How food matrices modulate folate bioaccessibility: A comprehensive overview of recent advances and challenges

The incomplete absorption of dietary folate makes it crucial to understand how food matrices affect folate bioaccessibility. Bioavailability encompasses bioaccessibility, which depicts the proportion that is liberated from the food matrix during digestion and becomes available for absorption. Bioavailability studies are expensive and difficult to control, whereas bioaccessibility studies utilize in vitro digestion models to parameterize the complex digestion, allowing the evaluation of the effect of food matrices on bioaccessibility. This review covers the folate contents in various food matrices, the methods used to determine and the factors affecting folate bioaccessibility, and the advances and challenges in understanding how food matrices affect folate bioaccessibility. The methods for determining bioaccessibility have been improved in the last decade. Current research shows that food matrices modulate folate bioaccessibility by affecting the liberation and stability of folate during digestion but do not provide enough information about folate and food component interactions at the molecular level. In addition, information on folate interconversion and degradation during digestion is scant, hindering our understanding of the impact of food matrices on folate stability. Moreover, the role of conjugase inhibitors should not be neglected when evaluating the nutritional value of food folates. Due to the complexity of food digestion, holistic methods should be applied to investigate bioaccessibility. By synthesizing the current state of knowledge on this topic, this review highlights the lack of in-depth understanding of the mechanisms of how food matrices modulate folate bioaccessibility and provides insights into potential strategies for accurate evaluation of the nutritional value of dietary folate.

Serum Folate and Vitamin B12 Modify the Associations of N6AMT1 Genetic Variants with Gestational Diabetes Mellitus: A Cross-Sectional Study in Chinese Pregnant Women

Purpose

This study aimed to explore the association between N-6 adenine-specific DNA methyltransferase 1 (N6AMT1) single nucleotide polymorphisms (SNPs) and gestational diabetes mellitus (GDM) and the modification of the relationship by folate and vitamin B12.

Methods

A cross-sectional study involving 1303 pregnant women (262 GDM and 1041 non-GDM) was performed in Tianjin, China. Nine SNPs in N6AMT1 were genotyped, and serum folate, vitamin B12, and homocysteine (Hcy) levels were measured. The logistic regression models determined the odds ratios (ORs) for SNPs in N6AMT1 and the gene-nutrition interactions on GDM.

Results

N6AMT1 rs7282280, rs1048546, and rs1997605 were related to GDM under the dominant model after adjusting for multiple covariates. Individuals carrying the N6AMT1 rs7282280 TC/TT genotypes had a lower risk of developing GDM, regardless of serum folate and vitamin B12 levels. However, rs1048546 TG/GG genotypes were associated with lower GDM risk when serum folate ≥ 6.0 ng/mL. Pregnancies with the risk genotypes in N6AMT1 and higher serum folate or lower vitamin B12 are more prone to GDM. The study also showed a statistically significant additive interaction between N6AMT1 rs1997605 GG genotypes and lower vitamin B12 (RERI: 2.54; 95% CI: 0.17, 4.92).

Conclusion

SNPs in N6AMT1 were found to be associated with GDM, and serum folate and vitamin B12 levels can modify their associations.

Customizable Porphyrin Platform Enables Folate Receptor PET Imaging Using Copper-64

Folate receptors including folate receptor α (FRα) are overexpressed in up to 90% of ovarian cancers. Ovarian cancers overexpressing FRα often exhibit high degrees of drug resistance and poor outcomes. A porphyrin chassis has been developed that is readily customizable according to the desired targeting properties. Thus, compound O5 includes a free base porphyrin, two water-solubilizing groups that project above and below the macrocycle plane, and a folate targeting moiety. Compound O5 was synthesized (>95% purity) and exhibited aqueous solubility of at least 0.48 mM (1 mg/mL). Radiolabeling of O5 with 64Cu in HEPES buffer at 37 °C gave a molar activity of 1000 μCi/μg (88 MBq/nmol). [64Cu]Cu-O5 was stable in human serum for 24 h. Cell uptake studies showed 535 ± 12% bound/mg [64Cu]Cu-O5 in FRα-positive IGROV1 cells when incubated at 0.04 nM. Subcellular fractionation showed that most radioactivity was associated with the cytoplasmic (39.4 ± 2.7%) and chromatin-bound nuclear (53.0 ± 4.2%) fractions. In mice bearing IGROV1 xenografts, PET imaging studies showed clear tumor uptake of [64Cu]Cu-O5 from 1 to 24 h post injection with a low degree of liver uptake. The tumor standardized uptake value at 24 h post injection was 0.34 ± 0.16 versus 0.06 ± 0.07 in the blocking group. In summary, [64Cu]Cu-O5 was synthesized at high molar activity, was stable in serum, exhibited high binding to FRα-overexpressing cells with high nuclear translocation, and gave uptake that was clearly visible in mouse tumor xenografts.

Homicide or Happiness: Did Folate Fortification and Public Health Campaigns Influence Homicide Rates and the Great American Crime Decline?

The last several years have witnessed a remarkable growth in research directed at nutrition and behavior, with increased interest in the field of nutritional criminology. It is becoming clear that dietary patterns and specific nutrients play an important role in cognition and behavior, including those related to aggression, violence, and antisocial activity. Included in this expanding knowledge base is the recognition that folate, through multiple pathways, including enzymatic reactions and gut microbiome ecology, plays a critical role in central nervous system functioning. These mechanistic advances allow for a retrospective analysis of a topic that remains unexplained-the sudden and unpredicted drop in homicide and other violent crime rates in the United States and other nations in the 1990s. Here, we revisit this marked reduction in homicide rates through the lens of the coincident public health campaign (and subsequent mandatory fortification) to increase folic acid intake. Based on objectively measured blood folate levels through the National Health and Nutrition Examination Surveys, there is little doubt that tissue folate witnessed a dramatic rise at the national level from 1988 through 2000. Drawing from accumulated and emerging research on the neurobehavioral aspects of folate, it is our contention that this relatively sudden and massive increase in tissue folate levels may have contributed to reductions in violent crime in the United States.

Vitamin D promotes the folate transport and metabolism in zebrafish (Danio rerio)

Vitamin D (VD) is a fat-soluble sterol that possesses a wide range of physiological functions. The present study aimed to evaluate the effects of VD on folate metabolism in zebrafish and further investigated the underlying mechanism. Wild-type (WT) zebrafish were fed with a diet containing 0 IU/kg VD3 or 800 IU/kg VD3 for 3 wk. Meanwhile, cyp2r1 mutant zebrafish with impaired VD metabolism was used as another model of VD deficiency. Our results showed that VD deficiency in zebrafish suppressed the gene expression of folate transporters, including reduced folate carrier (RFC) and proton-coupled folate transporter (PCFT) in the intestine. Moreover, VD influenced the gene expression of several enzymes related to cellular folate metabolism in the intestine and liver of zebrafish. Importantly, VD-deficient zebrafish contained a remarkably lower level of folate content in the liver. Notably, VD was incapable of altering folate metabolism in zebrafish when gut microbiota was depleted by antibiotic treatment. Further studies proved that gut commensals from VD-deficient fish displayed a lower capacity to produce folate than those from WT fish. Our study revealed the potential correlation between VD and folate metabolism in zebrafish, and gut microbiota played a key role in VD-regulated folate metabolism in zebrafish.NEW & NOTEWORTHY Our study has identified that VD influences intestinal uptake and transport of folate in zebrafish while also altering hepatic folate metabolism and storage. Interestingly, the regulatory effects of VD on folate transport and metabolism diminished after the gut flora was interrupted by antibiotic treatment, suggesting that the regulatory effects of VD on folate metabolism in zebrafish are most likely dependent on the intestinal flora.

A micronutrient supplement modulates homocysteine levels regardless of vitamin B biostatus in elderly subjects

Elevated homocysteine (Hcy) levels (≥15 μmol/L) in the elderly are frequently associated with a higher risk of cardiovascular disease and cognitive decline. Several studies have already shown an Hcy-lowering effect of B vitamin supplementation in cohorts deficient in these nutrients. The aim of this randomized, double-blinded 12-week intervention study was to investigate whether Hcy levels in healthy elderly subjects (75.4±4.5 years, n=133) could be lowered with a micronutrient supplement (i.e., 400 μg folic acid, 100 μg cobalamin). Difference in mean initial Hcy levels between intervention (17.6±7.1 μmol/L, n=65) and placebo group (18.9±6.1 μmol/L, n=68) was not significant. The prevalence of cobalamin and folate deficiency in the total study population was low: 27% had serum-cobalamin levels ≤150 pmol/L, 12% holo-transcobalamin (Holo-TC) levels ≤50 pmol/L, 13% low cobalamin status using the aggregated cobalamin marker 4cB12 and 10% red blood cell (RBC) folate ≤570 nmol/L. Nevertheless, the treated subjects still showed improved cobalamin and folate biostatus (serum cobalamin Δt12-t0: 63±48 pmol/L; Holo-TC Δt12-t0: 17±19 pmol/L; RBC folate Δt12-t0: 326±253 nmol/L) and Hcy levels (Δt12-t0: -3.6±5.7 μmol/L). The effects were statistically significant compared to the placebo group with p=0.005 (serum cobalamin), p=0.021 (Holo-TC), p=0.014 (RBC-folate) and p<0.001 (Hcy). The Hcy-lowering effect was dependent on the initial Hcy levels (p<0.001). Our findings suggest that elevated Hcy levels in elderly subjects can be lowered regardless of the initial cobalamin and folate biostatus.

