The use of propionic and lactic acid bacteria to produce cobalamin and folate in injera, an Ethiopian cereal-based fermented food.

Like in many developing countries, the traditional Ethiopian diet relies mainly on starchy staple foods and often lacks sufficient animal-sourced foods which are crucial for cobalamin intake. Furthermore, the concentration of folate in traditionally prepared injera, an Ethiopian cereal-based fermented staple food, is highly variable and injera contains biologically inactive corrinoids. This study aimed to improve the cobalamin and folate content of injera by using cobalamin-producing Propionibacterium freudenreichii and folate-producing Lactiplantibacillus plantarum strains, both individually and combined. Since injera is fermented using backslopping, we also assessed the ability of these strains to produce cobalamin and folate consistently across successive fermentation batches. Changes in the microbial ecosystem were monitored using real-time PCR. The theoretical contribution of the injera prepared using the selected strains to the cobalamin and folate intake of children and women of reproductive age was also calculated. Results showed that using the selected bacterial strains individually increased cobalamin (up to 19.2 µg/100 g of dry matter) and folate (up to 180.2 µg/100 g of dry matter) levels in the injera dough over several backslopping fermentation batches. Regular consumption of the injera with enhanced vitamin content produced using each strain alone would be capable of fulfilling the entire recommended nutrient intake for cobalamin and up to 29 % of the recommended intake for folate for children and women of reproductive age. However, when the strains were used together, the production of both vitamins was reduced. The presence of certain common endogenous bacterial species and genera exhibited significant variability, highlighting the complex response of the native microbiota to the different inoculation strategies employed. Future experiments should consider selecting a microbial consortium comprising non-competing microorganisms to ensure the simultaneous production of cobalamin and folate in fermented foods.

Microbially-produced folate forms support the growth of Roseburia intestinalis but not its competitive fitness in fecal batch fermentations.

BACKGROUND: Folate (vitamin B9) occurs naturally mainly as tetrahydrofolate (THF), methyl-tetrahydrofolate (M-THF), and formyl-tetrahydrofolate (F-THF), and as dietary synthetic form (folic acid). While folate auxotrophy and prototrophy are known for several gut microbes, the specific folate forms produced by gut prototrophs and their impact on gut auxotrophs and microbiota remain unexplored. METHODS: Here, we quantified by UHPLC-FL/UV folate produced by six predicted gut prototrophs (Marvinbryantia formatexigens DSM 14469, Blautia hydrogenotrophica 10507 T, Blautia producta DSM 14466, Bacteroides caccae DSM 19024, Bacteroides ovatus DSM 1896, and Bacteroides thetaiotaomicron DSM 2079 T) and investigated the impact of different folate forms and doses (50 and 200 µg/l) on the growth and metabolism of the gut auxotroph Roseburia intestinalis in pure cultures and during fecal anaerobic batch fermentations (48 h, 37 °C) of five healthy adults. RESULTS: Our results confirmed the production of folate by all six gut strains, in the range from 15.3 ng/ml to 205.4 ng/ml. Different folate forms were detected, with THF ranging from 12.8 to 41.4 ng/ml and 5-MTHF ranging from 0.2 to 113.3 ng/ml, and being detected in all strains. Natural folate forms, in contrast to folic acid, promoted the growth and metabolism of the auxotroph R. intestinalis L1-82, with dose-dependent effects. During fecal batch fermentations, folate forms at both levels had no detectable effect on total bacteria concentration, on gut community composition and metabolic activity and on Roseburia spp. abundance, compared to the control without folate addition. CONCLUSIONS: Our study demonstrates for the first time in vitro the production of different natural folate forms by predicted gut prototrophs and the stimulation on the growth of the folate auxotrophic butyrate-producing R. intestinalis L1-82. Surprisingly, folate did not impact fecal fermentations. Our data suggest that the dietary folate forms at the tested levels may only have limited effects, if any, on the human gut microbiota in vivo.

