Genome-wide Association Study Identifies Genetic Polymorphisms for Folate-related Biomarkers in Chinese Preconception Women.

BACKGROUND: SNP allele frequencies, dietary habits, folate status and their associations vary across ethnic populations. Little is known about the SNPs accounting for variations of folate-related biomarkers for Chinese preparing-for-pregnant females. OBJECTIVE: We aimed to identify SNPs contributing to RBC and serum folate, vitamin B-12, and homocysteine levels in Chinese female preconception population. METHODS: A GWAS was conducted on 1000 randomly selected preconception Chinese women from SPCC. SNPs were genotyped using Illumina chips, and associations with biomarkers were assessed using simple linear regression models under the assumption of an additive genetic model. Genome-wide significance was considered at P < 10-7. RESULTS: The MTHFR rs1801133 was the major genetic coding variant contributing to RBC folate, serum folate and homocysteine concentrations (P=2.28×10-16; P=8.85×10-8, and P=2.46×10-13). It is associated with increased RBC folate (ß=0.154 per additional risk allele after log transform), decreased serum folate (ß=-0.951 per additional risk allele) and increased serum homocysteine concentrations (ß=1.153 per additional risk allele). The predominant SNP associated with serum folate was rs147162222 in NTRK2 (P=2.55×10-8) while the one associated with homocysteine was rs77025184 located between PDE7B and LINC00271 (P=4.91×10-17). For vitamin B-12, FUT2 rs1047781 was the dominant genetic variant (P=1.59×10-10). The numbers of signals with P value <10-7 for RBC folate, serum folate, vitamin B-12 and homocysteine were 12, 18, 8 and 614 respectively. CONCLUSIONS: This study represents the first GWAS focusing on folate-related biomarkers in a Chinese preparing-for-pregnant female population. The contributions of dominent SNPs to each biomarker were partly different from other populations. The study detected rs1801133 (C677T) in MTHFR as the predominant genetic variant contributing to RBC folate and rs1047781 (A385T) in FUT2 as the primary one explaining vitamin B-12. Notably, the intronic rs147162222 and non-coding rs77025184 were both first detected as the predominant SNPs for serum folate and homocysteine respectively.

Negative associations between folate and bacterial vaginosis in the NHANES 2001 to 2004.

BACKGROUND: Bacterial vaginosis (BV) is one of the most common infections among women of reproductive age and accounts for 15-50% of infections globally. The role played by folate in the pathogenesis and progression of BV is poorly understood. The aim of this study was to investigate the association between serum folate, red blood cell (RBC) folate, and BV in American women. METHODS: 1,954 participants from the 2001-2004 National Health and Nutrition Examination Survey (NHANES) program were included in this study. Multiple logistic regression was used to analyze the association between serum folate, RBC folate, and BV, and covariates including race, age, education level, and body mass index were used to construct adjusted models. Stratified analysis was used to explore the stability of the above associations in different populations. RESULTS: In the present cross-sectional study, we found that serum folate and RBC folate were inversely associated with the risk of BV. In the fully adjusted model, the risk of BV was reduced by 35% (OR=0.65, 95% CI: 0.51~0.83, p=0.0007) in the highest serum folate group and 32% (OR=0.68, 95% CI: 0.53~0.87, p=0.0023) in the highest RBC folate group compared to the lowest group. CONCLUSIONS: The results of this study indicated that serum folate and RBC folate were inversely associated with the risk of BV folate supplementation may play an important role in the prevention and management of BV.

Association between red blood cell folate and Trichomonas vaginalis infection among women.

BACKGROUND: Increased folic acid has been found to be latently protective against gynecological infection, including several kinds of vaginosis. In this study, we laid emphasis on whether RBC (Red Blood Cell) folate was associated with the infectious ratio of Trichomonas vaginalis, a kind of anaerobic parasitic protozoan. METHODS: We set RBC folate as the exposure variable and Trichomonas vaginalis as the outcome variable. Other subsidiary variables were regarded as covariates that may work as potential effect modifiers. The cross-sectional study was conducted with two merged waves of the National Health and Nutrition Examination Survey (NHANES) from 2001 to 2004, and a sample of 1274 eligible women (1212 negative and 62 positive in Trichomonas vaginalis infection) was integrated for the exploration of the association between RBC folate and Trichomonas vaginalis infection. Multivariate regression analyses, subgroup analyses, and subsequent smooth curve fittings were conducted to estimate the relationship between RBC folate and Trichomonas vaginalis in women. RESULTS: In the multivariable logistic regression analyses, a negative association was observed between stratified RBC folate status and Trichomonas vaginalis infection with all confounders adjusted. Referencing the lowest RBC folate concentration quartile, the higher concentration quartiles reported a relatively lower infection ratio, while there was a weak correlation between total RBC folate concentration and T. vaginalis (Trichomonas vaginalis) infection. In subgroup analyses stratified by BMI and age, this association was only found significant in high age and BMI groups. CONCLUSIONS: The cross-sectional study indicated a negative association between RBC folic acid and Trichomonas vaginalis infection, and latent effects of BMI and age on the association were also found.