Association between early spontaneous abortion and homocysteine metabolism

Objective

The purpose of this study is to explore the effects of homocysteine (HCY) metabolism and related factors on early spontaneous abortion.

Methods

We conducted a hospital-based case-control study and included a total of 500 cases and 1,000 controls in Shaanxi China. Pregnant women waiting for delivery in the hospital were interviewed to report their characteristics and other relevant information during pregnancy. The unconditional Logisitic regression model was applied to assess the association between early spontaneous abortion and HCY metabolism and related factors. The multiplicative model was applied to assess the effects of interaction of HCY metabolism and related factors on early spontaneous abortion. The logit test method of generalized structural equation model (GSEM) was used to construct the pathway diagram of HCY metabolism and related factors affecting early spontaneous abortion.

Results

Folic acid supplementation and adequate folic acid supplementation during periconception were the protective factors of early spontaneous abortion (OR = 0.50, 95% CI: 0.38-0.65; OR = 0.44, 95% CI: 0.35-0.54). The serum folate deficiency, higher plasma HCY in early pregnancy, the women who carried the MTHFR 677TT genotype were the risk factors of early spontaneous abortion (OR = 5.87, 95% CI: 1.53-22.50; OR = 2.94, 95% CI: 1.14-7.57; OR = 2.32, 95% CI: 1.20-4.50). The women's educational level and maternal and child health care utilization affected the occurrence of early spontaneous abortion by influencing the folic acid supplementation during periconception. The folic acid supplementation during periconception affected the occurrence of early spontaneous abortion by influencing the level of serum folate or plasma HCY in early pregnancy. The maternal MTHFR 677 gene polymorphism affected the occurrence of early spontaneous abortion by influencing the level of serum folate in early pregnancy. In terms of the risks for early spontaneous abortion, there was multiplicative interaction between higher plasma HCY in early pregnancy, serum folate deficiency in early pregnancy and maternal MTHFR 677TT genotype (OR = 1.76, 95% CI: 1.17-4.03), and there was multiplicative interaction between higher plasma HCY and serum folate deficiency in early pregnancy (OR = 3.46, 95% CI: 2.49-4.81), and there was multiplicative interaction between serum folate deficiency in early pregnancy and maternal MTHFR 677TT genotype (OR = 3.50, 95% CI: 2.78-5.18). The above interactions are all synergistic. The occurrence risk of early spontaneous abortion was significantly increased if multiple factors existed at the same time.

Conclusion

Our study is the first time to construct the pathway of HCY metabolism and related factors affecting early spontaneous abortion, and provides a comprehensively new idea to prevent and reduce the occurrence of spontaneous abortion.

The gut microbiome regulates the clinical efficacy of sulfasalazine therapy for IBD-associated spondyloarthritis

Sulfasalazine is a prodrug known to be effective for the treatment of inflammatory bowel disease (IBD)-associated peripheral spondyloarthritis (pSpA), but the mechanistic role for the gut microbiome in regulating its clinical efficacy is not well understood. Here, treatment of 22 IBD-pSpA subjects with sulfasalazine identifies clinical responders with a gut microbiome enriched in Faecalibacterium prausnitzii and the capacity for butyrate production. Sulfapyridine promotes butyrate production and transcription of the butyrate synthesis gene but in F. prausnitzii in vitro, which is suppressed by excess folate. Sulfasalazine therapy enhances fecal butyrate production and limits colitis in wild-type and gnotobiotic mice colonized with responder, but not non-responder, microbiomes. F. prausnitzii is sufficient to restore sulfasalazine protection from colitis in gnotobiotic mice colonized with non-responder microbiomes. These findings reveal a mechanistic link between the efficacy of sulfasalazine therapy and the gut microbiome with the potential to guide diagnostic and therapeutic approaches for IBD-pSpA.

Iron deficiency: prevalence, mortality risk, and dietary relationships in general and heart failure populations

Background

Iron deficiency (ID) is the most common nutritional deficiency, with little research on its prevalence and long-term outcomes in the general population and those with heart failure (HF). Both the relationships between dietary iron and ID, as well as dietary folate and ID, are understudied.

Methods

We used data from the National Health and Nutrition Examination Survey from 1999 to 2002 to investigate the prevalence, prognosis, and relationship between dietary and ID defined by different criteria in the general population (n = 6,660) and those with HF (n = 182).

Results

There was no significant difference in the prevalence of ID between HF patients and the general population after propensity score matching. Transferrin saturation (TSAT) <20% was associated with higher 5-year all-cause mortality (HR: 3.49, CI: 1.40-8.72, P = 0.007), while ferritin <30 ng/ml was associated with higher 10-year (HR: 2.70, CI: 1.10-6.67, P = 0.031) and 15-year all-cause mortality (HR: 2.64, CI: 1.40-5.00, P = 0.003) in HF patients. Higher dietary total folate but dietary iron reduced the risk of ID (defined as ferritin <100 ng/ml) in HF patients (OR: 0.80; 95% CI: 0.65-1.00; P = 0.047).

Conclusions

The prevalence of ID was identical in HF and non-HF individuals. Ferritin <30 ng/ml was associated with long-term outcomes whereas TSAT <20% was associated with short-term prognosis in both the general population and HF patients. A diet rich in folate might have the potential for prevention and treatment of ID in HF patients.

Association between Biomarkers of Phthalate Exposure and Serum Folate Concentrations in Children: A Population-Based Cross-Sectional Study of the NHANES from 2011 to 2016

BACKGROUND

Although adverse health effects of phthalates have been reported, very few studies have assessed the associations between biomarkers of phthalate exposure and serum folate concentrations in children.

OBJECTIVES

We aimed to examine the association between urinary phthalate metabolites, as biomarkers of exposure to phthalates, and total serum folate concentrations in children using national data from the United States.

METHODS

We conducted cross-sectional analyses of 2100 individuals aged 6-18 y enrolled in the National Health and Nutrition Examination Survey, 2011-2016. Multivariable linear regression was applied to examine the relationship between natural logarithm (ln)-transformed urinary phthalate metabolites and serum folate concentrations. The quantile-based g-computation was used to assess the association of urinary phthalate metabolite mixture with serum folate levels. Subgroup analyses were conducted by sex, age, and race/ethnicity, and the interactions were assessed by adding interaction terms of these stratifying variables and phthalates and modeling through the Wald test.

RESULTS

In multiple linear regression models, for participants in the highest tertile of MEHHP, MEOHP, DEHP, MCPP, and MCOP, total serum folate concentrations were 1.566 [β: -1.566; 95% confidence interval: -2.935, -0.196], 1.423 (-1.423; -2.689, -0.157), 1.309 (-1.309; -2.573, -0.044), 1.530 (-1.530; -2.918, -0.142), and 1.381 (-1.381; -2.641, -0.122) ng/mL lower than those in the lowest tertile. The inverse associations were consistent in different subgroups by sex, age, and race/ethnicity (P for interaction ≥0.083 for all). In addition, the phthalate mixture showed a strong inverse correlation with serum folate; a quartile increase in the phthalate mixture on the ln scale was associated with 0.888 (-0.888; -1.677, -0.099) ng/mL decrease in the serum folate.

CONCLUSIONS

Higher concentrations of urinary phthalate metabolites were associated with lower serum folate concentrations in children. Although our findings should be validated through additional population and mechanistic studies, they support a potential adverse effect of phthalate exposure on folate metabolism in children.

Risk of Excess Maternal Folic Acid Supplementation in Offspring

Folate, also known as vitamin B9, facilitates the transfer of methyl groups among molecules, which is crucial for amino acid metabolism and nucleotide synthesis. Adequate maternal folate supplementation has been widely acknowledged for its pivotal role in promoting cell proliferation and preventing neural tube defects. However, in the post-fortification era, there has been a rising concern regarding an excess maternal intake of folic acid (FA), the synthetic form of folate. In this review, we focused on recent advancements in understanding the influence of excess maternal FA intake on offspring. For human studies, we summarized findings from clinical trials investigating the effects of periconceptional FA intake on neurodevelopment and molecular-level changes in offspring. For studies using mouse models, we compiled the impact of high maternal FA supplementation on gene expression and behavioral changes in offspring. In summary, excessive maternal folate intake could potentially have adverse effects on offspring. Overall, we highlighted concerns regarding elevated maternal folate status in the population, providing a comprehensive perspective on the potential adverse effects of excessive maternal FA supplementation on offspring.

Folate and vitamin B12 status and predicted neural tube defects risk among nonpregnant women of reproductive age from the Malawi National Micronutrient Survey, 2015-2016

BACKGROUND

Maternal folate and vitamin B12 deficiency can lead to serious adverse pregnancy outcomes. There are no nationally representative estimates on folate and vitamin B12 status among women of reproductive age (WRA) in Malawi.

OBJECTIVE

We assessed folate and vitamin B12 status among nonpregnant WRA in Malawi and predicted the risk of folate-sensitive neural tube defects (NTDs) were they to become pregnant.