Bacterial mercury methylation modulated by vitamin B9: An overlooked pathway leads to increased environmental risks.

There has been a serious health and environmental concern in conversion of inorganic mercury (Hg) to the neurotoxin, methylmercury (MeHg) by anaerobic microbes, while very little is known about the potential role of vitamin B9 (VB9) regulator in the biochemical generation of MeHg. This study innovatively investigated bacterial Hg methylation by Geobacter sulfurreducens PCA in the presence of VB9 under two existing scenarios. In the low-complexing scenario, the bacterial MeHg yield reached 68 % higher than that without VB9 within 72 h, which was attributed to free VB9-protected PCA cells relieving oxidative stress, as manifested by the increased expression of Hg methylation gene (hgcAB cluster by 19-48 %). The high-complexing scenario emphasized the intracellular Hg accumulation (38-45 %) after 12 h, as indicated by the increased expression of outer membrane protein-related and mercuric reductase-encoding genes, indicating the inefficient bioavailability of Hg due to a gradual shift from Hg reduction toward Hg0 re-oxidation controlled by competitive ligand exchange. These results suggested that VB9 application significantly raised the potential for bacterial Hg methylation and cellular accumulation, thus proposing insights into the biochemical behaviors of hazardous Hg in farming environments where vulnerable organisms are more possibly co-exposed to higher levels of Hg and VB9.

Folate Biomarkers, Folate Intake, and Risk of Death From All Causes, Cardiovascular Disease, and Cancer: A Systematic Review and Dose-Response Meta-Analysis of Prospective Cohort Studies.

CONTEXT: Existing evidence on the relation between folate intake and biomarkers with mortality risk is controversial. OBJECTIVE: Previous cohort studies were examined regarding folate intake and biomarkers in relation to risk of all-cause, cardiovascular disease- (CVD), and cancer-related mortality through a systematic review and meta-analysis. DATA SOURCES: A systematic search was performed of the PubMed, Scopus, and ISI Web of Science databases up to July 2023. DATA EXTRACTION: Prospective cohort studies examining the association of folate biomarkers (in serum, plasma, red blood cells) and intake with risk of all-cause, CVD-, and cancer-related mortality were considered. A random-effects model was applied to combine study-specific risk estimates. Dose-response relations were assessed by 1-stage weighted mixed-effects meta-analysis. DATA ANALYSIS: A total of 25 cohorts with 423 304 participants, 36 558 all-cause, 12 662 CVD-, and 2426 cancer-related deaths were included. No significant association was observed between the highest levels of folate biomarkers and all-cause mortality risk (hazard ratio [HR], 0.91; 95% CI, 0.77-1.06; n = 17; I2 = 89.4%; P < .001), CVD-related mortality risk (HR, 0.97; 95% CI, 0.87-1.06; n = 11; I2 = 0.0%; P = .57), and cancer-related mortality risk (HR, 0.85; 95% CI, 0.69-1.05; n = 6; I2 = 57.8%; P = .04) compared with the lowest. Furthermore, each 10 nmol/L increase was marginally related to a 12% reduced all-cause mortality risk but not to CVD- and cancer-related mortality risk. A significant inverse association was found between highest intake of dietary folate and the lowest, and risk of all-cause (HR, 0.87; 95% CI, 0.78-0.96; n = 3; I2 = 63.6%; P = .06) and CVD (HR, 0.77; 95% CI, 0.57-0.93; n = 4; I2 = 80.2%; P = .002) mortality. CONCLUSIONS: This meta-analysis revealed a significant inverse relation between dietary folate intake and risk of all-cause and CVD mortality. Such an association was not found in the case of folate biomarkers. Further prospective studies are warranted to confirm these findings. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42023401700.

Comparative Transcriptomic Analysis of Soybean Cyst Nematode Inbred Populations Non-adapted or Adapted on Soybean rhg1-a/Rhg4-Mediated Resistance.

