Vitamin B12 inhibits peptidylarginine deiminases and ameliorates rheumatoid arthritis in CAIA mice

Rheumatoid arthritis is an autoimmune disease whose early onset correlates with dysregulated citrullination, a process catalyzed by peptidylarginine deiminase isoform 4 (PADI-4). Here, we report that PADI-4 is a novel target of vitamin B12, a water-soluble vitamin that serves as a cofactor in DNA synthesis and the metabolism of fatty and amino acids. Vitamin B12 preferentially inhibited PADI-4 over PADI-2 with comparable inhibitory activity to the reference compound Cl-amidine in enzymatic inhibition assays, and reduced total cellular citrullination levels including that of histone H3 citrullination mediated by PADI-4. We also demonstrated that hydroxocobalamin, a manufactured form of vitamin B12, significantly ameliorated the severity of collagen type II antibody induced arthritis (CAIA) in mice and diminished gene expression of the rheumatoid inflammatory factors and cytokines IL17A, TNFα, IL-6, COX-II and ANXA2, as well PADI-4. Therefore, the use of vitamin B12 to treat rheumatoid arthritis merits further study.

The effect of feeding on serum concentrations of cobalamin, folate, trypsin-like immunoreactivity, and pancreatic lipase immunoreactivity in dogs with signs of chronic gastrointestinal disease

BACKGROUND

It is unknown if serum concentrations of cobalamin, folate, canine pancreatic lipase immunoreactivity (cPLI), and canine trypsin-like immunoreactivity (cTLI) obtained postprandially are equivalent to measurements obtained after withholding food in dogs with suspected gastrointestinal disease.

HYPOTHESIS/OBJECTIVES

Measurements of serum concentrations of cobalamin, folate, cPLI, and cTLI postprandially will be equivalent to measurements after 12 hours of withholding food in dogs with signs of chronic gastrointestinal disease. Changes observed will not alter clinical interpretation.

ANIMALS

51 client-owned dogs with signs of gastrointestinal disease.

METHODS

Prospective single arm clinical trial. Serum concentrations of cobalamin, folate, cPLI and cTLI 2, 4, and 8 hours postprandially were compared by equivalence testing to values after withholding food for 12 hours (baseline).

RESULTS

Mean serum cobalamin concentrations 2 hours (498.1 ± 213.1 ng/L; P = 0.024) and 4 hours (501.9 ± 207.4 ng/L; P = 0.008) postprandial were equivalent to baseline (517.3 ± 211.5 ng/L). Mean serum cTLI 2 hours (31.3 ± 14 μg/L; P < 0.001) and 4 hours (29.6 ± 13.1 μg/L; P = 0.027) postprandial were equivalent to baseline (31.1 ± 15 μg/L). Mean serum folate concentration 2 hours postprandial (15 ± 7.7 μg/L) was equivalent to baseline (13.7 ± 8.3 μg/L; P < 0.001). Equivalence could not be assessed for cPLI due to results below the lower limit of quantification. Feeding altered the clinical interpretation in 27% (cobalamin), 35% (folate), 20% (cTLI), and 12% (cPLI) of dogs.

CONCLUSIONS AND CLINICAL IMPORTANCE

The clinical interpretation for a substantial number of samples changed after feeding, therefore withholding food before sample collection is prudent.

Clinico-Etiopathogenesis of Vitamin B12, Folic Acid and Iron Deficiency in Severe Acute Malnutrition Children: A Tertiary Care Hospital Experience from Central India

In severe acute malnutrition, micronutrient deficiency as well as protein energy malnutrition is a major obstacle to growth & development. Iron deficiency dominates the spectrum of nutritional anemia. After taking informed consent, 211 SAM children and 211 age-and sex-matched healthy children with normal nutritional status were enrolled for the study. MUAC was used to diagnose SAM. A 5-part automated hematoanalyzer was used to measure the complete blood count and red cell indices, and the peripheral smear method to determine the red cell morphology. We measured serum ferritin, Vitamin B12, and folic acid using the ELISA method. Compared to controls, children with SAM had significantly lower red cell indices, platelet counts, and white cell counts. The most common clinical symptoms seen in SAM children were diarrhea, pneumonia, acute gastroenteritis, and acute respiratory infection. Children with SAM are more likely to suffer from iron deficiency and B12 deficiency. Severe vitamin B12 deficiency was more frequently associated with severe anemia. The severe anemia in SAM children constantly changes the body's defense mechanism, affecting the haematopoiesis. In this study, haematological indices are recommended for predicting severity of anemia, and hematopoietic changes are described, in order to improve anticipatory care and outcome in children with SAM.