Folate, vitamin B12 and vitamin D status in healthy and active home-dwelling people over 70 years.

BACKGROUND: Ageing is characterised by physiological changes that can affect the nutrient availability and requirements. In particular, the status of vitamin D, cobalamin and folate has often been found to be critical in older people living in residential care. However, there is a lack of studies investigating the status of these nutrients in healthy and active home-dwelling elderly people. METHODS: The aim of this cross-sectional study was to assess the status of vitamin D based on serum concentrations of 25-hydroxycholecalciferol [25-(OH)D], cobalamin based on serum concentrations of holotranscobalamin (holoTC) and folate based on red blood cell (RBC) folate in unsupplemented, healthy and active German home-dwelling subjects ≥ 70 years of age (n = 134, mean ± SD: 75.8 ± 4.5 years). Dietary intake was assessed by 3-day food recalls. The study was conducted between March and November of 2021 (during the COVID-19 pandemic). RESULTS: The mean 25-(OH)D concentration was high at 85.1 ± 26.0 nmol/L, while the majority of women (92%) and men (94%) had 25-(OH)D concentrations ≥ 50 nmol/L. Less than 10% of men and women had 25-(OH)D concentrations < 50 nmol/L. The mean holoTC concentration was 88.9 ± 33.7 pmol/L (94.8 ± 34.6 pmol/L in women and 73.6 ± 25.6 in men). Only 8% of the women were cobalamin deficient (< 50 pmol/L holoTC) compared to 22% of the men. The mean RBC folate concentration was 831 ± 244 nmol/L, while the prevalence of folate deficiency was 10%. Linear regression analysis showed that only folate equivalent intake was associated with the relevant nutrient status marker. CONCLUSION: Our findings suggest that healthy, independently living older people with high levels of education, physical activity, and health awareness are not necessarily at higher risk of vitamin D, folate and cobalamin deficiency. Further studies are needed to verify these findings and to identify lifestyle and dietary patterns that can predict adequate nutrient status for healthy ageing. TRIAL REGISTRATION: This study is officially recorded in the German Clinical Trials Register (DRKS00021302).

RBC Folate and Serum Folate, Vitamin B-12, and Homocysteine in Chinese Couples Prepregnancy in the Shanghai Preconception Cohort.

BACKGROUND: The protective effects of maternal folate on neural tube defects are well-established. Emerging evidence has shown paternal folate also is related to pregnancy outcome and offspring health. OBJECTIVES: This study aimed to assess the status of red blood cell (RBC) folate and serum folate, vitamin B-12, and homocysteine (Hcy) and their associated factors in a cohort of pregnancy-preparing couples. METHODS: This was a cross-sectional study involving 14,178 participants from the extension of the Shanghai Preconception Cohort conducted in 2018-2021. Circulating biomarker concentrations were measured, and the prevalence of abnormal status was reported. Linear and logistic regression analyses were conducted to examine associations of demographic factors (age, education, and income), lifestyle factors (smoking, drinking, and folic acid supplement use), and BMI with concentrations of the folate-related biomarkers, abnormal status of folate (deficiency and insufficiency) and vitamin B-12 (deficiency and marginal deficiency), and hyperhomocysteinemia. RESULTS: The geometric mean (95% CI) concentrations of RBC folate, serum folate, vitamin B-12, and Hcy were 490 nmol/L (485, 496 nmol/L), 20.1 nmol/L (19.8, 20.3 nmol/L), 353 pmol/L (350, 357 pmol/L), and 7.54 µmol/L (7.48, 7.60 µmol/L) in females, respectively, and 405 nmol/L (401, 409 nmol/L), 13.5 nmol/L (13.4, 13.7 nmol/L), 277 pmol/L (274, 279 pmol/L), and 12.0 µmol/L (11.9, 12.2 µmol/L) in males, respectively. Prevalence of abnormal status was higher in males than females for the 4 folate-related biomarkers: RBC folate deficiency (<340 nmol/L, 32.2% compared with 18.9%), serum folate deficiency (<10.0 nmol/L, 26.5% compared with 7.3%), RBC folate insufficiency (<906 nmol/L, 96.6% compared with 90.1%), serum folate insufficiency (<15.9 nmol/L, 65.5% compared with 31.4%), vitamin B-12 marginal deficiency (148-221 pmol/L, 21.4% compared with 8.8%), and hyperhomocysteinemia (>15.0 µmol/L, 22.1% compared with 2.5%). CONCLUSIONS: Most pregnancy-preparing couples failed to achieve the optimal RBC folate status (>906 nmol/L) as recommended by the WHO. These findings call for attention to the insufficiency status of folate and promising strategies to improve the folate status of the pregnancy-preparing population not exposed to folic acid fortification.