Soybean cyst nematode (SCN, Heterodera glycines) is most effectively managed through planting resistant soybean cultivars, but the repeated use of the same resistance sources has led to a widespread emergence of virulent SCN populations that can overcome soybean resistance. Resistance to SCN HG type 0 (Race 3) in soybean cultivar Forrest is mediated by an epistatic interaction between the soybean resistance genes rhg1-a and Rhg4. We previously developed two SCN inbred populations by mass-selecting SCN HG type 0 (Race 3) on susceptible and resistant recombinant inbred lines, derived from a cross between Forrest and the SCN-susceptible cultivar Essex, which differ for Rhg4. To identify SCN genes potentially involved in overcoming rhg1-a/Rhg4-mediated resistance, we conducted RNA sequencing on early parasitic juveniles of these two SCN inbred populations infecting their respective hosts, only to discover a handful of differentially expressed genes (DEGs). However, in a comparison with early parasitic juveniles of an avirulent SCN inbred population infecting a resistant host, we discovered 59 and 171 DEGs uniquely up- or downregulated in virulent parasitic juveniles adapted on the resistant host. Interestingly, the proteins coded by these 59 DEGs included vitamin B-associated proteins (reduced folate carrier, biotin synthase, and thiamine transporter) and nematode effectors known to play roles in plant defense suppression, suggesting that virulent SCN may exert a heightened transcriptional response to cope with enhanced plant defenses and an altered nutritional status of a resistant soybean host. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Vitamins B9 and B12 in children with attention deficit hyperactivity disorder (ADHD).

Background: Attention deficit hyperactivity disorder (ADHD) is a common childhood neurodevelopmental disorder that begins before age 12. Given the role of B group vitamins in cell metabolism, synthesis of nucleotides, and neurotransmitters, the present study systematically investigated the plasma levels of vitamins B9 and B12 in children with ADHD. Methods: We searched electronic databases including Web of Science, MEDLINE, EMBASE, Scopus, Iran MEDEX, Cochran database, and SID from conception to June 2023. Full-text case-control or cross-sectional studies were included in this study. Participants in the case group were children with ADHD aged 6-12 years. Review Manager Software (RevMan 5.4) was used for statistical analyses. Standardized mean differences (SMD) with 95% CIs were used to determine the differences between the two groups. Results: Six studies were included in the present meta-analysis. They included 982 children, of whom, 204 were girls and 744 were boys. The mean age of the children was 8.86±2.03 years. The level of vitamin B9 was significantly different between children with and without ADHD [SMD -0.80, 95% CI (-1.55, -0.04)]. Vitamin B12 was significantly lower in children with ADHD [SMD -0.29, 95% CI (-0.42, -0.16)]. However, due to high heterogeneity (I2 = 93%), sensitivity analysis was used, I2 fell to 21%, and significant difference was observed between the two groups [SMD -0.19, 95% CI (-0.34, -0.04)]. Conclusion: The results of this systematic review showed that the level of vitamins B9 and B12 in children with ADHD was significantly lower than that in healthy children.

In vitro studies of hemoglobin's affinity for the Vitamin B9 and control of its stability character.

Vitamin B9, known as folic acid, and hemoglobin play an important biological role in the human body. This study was designed to investigate the nature of the complex through multispectroscopic methods at physiological conditions due to the lack of research on the binding interactions between folic acid and hemoglobin. Structural analysis showed that the interactions between the molecules are mainly hydrophobic with binding constant of 0.73 × 104 L/mol at 37 °C. The secondary structure of the protein was stable after the addition of folic acid with a 20-fold excess of ligand per mol protein. The stability effect of folic acid on hemoglobin was examined as a function of release of iron ions and determination of the level of phenanthroline-Fe2+ complex. The protective function of folic acid was observed at a concentration of 6.12 nmol/L, and the release of iron ions was lower than in the control probe.

Folic Acid in the Treatment of Sickle Cell Disease: A Systematic Review.