Diet Pattern Analysis in Alzheimer's Disease Implicates Gender Differences in Folate-B12-Homocysteine Axis on Cognitive Outcomes

BACKGROUND & AIMS

Low plasma B12 and folate levels or hyperhomocysteinemia are related to cognitive impairment. This study explores the relationships among diet pattern, blood folate-B12-homocysteine levels, and cognition measurement in Alzheimer's disease (AD) while exploring whether a gender effect may exist.

METHODS

This cross-sectional study enrolled 592 AD patients (246 males, 346 females) and the demographic data, blood biochemical profiles, Mini-Mental State Examination (MMSE), and a Food Frequency Questionnaire (FFQ) for quantitative assessment of dietary frequency were collected. Structural Equation Modeling (SEM) was employed to explore the associations among dietary patterns, blood profiles, and cognition. A least absolute shrinkage and selection operator regression model, stratified by gender, was constructed to analyze the weighting of possible confounders.

RESULTS

Higher MMSE scores were related to higher frequencies of coffee/tea and higher educational levels, body mass index, and younger age. The SEM model revealed a direct influence of dietary frequencies (skimmed milk, thin pork, coffee/tea) and blood profiles (homocysteine, B12, and folate) on cognitive outcomes. At the same time, the influence of dietary pattern on cognition was not mediated by folate-B12-homocysteine levels. In males, a direct influence on the MMSE is attributed to B12, while in females, homocysteine is considered a more critical factor.

CONCLUSIONS

Dietary patterns and blood profiles are both associated with cognitive domains in AD, and there are gender differences in the associations of dietary patterns and the levels of B12 and homocysteine. To enhance the quality of dietary care and nutritional status for individuals with dementia, our study results still require future validations with multi-center and longitudinal studies.

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

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

Flexible B12 ecophysiology of Phaeocystis antarctica due to a fusion B12-independent methionine synthase with widespread homologues

Coastal Antarctic marine ecosystems are significant in carbon cycling because of their intense seasonal phytoplankton blooms. Southern Ocean algae are primarily limited by light and iron (Fe) and can be co-limited by cobalamin (vitamin B12). Micronutrient limitation controls productivity and shapes the composition of blooms which are typically dominated by either diatoms or the haptophyte Phaeocystis antarctica. However, the vitamin requirements and ecophysiology of the keystone species P. antarctica remain poorly characterized. Using cultures, physiological analysis, and comparative omics, we examined the response of P. antarctica to a matrix of Fe-B12 conditions. We show that P. antarctica is not auxotrophic for B12, as previously suggested, and identify mechanisms underlying its B12 response in cultures of predominantly solitary and colonial cells. A combination of proteomics and proteogenomics reveals a B12-independent methionine synthase fusion protein (MetE-fusion) that is expressed under vitamin limitation and interreplaced with the B12-dependent isoform under replete conditions. Database searches return homologues of the MetE-fusion protein in multiple Phaeocystis species and in a wide range of marine microbes, including other photosynthetic eukaryotes with polymorphic life cycles as well as bacterioplankton. Furthermore, we find MetE-fusion homologues expressed in metaproteomic and metatranscriptomic field samples in polar and more geographically widespread regions. As climate change impacts micronutrient availability in the coastal Southern Ocean, our finding that P. antarctica has a flexible B12 metabolism has implications for its relative fitness compared to B12-auxotrophic diatoms and for the detection of B12-stress in a more diverse set of marine microbes.

Unraveling the phylogenomic diversity of Methanomassiliicoccales and implications for mitigating ruminant methane emissions

BACKGROUND

Methanomassiliicoccales are a recently identified order of methanogens that are diverse across global environments particularly the gastrointestinal tracts of animals; however, their metabolic capacities are defined via a limited number of cultured strains.

RESULTS

Here, we profile and analyze 243 Methanomassiliicoccales genomes assembled from cultured representatives and uncultured metagenomes recovered from various biomes, including the gastrointestinal tracts of different animal species. Our analyses reveal the presence of numerous undefined genera and genetic variability in metabolic capabilities within Methanomassiliicoccales lineages, which is essential for adaptation to their ecological niches. In particular, gastrointestinal tract Methanomassiliicoccales demonstrate the presence of co-diversified members with their hosts over evolutionary timescales and likely originated in the natural environment. We highlight the presence of diverse clades of vitamin transporter BtuC proteins that distinguish Methanomassiliicoccales from other archaeal orders and likely provide a competitive advantage in efficiently handling B12. Furthermore, genome-centric metatranscriptomic analysis of ruminants with varying methane yields reveal elevated expression of select Methanomassiliicoccales genera in low methane animals and suggest that B12 exchanges could enable them to occupy ecological niches that possibly alter the direction of H2 utilization.

