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

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

Detection, isolation, and characterization of a novel impurity from several folic acid products.

Folic acid belongs to the group of water-soluble B vitamins and naturally exists in multiple forms in a wide variety of foods such as legumes, vegetables, liver, and milk (Iyer and Tomar, 2009; Lyon et al., 2020). It is involved in many biochemical reactions critical for cell division, such as purine and pyrimidine biosynthesis, DNA/RNA biosynthesis, and amino acid metabolism (Iyer and Tomar, 2009). Mammals cannot synthesize folic acid and thus they must acquire it from food. Although folic acid is ubiquitous in foods, folic acid deficiency still often occurs due to various causes such as unhealthy diet (Hildebrand et al., 2021; Iimura et al., 2022), disease-related malabsorption (Arcot and Shrestha, 2005), medication-related depletion (Arcot and Shrestha, 2005), or vitamin B12 deficiency (Fishman et al., 2000). Folic acid deficiency has been associated with several health problems, such as anemia (Carmel, 2005; Bailey and Caudill, 2012), cancer (Duthie, 1999), cardiovascular diseases (Wald et al., 2002), neural tube defects in newborns (van der Put et al., 2001), neuropsychiatric dysfunction (Shea et al., 2002), depression (Falade et al., 2021), inflammatory diseases (Suzuki and Kunisawa, 2015; Jones et al., 2019), and eye diseases (Sijilmassi, 2019). To prevent folic acid deficiency, its daily intake (400 µg/d) has been recommended for adults in the European Union, and its increased intake (600 µg/d) is advised for women before and during pregnancy (FAO/WHO, 2002; IOM, 2004). The New Zealand government mandated the fortification of non-organic wheat flour with folic acid in July 2021, and the UK government mandated the fortification of non-wholemeal wheat flour with folic acid in September 2021 (Haggarty, 2021).

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

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

Detection, isolation, and characterization of a novel impurity from several folic acid products / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Folic acid belongs to the group of water-soluble B vitamins and naturally exists in multiple forms in a wide variety of foods such as legumes, vegetables, liver, and milk (Iyer and Tomar, 2009; Lyon et al., 2020). It is involved in many biochemical reactions critical for cell division, such as purine and pyrimidine biosynthesis, DNA/RNA biosynthesis, and amino acid metabolism (Iyer and Tomar, 2009). Mammals cannot synthesize folic acid and thus they must acquire it from food. Although folic acid is ubiquitous in foods, folic acid deficiency still often occurs due to various causes such as unhealthy diet (Hildebrand et al., 2021; Iimura et al., 2022), disease-related malabsorption (Arcot and Shrestha, 2005), medication-related depletion (Arcot and Shrestha, 2005), or vitamin B12 deficiency (Fishman et al., 2000). Folic acid deficiency has been associated with several health problems, such as anemia (Carmel, 2005; Bailey and Caudill, 2012), cancer (Duthie, 1999), cardiovascular diseases (Wald et al., 2002), neural tube defects in newborns (van der Put et al., 2001), neuropsychiatric dysfunction (Shea et al., 2002), depression (Falade et al., 2021), inflammatory diseases (Suzuki and Kunisawa, 2015; Jones et al., 2019), and eye diseases (Sijilmassi, 2019). To prevent folic acid deficiency, its daily intake (400 μg/d) has been recommended for adults in the European Union, and its increased intake (600 μg/d) is advised for women before and during pregnancy (FAO/WHO, 2002; IOM, 2004). The New Zealand government mandated the fortification of non-organic wheat flour with folic acid in July 2021, and the UK government mandated the fortification of non-wholemeal wheat flour with folic acid in September 2021 (Haggarty, 2021).

B Vitamins and One-Carbon Metabolism: Implications in Human Health and Disease.

Vitamins B9 (folate) and B12 are essential water-soluble vitamins that play a crucial role in the maintenance of one-carbon metabolism: a set of interconnected biochemical pathways driven by folate and methionine to generate methyl groups for use in DNA synthesis, amino acid homeostasis, antioxidant generation, and epigenetic regulation. Dietary deficiencies in B9 and B12, or genetic polymorphisms that influence the activity of enzymes involved in the folate or methionine cycles, are known to cause developmental defects, impair cognitive function, or block normal blood production. Nutritional deficiencies have historically been treated with dietary supplementation or high-dose parenteral administration that can reverse symptoms in the majority of cases. Elevated levels of these vitamins have more recently been shown to correlate with immune dysfunction, cancer, and increased mortality. Therapies that specifically target one-carbon metabolism are therefore currently being explored for the treatment of immune disorders and cancer. In this review, we will highlight recent studies aimed at elucidating the role of folate, B12, and methionine in one-carbon metabolism during normal cellular processes and in the context of disease progression.