Sickle cell disease (SCD) is a group of inherited genetic disorders that is caused by a mutation in the gene that codes for hemoglobin subunit ß. This systematic review aimed to evaluate the effect of folic acid in the treatment of SCD patients. We retrieved 3730 articles from PubMed, PubMed Central, Google Scholar, and ScienceDirect databases. We employed a search technique that involved framing keywords, such as folic acid, folate, and sickle cell illness, and the Medical Subject Headings (MeSH) strategy in PubMed. We chose research articles that had been published during the last 10 years, as well as case reports, systematic reviews and meta-analyses, literature reviews, randomized controlled trials, and observational studies. Exclusion criteria included paid full-text articles, abstracts, non-English studies, and patients who do not have SCD. The 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria were used in the design of our systematic review. It was found that the majority of SCD patients were receiving regular folic acid supplements and that their plasma folate levels were either increased or within normal range, with no discernible impact on other clinical outcomes such as hemoglobin levels, infections, or pain crises. SCD patients produce more red blood cells than healthy individuals, and nearly all SCD patients receive daily folic acid supplements. On the other hand, not enough information is available on folic acid's potential benefits in the management of SCD; thus, there is a need for more large clinical trials.

Knowledge, awareness, and use of folic acid among women of childbearing age living in a peri-urban community in Ghana: a cross-sectional survey.

BACKGROUND: Folic acid, a water-soluble B-complex vitamin, plays a crucial role in DNA synthesis and maintenance, making it particularly significant during reproduction. Its well-known ability to reduce the risk of congenital anomalies during the periconceptional period underscores its importance. The increased requirement for folate during pregnancy and lactation is essential to support the physiological changes of the mother and ensure optimal growth and development of the foetus and offspring. This study assessed the knowledge, awareness, and use of folic acid among pregnant and lactating women of reproductive age residing in Dodowa in the Shai Osu-Doku District, Accra, Ghana. METHODS: The study was a cross-sectional design that involved 388 randomly selected participants (97 pregnant and 291 lactating women). Structured questionnaires were administered to gather information on the socioeconomic demographic characteristics, knowledge, awareness, and use of folic acid of the participants. Dietary intake was assessed using a food frequency questionnaire. The data were analysed using descriptive statistics and Pearson's chi-square analysis tests and are presented as frequencies and percentages, means, standard deviations, bar graphs, and pie charts. The significance of the results was determined at a 95% confidence interval. RESULTS: The mean age of the participants was 31 ± 5.0 years. Among the study participants, 46.1% demonstrated knowledge of folic acid deficiency, while approximately 68.3% had a high awareness of folic acid supplementation. Approximately 75% of the participants indicated that they had not used folic acid supplements within the week, and 15.5% reported consuming folic acid-fortified food per week. CONCLUSIONS: The women exhibited high awareness but poor knowledge regarding the usage of folic acid supplementation during pregnancy and lactation. Consequently, this lack of knowledge influenced the low use of folic acid supplements and low intake of folate-rich foods among pregnant and lactating mothers.

Recent Progress in Folic Acid Detection Based on Fluorescent Carbon Dots as Sensors: A Review.

Folic acid (FA) is a water-soluble vitamin found in diverse natural sources and is crucial for preserving human health. The risk of health issues due to FA deficiency underscores the need for a straightforward and sensitive FA detection methodology. Carbon dots (CDs) have gained significant attention owing to their exceptional fluorescence performance, biocompatibility, and easy accessibility. Consequently, numerous research studies have concentrated on developing advanced CD fluorescent probes to enable swift and precise FA detection. Despite these efforts, there is still a requirement for a thorough overview of the efficient synthesis of CDs and their practical applications in FA detection to further promote the widespread use of CDs. This review paper focuses on the practical applications of CD sensors for FA detection. It begins with an in-depth introduction to FA and CDs. Following that, based on various synthetic approaches, the prepared CDs are classified into diverse detection methods, such as single sensing, visual detection, and electrochemical methods. Furthermore, persistent challenges and potential avenues are highlighted for future research to provide valuable insights into crafting effective CDs and detecting FA.