CONCLUSIONS

We provide a comprehensive and updated account of divergent Methanomassiliicoccales lineages, drawing from numerous uncultured genomes obtained from various habitats. We also highlight their unique metabolic capabilities involving B12, which could serve as promising targets for mitigating ruminant methane emissions by altering H2 flow.

Dietary intake, nutritional adequacy and food sources of vitamins involved in the methionine-methylation cycle from Spanish children aged one to <10 years: results from the EsNuPI study

Background

Methionine-methylation cycle and the derived critical functions during infancy are key regulated by folates, vitamins B12, and B6. At present in Spain, there is an absence of studies that assess the intakes and dietary sources of total folates and B12 by children consuming all types of milks and those regularly consuming adapted milk formulas. Thus, our aim was to evaluate folates intakes alongside with vitamins B6 and B12 while describing their major dietary contributors in Spanish children aged one to <10 years.

Methods

A total of 1,448 children aged between 1 and 10 years (49.7% girls and 50.3% boys) from the EsNuPI, a prospective cross-sectional study, were allocated into two cohorts: one Spanish Reference Cohort (SRS) of the general population (n = 707), and another including children consuming adapted milks called Adapted Milk Consumers Cohort (AMS) (n = 741) completed two 24 h dietary recalls used to estimate their nutrient intakes and to compare them to the European Food Safety Authority (EFSA) Population Reference Intakes.

Results

The median intake of vitamin B6 was 1.35 (1.06-1.70) mg/day in the SRS and 1.45 (1.17-1.79) mg/day in the AMS, being significantly higher in the AMS for all age-groups. Prevalence of adequacy for vitamin B6 in the SRS and AMS was 97.7 and 98.7%, respectively. Total folates intakes in the AMS were significantly higher (p ≤ 0.001) in all age groups than in the SRS, independently of age. In addition, the prevalence of adequacy for folates intakes in all groups was more than 60%. Vitamin B12 intake increased with age independently of the type of milk consumed. The prevalence of adequacy for vitamin B12 was highly compliant by all population groups. The major contributors to vitamin B6 were milk and dairy products being significantly higher in AMS than SRS (p ≤ 0.001). The highest contributors to folates intakes were milk and dairy products, cereals, vegetables, and fruits in both groups whereas for vitamin B12 in the SRS sample were milk and dairy products followed by meat and meats products and for adapted milks, were milk and dairy products, followed by eggs, then meat and meats products.

Conclusion

A satisfactory prevalence of adequacy for vitamins B6, and B12 amongst the Spanish children population was observed, which was not the case for folates, regardless of the dietary group evaluated. Nevertheless, a possible strategy to increase folate intake among the youngest children is to increase the consumption of milk and dairy products within a healthier dietary pattern, as these may contribute significantly to the vitamin needs of the infant population.

Lack of vitamin B12 impairs innate and adaptive immunity of Cuban tree frog (Osteopilus septentrionalis) tadpoles

Vitamin B12 is a micronutrient required by a variety of organisms for healthy cellular functioning. Despite the systemic effects observed in cases of B12 deficiency, relatively little is known about how vitamin B12 affects immune health, especially in amphibians, which are declining at unprecedented rates. In this study, we tested how supplementing an algae diet with B12 affects the innate and adaptive immunity of Cuban tree frog (Osteopilus septentrionalis) tadpoles. We found that innate immunity, as measured by a bacterial killing assay, was significantly more robust in B12-supplemented tadpoles than control tadpoles, but no significant differences were found in natural antibody production or hematocrit between groups. Adaptive immunity, as measured by Aeromonas hydrophila-specific IgY antibodies, was significantly greater in tadpoles challenged with A. hydrophila and supplemented with B12 than in control tadpoles, those only challenged with A. hydrophila, and those only given B12. Our results suggest that vitamin B12 is an important factor in maintaining a functional immune system in tadpoles, which may also be true for all vertebrates.

Vitamin B12 effectiveness in the management of hospitalized COVID-19 and its clinical outcomes and complications: A randomized clinical trial

Background and Aims

Since 2019, severe acute respiratory syndrome coronavirus 2, has spread and challenged the health care system for treatment which is mainly limited to supportive care. It is well-established that malnutrition impedes the immunity in human bodies, and makes it vulnerable to microorganisms. Vitamin B12 is one of the agents that has critical roles in body systems. Thus, the following clinical trial was conducted to assess its possible therapeutic value in COVID-19 patients.