METHODS

Using data from the cross-sectional, nationally representative 2015-2016 Malawi Micronutrient Survey, we calculated the proportion of folate and vitamin B12 deficiency and insufficiency by demographic characteristics among 778 nonpregnant WRA (15-49 years). We predicted NTD prevalence using red blood cell (RBC) folate distributions and a published Bayesian model of the association between RBC folate and NTD risk. Analyses accounted for complex survey design.

RESULTS

Among WRA, 8.5% (95% CI: 6.2, 11.6) and 13.3% (10.0, 17.4) had serum (<7 nmol/L) and RBC folate (<305 nmol/L) deficiency, respectively. The proportion of vitamin B12 deficiency (<148 pmol/L) and insufficiency (≤221 pmol/L) was 11.8% (8.6, 16.0) and 40.6% (34.1, 47.4), respectively. RBC folate insufficiency (<748 nmol/L, defined as the concentration associated with the threshold for elevated NTD risk: >8 cases per 10,000 births) was widespread: 81.4% (75.0, 86.4). The predicted NTD risk nationally was 24.7 cases per 10,000 live births. RBC folate insufficiency and higher predicted NTD risk were more common among WRA living in urban areas or with higher education.

CONCLUSIONS

These findings highlight the importance of nutritional and NTD surveillance in Malawi and the opportunity for improving folate and vitamin B12 nutrition among Malawian WRA.

Altered placental immune cell composition and gene expression with isolated fetal spina bifida

PROBLEM

Fetal spina bifida (SB) is more common in pregnant people with folate deficiency or anomalies of folate metabolism. It is also known that fetuses with SB have a higher risk of low birthweight, a condition that is typically placental-mediated. We therefore hypothesized that fetal SB would associate with altered expression of key placental folate transporters and an increase in Hofbauer cells (HBCs), which are folate-dependent placental macrophages.

METHOD OF STUDY

Folate receptor-α (FRα), proton coupled folate receptor (PCFT), and reduced folate carrier (RFC) protein localization and expression (immunohistochemistry) and HBC phenotypes (HBC abundance and folate receptor-β [FRβ] expression; RNA in situ hybridization) were assessed in placentae from fetuses with SB (cases; n = 12) and in term (n = 10) and gestational age (GA) - and maternal body mass index - matched (n = 12) controls without congenital anomalies.

RESULTS

Cases had a higher proportion of placental villous cells that were HBCs (6.9% vs. 2.4%, p = .0001) and higher average HBC FRβ expression (3.2 mRNA molecules per HBC vs. 2.3, p = .03) than GA-matched controls. HBCs in cases were largely polarized to a regulatory phenotype (median 92.1% of HBCs). In sex-stratified analyses, only male cases had higher HBC levels and HBC FRβ expression than GA-matched controls. There were no differences between groups in the total percent of syncytium and stromal cells that were positive for FRα, PCFT, or RFC protein immunolabeling.

CONCLUSIONS

HBC abundance and FRβ expression by HBCs are increased in placentae of fetuses with SB, suggesting immune-mediated dysregulation in placental phenotype, and could contribute to SB-associated comorbidities.

5,10-methenyltetrahydrofolate synthetase deficiency: An extreme rare defect of folate metabolism in two Dutch siblings

Two siblings, presenting with a neurometabolic phenotype, were identified with 5, 10-methenyltetrahydrofolate synthetase (MTHFS) deficiency. Whole genome sequencing in both patients demonstrated an homozygous MTHFS variant NM_006441.3(MTHFS):c.434G > A, p.Arg145Gin, which has been described before. At baseline, both patients showed moderate hyperhomocysteinemia, decreased 5-methyltetrahydrofolate (5MTHF), and increased 5-formyltetrahydrofolate (5-FTHF) in whole blood. In CSF, 5MTHF levels were in the low-normal range and 5-FTHF was strongly increased. In our novel enzyme assay, MTHFS activity was deficient in cultured fibroblasts in both sisters. Oral treatment was initiated with escalating dose of 5-methyltetrahydrofolate (5MTHF) up to 12 mg and hydroxycobalamin 5 mg daily. Plasma homocysteine normalized and 5MTHF became elevated in the blood of both patients. The elevated 5FTHF levels increased further on treatment in blood and CSF. This regimen resulted in some clinical improvement of patient 1. In patient 2, the clinical benefits of 5MTHF supplementation were less obvious. It seems plausible that the alleviation of the deficient 5MTHF levels and normalization of homocysteine in blood are of some clinical benefit. On the other hand, the very high levels of 5FTHF may well be detrimental and may prompt us to decrease the dose of 5MTHF. In addition, we hypothesize that the crippled MTHFS enzyme may destabilize the purinosome, which is presumably not ameliorated by 5MTHF.

Low-dose daily folic acid (400 μg) supplementation does not affect regulation of folate transporters found present throughout the terminal ileum and colon of humans: a randomized clinical trial

BACKGROUND

Folic acid supplementation during the periconceptional period reduces the risk of neural tube defects in infants, but concern over chronic folic acid exposure remains. An improved understanding of folate absorption may clarify potential risks. Folate transporters have been characterized in the small intestine, but less so in the colon of healthy, free-living humans. The impact of folic acid fortification or supplementation on regulation of these transporters along the intestinal tract is unknown.

OBJECTIVE

The objective was to characterize expression of folate transporters/receptor (FT/R) and folate hydrolase, glutamate carboxypeptidase II (GCPII), from the terminal ileum and throughout the colon of adults and assess the impact of supplemental folic acid.

METHODS

In this 16-wk open-labeled randomized clinical trial, adults consumed a low folic acid-containing diet, a folate-free multivitamin, and either a 400 μg folic acid supplement or no folic acid supplement. Dietary intakes and blood were assessed at baseline, 8 wk, and 16 wk (time of colonoscopy). Messenger RNA (mRNA) expression and protein expression of FT/R and GCPII were assessed in the terminal ileum, cecum, and ascending and descending colon.

RESULTS

Among 24 randomly assigned subjects, no differences in dietary folate intake or blood folate were observed at baseline. Mean ± SD red blood cell folate at 16 wk was 1765 ± 426 and 911 ± 242 nmol/L in the 400 and 0 μg folic acid group, respectively (P < 0.0001). Reduced folate carrier, proton-coupled folate transporter, and folate-receptor alpha expression were detected in the terminal ileum and colon, as were efflux transporters of breast cancer resistance protein and multidrug resistance protein-3. Other than a higher mRNA expression of FR-alpha and GCPII in the 400 μg supplement group in the ascending colon, no treatment differences were observed (P < 0.02).

CONCLUSIONS

Folate transporters are present throughout the terminal ileum and colon; there is little evidence that a low dose of folic acid supplementation affects colonic absorption. This trial was registered at clinicaltrials.gov as NCT03421483.

Vitamin D nutritional status in early pregnancy and its relationship with periconceptional multiple micronutrients supplementation

BACKGROUND AND OBJECTIVES

To assess the vitamin D nutritional status (VDN) of pregnant women in early pregnancy and investigate the effects of periconceptional supplementation with multiple micronutrients (MMs) on this status.

METHODS AND STUDY DESIGN

Data were taken from the Pregnancy Health Care System and Hospital Information System in 2018 in Beijing. Vitamin D nutritional status in early pregnancy was evaluated among 4,978 pregnant women, and 4,540 women who took folic acid only (FA) or multiple mi-cronutrients supplements (MM) during the periconceptional period, were include to estimate the associations between periconceptional supplementation with MM and prevalence of vitamin D deficiency or insufficiency with logistic regression model.

RESULTS

The mean early-pregnancy vitamin D concentration was 18.6 (±7.5) ng/mL, and the rates of deficiency and insufficiency were 31.6% and 60.5%, respectively. Compared to the FA group, the adjusted odds ratio (aOR, 95%confidence interval, CI) for insufficiency or deficiency of the MM group were 0.25(0.18-0.34), and the aOR (95%CI) for deficiency of the MM group were 0.17 (0.12-0.23). Women who took MMs for a longer period of time, at higher frequencies, and with higher compliance scores had lower rates of deficiency and insufficiency. In winter, spring, and autumn, taking MMs could reduce deficiency by about 70%; in summer, there was little effect.

CONCLUSIONS

Among women in Beijing, serum concentrations of vitamin D in early pregnancy are relatively low, and the rates of deficiency and insufficiency are high. Taking MMs during the periconceptional period could improve this situation.

Knuckle hyperpigmentation in a young male: A clinical sign of B12 deficiency not to be missed

Vitamin B12 and folate deficiency are reversible causes of megaloblastic anemia. Strict vegetarians are at risk of megaloblastic anemia due to low cobalamin in their diet. Knuckle hyperpigmentation in patients with megaloblastic anemia is due to excess melanin synthesis in skin. Here we present a case of a young vegetarian male with megaloblastic anemia with knuckle hyperpigmentation managed successfully with intravenous followed by oral vitamin b12 and folate supplementation.