3D printing of electrochemical cell for voltammetric detection and photodegradation monitoring of folic acid in juice samples.

In this study, compact 3D-printed carbon black (CB) electrodes were manufactured for using in folic acid (FA) analysis in fruit samples. Before application in FA analysis, the electrode surfaces were characterized by high-resolution scanning electron microscopy and voltammetry using well-known redox probes. Square wave voltammetric study presented linear responses in the range between 10 and 200 µmol/L (R2 > 0.99), exhibited a suitable detection limit (LOD) of âˆ¼ 5.1 µmol/L and acceptable performance in terms of reproducibility and anti-interference experiments. The analysis of FA in four different food samples using the proposed method agreed statistically with a comparative technique based on spectrophotometric measurements. Moreover, results from photostability experiments indicated that FA can be degraded after 5 and 20 min of UV exposure. These results successfully demonstrated the analytical feasibility of the 3D-printed electrodes as sensing material and for monitoring the photostability of FA in different fruit matrices.

Nitrous oxide abuse direct measurement for diagnosis and follow-up: update on kinetics and impact on metabolic pathways.

Recreational use of nitrous oxide (N2O) has become a major health issue worldwide, with a high number of clinical events, especially in neurology and cardiology. It is essential to be able to detect and monitor N2O abuse to provide effective care and follow-up to these patients. Current recommendations for detecting N2O in cases of recreational misuse and consumption markers are lacking. We aimed to update current knowledge through a review of the literature on N2O measurement and kinetics. We reviewed the outcomes of experiments, whether in preclinical models (in vitro or in vivo), or in humans, with the aim to identify biomarkers of intoxication as well as biomarkers of clinical severity, for laboratory use. Because N2O is eliminated 5 min after inhalation, measuring it in exhaled air is of no value. Many studies have found that urine and blood matrices concentrations are connected to ambient concentrations, but there is no similar data for direct exposure. There have been no studies on N2O measurement in direct consumers. Currently, patients actively abusing N2O are monitored using effect biomarkers (biomarkers related to the effects of N2O on metabolism), such as vitamin B12, homocysteine and methylmalonic acid.

Deep-Learning-Assisted Discriminative Detection of Vitamin B12 and Vitamin B9 by Fluorescent MoSe2 Quantum Dots.

A facile and environmentally mindful approach for the synthesis of MoSe2 QDs was developed via the hydrothermal method from bulk MoSe2. In this, the exfoliation of MoSe2 was enhanced with the aid of an intercalation agent (KOH), which could reduce the exfoliation time and increase the exfoliation efficiency to form MoSe2 QDs. We found that MoSe2 QDs display blue emission that is suitable for different applications. This fluorescence property of MoSe2 QDs was harnessed to fabricate a dual-modal sensor for the detection of both vitamin B12 (VB12) and vitamin B9 (VB9), employing fluorescence quenching. We performed a detailed study on the fluorescence quenching mechanism of both analytes. The predominant quenching mechanism for VB12 is via Förster resonance energy transfer. In contrast, the recognition of VB9 primarily relies on the inner filter effect. We applied an emerging and captivating approach to pattern recognition, the deep-learning method, which enables machines to "learn" patterns through training, eliminating the need for explicit programming of recognition methods. This attribute endows deep-learning with immense potential in the realm of sensing data analysis. Here, analyzing the array-based sensing data, the deep-learning technique, "convolution neural networks", has achieved 93% accuracy in determining the contribution of VB12 and VB9.

Nutrigenomics: SNPs correlated to vitamins' deficiencies.