Method

The present randomized clinical trial was carried out in Baharlou Hospital, and patients with confirmed COVID-19 infection within 24 h of admission were included. We used quadruple blocks randomization to divide patients into groups of case and control. The case group received 1000 mg of vitamin B12, daily for 7 day while the patients in control group were administered distilled water as placebo. The studied outcomes were duration of hospitalization, need for intensive care unit (ICU), mechanical ventilation, mortality rate and laboratory findings. The statistical analysis was done via SPSS version 22.

Results

After implementing inclusion and exclusion criteria, 34 participants were included in the study, 20 of which were male. Serum levels of creatinine, LDH (Lactate dehydrogenase), Ferritin, and CRP (C-reactive protein) had decreased in both groups. The improving changes of CRP, LDH, ferritin and creatinine was higher in case group. The increase of Alanine Transaminase and D-dimer was higher in control group. however there was no statistically significant difference. More patients were admitted to ICU in the control group but the difference was not statistically significant. Duration of hospitalization did not differ statistically between the groups. No in hospital mortality has been recorded.

Conclusion

Our study suggests that vitamin B12 supplementation seem to have curative effect in COVID-19. Nutritious diet is necessary for proper functioning of the immune system. Since malnutrition is associated with poor prognosis in COVID-19 patients, and limited number of participants in this study, we suggest performing meta-analysis on similar studies to reach reliable result.

Efficient NADPH-dependent dehalogenation afforded by a self-sufficient reductive dehalogenase

Reductive dehalogenases are corrinoid and iron-sulfur cluster-containing enzymes that catalyze the reductive removal of a halogen atom. The oxygen-sensitive and membrane-associated nature of the respiratory reductive dehalogenases has hindered their detailed kinetic study. In contrast, the evolutionarily related catabolic reductive dehalogenases are oxygen tolerant, with those that are naturally fused to a reductase domain with similarity to phthalate dioxygenase presenting attractive targets for further study. We present efficient heterologous expression of a self-sufficient catabolic reductive dehalogenase from Jhaorihella thermophila in Escherichia coli. Combining the use of maltose-binding protein as a solubility-enhancing tag with the btuCEDFB cobalamin uptake system affords up to 40% cobalamin occupancy and a full complement of iron-sulfur clusters. The enzyme is able to efficiently perform NADPH-dependent dehalogenation of brominated and iodinated phenolic compounds, including the flame retardant tetrabromobisphenol, under both anaerobic and aerobic conditions. NADPH consumption is tightly coupled to product formation. Surprisingly, corresponding chlorinated compounds only act as competitive inhibitors. Electron paramagnetic resonance spectroscopy reveals loss of the Co(II) signal observed in the resting state of the enzyme under steady-state conditions, suggesting accumulation of Co(I)/(III) species prior to the rate-limiting step. In vivo reductive debromination activity is readily observed, and when the enzyme is expressed in E. coli strain W, supports growth on 3-bromo-4-hydroxyphenylacetic as a sole carbon source. This demonstrates the potential for catabolic reductive dehalogenases for future application in bioremediation.

Population Status of Vitamin B12 Values in the General Population and in Individuals with Type 2 Diabetes, in Southwestern Colombia

Vitamin B12 (B12) is necessary for the proper functioning of the central and peripheral nervous systems. Although there is no exact definition for B12 levels, a value of 200 pg/mL is compatible with deficiency, 200-299 pg/mL is considered borderline, and 300 pg/mL is considered normal. In population studies, the prevalence of B12 deficiency ranges between 2.9% and 35%. Furthermore, many medications, such as metformin [for type 2 diabetes mellitus (T2DM)], can cause B12 deficiency. The objectives of this study were to determine the population status of B12 in southwestern Colombia (and the status of B12 in subjects with T2DM). In the total population (participants with and without T2DM), the prevalence of B12 deficiency was 17.8%; that of borderline was 19.3%; and that of normal levels was 62.9%. The prevalence of deficiency increased with age and was significantly higher in those aged ≥60 years (p = 0.000). In T2DM subjects, the prevalence of deficiency was significantly higher concerning those without T2DM (p = 0.002) and was significantly higher in those who received >1 gm/day of metformin (p = 0.001). Thus, the prevalence of deficiency and borderline levels of B12 in our population was high, particularly in those >60 years of age. B12 deficiency was significantly higher in individuals with T2DM than in individuals without T2DM, especially among those receiving high doses of metformin.