Red cell folate status among a subset of Canadian children with Down Syndrome post-fortification.

BACKGROUND: Trisomy 21 or Down Syndrome (DS) is associated with altered methylation pathways. Children with DS may therefore represent a population subgroup with vulnerability to increased exposures to folic acid, which is involved in one-carbon metabolism. Folic acid (FA) fortification of flour and maternal FA supplementation are intended to reduce neural tube defects related to folate deficiency. The interventions have been widely successful in Canada. Emerging evidence suggests that higher FA exposures may also have potential negative consequences, including implications for DNA methylation. This retrospective chart review provides insight on the red blood cell (RBC) folate status of a subset of Canadian children and infants with DS, post-fortification. METHODS: Children with DS in two Canadian provinces were assessed in the community. Access to RBC folate testing was variable, limiting sample size to 39 (n = 27 for children ≤6 years; n = 12 for children 6-18 years). All children with DS and an RBC folate result were included. The use of FA-containing supplements and formula was documented. RESULTS: Among children 6-18 years, 100% had RBC folates >1000 nmol/L, 50% were >2000 nmol/L and 25% had levels above the upper laboratory reporting limit. Among the younger children (<6 years), 52% had RBC folates >2000 nmol and 2 children exceeded 3000 nmol/L. Among exclusively breast-fed infants (<12 months), 100% had RBC folates >1000 nmol/L and 50% had levels >2000 nmol/L, suggestive of in-utero or maternal exposures. RBC folate status among this subset of Canadian children with DS is higher than documented for the larger Canadian population, and higher than among US children with DS. CONCLUSIONS: Young Canadian children with DS demonstrated high post-fortification RBC folate status. RBC folate status was higher than reported for the larger Canadian population, and higher than for US children with Down Syndrome. Consumption of folic acid-containing formula and/or supplements was relatively low among these Canadian children with DS, suggesting maternal FA supplements and/or FA-fortified foods may be important etiological factors. A larger, prospective study is needed to validate these results, and to explore potential health implications among this vulnerable population.

Folate Forms in RBC and Whole-Blood Lysates Appear Stable When Stored Frozen for 2 Years.

BACKGROUND: The use of RBC lysate (RBC-Lys) eliminates the need for serum folate and hematocrit (Hct) measurement to calculate RBC folate. Information on the long-term frozen storage stability of RBC-Lys is missing. OBJECTIVES: We aimed to assess the comparability of RBC folate forms in whole-blood lysate (WB-Lys) and RBC-Lys and the folate stability in both matrices. METHODS: We prepared conventional WB-Lys (1:11 dilution with 1% ascorbic acid) and RBC-Lys (1:11 dilution of washed and saline-diluted RBCs with 1% ascorbic acid) from EDTA blood (n = 60 adult donors) and stored lysates at -70°C until analysis at baseline (1 wk), 3, 6, 12, and 24 mo. Before analysis by HPLC-tandem MS, we incubated the WB-Lys (4 h at 37°C) and treated the RBC-Lys with human recombinant γ-glutamyl hydrolase for folate polyglutamate deconjugation. We analyzed RBC-Lys samples for hemoglobin (Hb) (same aliquot) to normalize for the preanalytical dilution; Hb-folate was converted to RBC folate for each folate form using the mean corpuscular Hb concentration. We analyzed Hct as well as folate forms in matching serum samples for traditional RBC folate calculation. We conducted descriptive data analyses (correlation, Bland-Altman plot, Deming regression). RESULTS: At baseline, results for RBC folate forms derived from WB-Lys compared with RBC-Lys samples showed excellent correlation (Pearson r ≥ 0.97). Mean ± SD concentrations compared well for total folate (WB-Lys: 886 ± 255 compared with RBC-Lys: 899 ± 271 nmol/L), 5-methyltetrahydrofolate (WB-Lys: 831 ± 258 compared with RBC-Lys: 843 ± 276 nmol/L), and nonmethyl folate (WB-Lys: 53.3 ± 74.4 compared with RBC-Lys: 52.9 ± 70.7 nmol/L), but were 17% higher in RBC-Lys for pyrazino-s-triazine derivative of 4α-hydroxy-5-CH3-H4folate (MeFox) (WB-Lys: 147 ± 44.1 compared with RBC-Lys: 172 ± 53.5 nmol/L). Frozen storage of WB-Lys and RBC-Lys samples for ≤24 mo showed ≤5%, ≤5%, ≤13%, and ≤11% change in total folate, 5-methyltetrahydrofolate, nonmethyl folate, and MeFox, respectively. CONCLUSIONS: Erythrocyte folate forms appear to be stable in RBC-Lys samples stored frozen at -70°C for ≤2 y. The relatively small changes in folate concentrations over time were comparable between RBC-Lys and conventionally prepared WB-Lys samples.