Associations of prenatal one-carbon metabolism nutrients and metals with epigenetic aging biomarkers at birth and in childhood in a US cohort

Epigenetic gestational age acceleration (EGAA) at birth and epigenetic age acceleration (EAA) in childhood may be biomarkers of the intrauterine environment. We investigated the extent to which first-trimester folate, B12, 5 essential, and 7 non-essential metals in maternal circulation are associated with EGAA and EAA in early life. Bohlin EGAA and Horvath pan-tissue and skin and blood EAA were calculated using DNA methylation measured in cord blood (N=351) and mid-childhood blood (N=326; median age = 7.7 years) in the Project Viva pre-birth cohort. A one standard deviation increase in individual essential metals (copper, manganese, and zinc) was associated with 0.94-1.2 weeks lower Horvath EAA at birth, and patterns of exposures identified by exploratory factor analysis suggested that a common source of essential metals was associated with Horvath EAA. We also observed evidence nonlinear associations of zinc with Bohlin EGAA, magnesium and lead with Horvath EAA, and cesium with skin and blood EAA at birth. Overall, associations at birth did not persist in mid-childhood; however, arsenic was associated with greater EAA at birth and in childhood. Prenatal metals, including essential metals and arsenic, are associated with epigenetic aging in early life, which might be associated with future health.

Deficiencies in one-carbon metabolism led to increased neurological disease risk and worse outcome: homocysteine is a marker of disease state

Elevated plasma homocysteine levels have been identified as a significant, independent risk factor for the development of cognitive decline including Alzheimer's disease. While several studies have explored the link between homocysteine and disease risk, the associations have not been entirely clear. Elevated levels of homocysteine serve as a disease marker and understanding the underlying cause of these increased levels (e.g., dietary or genetic deficiency in one-carbon metabolism, 1C) will provide valuable insights into neurological disease risk and outcomes. Previous cell culture experiments investigating the mechanisms involved used ultra-high levels of homocysteine that are not observed in human patients. These studies have demonstrated the negative impacts of ultra-high levels of homocysteine can have on for example proliferation of neuroprogenitor cells in the adult hippocampus, as well as triggering neuronal apoptosis through a series of events, including DNA damage, PARP activation, NAD depletion, mitochondrial dysfunction, and oxidative stress. The aim of this mini-review article will summarize the literature on deficiencies in 1C and how they contribute to disease risk and outcomes and that homocysteine is a marker of disease.

B Vitamins in Legume Ingredients and Their Retention in High Moisture Extrusion

Legumes have been recognised as healthy and environmentally friendly protein sources. Knowledge about the vitamin B contents in legume ingredients and extrudates is scarce. In this study, we investigated thiamin, riboflavin, niacin, and folate in various faba bean, lupin, and pea ingredients. Further, the retention of B vitamins in high moisture extrusion was studied. Prior to liquid chromatographic determinations of thiamin, riboflavin, niacin, and folate, vitamins were extracted by acid hydrolysis (niacin), enzymatic treatment (folate), or their combination (thiamin and riboflavin). The contents (on a dry matter basis) varied greatly among different ingredients: the thiamin content was 0.2-14.2 µg/g; riboflavin, 0.3-5.9 µg/g; niacin, 8.8-35.5 µg/g, and folate, 45-1453 ng/g. Generally, the highest levels were in flours and protein concentrates, whereas low levels were observed in isolates. The retention of B vitamins was excellent in high moisture extrusion, except for folate in faba bean, where the folate contents were 42-67% lower in the extrudates than in the respective ingredient mixtures. In terms of both vitamin B contents and their retention, extrudates containing substantial amounts of flour or protein concentrate are promising plant-based sources of thiamin, riboflavin, niacin, and folate.

Assessing Nutritional Anemia Among University Students in Jazan, Saudi Arabia: A Public Health Perspective

Background

Nutritional anemia is a significant public health concern worldwide, particularly affecting young adults and children in Saudi Arabia, where inadequate nutrition is considered a primary contributing factor. This study aims to (i) examine the levels of serum iron, folate, and vitamin B12 in young adult students, with a focus on identifying any deficiencies and their association with anemia; (ii) explore the prevalence of mixed-deficiency anemia resulting from deficiencies in serum iron, folate, and vitamin B12 (iii) explore how sociodemographic characteristics and dietary habits influence serum iron, folate, and vitamin B12 levels.

Materials and Methods

This cross-sectional study encompassed 158 young adult students at Jazan University, Saudi Arabia. Blood samples were collected following a comprehensive questionnaire addressing sociodemographic and health characteristics. These samples were analyzed for complete blood count, serum iron, folate, and vitamin B12 levels.

Results

The findings of this study revealed a significant decrease in serum iron levels, with 70.6% of males and 88% in females exhibiting reduced level. Additionally, low levels of folate were observed in 4% of the study population, while deficiency in vitamin B12 was found in 2.2% of the study population. However, the simultaneous presence of low serum iron levels along with deficiencies in folate or vitamin B12 was not observed in the study participants.

Conclusion

The study indicates that there is a high incidence of low serum iron and ferritin levels among university students in Saudi Arabia, which poses a considerable public health concern. Conversely, the prevalence of folate and vitamin B12 deficiencies among the students was comparatively low, and notably, there were no cases where these deficiencies were observed alongside iron deficiency.

Assessment of blood one-carbon metabolism indexes during mid-to-late pregnancy in 397 Chinese pregnant women

Objectives

One-carbon metabolism (OCM) significantly influences fetal growth and neurodevelopment through transferring methyl group to biomolecules, during which folate, methionine, choline and betaine function as methyl donor nutrients, while vitamin B2, B6, B12 function as enzyme cofactors, and homocysteine (Hcy) and S-adenosyl methionine (SAM) are functional metabolites. This study aimed to assess blood OCM index levels and explore their relationships among Chinese pregnant women.

Methods

Data were obtained from the baseline of the Mother-Child Nutrition and Health Cohort Study. Pregnant women, voluntarily recruited from September 2020 to June 2022 during antenatal examinations in five Chinese cities at 24-32 gestational weeks, provided fasting venous blood samples. Measurements included RBC and serum folate, serum vitamin B2, B6, B12, choline, betaine, methionine, total Hcy (tHcy), and plasma SAM. Sociodemographic characteristics and pregnancy-related conditions were collected via a self-designed questionnaire.

Results

Of 397 participants, 82.6% were in mid-pregnancy (24-27 gestational weeks) and 17.4% were in late-pregnancy (28-32 gestational weeks). Serum folate, vitamin B6, and B12 deficiencies were 2.5, 1.3, and 8.3%, respectively. Elevated tHcy (≥10 μmol/L) was observed in 1.8% of pregnant women. Elderly pregnant women (aged 35 and above) exhibited significantly lower serum methionine levels (p < 0.05), while multiparous women had lower RBC folate levels (p < 0.05), and lower serum methionine and vitamin B12 levels (p < 0.10, not statistically significant). Partial correlation analysis revealed positive associations between RBC folate and cofactor vitamin B12 (r = 0.244, p < 0.05) in the folate cycle, as well as significant correlations between two methyl donor paths [serum folate was significantly related to serum choline (r = 0.172) and betaine (r = 0.193)]. As functional biomarkers of OCM, serum tHcy exhibited negative associations with RBC folate (β = -0.330, p < 0.05) and vitamin B6 (β = -0.317, p < 0.05), and plasma SAM displayed a positive association with serum betaine (β = 0.610, p < 0.05), while negatively associated with serum vitamin B6 (β = -0.181, p < 0.05).

Conclusion

The blood OCM exhibited imbalances during mid-to-late pregnancy, characterized by lower levels of folate, vitamin B6, and B12, alongside elevated tHcy levels. Adequate folate and vitamin B6 emerged as significant predictors of lower tHcy levels. Additionally, serum betaine showed a positive correlation with plasma SAM. This suggests the importance of not only ensuring sufficient folate but also optimizing other OCM-related nutrients throughout pregnancy.

Serum levels of folate, vitamin B6, and vitamin B12 are associated with cognitive impairments in depression patients

INTRODUCTION

Depression is a common mental disorder that endangers physical and mental health. In our study, we aimed to explore whether B vitamins are associated with depression and cognitive dysfunction.

METHODS

We enrolled a total of 220 patients with depression and selected 100 controls at the same time. We determined depression and cognitive impairment by assessments. We recorded the basic parameters of the participants and collected blood samples. In addition, we measured serum levels of B vitamins and brain-derived neurotrophic factor (BDNF).

RESULTS

We found significant differences in the duration of depression, education, and Hamilton Depression Rating Scale scores between the D-NCI and D-CI groups. We also identified the independent risk factors for patients with depression and cognitive dysfunction. Compared with the healthy controls, serum folate, vitamin B6, and vitamin B12 positively correlated with cognitive dysfunction. The patients with depression and cognitive dysfunction had the lowest levels of B vitamins compared with the other two groups. Our results also showed that the levels of serum folate, vitamin B6, and vitamin B12 in the patients with depression had a positive correlation with each other.

CONCLUSION

Our results indicate that vitamin B is associated with depression and cognitive dysfunction and is positively associated with cognitive dysfunction.

Intake and biomarkers of folate and folic acid as determinants of chemotherapy-induced toxicities in patients with colorectal cancer: a cohort study

BACKGROUND

Capecitabine is an oral chemotherapeutic drug showing antitumor activity through inhibition of thymidylate synthase, an enzyme involved in folate metabolism. There are concerns about the high intake of certain vitamins, and specifically folate, during chemotherapy with capecitabine. Whether folate or folic acid, the synthetic variant of the vitamin, impact treatment toxicity remains unclear.

OBJECTIVE

We studied associations between intake and biomarkers of folate as well as folic acid and toxicities in patients with colorectal cancer (CRC) receiving capecitabine.