Maternal anemia and childhood cancer: a population-based case-control study in Denmark

BACKGROUND

Childhood cancer risk is associated with maternal health during pregnancy. Anemia in pregnancy is a common condition, especially in low-income countries, but a possible association between maternal anemia and childhood cancer has not been widely studied.

METHODS

We examined the relation in a population-based study in Denmark (N = 6420 cancer cases, 160,485 controls). Cases were taken from the Danish Cancer Registry, and controls were selected from national records. We obtained maternal anemia diagnoses from the National Patient and Medical Births registries. In a separate analysis within the years available (births 1995-2014), we examined cancer risks among mothers taking prescribed vitamin supplements, using data from the National Prescription Register. We estimated the risks of childhood cancer using conditional logistic regression.

RESULTS

The risks of neuroblastoma [odds ratio (OR= 1.83, 95% confidence interval (CI): 1.04, 3.22] and acute lymphoblastic leukemia (OR= 1.46, 95% CI 1.09, 1.97) were increased in children born to mothers with anemia in pregnancy. There was a two-fold increased risk for bone tumors (OR= 2.59, 95% CI: 1.42, 4.72), particularly osteosarcoma (OR= 3.54, 95% CI 1.60, 7.82). With regards to prescribed supplement use, mothers prescribed supplements for B12 and folate deficiency anemia (OR= 4.03, 95% CI 1.91, 8.50) had an increased risk for cancer in offspring.

CONCLUSION

Our results suggest that screening for anemia in pregnancy and vitamin supplementation may be an actionable strategy to prevent some cases of childhood cancer.

Water-soluble vitamin insufficiency, deficiency and supplementation in children and adolescents with a psychiatric disorder: a systematic review and meta-analysis

Nutrition is fundamental for brain development, but relatively little is known about water-soluble vitamin (WSV) levels and the effect of supplementation on psychiatry symptoms in children and adolescents (CAD) with psychiatric disorders. Our team systematically reviewed all studies concerning WSV abnormalities or supplementation in CAD with any psychiatric disorder. We searched for original studies published between 1990 and 15/05/2020 which were not based on retrospective chart review and which included WSV blood level measurements or investigated the effect of WSV supplementation on psychiatric symptoms in psychiatric patients aged 18 or under. Forty-two articles were included, 69% of which (N = 29) examined Autism Spectrum Disorders (ASD), with most of these assessing folate or vitamin B₁₂ supplementation (N = 22, 75.9% of ASD studies). Meta-analyses showed significantly lower vitamin B₁₂ levels in ASD and ADHD patients vs. healthy controls (HC), while folate levels were higher in ADHD patients vs. HC. Most of the studies (9/10, 90%) showed a decrease in symptoms as measured by clinical scales after supplementation. There was significant heterogeneity between the studies, however many found different types of vitamin abnormalities in CAD with psychiatric disorders.

Folate and Vitamin B(12) Deficiency Exacerbate Inflammation during Mycobacterium avium paratuberculosis (MAP) Infection

Folate and vitamin B₁₂ deficiency is highly prevalent among Crohn's disease (CD) patients. Furthermore, CD pathology can be mediated by Mycobacterium avium subsp. paratuberculosis (MAP) infection. However, the direct effect of folate (B₉) and cobalamin (B₁₂) deficiency during MAP infection remains uncharacterized. This study investigates how folate and B₁₂ deficiency impedes macrophage apoptosis and exacerbates the inflammation in macrophages infected with MAP isolated from CD patients. Accordingly, we measured folate and B₁₂ in ex vivo plasma samples collected from CD patients with or without MAP infection (N = 35 per group). We also measured the expression of the pro-inflammatory cytokines IL-1β and TNF-α, cellular apoptosis and viability markers, and bacterial viability in MAP-infected macrophages cultured in folate and B₁₂ deficient media. We determined that MAP-positive CD patients have significantly lower plasma folate and B₁₂ in comparison to MAP-negative CD patients [414.48 ± 94.60 pg/mL vs. 512.86 ± 129.12 pg/mL, respectively]. We further show that pro-inflammatory cytokines IL-1β and TNF-α are significantly upregulated during folate and vitamin B₁₂ deprivation following MAP infection by several folds, while supplementation significantly reduces their expression by several folds. Additionally, depletion of folate, B₁₂, and folate/B₁₂ following MAP infection, led to decreased macrophage apoptosis from 1.83 ± 0.40-fold to 1.04 ± 0.08, 0.64 ± 0.12, and 0.45 ± 0.07 in folate-low, B₁₂-low, and folate/B₁₂-low cells, respectively. By contrast, folate and folate/B₁₂ supplementation resulted in 3.38 ± 0.70 and 2.58 ± 0.14-fold increases in infected macrophages. Interestingly, changes in overall macrophage viability were only observed in folate-high, folate/B₁₂-high, and folate/B₁₂-low media, with 0.80 ± 0.05, 0.82 ± 0.02, and 0.91 ± 0.04-fold changes, respectively. Incubation of Caco-2 intestinal epithelial monolayers with supernatant from infected macrophages revealed that folate/B₁₂ deficiency led to increased LDH release independent of oxidative stress. Overall, our results indicate that folate and B₁₂ are key vitamins affecting cell survival and inflammation during MAP infection.