Dietary and lifestyle predictors of folate insufficiency in non-supplemented German women.

Low folate status is a risk factor for birth defects. We studied concentrations of red blood cell (RBC)- and serum folate in 198 German women in relation to information on dietary folate intake, demographic and lifestyle factors. Median serum- and RBC-folate levels were; (14.7 and 589 nmol/L, respectively. Serum < 7.0 nmol/L or RBC-folate < 405 nmol/L were observed in 3.5% and 18.7% of the women, respectively. Three per cent of the women had both lowered serum and RBC-folate. Whereas RBC-folate > 952 nmol/L (optimal levels around conception) were observed in 9.6%. Serum- and RBC-folate were positively associated; they showed the expected correlations with homocysteine, but only weak correlations with folate intake. Younger age, lower fibre and higher carbohydrate intakes were associated with lower blood folate. Thus, folate intake of approximately 278 µg/d was not sufficient to achieve optimal folate status in young women. In conclusion, in the absence of fortification with folic acid, the majority of the women did not achieve folate status that is optimal for prevention of birth defects.

The effectiveness of daily supplementation with 400 or 800 µg/day folate in reaching protective red blood folate concentrations in non-pregnant women: a randomized trial.

PURPOSE: Folate required to achieve desirable red blood cell (RBC) folate concentrations within 4-8 weeks pre-pregnancy is not known. We studied the effect of supplementation with 400 or 800 µg/day folate in achieving RBC-folate ≥906 nmol/L. METHODS: Non-pregnant women were randomized to receive multinutrient supplements containing 400 µg/day (n = 100) or 800 µg/day (n = 101) folate [folic acid and (6S)-5-CH3-H4folate-Ca (1:1)]. The changes of folate biomarkers were studied after 4 and 8 weeks in the 198 women who returned at least for visit 2. RESULTS: At baseline, 12 of the 198 participants (6.1%) had RBC-folate <340 nmol/L, but 88% had levels <906 nmol/L. The RBC-folate concentrations increased significantly in the 800 µg/day (mean ± SD = 652 ± 295 at baseline; 928 ± 330 at 4 weeks; and 1218 ± 435 nmol/L at 8 weeks) compared with the 400 µg/day [632 ± 285 at baseline (p = 0.578); 805 ± 363 at 4 weeks (p < 0.001); 1021 ± 414 nmol/L at 8 weeks (p < 0.001)]. The changes of RBC-folate were greater in the 800 µg/day than in the 400 µg/day at any time (changes after 8 weeks: 566 ± 260 vs. 389 ± 229 nmol/L; p < 0.001). Significantly more women in the 800 µg group achieved desirable RBC-folate concentrations at 4 weeks (45.5 vs. 31.3%; p = 0.041) or 8 weeks (83.8 vs. 54.5%; p < 0.001) compared with the 400 µg group. RBC-folate levels below the population median (590 nmol/L) were associated with a reduced response to supplements. CONCLUSIONS: 88% of the women had insufficient RBC-folate to prevent birth defects, while 6.1% had deficiency. Women with low RBC-folate were unlikely to achieve desirable levels within 4-8 weeks, unless they receive 800 µg/day. The current supplementation recommendations are not sufficient in countries not applying fortification. TRIALS REGISTER: The trial was registered at The German Clinical Trials Register: DRKS-ID: DRKS00009770.

Biomarkers of Nutrition for Development-Folate Review.