METHODS

Within the prospective COLON (Colorectal cancer: Longitudinal, Observational study on Nutritional and lifestyle factors that influence recurrence, survival, and quality of life) cohort, 290 patients with stage II to III CRC receiving capecitabine were identified. Dietary and supplemental intake of folate and folic acid were assessed at diagnosis and during chemotherapy using questionnaires (available for 280 patients). Plasma folate and folic acid levels were determined by liquid chromatography tandem mass spectrometry (LC-MS/MS) and were available for 212 patients. Toxicities were defined as toxicity-related modifications of treatment, including dose reductions, regimen switches, and early discontinuation. Associations of intake and biomarkers of folate and folic acid with toxicities were determined using Cox proportional hazards regression adjusted for age and sex.

RESULTS

In total, 153 (53%) patients experienced toxicities leading to modification of capecitabine treatment. Folate intake and plasma folate levels were not associated with risk of toxicities. However, use of folic acid-containing supplements during treatment (hazard ratio (HR) 1.81 and 95% confidence interval (CI) 1.15-2.85) and presence of folic acid in plasma at diagnosis (HR 2.09, 95% CI: 1.24, 3.52) and during treatment (HR 2.31, 95% CI: 1.29, 4.13) were associated with an increased risk of toxicities.

CONCLUSIONS

This study suggests a potential association between folic acid and capecitabine-induced toxicities, providing a rationale to study diet-drug interactions and raise further awareness of the use of dietary supplements during oncological treatment.

CLINICAL TRIAL DETAILS

This trial was registered at clinicaltrials.gov as NCT03191110.

Association between Serum Folate and Vaginal High-Risk Human Papillomavirus Infections in United States Women

BACKGROUND

Serum concentration of folate was inversely associated with cervical intraepithelial neoplasia and cervical cancer in some studies. The association between folate and human papillomavirus (HPV) infection, a necessary cause of cervical cancer, has not been well elucidated.

OBJECTIVES

We evaluated whether serum folate concentrations were associated with high-risk HPV (hrHPV) infection.

METHODS

The study population was 11,801 females, aged 18-59 y, enrolled in the National Health and Nutrition Examination Survey (NHANES), from 2003 to 2016, in the United States. In this cross-sectional study, prevalence ratios (PRs) of vaginal hrHPV were calculated using logistic regression models, by quintiles of serum folate.

RESULTS

Females in the lowest quintile had <21.3 nmol/L of folate. Approximately 23% of the females (2733/11,801) were hrHPV positive. In age-adjusted models, folate was significantly associated with hrHPV infection. The PRs and 95% confidence intervals (CIs) were (PR: 1.52; 95% CI: 1.37, 1.70) for the first, (PR: 1.29; 95% CI: 1.15, 1.44) for the second, (PR: 1.19; 95% CI: 1.06, 1.34) for the third, and (PR: 1.09; 95% CI: 0.96, 1.23) for the fourth quintiles, compared with the females in the highest quintile, with a significant P value for trend, <0.0001. The association remained statistically significant after the models were further adjusted for lifestyle and sexual risk factors for hrHPV infection; the females in the lowest quintile were more likely to have hrHPV infection than those in the highest quintile (PR: 1.40; 95% CI: 1.11, 1.53).

CONCLUSIONS

Results from this sample of females in the United States suggest that serum folate concentration is inversely associated with hrHPV infection.

Metabolomic Effects of Folic Acid Supplementation in Adults: Evidence from the FACT Trial

BACKGROUND

Folic acid (FA) is the oxidized form of folate found in supplements and FA-fortified foods. Most FA is reduced by dihydrofolate reductase to 5-methyltetrahydrofolate (5mTHF); the latter is the form of folate naturally found in foods. Ingestion of FA increases the plasma levels of both 5mTHF and unmetabolized FA (UMFA). Limited information is available on the downstream metabolic effects of FA supplementation, including potential effects associated with UMFA.

OBJECTIVE

We aimed to assess the metabolic effects of FA-supplementation, and the associations of plasma 5mTHF and UMFA with the metabolome in FA-naïve Bangladeshi adults.

METHODS

Sixty participants were selected from the Folic Acid and Creatine Trial; half received 800 μg FA/day for 12 weeks and half placebo. Plasma metabolome profiles were measured by high-resolution mass spectrometry, including 170 identified metabolites and 26,541 metabolic features. Penalized regression methods were used to assess the associations of targeted metabolites with FA-supplementation, plasma 5mTHF, and plasma UMFA. Pathway analyses were conducted using Mummichog.

RESULTS

In penalized models of identified metabolites, FA-supplementation was associated with higher choline. Changes in 5mTHF concentrations were positively associated with metabolites involved in amino acid metabolism (5-hydroxyindoleacetic acid, acetylmethionine, creatinine, guanidinoacetate, hydroxyproline/n-acetylalanine) and 2 fatty acids (docosahexaenoic acid and linoleic acid). Changes in 5mTHF concentrations were negatively associated with acetylglutamate, acetyllysine, carnitine, propionyl carnitine, cinnamic acid, homogentisate, arachidonic acid, and nicotine. UMFA concentrations were associated with lower levels of arachidonic acid. Together, metabolites selected across all models were related to lipids, aromatic amino acid metabolism, and the urea cycle. Analyses of nontargeted metabolic features identified additional pathways associated with FA supplementation.

CONCLUSION

In addition to the recapitulation of several expected metabolic changes associated with 5mTHF, we observed additional metabolites/pathways associated with FA-supplementation and UMFA. Further studies are needed to confirm these associations and assess their potential implications for human health.

TRIAL REGISTRATION NUMBER

This trial was registered at https://clinicaltrials.gov as NCT01050556.

Evaluation of In Vivo Folic Acid Bioavailability in Different Mouse Strains Using Enzymatic Digestion Combined with Ultra Performance Liquid Chromatography

By analyzing the folic acid content of various mouse strains through the use of in vivo studies, this study sought to determine whether folic acid bioavailability varies between hosts. In order to examine the stability of folic acid in the gastrointestinal tract, the rate at which it enters the blood, its retention in the organs, and its entry into the brain, folic acid was gavaged for 10 days into male and female mice of the following four strains: C57BL/6, BALB/c, ICR, and Kunming. Folic acid was extracted from eight groups of mice via solid phase extraction and triple enzyme extraction; the folic acid was subsequently quantified by ultraperformance liquid chromatography. In contrast to the other groups, female C57BL/6 mice exhibited substantially greater bioavailability as well as variations in organ retention and blood entry rates, as indicated by the experimental findings. This finding indicated that using female C57BL/6 mice to evaluate the bioavailability of folic acid is more effective.

Folate supports IL-25-induced tuft cell expansion following enteroviral infections

Intestinal tuft cells, a kind of epithelial immune cells, rapidly expand in response to pathogenic infections, which is associated with infection-induced interleukin 25 (IL-25) upregulation. However, the metabolic mechanism of IL-25-induced tuft cell expansion is largely unknown. Folate metabolism provides essential purine and methyl substrates for cell proliferation and differentiation. Thus, we aim to investigate the roles of folate metabolism playing in IL-25-induced tuft cell expansion by enteroviral infection and recombinant murine IL-25 (rmIL-25) protein-stimulated mouse models. At present, enteroviruses, such as EV71, CVA16, CVB3, and CVB4, upregulated IL-25 expression and induced tuft cell expansion in the intestinal tissues of mice. However, EV71 did not induce intestinal tuft cell expansion in IL-25-/- mice. Interestingly, compared to the mock group, folate was enriched in the intestinal tissues of both the EV71-infected group and the rmIL-25 protein-stimulated group. Moreover, folate metabolism supported IL-25-induced tuft cell expansion since both folate-depletion and anti-folate MTX-treated mice had a disrupted tuft cell expansion in response to rmIL-25 protein stimulation. In summary, our data suggested that folate metabolism supported intestinal tuft cell expansion in response to enterovirus-induced IL-25 expression, which provided a new insight into the mechanisms of tuft cell expansion from the perspective of folate metabolism.

Exploring the complexities of 1C metabolism: implications in aging and neurodegenerative diseases

The intricate interplay of one-carbon metabolism (OCM) with various cellular processes has garnered substantial attention due to its fundamental implications in several biological processes. OCM serves as a pivotal hub for methyl group donation in vital biochemical reactions, influencing DNA methylation, protein synthesis, and redox balance. In the context of aging, OCM dysregulation can contribute to epigenetic modifications and aberrant redox states, accentuating cellular senescence and age-associated pathologies. Furthermore, OCM's intricate involvement in cancer progression is evident through its capacity to provide essential one-carbon units crucial for nucleotide synthesis and DNA methylation, thereby fueling uncontrolled cell proliferation and tumor development. In neurodegenerative disorders like Alzheimer's and Parkinson's, perturbations in OCM pathways are implicated in the dysregulation of neurotransmitter synthesis and mitochondrial dysfunction, contributing to disease pathophysiology. This review underscores the profound impact of OCM in diverse disease contexts, reinforcing the need for a comprehensive understanding of its molecular complexities to pave the way for targeted therapeutic interventions across inflammation, aging and neurodegenerative disorders.

Association Between High Blood Folate Levels and Glaucoma in a Representative Korean Population

Purpose

This study aimed to investigate the association between folate levels and the prevalence of glaucoma.