Abstract: Nutrients can influence the physiological processes in the body by interacting with molecular systems. Including nutrigenetics and nutrigenomics, nutritional genomics focuses on how bio-active food components interact with the genome. The purpose of this study is to clarify how nutrigenomics and vitamin dietary deficits relate to one another. Food tolerances among human sub-populations are known to vary due to genetic variation, which may also affect dietary needs. This raises the prospect of tailoring a person's nutritional intake for optimum health and illness prevention, based on their unique genome. To better understand the interplay between genes and nutrients and to plan tailored weight loss, nutrigenetic testing may soon become a key approach.

Development of a highly sensitive voltammetric sensor for the detection of folic acid by using MoS2 and ionic liquid-modified carbon paste electrode.

Background and purpose: Sensitive analytical determination of folic acid is important in clinical laboratories due to its versatile biological functions. Experimental approach: A simple folic acid sensor was successfully fabricated based on two-dimensional transition metal dichalcogenide MoS2 modified carbon ionic liquid paste electrode (MoS2-CILPE). The electrochemical properties of the fabricated electrode were investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and chronoamperometry. Key results: The fabricated sensor displayed excellent electroactivity towards folic acid using CV. Under optimal conditions (0.1 M PBS (pH 7.0)), the DPV oxidation peak current was proportional to folic acid concentration in the range from 5.0 µM to 100.0 µM with an estimated limit of detection of 1.0 µM and limit of quantification of 5.0 µM. Conclusion: The ability of the sensor for routine analyses was demonstrated by the detection of folic acid present in folic acid tablets and urine samples with appreciable recovery values.

Propionibacteria as promising tools for the production of pro-bioactive scotta: a proof-of-concept study.

Dairy propionibacteria are Gram positive Actinomycetota, routinely utilized as starters in Swiss type cheese making and highly appreciated for their probiotic properties and health promoting effects. In this work, within the frame of a circular economy approach, 47 Propionibacterium and Acidipropionibacterium spp. were isolated from goat cheese and milk, and ewe rumen liquor, and characterized in view of their possible utilization for the production of novel pro-bioactive food and feed on scotta, a lactose rich substrate and one of the main by-products of the dairy industry. The evaluation of the Minimum Inhibitory Concentration (MIC) of 13 among the most common antibiotics in clinical practice revealed a general susceptibility to ampicillin, gentamycin, streptomycin, vancomycin, chloramphenicol, and clindamycin while confirming a lower susceptibility to aminoglycosides and ciprofloxacin. Twenty-five isolates, that proved capable of lactose utilization as the sole carbon source, were then characterized for functional and biotechnological properties. Four of them, ascribed to Propionibacterium freudenreichii species, and harboring resistance to bile salts (growth at 0.7-1.56 mM of unconjugated bile salts), acid stress (>80% survival after 1 h at pH 2), osmostress (growth at up to 6.5% NaCl) and lyophilization (survival rate > 80%), were selected and inoculated in scotta. On this substrate the four isolates reached cell densities ranging from 8.11 ± 0.14 to 9.45 ± 0.06 Log CFU mL-1 and proved capable of producing different vitamin B9 vitamers after 72 h incubation at 30°C. In addition, the semi-quantitative analysis following the metabolomics profiling revealed a total production of cobalamin derivatives (vitamin B12) in the range 0.49-1.31 mg L-1, thus suggesting a full activity of the corresponding biosynthetic pathways, likely involving a complex interplay between folate cycle and methylation cycle required in vitamin B12 biosynthesis. These isolates appear interesting candidates for further ad-hoc investigation regarding the production of pro-bioactive scotta.

Notes from the 2022 Folate, Vitamin B12, and One-Carbon Metabolism Conference.

Here, we present notes from the Folate, Vitamin B12, and One-Carbon Metabolism Conference organized by The Federation of American Societies for Experimental Biology (FASEB), held in Asheville, North Carolina, USA, 14-19 August 2022. We aim to share the most recent findings in the field with members of our scientific community who did not attend the meeting and who are interested in the research that was presented. The research described includes discussions of one-carbon metabolism at the biochemical and physiological levels and studies of the role of folate and B12 in development and in the adult, and from bacteria to mammals. Furthermore, the summarized studies address the role of one-carbon metabolism in disease, including COVID-19, neurodegeneration, and cancer.