The Biomarkers of Nutrition for Development (BOND) project is designed to provide evidence-based advice to anyone with an interest in the role of nutrition in health. Specifically, the BOND program provides state-of-the-art information and service with regard to selection, use, and interpretation of biomarkers of nutrient exposure, status, function, and effect. To accomplish this objective, expert panels are recruited to evaluate the literature and to draft comprehensive reports on the current state of the art with regard to specific nutrient biology and available biomarkers for assessing nutrients in body tissues at the individual and population level. Phase I of the BOND project includes the evaluation of biomarkers for 6 nutrients: iodine, iron, zinc, folate, vitamin A, and vitamin B-12. This review represents the second in the series of reviews and covers all relevant aspects of folate biology and biomarkers. The article is organized to provide the reader with a full appreciation of folate's history as a public health issue, its biology, and an overview of available biomarkers (serum folate, RBC folate, and plasma homocysteine concentrations) and their interpretation across a range of clinical and population-based uses. The article also includes a list of priority research needs for advancing the area of folate biomarkers related to nutritional health status and development.

U.S. women of childbearing age who are at possible increased risk of a neural tube defect-affected pregnancy due to suboptimal red blood cell folate concentrations, National Health and Nutrition Examination Survey 2007 to 2012.

BACKGROUND: Red blood cell (RBC) folate concentrations are a potential biomarker of folate-sensitive neural tube defect (NTD) risk in the population. The purpose of this analysis was to describe women in the U.S. population with RBC folate concentrations below those associated with optimal NTD prevention. METHODS: We used data from the 2007 to 2012 National Health and Nutrition Examination Survey (NHANES) to assess the RBC folate status of U.S. women of childbearing age relative to risk categories for NTD risk based on RBC folate concentrations. We defined suboptimal RBC folate concentrations as those associated with a prevalence of ≥9 NTDs per 10,000 live births. RESULTS: Among nonpregnant women age 12 to 49 years, 22.8% (95% Confidence Interval: 21.1, 24.6) had suboptimal RBC folate concentrations. Women had greater odds of having a suboptimal RBC folate concentration if they did not use dietary supplements containing folic acid; had mandatorily fortified enriched cereal grain products as their only source of folic acid; were non-Hispanic black or Hispanic; or were current smokers. CONCLUSION: Based on RBC folate concentrations, we would predict that the majority of U.S. women of reproductive age are not at increased risk for folate sensitive NTDs in the presence of mandatory folic acid fortification. Prevention policies and programs can be aimed at population subgroups identified as having higher predicted risk for folate-sensitive NTDs based on RBC folate concentrations.

Association Between Use of Oral Contraceptives and Folate Status: A Systematic Review and Meta-Analysis.

OBJECTIVE: To conduct a systematic review and meta-analysis of the effect of oral contraceptive use on plasma and red blood cell (RBC) folate concentrations. METHODS: We searched Medline, EMBASE, Web of Science, and the Cochrane library for human studies published from inception to June 2013 evaluating oral contraceptive use and folate status. Case-control studies, cohort studies, and clinical trials were included. A random-effects model of outcomes was used for the meta-analysis. RESULTS: A total of 2831 women in 17 studies were included in the analysis. In those whose plasma folate concentrations were available, there was a significant folate-lowering effect of oral contraceptives observed (mean reduction 1.27 µg/L; 95% CI 1.85 to 0.69, P < 0.001). Similarly, after analyzing data from 1389 women in 12 studies whose RBC folate concentrations were available, significantly lower folate status was observed among oral contraceptive users (mean reduction 59.32 µg/L; 95% CI 58.03 to 23.04, P < 0.001). CONCLUSION: Because of the reduction in blood folate concentrations associated with the use of oral contraceptives, it is critical for women of childbearing age to continue folate supplementation during oral contraceptive use.

Objectif : Mener une analyse systématique et une méta-analyse quant à l'effet du recours à la contraception orale sur les concentrations plasmatiques et érythrocytaires en folate. Méthodes : Nous avons mené des recherches dans Medline, EMBASE, Web of Science et la Cochrane library en vue d'en tirer les études menées chez l'homme, publiées entre le début de nos travaux et juin 2013, qui ont évalué l'utilisation de contraceptifs oraux et les taux de folate. Les études cas-témoins, les études de cohorte et les essais cliniques ont été admis aux fins de notre analyse. Un modèle à effets aléatoires quant aux issues a été utilisé dans le cadre de la méta-analyse. Résultats : Au total, 2 831 femmes issues de 17 études ont été admises à l'analyse. Chez les femmes pour lesquelles les concentrations plasmatiques en folate étaient disponibles, nous avons constaté que les contraceptifs oraux exerçaient un effet considérable d'atténuation de ces concentrations (baisse moyenne, 1,27 µg/l; IC à 95 %, 1,85 - 0,69, P < 0,001). De façon semblable, après avoir analysé les données traitant de 1 389 femmes issues de 12 études pour lesquelles les concentrations érythrocytaires en folate étaient disponibles, nous avons constaté une baisse considérable de ces concentrations chez les utilisatrices de contraceptifs oraux (baisse moyenne, 59,32 µg/l; IC à 95 %, 58,03 - 23,04, P < 0,001). Conclusion : En raison de la baisse des concentrations sanguines en folate qui sont associées à l'utilisation de contraceptifs oraux, il est crucial que les femmes en âge de procréer qui ont recours à une telle contraception continuent à prendre une supplémentation en folate.

