Folic acid accumulation in blood plasma and erythrocytes in women of reproductive age depending on vitamin B₉ forms and polymorphic variants of folate pathway genes

RETIRED: Pre-conceptional Vitamin/Folic Acid Supplementation 2007: The Use of Folic Acid in Combination With a Multivitamin Supplement for the Prevention of Neural Tube Defects and Other Congenital Anomalies

Background: Folic acid deficiency is one of the most common vitamin deficiencies among women of childbearing-age. Folic acid is a water-soluble B-complex vitamin. Although the deficiency is easily corrected by administration of folic acid, but still the prevalence of folic acid deficiency is high. It can lead to neural tube defects (NTDs) in fetus, which are a major cause of severe disability and mortality among infant population, occurring in over one quarter of a million new-borns per year, worldwide. NTDs occur in the very early phase of pregnancy when the mother herself does not know that she is pregnant. This study has assessed awareness of women of childbearing age on folic acid i.e., timing of folic acid supplementation, different sources, symptoms of its deficiency, toxicity and its effect on fetus. Study was conducted in Ha’il region and its suburbs, Kingdom of Saudi Arabia in the period between October 2020 and February 2021.
 Methodology: An analytical cross-sectional community-based study was carried out among 842 women aged between18 and 45 years using a close-ended questionnaire.
 Results: In total, Folic Acid was taken by just 23.87% of participants. Only 33% knew that Folic Acid deficiency causes neural tube defects in fetus. Further it was revealed that postgraduates had a significantly better knowledge on Folic Acid 0.000) than others. Similarly, those who belonged to household where total monthly income was 5000 Saudi Riyals or more had better awareness on Folic Acid than participants who belonged to low socioeconomic status ( 0.05).
 Conclusion: It’s concluded that in Ha’il and its suburb area, women of childbearing age do not possess adequate knowledge on Folic Acid. Neural tube defects in fetus due to folic acid deficiency were not known by a large majority of respondents. However, awareness has a strong association with educational level and socioeconomic status. Hence it is recommended that female literacy and female employment should be promoted, encouraged and supported in Kingdom in order to improve our health indicators.

Background: Folate and Vitamin B12 are important micronutrients necessary for fetal growth and development. Deficiencies of these vitamins in women of reproductive age results in adverse pregnancy outcome.
 Objective: To determine red blood cell folate and serum Vitamin B12 levels in apparently healthy women of reproductive age group.
 Methodology: The study was conducted in Baqai medical university, Karachi. Apparently healthy volunteer women (N=196) between ages of 15 and 49 years residing in different areas of Karachi were selected after fulfilling the inclusion and exclusion criteria. The cut off values for defining Vitamin B12 deficiency, marginal insufficiency and folate insufficiency were <203 pg/mL, 203-299 pg/mL, and <400 ng/mL, respectively. Analysis of red blood cell folate and serum vitamin B12 levels was done after complete blood count and peripheral smear morphology.
 Results: The mean serum vitamin B12 and red blood cell folate levels were 233.69 ± 54.10 pg/mL and 540.34 ± 54.04 ng/mL. Percent values of Vitamin B12 deficiency and marginal insufficiency were 42% and 46%. All of the study participants had red blood cell folate levels >400 pg/mL. A significant negative association was present between age and serum vitamin B12 levels.
 Conclusion: Low serum levels of vitamin B12 in women of reproductive age group can be considered an important etiologic factor for adverse pregnancy outcomes especially neural tube defects. The need is to asses pre-conceptional level of vitamin B12 and to implement public health program especially food fortification to improve vitamin B12 status.