Methods

This nationwide population-based cross-sectional study included 1790 participants aged ≥40 years. We analyzed data regarding the participants obtained in the 2016-2018 Korean National Health and Nutrition Examination Survey. The diagnosis of glaucoma was defined according to the International Society of Geographical and Epidemiological Ophthalmology criteria. Logistic regression analyses were used to investigate the relationship between blood folate levels and glaucoma.

Results

There was a significantly lower prevalence of glaucoma in the highest quartile of blood folate levels than in the lowest quartile, after adjusting for confounding factors such as age, sex, systemic hypertension, diabetes, hypercholesterolemia, and smoking (odds ratio [OR] = 0.470; 95% confidence interval [CI], 0.291-0.759; P for trend = 0.017). There was a significantly lower risk of glaucoma in the highest quartile of blood folate levels than in the lowest quartile among women (OR = 0.188; 95% CI, 0.099-0.357; P for trend <0.001) and younger participants (OR =0.443; 95% CI, 0.229-0.856; P for trend = 0.045).

Conclusions

Our findings indicate a strong inverse correlation between blood folate levels and glaucoma.

Spina Bifida Prevention: A Narrative Review of Folic Acid Supplements for Childbearing Age Women

Neural tube defects (NTDs) are malformations that occur during embryonic development, and they account for most central nervous system birth anomalies. Genetic and environmental factors have been shown to play a role in the etiology of NTDs. The different types of NTDs are classified according to anatomic location and severity of the defect, with most of the neural axis anomalies occurring in the caudal spinal or cranial areas. Spina bifida is a type of NTD that is characterized by an opening in the vertebral arch, and the level of severity is determined by the extent to which the neural tissue protrudes through the opened arch(es). Prevention of NTDs by administration of folic acid has been studied and described in the literature, yet there are approximately 300,000 cases of NTDs that occur annually, with 88,000 deaths occurring per year worldwide. A daily intake of at least 400 μg of folic acid is recommended especially for women of childbearing age. To provide the benefits of folic acid, prenatal vitamins are recommended in pregnancy, and many countries have been fortifying foods such as cereal grain products with folic acid; however, not all countries have instituted folic acid fortification programs. The present investigation includes a description of the pharmacology of folic acid, neural tube formation, defects such as spina bifida, and the relevance of folic acid to developing spina bifida. Women's knowledge and awareness of folic acid regarding its importance in the prevention of spina bifida is a major factor in reducing incidence worldwide.

Folic acid: friend or foe in cancer therapy

Folic acid plays a crucial role in diverse biological processes, notably cell maturation and proliferation. Here, we performed a literature review using articles listed in electronic databases, such as PubMed, Scopus, MEDLINE, and Google Scholar. In this review article, we describe contradictory data regarding the role of folic acid in cancer development and progression. While some studies have confirmed its beneficial effects in diminishing the risk of various cancers, others have reported a potential carcinogenic effect. The current narrative review elucidates these conflicting data by highlighting the possible molecular mechanisms explaining each point of view. Further multicenter molecular and genetic studies, in addition to human randomized clinical trials, are necessary to provide a more comprehensive understanding of the relationship between folic acid and cancer.

Investigating the association between vitamin D dietary intake during pregnancy and incidence of clubfoot in neonates

AIMS

Talipes equinovarus (clubfoot) is a congenital lower foot deformity that results from a neuromuscular deficiency, but the precise etiology remains elusive. Vitamin D is important for fetal neuromuscular development. In this study, we investigated the association between dietary vitamin D intake during pregnancy and incidence of clubfoot in neonates, since such a question has thus far been overlooked.

METHODS

We conducted a secondary analysis of data collected in the United States, between 2007 and 2011 for a case-control study of children born with clubfoot. Participating mothers were interviewed by telephone about dietary and other health and life-style indicators. Exposure to vitamin D was recorded as the average daily intake of dietary vitamin D over a period of 6 months before pregnancy began. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression.

RESULTS

The dataset included 2667 study participants, of which 663 were cases. Logistic regression showed no significant association between dietary vitamin D or log10 (Vitamin D) intake during pregnancy and incidence of clubfoot in neonates (OR = 1.00, CI = 1.00-1.00, OR = 1.51, CI = 0.83-2.82, respectively). No interaction in the regression model was found between vitamin D and other predictor variables. Results were not confounded by supplement intake of vitamin D during pregnancy.

CONCLUSIONS

Results show no evidence of an association between dietary vitamin D intake and incidence of clubfoot in neonates. The lack of association is not confounded by consumption of vitamin D supplements during pregnancy.

Hypothetical Regulation of Folate Biosynthesis and Strategies for Folate Overproduction in Lactic Acid Bacteria

Folate (vitamin B9) is an essential nutrient for cell metabolism, especially in pregnant women; however, folate deficiency is a major global health issue. To address this issue, folate-rich fermented foods have been used as alternative sources of natural folate. Lactic acid bacteria (LAB), which are commonly involved in food fermentation, can synthesize and excrete folate into the medium, thereby increasing folate levels. However, screening for folate-producing LAB strains is necessary because this ability is highly dependent on the bacterial strain. Some strains of LAB consume folate, and their presence in a fermentation mix can lower the folate levels of the final product. Since microorganisms efficiently regulate folate biosynthesis to meet their growth needs, some strains of folate-producing LAB can deplete folate levels if folate is available in the media. Such folate-efficient producers possess a feedback inhibition mechanism that downregulates folate biosynthesis. Therefore, the application of folate-overproducing strains may be a key strategy for increasing folate levels in media with or without available folate. Many studies have been conducted to screen folate-producing bacteria, but very few have focused on the identification of overproducers. This is probably because of the limited understanding of the regulation of folate biosynthesis in LAB. In this review, we discuss the roles of folate-biosynthetic genes and their contributions to the ability of LAB to synthesize and regulate folate. In addition, we present various hypotheses regarding the regulation of the feedback inhibition mechanism of folate-biosynthetic enzymes and discuss strategies for obtaining folate-overproducing LAB strains.

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.

MTHFR and risk of stroke and heart disease in a low-folate population: a prospective study of 156 000 Chinese adults

BACKGROUND

The relevance of folic acid for stroke prevention in low-folate populations such as in China is uncertain. Genetic studies of the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, which increases plasma homocysteine (tHcy) levels, could clarify the causal relevance of elevated tHcy levels for stroke, ischaemic heart disease (IHD) and other diseases in populations without folic acid fortification.

METHODS

In the prospective China Kadoorie Biobank, 156 253 participants were genotyped for MTHFR and 12 240 developed a stroke during the 12-year follow-up. Logistic regression was used to estimate region-specific odds ratios (ORs) for total stroke and stroke types, IHD and other diseases comparing TT genotype for MTHFR C677T (two thymine alleles at position 677 of MTHFR C677T polymorphism) vs CC (two cytosine alleles) after adjustment for age and sex, and these were combined using inverse-variance weighting.

RESULTS

Overall, 21% of participants had TT genotypes, but this varied from 5% to 41% across the 10 study regions. Individuals with TT genotypes had 13% (adjusted OR 1.13, 95% CI 1.09-1.17) higher risks of any stroke [with a 2-fold stronger association with intracerebral haemorrhage (1.24, 1.17-1.32) than for ischaemic stroke (1.11, 1.07-1.15)] than the reference CC genotype. In contrast, MTHFR C677T was unrelated to risk of IHD or any other non-vascular diseases, including cancer, diabetes and chronic obstructive lung disease.

CONCLUSIONS

In Chinese adults, the MTHFR C677T polymorphism was associated with higher risks of stroke. The findings warrant corroboration by further trials of folic acid and implementation of mandatory folic acid fortification programmes for stroke prevention in low-folate populations.

Climate Stressors and Physiological Dysregulations: Mechanistic Connections to Pathologies

This review delves into the complex relationship between environmental factors, their mechanistic cellular and molecular effects, and their significant impact on human health. Climate change is fueled by industrialization and the emission of greenhouse gases and leads to a range of effects, such as the redistribution of disease vectors, higher risks of disease transmission, and shifts in disease patterns. Rising temperatures pose risks to both food supplies and respiratory health. The hypothesis addressed is that environmental stressors including a spectrum of chemical and pathogen exposures as well as physical and psychological influences collectively impact genetics, metabolism, and cellular functions affecting physical and mental health. The objective is to report the mechanistic associations linking environment and health. As environmental stressors intensify, a surge in health conditions, spanning from allergies to neurodegenerative diseases, becomes evident; however, linkage to genetic-altered proteomics is more hidden. Investigations positing that environmental stressors cause mitochondrial dysfunction, metabolic syndrome, and oxidative stress, which affect missense variants and neuro- and immuno-disorders, are reported. These disruptions to homeostasis with dyslipidemia and misfolded and aggregated proteins increase susceptibility to cancers, infections, and autoimmune diseases. Proposed interventions, such as vitamin B supplements and antioxidants, target oxidative stress and may aid mitochondrial respiration and immune balance. The mechanistic interconnections of environmental stressors and disruptions in health need to be unraveled to develop strategies to protect public health.

