blood status of folate, vitamin B12, vitamin B6, homocysteine, and major one-carbon metabolism-related polymorphisms in healthy, males and females blood donors, aged 18-65 years were evaluated. General characteristics and lifestyle factors were also investigated.

METHODS

An explorative cross-sectional study design was used to evaluate a sample of blood donors attending the Unit of Transfusion Medicine of the Verona University Hospital, Italy. From April 2016 to May 2018, 499 subjects were enrolled (255 men, 244 women of whom 155 of childbearing age). Major clinical characteristics including lifestyle and dietary habits, B vitamins and homocysteine were analyzed. The MTHFR 677 C>T, cSHMT 1420 C>T, DHFR 19 bp ins/del, RFC1 80 G>A polymorphisms were also determined.

RESULTS

Mean plasma concentrations of folate, vitamin B12, vitamin B6 and homocysteine were 14.2 nmol/L (95% CI 13.7-14.8), 271.9 pmol/L (95% CI 262.6-281.5), 51.0 nmol/L (95% CI 48.7-53.4) and 13.5 µmol/L (95% CI 13.1-14.0), respectively. Plasma folate, was adequate (> 15 nmol/L) in 44.7% of all subjects, 39.0% of males and 42.5% of women < 45 years. Similarly, vitamin B12 was adequate (> 350 pmol/L) in 25.1% of all subjects and in 20.3% of men ≥ 45 years. The rare allele frequencies were 0.21 for MTHFR 677TT, 0.11 for cSHMT 1420TT, 0.18 for DHFR 19 bp del/del, 0.20 for RFC1 80AA, and a gene-nutrient interaction was confirmed for folate concentrations according to MTHFR 677C>T and DHFR 19 bp del/del.

CONCLUSION

An Italian sample of healthy blood donors shows that an adequate concentration of plasma folate and vitamin B12 is reached only in a limited percentage of subjects, thus encouraging consideration for specific public health strategies.