Mandatory fortification of the American food supply with synthetic folic acid (SFA) began in 1998. Since then, the incidence of neural tube defects has decreased by 16–31% and red blood cell folate levels have increased significantly in the general population. However, reproductive-age women with limited resources, as well as some ethnic minorities, may still be at risk of sub-optimal folate status. The purpose of this study was to assess folate intake by low-income women of childbearing age in California. Participants in this cross-sectional study were 195 non-pregnant women, ages 18–45, who were participating in the Food Stamp Nutrition Education Program. Each participant completed a demographic questionnaire and the Block Dietary Folate Equivalents (DFE) Screener. The estimated mean intake (± SE) was 911 ± 33 μg DFE, which included 419 ± 18 μg SFA. Although the mean intake was adequate, a substantial number of the women were identified as at risk of sub-optimal folate status. Of the 195 respondents, 114 (58%) did not meet the Institute of Medicine’s recommendation for women of childbearing age to consume at least 400 μg SFA daily. Significant differences in folate intake were detected between ethnic groups. Hispanic women consumed significantly more total dietary folate than both white women and black women (p < 0.01), as well as more SFA than black women (p < 0.05). The results from this study suggest that folic acid consumption may still be inadequate among low-income women of reproductive age in California. Nutrition education about folic acid that is targeted for low-income audiences may help raise awareness about the importance of the vitamin. This work was funded in part by the USDA.

Effect of folic acid and vitamin C supplementation on folate status and homocysteine level: a randomised controlled trial in Italian smoker–blood donors

To the Editor: Low concentrations of folate are associated with an increased risk of neural tube defects, while preconception supplementation with folic acid attenuates that risk. 1 The government of Canada mandated that all flour and some corn and rice products be fortified with folic acid, a policy that was fully implemented by January 1998 [G. Carson, Grain Based Products, Robin Hood Multifoods, Inc., Canada, personal communication, 2001]. We studied the effect of this fortification program among women of reproductive age, age 18–42 years. Comparing data from before and after fortification, we considered all red blood cell (RBC) folate and serum vitamin B12 (Se B12) samples analyzed by MDS Laboratories (Toronto, Ontario, Canada), which provides diagnostic services to approximately one-third of community-based patients in the province of Ontario. These tests, paid for under Ontario’s publicly funded universal Ontario Health Insurance Plan, were ordered on clinical grounds, but the reasons were not available. Vitamin concentrations were determined by competitive protein binding (Bio-Rad Laboratories, Mississauga, Ontario, Canada), with a maximum reporting limit of 1,450 nmol/L for RBC folate and 1,600 pmol/L for Se B12. Identifiers were removed to protect patient confidentiality, and the Ethics Review Boards of Sunnybrook and Women’s College Health Sciences Centre and MDS Laboratories approved this study. A total of 8,408 consecutive, nonredundant samples were analyzed for the intervals of January 1, 1996 to December 31, 1997 (prefortification) and 30,061 samples for January 1, 1998 to December 31, 2000 (postfortification). The mean participant age was 31.8 years for both periods. The geometric mean RBC folate concentration rose from 527 nmol/L prefortification to 741 nmol/L after January 1, 1998 (mean difference 214 nmol/L) (Table 1 and Figure 1). The respective mean concentrations for Se B12 were 276 and 270 pmol/L (mean difference −6 pmol/L) (Table 1 and Figure 1). Similar trends were seen for the fifth-percentile concentrations of RBC folate and Se B12 (Table 1). Table 1: Red Blood Cell (RBC) -Folate and Serum Vitamin B12 (Se B12) Concentrations before and after Folic AcidFIGURE 1: Mean and 95% confidence interval concentrations of red blood cell (RBC) folate (upper curve) and serum vitamin B12 (Se B12; lower curve) after folic acid fortification (vertical line).We did not obtain information on the clinical indications for folate and cobalamin (vitamin B12) testing, which is a potential source of study bias. Furthermore, we did not account for use of folic acid supplements, which, in addition to lead-time compliance with folate fortification by the milling industry, could also explain the rise in RBC folate concentrations before January 1998. Because Se B12 levels have remained nearly constant over time, however, multivitamin supplement use could not account for more than a small portion of the rise in RBC folate. As in the U.S. general population, 2,3 Canada’s national folic acid fortification program has probably enhanced the folate status of women of reproductive age. Experimental data have demonstrated that withdrawal of dietary folic acid for as little as 12 weeks can significantly reduce RBC folate concentrations in women, 4 suggesting that an increase in RBC folate concentrations would be evident soon after the addition of folic acid to flour. We must highlight the fact that Se B12 concentrations have remained relatively constant since folic acid food fortification was introduced. Although cobalamin deficiency too has been implicated in the formation of neural tube defects, 5 its detection before and during pregnancy is a point of controversy. 6–8 Thus, with the rising popularity of ovo-lacto vegetarianism, 9 unrecognized vitamin B12 insufficiency may become an issue among women of reproductive age. 6 There is an urgent need to consider both the addition of synthetic vitamin B12 to current fortification programs 10 and the long-term health consequences of fortifying flour with folic acid but not cobalamin. 11 Joel G. Ray Marian J. Vermeulen Sheila C. Boss David E. C. Cole