The Implication of a Polymorphism in the Methylenetetrahydrofolate Reductase Gene in Homocysteine Metabolism and Related Civilisation Diseases

Methylenetetrahydrofolate reductase (MTHFR) is a key regulatory enzyme in the one-carbon cycle. This enzyme is essential for the metabolism of methionine, folate, and RNA, as well as for the production of proteins, DNA, and RNA. MTHFR catalyses the irreversible conversion of 5,10-methylenetetrahydrofolate to its active form, 5-methyltetrahydrofolate, a co-substrate for homocysteine remethylation to methionine. Numerous variants of the MTHFR gene have been recognised, among which the C677T variant is the most extensively studied. The C677T polymorphism, which results in the conversion of valine to alanine at codon 222, is associated with reduced activity and an increased thermolability of the enzyme. Impaired MTHFR efficiency is associated with increased levels of homocysteine, which can contribute to increased production of reactive oxygen species and the development of oxidative stress. Homocysteine is acknowledged as an independent risk factor for cardiovascular disease, while chronic inflammation serves as the common underlying factor among these issues. Many studies have been conducted to determine whether there is an association between the C677T polymorphism and an increased risk of cardiovascular disease, hypertension, diabetes, and overweight/obesity. There is substantial evidence supporting this association, although several studies have concluded that the polymorphism cannot be reliably used for prediction. This review examines the latest research on MTHFR polymorphisms and their correlation with cardiovascular disease, obesity, and epigenetic regulation.

Complete genome sequence of the probiotic Bifidobacterium adolescentis strain iVS-1

Bifidobacterium adolescentis iVS-1 is a human-isolated strain known to possess several probiotic properties. Here, its genome was completely sequenced to examine genes associated with lactose metabolism and other potentially beneficial traits, such as the production of folate and gamma-aminobutyric acid (GABA).

Analysis of the mediating role of BMI in associations of different folate forms with hepatic steatosis and liver fibrosis in adolescents in the USA: results from the NHANES 2017-2018

Background

Most studies have explored the relationship between serum total folate and nonalcoholic fatty liver disease (NAFLD) in adults, but there has been no study on the relationship between different folate forms and hepatic steatosis or liver stiffness in adolescents.

Objective

To investigate the association of different folate forms with hepatic steatosis or liver stiffness in adolescents, and further explore the intermediary role of BMI in this relationship.

Methods

The cross-sectional study included 549 participants from the 2017-2018 National Health and Nutrition Inspection Survey (NHANES) survey cycle who had complete data. Four folate data (red blood cell folate, serum total folate, 5-methyl-tetrahydrofolate and folic acid) were included in our study. Controlled attenuation parameters (CAP) and liver stiffness came from the results of liver ultrasound transient elastography. We used linear regression to analyze the relationship between different forms of folate and CAP or liver stiffness, and logistic regression to analyze the relationship between different forms of folate and NAFLD or significant fibrosis. We also used restricted cubic splines to analyze the nonlinear relationship between different forms of folate and NAFLD or significant fibrosis. Finally, we used regression-based intermediary analysis to distinguish the direct and BMI-mediated effects of folate on CAP or liver stiffness. All the analyses adjusted the relevant covariates.

Results

The means of CAP and liver hardness in this study were 223.02dB/m and 5.03kPa, respectively. We found that in model 2, there was a negative correlation between serum total folate (β: -18.53; 95%CI: -29.32 to -7.73) or 5-methyltetrahydrofolate (β: -14.13; 95%CI: -28.98 to -7.86) and CAP. However, when the BMI was further adjusted in model 3, this negative correlation no longer existed (serum total folate: β: -8.36; 95%CI: -17.69 to 0.97; 5-methyltetrahydrofolate: β: -8.05; 95%CI: -17.19 to 1.09). Similarly, we found a negative correlation between serum total folate or 5-Methyl-tetrahydrofolate and liver stiffness in model 2. There was no significant correlation between red blood cell folate or folic acid and CAP or liver stiffness in either model 2 or model 3. The nonlinear relationship between different folate forms and NAFLD or significant fibrosis was not significant. It is estimated that 76% of the total association between serum total folate and CAP is mediated by BMI. The mediating proportion of BMI in the total correlation between serum total folate and liver stiffness was 50%. Similarly, we found that BMI significantly mediated the relationship between 5-Methyl-tetrahydrofolate and CAP or liver stiffness, with a mediating ratio of 77% and 49%, respectively.

Conclusion

Our results show that serum total folate or 5-Methyl-tetrahydrofolate are negatively correlated with hepatic steatosis or liver stiffness in adolescents, and BMI plays major mediating role in this relationship. Our findings emphasize the importance of monitoring the concentration of serum folate, not just the serum total folate concentration.

A high-throughput single-cell RNA expression profiling method identifies human pericyte markers

AIMS

We sought to identify and optimise a universally available histological marker for pericytes in the human brain. Such a marker could be a useful tool for researchers. Further, identifying a gene expressed relatively specifically in human pericytes could provide new insights into the biological functions of this fascinating cell type.

METHODS

We analysed single-cell RNA expression profiles derived from different human and mouse brain regions using a high-throughput and low-cost single-cell transcriptome sequencing method called EasySci. Through this analysis, we were able to identify specific gene markers for pericytes, some of which had not been previously characterised. We then used commercially (and therefore universally) available antibodies to immunolabel the pericyte-specific gene products in formalin-fixed paraffin-embedded (FFPE) human brains and also performed immunoblots to determine whether appropriately sized proteins were recognised.

RESULTS

In the EasySci data sets, highly pericyte-enriched expression was notable for SLC6A12 and SLC19A1. Antibodies against these proteins recognised bands of approximately the correct size in immunoblots of human brain extracts. Following optimisation of the immunohistochemical technique, staining for both antibodies was strongly positive in small blood vessels and was far more effective than a PDGFRB antibody at staining pericyte-like cells in FFPE human brain sections. In an exploratory sample of other human organs (kidney, lung, liver, muscle), immunohistochemistry did not show the same pericyte-like pattern of staining.

CONCLUSIONS

The SLC6A12 antibody was well suited for labelling pericytes in human FFPE brain sections, based on the combined results of single-cell RNA-seq analyses, immunoblots and immunohistochemical studies.

Vitamin B12 and Folate Status in Pregnant Females and Their Infants in Norway: Secondary Analysis from the Mommy's Food Study

BACKGROUND

Vitamin B12 and folate are essential micronutrients important for normal infant growth and development.

OBJECTIVES

The aims were to describe vitamin B12 and folate status in pregnant females and their infants according to commonly used status cutoffs and examine the associations between maternal status, maternal supplement use, and breastfeeding and infant status.

METHODS

Pregnant females were recruited at 18 wk gestation in Bergen, Norway. Maternal vitamin B12 and folate status were measured at gestational weeks 18 (n = 136) and 36 (n = 116), and infant status was measured at ages 3 (n = 73) and 6 (n = 74) mo.

RESULTS

At gestational weeks 18 and 36, respectively, 4.4% and 2.6% of the mothers had plasma cobalamin concentrations <148 pmol/L, 0.7% and 6.9% had methylmalonic acid (MMA) concentrations >0.26 μmol/L, and 3.7% and 30% had folate concentrations <10 nmol/L. None of the females had total homocysteine (t-Hcy) concentrations >13 μmol/L or 3 combined indicator of vitamin B12 (cB12) < -0.5. At 3 and 6 mo, respectively, 4.1% and 5.4% of the infants had cobalamin concentrations <148 pmol/L, 63% and 74% had t-Hcy concentrations >6.5 μmol/L, 59% and 66% had MMA concentrations >0.26 μmol/L, and 47% and 60% had cB12 > -0.5. None of the infants had folate concentrations <10 nmol/L. Several of the vitamin B12 biomarkers in infants were associated with maternal vitamin B12 status during pregnancy. Breastfed infants had lower vitamin B12 status (as indicated by plasma cobalamin, t-Hcy, and cB12) than nonbreastfed infants at both 3 and 6 mo. Use of supplements during pregnancy was associated with better vitamin B12 status among infants at 3 and 6 mo, as indicated by infants' cobalamin and t-Hcy concentrations.

CONCLUSIONS

Subclinical vitamin B12 deficiency among infants was common and associated with maternal vitamin B12 status during pregnancy and breastfeeding. Among the mothers, an increase in biochemical folate deficiency was discovered toward the end of gestation. Further studies are needed to investigate clinical consequences. This trial was registered at clinicaltrials.gov as NCT02610959.

Intakes of folate, vitamin B6, and vitamin B12 and cardiovascular disease risk: a national population-based cross-sectional study

Background

Only a few studies that investigated dietary intakes of folate, vitamin B6, and vitamin B12 in relation to cariovascular disease (CVD). This study aimed to assess the association of dietary folate, vitamin B6, and vitamin B12 with CVD in the United States population.

Methods

A cross-sectional analysis of 65,322 adults aged ≥ 20 years who participated in the Third National Health and Nutrition Examination Survey (NHANES III) and NHANES 1999-2018. Before 2003, dietary intake data were assessed using a 24-hour dietary call, and two 24-hour dietary calls were used during 2003 and 2018. Odds ratios and 95% confidence intervals (CIs) for CVD associated with dietary folate, vitamin B6, and vitamin B12 were estimated using multivariate logistic regression models.

Results

Dietary vitamin B6 intake were inversely associated with the odds of CVD. In males, the multivariable OR for the highest vs. lowest quartiles of vitamin B6 was 0.77 (95%CI: 0.61-0.97, Ptrend = 0.013) for the odds of CVD. In females, the adjusted OR for the highest quartile of vitamin B6 compared with the lowest quartile was 0.73 (95%CI: 0.56-0.95, Ptrend = 0.038) for the odds of CVD. No significant association was observed between dietary folate and vitamin B12 intakes and the odds of CVD.