Radical SAM enzymes: Nature's choice for radical reactions

Enzymes that use a [4Fe-4S]1+ cluster plus S-adenosyl-l-methionine (SAM) to initiate radical reactions (radical SAM) form the largest enzyme superfamily, with over half a million members across the tree of life. This review summarizes recent work revealing the radical SAM reaction pathway, which ultimately liberates the 5'-deoxyadenosyl (5'-dAdo•) radical to perform extremely diverse, highly regio- and stereo-specific, transformations. Most surprising was the discovery of an organometallic intermediate Ω exhibiting an Fe-C5'-adenosyl bond. Ω liberates 5'-dAdo• through homolysis of the Fe-C5' bond, in analogy to Co-C5' bond homolysis in B12 , previously viewed as biology's paradigmatic radical generator. The 5'-dAdo• has been trapped and characterized in radical SAM enzymes via a recently discovered photoreactivity of the [4Fe-4S]+ /SAM complex, and has been confirmed as a catalytically active intermediate in enzyme catalysis. The regioselective SAM S-C bond cleavage to produce 5'-dAdo• originates in the Jahn-Teller effect. The simplicity of SAM as a radical precursor, and the exquisite control of 5'-dAdo• reactivity in radical SAM enzymes, may be why radical SAM enzymes pervade the tree of life, while B12 enzymes are only a few.

Nitrous oxide-induced myeloneuropathy: an emerging public health issue

Increasing use of nitrous oxide as a recreational drug has been reported among young adults in western countries over the past decade. We present two cases of young males presenting to the Emergency Department (ED) of a large urban university hospital in Dublin with progressive neurological dysfunction related to nitrous oxide use. We review the pathophysiology, clinical features and treatment of nitrous oxide neurotoxicity. It is important that clinicians are aware of this evolving public health issue and are able to recognize the clinical features of this rare presentation, which may become more common in Irish EDs and GP surgeries as nitrous oxide abuse becomes more prevalent.

Microalgae/cyanobacteria: the potential green future of vitamin B12 production

This review summarizes the available information about potential sources of vitamin B12, especially for people who follow a vegan or vegetarian diet and inhabitants of poor countries in the developing world. Cyanobacteria and microalgae approved for food purposes can play a critical role as promising and innovative sources of this vitamin. This work involves a discussion of whether the form of vitamin B12 extracted from microalgae/cyanobacteria is biologically available to humans, specifically focusing on the genera Arthrospira and Chlorella. It describes analyses of their biomass composition, cultivation requirements, and genetic properties in B12 production. Furthermore, this review discusses the function of cobalamin in microalgae and cyanobacteria themselves and the possibility of modification and cocultivation to increase the content of B12 in their biomass.

Beneficial effects of vitamin B12 treatment in pediatric patients diagnosed with vitamin B12 deficiency regarding total-native thiol, oxidative stress, and mononuclear leukocyte DNA damage

Vitamin B₁₂ is involved in biochemical metabolic pathways. B₁₂ deficiency is common in childhood when the need for the vitamin increases and growth and development occur. Various hematological, neurological, psychiatric, and gastrointestinal disorders are observed in its deficiency. In addition, B₁₂ deficiency is associated with oxidative stress and DNA damage. Therefore, the aim of our study is to evaluate oxidative stress, thiol/disulfide homeostasis, and DNA damage pre and post-treatment in children diagnosed with B₁₂ deficiency. A total of 40 children with B₁₂ deficiency were included in the study after the consent form was approved. Blood was drawn from children pre and posttreatment. Hemoglobin (HGB), hematocrit (HCT), and red blood cells (RBC) were measured by autoanalyzer; total antioxidant status (TAS), total oxidant status (TOS), total thiol (TT), and native thiol (NT) were measured by the photometric method, and DNA damage was analyzed by the comet assay method. Oxidative stress index (OSI) and disulfide (DIS) values were calculated. As a result of the experiments, HGB, HCT, and RBC increased with treatment. While TAS, TT, and NT as antioxidant parameters increased; TOS, OSI, and DIS decreased with treatment compared to pretreatment. DNA damage was also found to decrease with treatment. Additionally, these data were statistically significant (p < 0.001). It was found that oxidative stress and DNA damage decreased with oral B₁₂ treatment in children with B₁₂ deficiency, and clinical parameters were also improved.