An optimal periconception maternal folate status for embryonic size: the Rotterdam Predict study.

OBJECTIVE: To investigate the association between periconception maternal folate status and embryonic size. DESIGN: Prospective periconception cohort study. SETTING: Erasmus University Medical Centre, Rotterdam, the Netherlands. POPULATION: Seventy-seven singleton pregnancies recruited in 2009 and 2010. METHODS: We recruited women before 8 weeks of gestation and performed weekly three-dimensional ultrasound scans from enrolment up to 13 weeks of gestation. As a measure of embryonic growth, crown-rump length (CRL) measurements were performed using V-Scope software in the BARCO I-Space. Maternal blood was collected to determine first-trimester long-term red blood cell (RBC) folate status. Non-malformed live births were included in the analysis. We calculated quartiles of RBC folate, square root-transformed CRL data and performed multivariable linear mixed model analyses. MAIN OUTCOME MEASURES: Serial first-trimester CRL measurements. RESULTS: In total, 484 ultrasound scans were performed in 77 women, in 440 (90.7%) of which CRLs could be measured. RBC folate in the third quartile (1513-1812 nmol/l) was significantly associated with an increased CRL compared with the first two quartiles (814-1512 nmol/l) and the upper quartile (1813-2936 nmol/l; P(overall) = 0.03; adjusted for gestational age, smoking, body mass index and fetal sex). Compared with the third quartile, embryos in the upper quartile were 24.2% smaller at 6(+0) weeks [4.1 mm (95% confidence interval 3.5, 4.7) versus 5.4 mm (95% confidence interval 4.8, 6.1)] and 7.6% smaller at 12(+0) weeks [55.1 mm (95% confidence interval 52.9, 57.3) versus 59.6 mm (95% confidence interval 57.4, 62.0)] of gestation. CONCLUSIONS: This study suggests that a very high maternal periconception folate status is associated with reduced embryonic size. Whether these effects are beneficial or harmful requires further investigation.

Evaluation of C677T polymorphism of the methylenetetra hydrofolate reductase gene and its association with levels of serum homocysteine, folate, and vitamin B12 as maternal risk factors for Down syndrome.

AIMS AND OBJECTIVE: Evaluation of C677T polymorphisms of the methylenetetra hydrofolate reductase (MTHFR) gene and its association with level of serum homocysteine, folate, and vitamin B12 as possible maternal risk factors for Down syndrome. DESIGN: This was a case-control study. MATERIAL AND METHODS: Fifty-two mothers (mean age 27.6 years) with babies having free trisomy 21 of North Indian ethnicity and 52 control nonlactating mothers (mean age 24.9 years) of same ethnicity attending services of genetic lab for bloodletting for other causes were enrolled after informed written consent. Fasting blood was collected and was used for determination of plasma homocysteine, vitamin B12, and folate (serum and RBC), and for PCR amplification of the MTHFR gene. RESULTS: The prevalence of MTHFR C677T polymorphism in north Indian mothers of babies with trisomy 21 Down syndrome was 15.38% compared to 5.88 % in controls. The difference between two groups was not statistically significant (P = 0.124). Low serum folate was demonstrated in 34.62% of cases vs. 11.54% in controls, which was significant (P = 0.005). Low RBC folate was found in 30.7% of cases versus 11.53% in controls, which was not significant (P = 0.059), when analyzed independently. But on multiple regression analysis the difference was statistically significant. Low serum vitamin B12 was found in 42.31% of cases versus 34.62% in controls, which was not significant (P = 0.118). The mean serum homocysteine in cases was 10.35 ± 0.68 while controls were 9.02 ± 0.535. CONCLUSION: Serum levels of folate were low in cases. The RBC folate levels were comparable in both groups. However the combined serum folate and RBC folate were low in cases compared to control groups. Homocysteine levels in our study were higher in Down syndrome mothers compared to controls; however high-serum level of Homocysteine had no association with MTHFR polymorphism. No association of serum vitamin B12 with MTHFR polymorphism in occurrence of Down syndrome births was found. Peri- or preconceptional folate supplementation may therefore lead to a decline in DS births, if supported by larger studies.