Conclusions

Our findings indicate that higher intake of dietary vitamin B6 may be associated with lower prevalence of CVD, suggesting that dietary vitamin B6 has major public health implications in the prevention of CVD in the United States population.

Associations between homocysteine, vitamin B12, and folate and the risk of all-cause mortality in American adults with stroke

Objective

Associations between plasma homocysteine (Hcy), vitamin B12, and folate and the risk of all-cause mortality are unclear. This study aimed to examine whether plasma Hcy, vitamin B12, and folate levels independently predict the risk of all-cause mortality in American adults with stroke.

Methods

Data from the United States National Health and Examination Survey (NHANES; 1999-2006) were used and linked with the latest (2019) National Death Index (NDI). Cox proportional hazards models and restricted cubic splines were used to estimate the hazard ratios (HR) and 95% confidence intervals (CI) of all-cause mortality for Hcy, folate, and B12 levels in adults with stroke. Sample weights were calculated to ensure the generalizability of the results.

Results

A total of 431 participants were included (average age: 64.8 years). During a median follow-up of 10.4 years, 316 deaths occurred. Hcy was positively associated with all-cause mortality in adults with stroke (HR, 1.053; 95% CI: 1.026-1.080). Stroke patients with plasma Hcy levels in the fourth quartile had a 1.631-fold higher risk of all-cause mortality (HR, 1.631; 95% CI: 1.160-2.291) than those in the first quartile. The association between plasma Hcy and all-cause mortality was strong significant in older patients (p for interaction = 0.020). Plasma folate and vitamin B12 concentrations were inversely correlated with Hcy concentrations [B-value (95% CI): -0.032 (-0.056- -0.008), -0.004 (-0.007- -0.002), respectively]. No significant associations were observed between folate, vitamin B12 levels, and all-cause mortality in adults with stroke.

Conclusion

Plasma Hcy levels were positively associated with all-cause mortality in older adults with stroke. Folate and vitamin B12 levels were inversely correlated with Hcy. Plasma Hcy may serve as a useful predictor in mortality risk assessment and targeted intervention in adults with stroke.

Relationship between Serum Homocysteine Concentration and Dietary Factors in Young Japanese Women

Homocysteine is a methionine metabolism intermediate and its increased blood levels are associated with a higher risk of noncommunicable diseases. Reportedly, blood homocysteine levels increase with inadequate folate, vitamin B6, and vitamin B12 intake; however, its relationship with dietary factors other than these three vitamins remains unknown. Thus, we investigated the relationship of homocysteine with other nutrient intake. We performed a dietary survey on 227 young women using a food record with approximate amounts for 7 consecutive days in conjunction with digital imaging. We collected early morning fasting blood samples the day after the dietary survey was completed and analyzed the serum homocysteine levels. We observed that the serum homocysteine concentrations were significantly negatively associated with soluble, insoluble, and total fiber intake. In addition, participants with high fruit and mushroom intake displayed lower serum homocysteine concentrations, suggesting dietary fiber involvement from these foods. However, we observed no serum homocysteine concentration-related association with cereals and vegetables (well-documented dietary fiber sources) or with fruits and mushrooms. In conclusion, fiber quality-related differences could thus be caused by different sources, including antioxidant components such as fruit polyphenols and mushroom antioxidant and anti-inflammatory factors.

Uncovering the Hidden Dangers and Molecular Mechanisms of Excess Folate: A Narrative Review

This review delves into the intricate relationship between excess folate (vitamin B9) intake, especially its synthetic form, namely, folic acid, and its implications on health and disease. While folate plays a pivotal role in the one-carbon cycle, which is essential for DNA synthesis, repair, and methylation, concerns arise about its excessive intake. The literature underscores potential deleterious effects, such as an increased risk of carcinogenesis; disruption in DNA methylation; and impacts on embryogenesis, pregnancy outcomes, neurodevelopment, and disease risk. Notably, these consequences stretch beyond the immediate effects, potentially influencing future generations through epigenetic reprogramming. The molecular mechanisms underlying these effects were examined, including altered one-carbon metabolism, the accumulation of unmetabolized folic acid, vitamin-B12-dependent mechanisms, altered methylation patterns, and interactions with critical receptors and signaling pathways. Furthermore, differences in the effects and mechanisms mediated by folic acid compared with natural folate are highlighted. Given the widespread folic acid supplementation, it is imperative to further research its optimal intake levels and the molecular pathways impacted by its excessive intake, ensuring the health and well-being of the global population.

Vitamin B12 status among asymptomatic young adult females and its association with some anthropometric and biochemical parameters: A cross-sectional study from Makkah (cobalamin deficiency in young adult females)

This study was designed to measure the prevalence of vitamin B12 deficiency among young adult females in Makkah City and study its correlation with some anthropometric and biochemical indicators. A cross-sectional study and a detailed questionnaire were used to collect information from 402 young women aged 19 to 22 years, who were university students. Moreover, dietary assessments using a validated food frequency questionnaire and anthropometric measurements were performed. The mean values of serum vitamin B12, serum folate, hemoglobin, and body mass index (BMI) were 343.29 ± 148.16 pg/mL, 12.72 ± 2.62 ng/mL, 12.69 ± 1.41 g/dL, and 22.64 ± 4.24 kg/m2, respectively. About three-quarters of the study sample had normal vitamin B12 levels, while the rest had vitamin B12 deficiency. Meanwhile, a significant negative association (r = -0.201, P = .048) was found between abdominal fat and serum vitamin B12 levels. This study concluded that the young adult females' population from Makkah City is among the risk groups for vitamin B12 deficiency, which is highly correlated with inappropriate values of weight, body fat, and some blood indices. Appropriate dietary interventions and awareness are needed for this population.

Safety of monosodium salt of l-5-methyltetrahydrofolic acid as a novel food pursuant to Regulation (EU) 2015/2283 and the bioavailability of folate from this source in the context of Directive 2002/46/EC, Regulation (EU) No 609/2013 and Regulation (EC) No 1925/2006

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on monosodium salt of l-5-methyltetrahydrofolic acid (5-MTHF) as a novel food (NF) pursuant to Regulation (EU) 2015/2283 and to address the bioavailability of folate from this source in the context of Directive 2002/46/EC, Regulation (EU) No 609/2013 and Regulation (EC) No 1925/2006. The NF is produced by chemical synthesis and consists of at least 95% (w/w) of 5-MTHF and 4%-5% (w/w) of sodium. It is proposed to be used as a partial or complete substitute to folic acid and other sources of added folate in a number of food categories. The production process, composition, specifications and stability of the NF do not raise safety concerns. When used as an ingredient in different food matrices, proper processing/storage conditions need to be considered to preserve the stability of the NF. Regarding bioavailability, the Panel considers that the NF readily dissociates into Na and l-methylfolate ions, which subsequently are absorbed and enter the circulation. Thus, the bioavailability of 5-MTHF from the NF is comparable to that of other currently authorised salts of 5-MTHF. The Panel considers that the consumption of the NF is not nutritionally disadvantageous as long as the combined intake of the NF and the other supplemental forms of folate under their authorised conditions of use is below the ULs established for the different age groups of the general population. The Panel concludes that the NF is safe under the proposed conditions of use. The Panel also concludes that the NF is a source from which folate is bioavailable.

Nutritional deficiency anemia and post-acute sequelae in patients with severe acute respiratory syndrome coronavirus 2 infection: A six-month retrospective cohort analysis of 30 892 patients

The effect of anemia on the post-acute outcome of patients with severe acute respiratory syndrome coronavirus 2 infection was unclear. This study aimed to investigate the potential association between nutritional deficiency anemia (NDA) status and post-acute sequelae of patients with SARS-CoV-2 infection. This retrospective cohort study included patients with coronavirus disease (COVID-19) from January 1, 2022 to November 30, 2022 using the TriNetX research network. The patients were grouped into the NDA group comprising patients diagnosed with NDA and the control group comprising patients without NDA, and propensity score matching (PSM) was performed to balance the two groups. The primary outcome was a composite of post-COVID-19 condition, all-cause hospitalization, and all-cause death. The secondary outcomes were any individual outcomes of the primary composite. The follow-up period was set at 90-180 days after COVID-19 diagnosis. Two cohorts comprising 15 446 nonhospitalized patients with COVID-19 in each group with balanced baseline characteristics were created using PSM. During the follow-up period, the NDA group demonstrated a higher risk of the composite primary outcome, including post-COVID-19 condition, all-cause hospitalization, or all-cause death (hazard ratio [HR], 1.896; 95% confidence interval [CI] =  1.757-2.045). Regarding secondary outcomes, the NDA group was associated with worse outcomes, including post-COVID-19 condition (HR, 1.992; 95% CI = 1.403-2.828), all-cause hospitalization (HR, 1.856; 95% CI = 1.714-2.009), and all-cause death (HR, 3.922; 95% CI = 2.910-5.285) compared to the control group. Among nonhospitalized patients with COVID-19, NDA was associated with a higher risk of post-COVID-19 condition, all-cause hospitalization, and all-cause death during the 90-180-day follow-up period.