Focused Revision: Policy statement on folic acid and neural tube defects

Introduction:Single-nucleotide polymorphism (SNP) is a single-nucleotide change in a deoxyribose nucleic acid (DNA) sequence that occurs in >1% of population. Methylene tetra hydro folate reductase (MTHFR) C677T (rs1801133) and methionine synthase enzyme (MTR) A2756G (rs1805087) are two such SNPs occurring in coding sequence of the respective genes, which are frequently seen with neural tube defects (NTDs). MTHFR and MTR genes are involved in folate metabolism. The folate level in the course of pregnancy is treated as vital in the etiopathogenesis of NTDs. This study aims to explore the association of SNPs of both genes and red blood cell (RBC) folate levels in the predisposition to NTDs.Aims and Objective:The purpose of this investigation was to determine the relationship of NTDs with polymorphisms in MTHFR and MTR genotype and to estimate and compare the RBC folate levels in NTD patients and controls.Materials and Methods:A total of 397 individuals were enrolled (163 patients and 234 controls) for this observational study. Genotyping to find out MTHFR C677T and MTR A2756G was performed by polymerase chain reaction–restriction fragment length polymorphism technique from DNA extracted from the subject's blood. RBC folate level was estimated by chemiluminescence immunoassay method with the same blood sample.Results:The total RBC folate levels were significantly less among cases compared to controls (P = 0.020). A significant difference for RBC folate was observed between case and control groups of various genotypes of MTHFR C677T, except heterozygote CT (P = 0.459). Among MTR A2756G, genotypes with only homozygous AA have significant difference (P = 0.003) for RBC folate levels. Among different types of NTDs, there were no significant differences for RBC folate levels. Among MTHFR C677T, T allele possessed 1.9 times risk compared to C allele for the occurrence of NTDs. In MTR A2756G polymorphism, the odds of developing NTDs were 1.6 times in heterozygous AG compared to homozygous AA. Similarly, the risk for NTDs was three times higher in subjects with both heterozygous AG and CT genotypes compared to wild-type homozygous AA and CC genotypes.Conclusion:The total RBC folate levels were significantly less among cases compared to controls, and the genotypes had no such effect in decrease in RBC folate levels. The presence of mutant allele in homozygous or heterozygous condition for both SNPs had increased risk associated with NTDs.