"Macro transcobalamin causing raised vitamin B12: Case-based laboratory investigation"

Determination of plasma vitamin B12 (B12) is a frequently requested laboratory analysis, mainly employed to establish B12 deficiency. However, an increased level of B12 is a common unexpected finding that may be related to an increased concentration of one of the B12 binding proteins, haptocorrin or transcobalamin. This paper describes the extensive laboratory evaluation of a patient with an elevated level of plasma B12 with various well-established assays. Initial studies suggested the presence of a macromolecule consisting of haptocorrin bound B12. Specific determinations of the B12-binding proteins revealed normal amounts of haptocorrin but a markedly increase in both total and B12 saturated transcobalamin (holo-TC). The results are in accord with the presence of macro-transcobalamin. These experiments reveal that determination of the nature of the B12-macromolecules is troublesome due to differences in assays applied to measure these proteins. In addition, this publication creates awareness of macro-holo-TC as a cause of an unexplained increased B12 level.

Can We Arrest the Evolution of Antibiotic Resistance? The Differences between the Effects of Silver Nanoparticles and Silver Ions

Silver nanoparticles (AgNPs) are effective antimicrobial substances that show promise in combatting multidrug resistance. The potential application and release of AgNPs into the environment may neutralize the selective advantage of antibiotic resistance. Systemic knowledge regarding the effect of NPs on the evolution of antibiotic resistance is lacking. Our results showed that bacteria slowly developed adaptive tolerance to ciprofloxacin (CIP) under cyclic CIP and silver ion (Ag⁺) cotreatment, and no resistance/tolerance was discernible when CIP and AgNP exposure was alternated. In contrast, rapid CIP resistance was induced under continuous selection by treatment with only CIP. To combat the effects of CIP and Ag⁺, bacteria developed convergent evolutionary strategies with similar adaptive mechanisms, including anaerobic respiration transitioning (to reduce oxidative stress) and stringent response (to survive harsh environments). Alternating AgNP exposure impeded evolutionary resistance by accelerating B12-dependent folate and methionine cycles, which reestablished DNA synthesis and partially offset high oxidative stress levels, in contrast with the effect of CIP-directed evolutionary pressure. Nevertheless, CIP/AgNP treatment was ineffective in attenuating virulence, and CIP/Ag⁺ exposure even induced the virulence-critical type III secretion system. Our results increase the basic understanding of the impacts of NPs on evolutionary biology and suggest prospective nanotechnology applications for arresting evolutionary antibiotic resistance.

Metabolism-mediated thrombotic microangiopathy and B12

Thrombotic microangiopathies (TMAs) are a group of life-threatening conditions requiring urgent management and characterized by a clinical triad of microangiopathic hemolytic anemia, thrombocytopenia, and ischemic tissue injury. Severe vitamin B12 (Cobalamin-Cbl) deficiency or defective cobalamin metabolism, particularly defects in intracellular B12 metabolism, may lead to a TMA-like picture. The latter has been termed metabolism-mediated TMA (MM-TMA). This confusing picture is mediated partly by ineffective erythropoiesis with significant red cell fragmentation resulting in a hemolytic pattern, coupled with reduced platelet production and endothelial injury with organ damage resulting from accumulated toxic byproducts of B12 dysmetabolism. However, unlike in classic thrombotic thrombocytopenic purpura, where therapeutic plasma exchange has to be initiated promptly, cases of MM-TMA can be treated, if diagnosed properly, with adequate B12 replacement.

Evolution of Methods for the Study of Cobalamin-Dependent Radical SAM Enzymes

While bioinformatic evidence of cobalamin-dependent radical S-adenosylmethionine (SAM) enzymes has existed since the naming of the radical SAM superfamily in 2001, none were biochemically characterized until 2011. In the past decade, the field has flourished as methodological advances have facilitated study of the subfamily. Because of the ingenuity and perseverance of researchers in this field, we now have functional, mechanistic, and structural insight into how this class of enzymes harnesses the power of both the cobalamin and radical SAM cofactors to achieve catalysis. All of the early characterized enzymes in this subfamily were methylases, but the activity of these enzymes has recently been expanded beyond methylation. We anticipate that the characterized functions of these enzymes will become both better understood and increasingly diverse with continued study.