Folic Acid Ionic-Liquids-Based Separation: Extraction and Modelling.

Folic acid (vitamin B9) is an essential micronutrient for human health. It can be obtained using different biological pathways as a competitive option for chemical synthesis, but the price of its separation is the key obstacle preventing the implementation of biological methods on a broad scale. Published studies have confirmed that ionic liquids can be used to separate organic compounds. In this article, we investigated folic acid separation by analyzing 5 ionic liquids (CYPHOS IL103, CYPHOS IL104, [HMIM][PF6], [BMIM][PF6], [OMIM][PF6]) and 3 organic solvents (heptane, chloroform, and octanol) as the extraction medium. The best obtained results indicated that ionic liquids are potentially valuable for the recovery of vitamin B9 from diluted aqueous solutions as fermentation broths; the efficiency of the process reached 99.56% for 120 g/L CYPHOS IL103 dissolved in heptane and pH 4 of the aqueous folic acid solution. Artificial Neural Networks (ANNs) were combined with Grey Wolf Optimizer (GWO) for modelling the process, considering its characteristics.

The Importance of Natural Antioxidants in Female Reproduction.

Oxidative stress (OS) has an important role in female reproduction, whether it is ovulation, endometrium decidualization, menstruation, oocyte fertilization, or development andimplantation of an embryo in the uterus. The menstrual cycle is regulated by the physiological concentration of reactive forms of oxygen and nitrogen as redox signal molecules, which trigger and regulate the length of individual phases of the menstrual cycle. It has been suggested that the decline in female fertility is modulated by pathological OS. The pathological excess of OS compared to antioxidants triggers many disorders of female reproduction which could lead to gynecological diseases and to infertility. Therefore, antioxidants are crucial for proper female reproductive function. They play a part in the metabolism of oocytes; in endometrium maturation via the activation of antioxidant signaling pathways Nrf2 and NF-κB; and in the hormonal regulation of vascular action. Antioxidants can directly scavenge radicals and act as a cofactor of highly valuable enzymes of cell differentiation and development, or enhance the activity of antioxidant enzymes. Compensation for low levels of antioxidants through their supplementation can improve fertility. This review considers the role of selected vitamins, flavonoids, peptides, and trace elements with antioxidant effects in female reproduction mechanisms.

The association between B vitamins and the risk of COVID-19.

The fast spread of the coronavirus disease 2019 (COVID-19) epidemic and its high mortality were quickly noticed by the health community. B vitamins are essential micronutrients for the body with antioxidant, anti-inflammatory and immune-regulating properties. The present study can provide a comprehensive picture of the associations between B vitamins and COVID-19 incidence. This study was undertaken on 9189 adult participants of the Yazd Health Study (YaHS) and Taghzieh Mardom-e-Yazd (TAMIZ) study aged 20 to 69 years. Data on dietary intakes were obtained using a validated FFQ. Multivariable logistic regression analysis was used to evaluate the association between B vitamins and COVID-19. Our findings indicated that participants in the fourth quartile of vitamin B5 intake compared with the first quartile had a protective effect against COVID-19 (OR: 0·53, 95 % CI 0·28, 0·99, P-trend = 0·02) after adjustment for all possible confounds in model 3. In addition, participants in the third quartile of vitamin B12 intake compared with the first quartile (OR: 0·63, 95 % CI 0·40, 0·98, P-trend = 0·11) had fewer odds of COVID-19 after full adjustments for confounders. Our findings indicated no significant relationship between dietary intake of vitamin B1, B2, B3, B9 and B-complex and COVID-19. A higher intake of vitamin B5 could reduce the odds of COVID-19 by 47 %, and a moderate intake of vitamin B12 had a protective effect on COVID-19. Although our study has promising results, stronger clinical studies are needed.