Folate Status and Mortality in US Adults With Diabetes: A Nationally Representative Cohort Study.

Background: Public health concerns have gradually shifted from inadequate intakes to potential adverse effects associated with excessive folate intakes following the full implementation of mandatory folate fortification. This study aimed to examine the associations of red blood cell (RBC) folate with all-cause and cardiovascular disease (CVD) mortality among patients with diabetes. Methods: Data of 15,514 adults aged 20 years or older, who participated in the National Health and Nutrition Examination Survey (1988-1994), were analyzed as the baseline examination. The participants were linked to mortality data from the survey date until December 31, 2015. The associations of RBC folate with all-cause and CVD mortality were examined using multivariable Cox regression models. Results: During 297,708 person-years of follow-up (median of 19.2 years), 6,106 total deaths occurred, including 1,867 deaths from CVD, 1452 deaths from ischemic heart disease, and 415 deaths from stroke disease. The participants with the highest quartile of RBC folate had higher odds of diabetes (fully-adjusted odds ratio: 1.94 [95% CI: 1.53-2.48]). In Cox regression analyses, compared with the participants with the lowest quartile of RBC folate for diabetes, those from quartile 3 and quartile 4 had HRs (95% CIs) of 1.12 (0.87, 1.43) and 1.30 (1.04, 1.63) in all-cause mortality, respectively; in CVD mortality, the HRs were 1.73 (1.08, 2.76) and 1.47 (0.98, 2.22); in ischemic heart disease mortality, they were 2.01 (1.19, 3.39) and 1.62 (1.05, 2.50), respectively. However, high levels of RBC folate were negatively associated with all-cause mortality, CVD mortality and ischemic heart disease mortality in non-diabetes. Conclusion: From the nationally representative data, increasing levels in RBC folate were independently associated with an increased risk of all-cause and CVD mortality among those diagnosed with diabetes, but high levels of RBC folate had a mild protective effect in non-diabetes. The underlying mechanism regarding folate and adverse outcomes in diabetes warrants further clarification.

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

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

Plasma 25-hydroxyvitamin D is positively associated with folate and vitamin B12 levels in adolescents.

Vitamin D affects the absorption of folate in vitro, and perhaps of vitamin B12 (B12). However, epidemiological studies on the association of vitamin D with folate and B12 are inconclusive. We hypothesized a positive association of plasma 25-hydroxyvitamin D [25(OH)D] with folate and B12 levels in adolescents. This hypothesis was tested in a cross-sectional study of healthy adolescents (11-16 years old; n = 1416), selected from public middle schools from across Kuwait, using stratified multistage cluster random sampling. Plasma 25(OH)D was measured by LC-MS/MS. Serum B12 and total folate in hemolyzed whole blood were analyzed with commercial kits; RBC and plasma folate were calculated from total folate. Data on potential confounders were collected from the parents and adolescents. In a univariable model, 25(OH)D as a continuous variable was positively associated with each of total, RBC, and plasma folate (P < .001). After adjusting for potential confounders, this association remained significant with total folate (ß = 2.0, P < .001) and red blood cell folate (ß = 1.8, P < .001), but not with plasma folate (ß = 0.2, P = .34). A similar pattern of association was evident when 25(OH)D was fitted as categorical variable. Correlation between B12 and 25(OH)D was weak but significant (ρ = 0.1, P < .001). 25(OH)D was positively associated with B12 in both univariable and multivariable models (P < .001) when fitted as a categorical variable only. Simultaneous quantile regression confirmed these results. We conclude that plasma 25(OH)D is positively associated with folate and B12 levels in adolescents. Properly designed large-scale randomized controlled trials are warranted to investigate the causal role of vitamin D in folate and B12 absorption.

Red blood cell folate and cardiovascular deaths among hypertensive adults, an 18-year follow-up of a national cohort.