BackgroundThe benefits of folic acid for prevention of congenital anomalies are well known. For the Inuit of Canada, where vitamin use is low and access to folate-rich foods limited, fortification is likely a major source of intake. We sought to determine whether red blood cell folate (RBCF) levels of Inuit women reached accepted target levels.MethodsThe Inuit Health Survey, 2007–2008, included evaluation of RBCF levels among 249 randomly selected non-pregnant women of reproductive age. Using descriptive statistics and linear regression analyses, RBCF levels were assessed and compared across several socio-demographic variables to evaluate the characteristics associated with RBCF status.ResultsMean (SD) RBCF levels of 935.5 nmol/L (± 192) reached proposed target levels (> 906 nmol/L); however, 47% of women had lower than target levels. In bivariate analysis, non-smoking, higher education, higher income, food security, increased body mass index, and vitamin use were each significantly associated with higher RBCF. Increased levels of smoking had a negative association with RBCF levels (− 5.8 nmol/L per cigarette smoked per day (p = 0.001)). A total of 6.8% of women reported taking vitamin supplements, resulting in a 226 nmol/L higher RBCF level on average compared to non-users (p < 0.001).ConclusionWhile mean levels of folate reached target levels, this was largely driven by the small number of women taking vitamin supplements. Our results suggest that folate status is often too low in Inuit women of childbearing years. Initiatives to improve food security, culturally relevant education on folate-rich traditional foods, vitamin supplements, and smoking cessation/reduction programs may benefit Inuit women and improve birth outcomes.

Observational studies and clinical trials have shown conclusive evidence that periconceptional folic acid supplementation prevents up to 70 % of neural tube defects (NTD). The Honduran government wanted to implement a supplementation programme of folic acid but needed to assess the relative effects of two dosages of folic acid. To determine the effect of two dosages of folic acid on blood folate levels in Honduran female factory workers aged 18 to 49 years. This was a randomized, double-blind control supplementation trial conducted in Choloma, Honduras. A total of 140 eligible women were randomly assigned to two dosage groups and followed up for 12 weeks. One group received a daily dosage of 1 mg folic acid and the other a once weekly dosage of 5 mg. Serum folate and red blood cell folate levels were determined by radioassay at baseline, 6 weeks and 12 weeks. Serum folate levels increased from 6.3 (se 0.2) to 14.9 (se 0.6) ng/ml (P < 0.0001) in women assigned to the 1 mg/d group and from 6.9 (se 0.3) to 10.1 (se 0.4) ng/ml (P < 0.0001) in those assigned to the 5 mg/week group. Red blood cell folate concentrations also increased significantly in both groups, albeit more slowly. Educational level, age and BMI were not associated with the changes in serum and red blood cell folate levels during the supplementation period. However, a differential effect on serum folate levels by dosage group and time was observed. Although both folate supplementation regimens increased serum and red blood cell folate levels significantly among the women studied, blood folate levels that are considered to be protective of NTD were reached faster with the daily dosage of 1 mg folic acid.

Since 1998, the U.S. has mandated folic acid (FA) fortification of certain grain products to reduce the risk of neural tube defects. Folate intake and red blood cell (RBC) folate concentrations increased substantially post-intervention, although recent studies raise concerns about the level of ongoing benefit. This study investigated blood folate level determinants in healthy young adults, including intake of naturally occurring food folate, synthetic FA, and the interaction of naturally occurring food folate with a common missense variant in the FOLH1 gene thought to affect absorption. Participants (n = 265) completed the Diet History Questionnaire II, RBC folate testing, and were genotyped for the 484T>C FOLH1 variant. Men reported significantly greater intake of all folate sources except for supplemental FA, but RBC folate levels did not significantly differ by sex. Synthetic FA was a stronger predictor of RBC folate than naturally occurring food folate. In the largest racial group, synthetic FA and the interaction of FOLH1 genotype with naturally occurring food folate significantly predicted RBC folate, with the overall model accounting for 13.8% of the variance in RBC folate levels. Blood folate levels rely on a complex interaction of natural and synthetic folate intake as well as FOLH1 genotype.