First-Trimester Maternal Folic Acid Supplementation Reduced Risks of Severe and Most Congenital Heart Diseases in Offspring: A Large Case-Control Study.

Background Maternal folic acid supplementation (FAS) reduces the risk of neural tube defects in offspring. However, its effect on congenital heart disease (CHDs), especially on the severe ones remains uncertain. This study aimed to assess the individual and joint effect of first-trimester maternal FAS and multivitamin use on CHDs in offspring. Methods and Results This is a case-control study including 8379 confirmed CHD cases and 6918 controls from 40 healthcare centers of 21 cities in Guangdong Province, China. Adjusted odds ratios (aORs) of FAS and multivitamin use between CHD cases (overall and specific CHD phenotypes) and controls were calculated by controlling for parental confounders. The multiplicative interaction effect of FAS and multivitamin use on CHDs was estimated. A significantly protective association was detected between first-trimester maternal FAS and CHDs among offspring (aOR, 0.69; 95% CI, 0.62-0.76), but not for multivitamin use alone (aOR, 1.42; 95% CI, 0.73-2.78). There was no interaction between FAS and multivitamin use on CHDs (P=0.292). Most CHD phenotypes benefited from FAS (aORs ranged from 0.03-0.85), especially the most severe categories (ie, multiple critical CHDs [aOR, 0.16; 95% CI, 0.12-0.22]) and phenotypes (ie, single ventricle [aOR, 0.03; 95% CI, 0.004-0.21]). Conclusions First-trimester maternal FAS, but not multivitamin use, was substantially associated with lower risk of CHDs, and the association was strongest for the most severe CHD phenotypes. We recommend that women of childbearing age should supplement with folic acid as early as possible, ensuring coverage of the critical window for fetal heart development to prevent CHDs.

Risk Factors for Anemia and Micronutrient Deficiencies among Women of Reproductive Age-The Impact of the Wheat Flour Fortification Program in Uzbekistan.

Food fortification can be effective in reducing the prevalence of anemia and micronutrient deficiencies. This study assessed risk factors for-and the impact of the wheat flour program in Uzbekistan on-anemia, and iron and folate deficiency (FD) in non-pregnant women (NPW) of reproductive age. National data were analyzed for risk factors using multivariable regression. Additional iron intake from fortified flour was not associated with iron deficiency (ID) and did not result in a significantly different prevalence of anemia regardless of the levels, whereas women with additional folic acid intake had a lower relative risk (RR) of FD (RR: 0.67 [95% CI: 0.53, 0.85]). RR for anemia was greater in women with ID (RR: 4.7; 95% CI: 3.5, 6.5) and vitamin A insufficiency (VAI; RR 1.5; 95% CI: 1.3, 1.9). VAI (RR: 1.4 [95% CI: 1.3, 1.6]) and breastfeeding (RR: 1.1 [95% CI: 0.99, 1.2]) were associated with increased risk of ID, while being underweight reduced the risk (RR: 0.74 [95% CI: 0.58, 0.96]). Breastfeeding (RR: 1.2 [95% CI: 1.1, 1.4]) and inflammation (RR: 1.2 [95% CI: 1.0, 1.3]) increased risk of FD. FD results indicate that the fortification program had potential for impact, but requires higher coverage of adequately fortified wheat flour and a more bioavailable iron fortificant.

Sisters Together: Lessons Learned from Implementing a Grocery Store Campaign in Michigan Communities at Risk for Neural Tube Defects.

BACKGROUND: Sisters Together intended to develop and disseminate folic acid (FA) educational materials through a point-of-purchase program in low-income predominantly African American communities in Southeastern Michigan counties with high prevalence of neural tube defects (NTDs). METHODS: Guided by the Theory of Reasoned Action and the Consumer Information Processing Model, 17 supermarkets hosted displays, shelf-signs, and food tastings and tracked purchases of FA sources, alongside customer-intercept and store manager surveys, and observational logs. RESULTS: Stocking and signage were implemented with moderate-to-high fidelity, and food tastings with high reach and dose. Purchases of black beans, spinach, orange juice, and supplements showed increases, although only a third of the women identified them as sources of FA. Only 21/122 women (17%) surveyed reported seeing the shelf-signs. CONCLUSIONS: Theory-driven, grocery store-centric interventions are effective strategies to address gaps in FA education, with the key behavior change mechanism appearing to be modeling "procedural knowledge."