A shift towards high folate concentration has emerged following folate fortification. However, the association between folate and health outcomes beyond neural tube defects remains inconclusive. To assess the relationship between red blood cell (RBC) folate and the risk of cardiovascular death among hypertensive patients, we analyzed the data of 2,986 adults aged 19 or older with hypertension who participated in the National Health and Nutrition Examination Survey (1991-1994) as the baseline examination and were followed up through December 31, 2010. After 32,743 person-years of follow-up with an average of 11.7 (standard error = 0.03) years, 1192 deaths were recorded with 579 cardiovascular deaths. The median survival time was significantly shorter in adults in the high folate quartile than in patients in the low folate quartile: 11.97 vs. 13.85 years for heart diseases and 13.37 vs. 14.82 years for myocardial infarction deaths. The cardiovascular mortality was 13.04, 16.95, and 26.61/1,000 person-years for the groups with low, intermediate and high folate quartiles, respectively. After adjustment for age, sex and other factors, a J-shaped association emerged. The hazard ratios (HRs) of all cardiovascular deaths in patients with low, intermediate, and high folate quartiles were 1.09 (0.94, 1.27), 1.00 (reference), and 1.44 (1.31, 1.58), respectively. The corresponding HRs of acute myocardial infarction were 1.13 (0.86, 1.50), 1.00, and 2.13 (1.77, 2.57), respectively. The estimates remained significant after adjustment for BMI and medication use. Compared to moderate RBC folate levels, high folate levels were significantly associated with an increased risk of cardiovascular deaths, especially acute myocardial infarction.

Interpretation of vitamin B-12 and folate concentrations in population-based surveys does not require adjustment for inflammation: Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project.

BACKGROUND: Vitamin B-12 and folate deficiencies in women and children have important public health implications. However, the evidence is conflicting and limited on whether the influence of inflammation on biomarker concentrations may be sufficiently and consistently influenced by inflammation to require adjustment for interpreting concentrations or estimating population prevalence of deficiencies. OBJECTIVE: We examined correlations between concentrations of the inflammation biomarkers C-reactive protein (CRP) and α1-acid glycoprotein (AGP) and serum vitamin B-12 and serum and RBC folate among nonpregnant women of reproductive age (WRA; 15-49 yr) and preschool children (PSC; 6-59 mo). METHODS: We analyzed cross-sectional data from 16 nationally representative nutrition surveys conducted in WRA (n = 32,588) and PSC (n = 8,256) from the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia project. Spearman correlations between CRP or AGP and vitamin B-12 or folate concentrations were examined, taking into account complex survey design effects. RESULTS: Correlations between inflammation and vitamin B-12 or folate were weak, with no clear pattern of association in either WRA or PSC. Correlation coefficients between CRP and vitamin B-12 for WRA and PSC ranged from -0.25 to 0.16, and correlations between AGP and vitamin B-12 ranged between -0.07 and 0.14. Similarly, correlations between CRP and serum folate ranged from -0.13 to 0.08, and correlations between AGP and serum folate between -0.21 and 0.02. Only 3 surveys measured RBC folate, and among them, correlations for WRA ranged from -0.07 to 0.08 for CRP and -0.04 for AGP (1 country). CONCLUSIONS: Based on the weak and inconsistent correlations between CRP or AGP and vitamin B-12 or folate biomarkers, there is no rationale to adjust for inflammation when estimating population prevalence of vitamin B-12 or folate deficiencies in WRA or PSC.

Serum homocysteine level, vitamin B12 levels, and erythrocyte folate in psoriasis: A case-control study.

BACKGROUND: One of the most important organ involvements in psoriasis is atherosclerotic cardiovascular disease. Homocysteine is known to have atherogenic properties, but some inconsistency exists in the literature about its probable role as a risk factor of cardiovascular disorder in patients with psoriasis. OBJECTIVE: Because of some controversies, we compared homocysteine levels and related parameters of metabolic cycles in patients with psoriasis and healthy individuals. METHODS: This case-control study was conducted on 50 patients with psoriasis and 50 healthy individuals as the controls. Serum homocysteine, vitamin B12 levels, and erythrocyte folate concentrations were checked in all participants. RESULTS: Mean serum homocysteine, erythrocyte folate, and vitamin B12 levels did not show any significant difference between the two groups (p > .05), but interestingly, in patients with psoriasis, men had a significantly higher incidence of hyperhomocysteinemia and lower levels of erythrocyte folate (p = .14). Overall, there is no significant difference in serum levels of homocysteine and metabolic-related parameters between the case and control group. There was no significant relationship between the severity of psoriasis and the body mass index of patients (p > .05). CONCLUSION: Patients with psoriasis had a higher body mass index and higher levels of homocysteine in men. Hyperhomocysteinemia could be a predisposing factor of cardiovascular events, but more evaluations as a part of metabolic syndrome in patients with psoriasis are needed.