Research suggests that folic acid contributes to improving cognitive function. However, there is a lack of systematic research on the association of dietary intake of folate and serum, and red blood cell (RBC) folate levels with global cognitive impairment (CoI) in the elderly population. Importantly, excessive supplementation with folate among American adults at high risk of cardiovascular disease (CVD) may have harmful effects. CVD often leads to worse cognitive function; therefore, it is necessary to explore the characteristics of the association of folate with CoI in both CVD and non-CVD populations. Participants aged ≥ 60 years from the national health and nutrition examination survey (NHANES) 2011–2014 were included. Dietary intake of folate and serum and RBC folate levels were determined through questionnaires or laboratory measurements. Global cognitive function was assessed via the results of three cognitive assessments. Multivariable logistic regression and restricted cubic splines (RCS) were employed to assess the odds ratios (ORs), 95% confidence intervals (CIs), and potential non-linearities of folate with cognition. Additionally, the interaction term of CVD with RBC folate was included in the model, and effect modification was detected through likelihood ratio tests. Finally, several sensitivity analyses were conducted to validate our findings. This study included 2104 participants with complete data and a median age of 68 years, with females comprising 51% of the participants. Of the participants, 444 individuals were defined as having CoI. In the NHANES, Pearson correlation analysis revealed moderate to weak correlations between dietary, serum, and RBC folate levels and CoI (all < 0.6). In addition, when different sources of folate were included separately in the models, fully adjusted logistic regression with continuous variables included in the model revealed that only RBC folate was significantly associated with CoI [odds ratio (OR) 0.86, 95% confidence interval (95% CI) 0.75–0.97, P = 0.02]. According to tertile groups, compared with participants in the lowest tertile, individuals in the highest tertile of total dietary folate levels (OR 0.67, 95% CI 0.48–0.94, P = 0.02), folic acid levels (OR 0.57, 95% CI 0.38–0.86, P = 0.01), and RBC folate levels (OR 0.62, 95% CI 0.44–0.85, P = 0.004) had significantly lower odds of having CoI. The RCS showed a linear negative correlation between RBC folate levels and CoI. Furthermore, interaction analysis suggested that CVD attenuated the protective effect of RBC folate. Several sensitivity analyses also suggested a modifying effect of CVD on the association between RBC folate and CoI. A significant negative correlation exists between RBC folate levels and CoI in the elderly population of the United States, and this association is stronger than that of other folate measures. However, the protective effect of RBC folate on CoI is negated in patients with CVD, and further investigation is needed to explore the underlying mechanisms involved.

Steady state folate concentrations achieved with 5 compared with 1.1 mg folic acid supplementation among women of childbearing age

Neural tube defects are among the abnormalities in the fetus that most often occur after heart defects and abnormalities in the genitourinary system. The causes of neural tube accidents are generally multifactorial. One of the causes of neural tube defects is a folic acid deficiency. Folic acid is essential for embryological development during pregnancy. Most cases of folic acid deficiency often go undiagnosed. Many pregnant women do not realize that they have a folic acid deficiency. The purpose of this paper is to examine the effect of folic acid supplementation on reducing the risk of neural tube defects in the fetus. This study uses the literature review method with searches sourced from the NCBI database, the researcher only captures articles published in the period between 2010 - 2020. Of all the articles obtained, 25 selected articles were analyzed using the systematic literature review method by comparing it from the title, approach, objectives, results, and discussion, then analyzed and arranged systematically. From several sources that have been found, it is stated that folic acid supplementation can reduce the risk of neural tubes in the fetus.

Aim: To investigate the association between serum homocysteine (HCY) levels, red blood cell folate (RCF) levels, methylenetetrahydrofolate reductase (MTHFR) gene polymorphism and infertility.Materials & methods: Serum HCY and RCF levels and C677T polymorphism of MTHFR gene were analyzed in 149 infertile patients and 223 women of normal reproductive age with healthy childbirth history.Results: The HCY level of MTHFR C677T TT genotype infertility patients was higher than that of women of normal reproductive age, while the RCF level was not significantly different between the two groups.Conclusion: Serum HCY levels increased in infertility patients, and the MTHFR C677T TT genotype in childbearing-aged women are associated with a higher risk of infertility. The results showed that HCY level and MTHFR C677T genotype were closely related to infertility.