Folic acid consumption based on the theory of planned behaviour in pregnant women.

Folic Acid reduces the risk of neural tube defects. This study was aimed to investigate the consumption of folic acid to prevent deficiency anaemia based on the theory of planned behaviour on pregnant women in Neyshabur, Iran. This study included 180 pregnant women, who were gathered from 12 healthcare centres in the city of Neyshabur, Iran in 2018. Using a questionnaire and blood lab exam (folat) were measured and analysed. The average rates of knowledge, attitude, perceived behavioural control, intention, behaviour in the education group were meaningfully increased (p value < .05); however, these changes were not meaningful in the control group (p value > .05). Also, no statistically meaningful difference was obtained in subjective norm between the groups after the intervention (p = .924). It is suggested that folic acid supplementation promotion workshops should be held in health centres with the aim of preventing folic acid deficiency anaemia.Impact statementWhat is already known on this subject? The results of this study showed that by using education based on the theory of planned behaviour that emphasises the important psychological factors of behaviour or change, folic acid can be consumed in pregnant women. That women receive adequate and proper knowledge, along with a positive attitude toward taking folic acid, and feel that taking folic acid is at their discretion in terms of environmental factors (facilities and barriers), increases intent to use folic acid.What do the results of this study add? The results of this study also showed that the amount of folic acid intake during pregnancy increased by pregnant women and anaemia decreased.What are the implications of these findings for clinical practice and/or further research? The study showed the importance of the role of education based on theory of planned behaviour in consumption promoting folic acid.

Quinoa pasta fermented with lactic acid bacteria prevents nutritional deficiencies in mice.

In recent years, quinoa (Chenopodium quinoa Willd), an ancestral crop of the Andean region of South America, has gained worldwide attention due to its high nutritional value. This grain is a good source of several vitamins and minerals; however, their bioavailability is decreased by the presence of antinutritional factors such as phytic acid. These compounds can be reduced using lactic acid bacteria (LAB), that have a GRAS (Generally Recognized as Safe) status and have traditionally been associated with food fermentation due to their biosynthetic capacity and metabolic versatility. The objective of this study was to evaluate the effectiveness of a pasta made with quinoa sourdough fermented by L. plantarum strains producing vitamins B2 and B9 and phytase to prevent vitamins and minerals deficiency using an in vivo mouse model. The results showed that the pasta fermented with the mixed culture containing L. plantarum CRL 2107 + L. plantarum CRL 1964 present increased B2 and B9 levels in mice blood. Likewise, higher concentrations of P, Ca+2, Fe+2, Mg+2 (18.75, 10.70, 0.37, 4.85 mg/dL, respectively) were determined with respect to the deficient group (DG) (9.85, 9.90, 0.26, 3.34 mg/dL, respectively). Hematological studies showed an increase in hemoglobin (14.4 ±â€¯0.6 g/dL), and hematocrit (Htc, 47.0 ±â€¯0.6%) values, compared to the DG (Hb: 12.6 ±â€¯0.5 g/dL, Hto: 39.9 ±â€¯1.1%). Furthermore, histological evaluations of the intestines showed an increase of the small intestine villi length in this latter group. The results allow us to conclude that bio-enrichment of quinoa pasta using LAB could be a novel strategy to increase vitamin and minerals bioavailability in cereal/pseudocereal - derived foods.

Why is folate effective in preventing neural tube closure defects?

Neural tube defects (NTDs) originate from a failure of the embryonic neural tube to close. The pathogenesis of NTDs is largely unknown. Fortunately, adequate maternal folate application is known to reduce the risk of human NTDs. However, why folate reduces NTDs is largely unknown. The main cause for NTDs is the disturbance of the cell growth in the neuroepithelium. Of course, rapid cell growth needs enough synthesis of nuclei acids. Interestingly, folate is used as a source for the synthesis of nucleic acids. Furthermore, glycine cleavage system (GCS) is essential for the synthesis of nucleic acids from folate, and very strongly expressed in neuroepithelial cells, suggesting that these highly proliferating cells need enough synthesis of nuclei acids and high amounts of folate. Taken together, I speculate the following hypothesis; (1) The closure of the neural tube requires rapid growth of neuroepithelial cells. (2) High rates of nuclei acids synthesis are needed for the rapid growth. (3) GCS, which is requisite in nucleic acid synthesis from folate, is expressed very strongly and functions robustly in neuroepithelial cells. (4) Pregnant women require 5-10-fold higher amounts of folate compared to non-pregnant women. (5) So, folate-deficient situations are easy to occur in neuroepithelial cells, resulting in NTDs. (6) Thus, folate is effective to prevent NTDs.

Low Prevalence of Folic Acid Supplementation during Pregnancy: A Multicenter Study in Vietnam.

Periconceptional folic acid (FA) supplementation is recommended to prevent neural tube defects (NTDs), but little information is known about its use in Vietnam. It is important that FA supplements start to be taken when planning a pregnancy and continued through the first trimester to prevent NTDs, as the neural tube closes in the first month of pregnancy. However, FA supplementation in Vietnam is usually recommended to commence from the first antenatal visit, which is usually at 16 weeks, and very few women take FA before their first visit. This multicenter study aimed to determine the prevalence of FA supplement use and associated maternal characteristics in Vietnam. FA supplementation was assessed in 2030 singleton pregnant women between 2015 and 2016. In total, 654 (32.2%) women reported taking either supplements containing FA alone or multivitamins containing FA, and 505 (24.9%) reported correctly taking supplements containing FA alone. Women who were aged 30 years or over, had low education levels, had formal employment, and whose current pregnancy was first or unplanned were less likely to supplement with FA. Education programs are needed to encourage FA supplementation when contemplating pregnancy.

Renal Reabsorption of Folates: Pharmacological and Toxicological Snapshots.

Folates are water-soluble B9 vitamins that serve as one-carbon donors in the de novo synthesis of thymidylate and purines, and in the conversion of homocysteine to methionine. Due to their key roles in nucleic acid synthesis and in DNA methylation, inhibiting the folate pathway is still one of the most efficient approaches for the treatment of several tumors. Methotrexate and pemetrexed are the most prescribed antifolates and are mainly used in the treatment of acute myeloid leukemia, osteosarcoma, and lung cancers. Normal levels of folates in the blood are maintained not only by proper dietary intake and intestinal absorption, but also by an efficient renal reabsorption that seems to be primarily mediated by the glycosylphosphatidylinositol- (GPI) anchored protein folate receptor α (FRα), which is highly expressed at the brush-border membrane of proximal tubule cells. Folate deficiency due to malnutrition, impaired intestinal absorption or increased urinary elimination is associated with severe hematological and neurological deficits. This review describes the role of the kidneys in folate homeostasis, the molecular basis of folate handling by the kidneys, and the use of high dose folic acid as a model of acute kidney injury. Finally, we provide an overview on the development of folate-based compounds and their possible therapeutic potential and toxicological ramifications.

Supplementation with 5-formyltetrahydrofolate alleviates ultraviolet B-inflicted oxidative damage in folate-deficient zebrafish.

Ultraviolet (UV) is an omnipresent environmental carcinogen transmitted by sunlight. Excessive UV irradiation has been correlated to an increased risk of skin cancers. UVB, the most mutagenic component among the three UV constituents, causes damage mainly through inducing DNA damage and oxidative stress. Therefore, strategies or nutrients that strengthen an individual's resistance to UV-inflicted harmful effects shall be beneficial. Folate is a water-soluble B vitamin essential for nucleotides biosynthesis, and also a strong biological antioxidant, hence a micronutrient with potential of modulating individual's vulnerability to UV exposure. In this study, we investigated the impact of folate status on UV sensitivity and the protective activity of folate supplementation using a zebrafish model. Elevated reactive oxygen species (ROS) level and morphological injury were observed in the larvae exposed to UVB, which were readily rescued by supplementing with folic acid, 5-formyltetrahydrofolate (5-CHO-THF) and N-acetyl-L-cysteine (NAC). The UVB-inflicted abnormalities and mortality were worsened in Tg(hsp:EGFP-γGH) larvae displaying folate deficiency. Intriguingly, only supplementation with 5-CHO-THF, as opposed to folic acid, offered significant and consistent protection against UVB-inflicted oxidative damage in the folate-deficient larvae. We concluded that the intrinsic folate status correlates with the vulnerability to UVB-induced damage in zebrafish larvae. In addition, 5-CHO-THF surpassed both folic acid and NAC in preventing UVB-inflicted oxidative stress and injury in our current experimental zebrafish model.

Nation-wide failure of voluntary folic acid fortification of corn masa flour and tortillas with folic acid.

BACKGROUND: The United States Food and Drug Administration (FDA) required all enriched cereal grains to be fortified with folic acid in 1998. In April 2016, the FDA published regulations allowing voluntary fortification of corn masa flour with folic acid to address the high prevalence of folic acid-preventable spina bifida and anencephaly among Hispanics. Our objective was to survey folic acid-fortified corn masa and corn tortilla products in the country using a national social media campaign. METHODS: In January 2019, we conducted a social media campaign (#FindFolicAcid) engaging citizens nationwide to survey local stores for folic acid in corn masa flour and corn tortilla products. Photos of products and nutrition labels were shared with the researchers on various social media portals (e.g., Twitter, Facebook, and Instagram). The posts were summarized for a descriptive analysis. RESULTS: People from 28 states shared photos of 132 products, including 43 unique corn masa flour or corn tortilla products. Of those, only three corn masa flour products included folic acid: (a) Maseca Instant White (4.4 lb bag); (b) Masa Brosa Instant; and (c) Masa Brosa Instant Blue. None of the corn tortilla products were fortified. CONCLUSION: There is a failure of voluntary folic acid fortification of corn masa flour and products nationally. Until folic acid fortification of corn masa products is implemented fully in the country, Hispanic women of reproductive age should take a daily vitamin supplement which includes at least 400 mcg of folic acid to prevent spina bifida and anencephaly.

Driving Policy Change to Improve Micronutrient Status in Women of Reproductive Age and Children in Southeast Asia: The SMILING Project.

Objective The SMILING (Sustainable Micronutrient Interventions to Control Deficiencies and Improve Nutritional Status and General Health in Asia) project aimed at creating awareness and improving policies around micronutrient deficiencies in five Southeast Asian countries (Vietnam, Laos, Thailand, Cambodia and Indonesia). Results The project showed large gaps in recent data on micronutrient status in most of the five countries. By updating existing, or creating national food composition tables, the SMILING project enabled analyses of food consumption in women of reproductive age and young children. Linear programming showed a high risk for multiple micronutrient deficiencies in these groups, and especially in pregnant women. Most programs to improve micronutrient status target iodine, iron and vitamin A deficiency. However, the high prevalence of zinc, vitamin D, thiamine and folate deficiency in the region warrant interventions too. For certain micronutrients (zinc, iron, calcium), dietary changes alone appeared not enough to fulfill requirements. Food fortification was identified to be a sustainable, long-term solution to improve micronutrient intake. Multiple criteria mapping by stakeholders in each country resulted in a list of country-specific priority interventions. Surprisingly, food fortification was ranked low, due to concerns on quality control and organoleptic changes of the fortified food. More advocacy is needed for new, innovative interventions such as delayed cord clamping. Conclusions for practice The SMILING project recommends regular surveys to monitor micronutrient status of population, to measure impact of interventions and to guide nutrition policies.

Reductions in child mortality by preventing spina bifida and anencephaly: Implications in achieving Target 3.2 of the Sustainable Development Goals in developing countries.

BACKGROUND: There is an opportunity to reduce child mortality by preventing folic acid-preventable spina bifida and anencephaly (FAP SBA) in developing countries. We estimated reductions in FAP SBA-associated child mortality in 69 countries with an immediate potential for mandatory fortification of wheat flour. METHODS: Using data from multiple sources, we estimated the percent reductions in neonatal, infant, and under-five mortality that would have occurred by preventing FAP SBA; and the contributions of these reductions toward each country's Sustainable Development Goals (SDG) for child mortality reduction. We used the combined prevalence of spina bifida and anencephaly in selected countries before fortification, and estimated preventable child mortality associated with FAP SBA, assuming 0.5 per 1,000 live births as minimum achievable prevalence from mandatory fortification. RESULTS: Annually, 56,785 live births with FAP SBA occurred in the 69 countries examined. Of these, about 49,680 (87%) would have resulted in deaths under age 5 years, and are preventable through mandatory folic acid fortification. On average, compared to current rates, prevention of FAP SBA would have reduced the neonatal, infant, and under-five mortality by 19% (95% uncertainty interval [UI]: 16-24%), 15% (UI: 13-17%), and 14%, (95% UI: 13-17%), respectively. Prevention of FAP SBA seemed to contribute toward achieving SDG on neonatal and under-five mortality in developing countries. CONCLUSIONS: Prevention of FAP SBA will lead to notable and immediate reductions in child mortality. Many countries have an opportunity to effectively move toward child mortality-related SDG targets with existing milling infrastructure for food fortification.