Controlling Non-Native Cobalamin Reactivity and Catalysis in the Transcription Factor CarH

Vitamin B₁₂ derivatives catalyze a wide range of organic transformations, but B₁₂-dependent enzymes are underutilized in biocatalysis relative to other metalloenzymes. In this study, we engineered a variant of the transcription factor CarH, called CarH*, that catalyzes styrene C-H alkylation with improved yields (2-6.5-fold) and selectivity relative to cobalamin. While the native function of CarH involves transcription regulation via adenosylcobalamin (AdoCbl) Co(III)-carbon bond cleavage and β-hydride elimination to generate 4',5'-didehydroadenosine, CarH*-catalyzed styrene alkylation proceeds via non-native oxidative addition and olefin addition coupled with a native-like β-hydride elimination. Mechanistic studies on this reaction echo findings from earlier studies on AdoCbl homolysis to suggest that CarH* selectivity results from its ability to impart a cage effect on radical intermediates. These findings lay the groundwork for the development of B₁₂-dependent enzymes as catalysts for non-native transformations.

How I investigate acquired megaloblastic anemia

In this review of megaloblastic anemia (MA), an overview of vitamin B₁₂ and folate body requirements, biochemical pathways, and laboratory testing strategies will be provided. However, the focus of this review is the classic and unique features of MA in blood and bone marrow. Acquired MA is a benign disorder for many, but can be detrimental for some. The clinical presentation can vary considerably, and the spectrum of symptoms and signs is diverse and quite broad. Prompt recognition and therapy are critical to prevent potential irreversible damage and clinical sequelae, especially in patients with vitamin B₁₂ deficiency. A delay in diagnosis of vitamin B₁₂ deficiency can result in significant neurologic sequelae that may not fully resolve with treatment, including in neonates and young infants. The blood and bone marrow features in MA can closely mimic thrombocytopenic purpura, myelodysplasia, and other myeloid neoplasms. Both pancytopenia and normal MCV at presentation are common in MA and raise unique challenges for the diagnostician. Partially treated MA is also a significant diagnostic "trap". MA is highly responsive to treatment, and patients tend to improve rapidly upon treatment initiation. However, the broad range of clinical and hematologic features makes the rapid, successful diagnosis of MA a unique challenge for the hematopathologist. Even in the era of state-of-the-art laboratory testing, a high suspicion is required.

Vitamin B6, B9, and B12 Intakes and Cognitive Performance in Elders: National Health and Nutrition Examination Survey, 2011-2014

PURPOSE

This research intended to investigate vitamin B₆, B₉, and B₁₂ consumption in relation to the risk of low cognitive performance (LCP) among elderly adults.

PATIENTS AND METHODS

We analyzed data of 2421 participants retrieved from the National Health and Nutrition Examination Survey (NHANES) 2011-2014 database in this cross-sectional study. Cognitive performance was evaluated by the Consortium to Establish a Registry for Alzheimer's disease (CERAD) word learning and recall modules, the animal fluency test (AF), and the digit symbol substitution test (DSST). Participants who scored the lowest 25th percentile were categorized in the LCP group. The Dietary Interview-Total Nutrient Intakes dataset was used to determine the dietary intake of B vitamins in the participants. The low intake group and adequate intake group were differentiated based on the recommended dietary allowance. Subgroup analyses were conducted to assess the relations between 3 B vitamins and cognitive performance among different sex, race, and age groups.

RESULTS

Compared with low vitamin B₆ intake (<1.7 mg/day), adequate vitamin B₆ intake (≥1.7 mg/day) corresponded to a 31.7% decrease in LCP odds in the DSST tests. Participants who consumed adequate B₉ (≥400 mcg/day) were associated with 31.2%, 33.8%, and 46.5% declines in the risk of LCP in the CERAD, AF, and DSST tests in contrast to those having low B₉ intake (<400 mcg/day). Adequate vitamin B₁₂ intake (≥2.4 mcg/day) correlated with a lower LCP occurrence in the CERAD, AF, and DSST tests, with 30.5%, 21.5%, and 33.3% reductions, respectively. Further, the relations between 3 B vitamins and cognitive performance varied across different sex, race, and age groups of people.

CONCLUSION

Adequate dietary vitamin B₉ and B₁₂ intakes are significantly associated with a better cognitive performance in immediate and delayed memory recall, categorical verbal fluency, processing speed, sustained attention, and working memory among elders assessed in the CERAD, AF, and DSST tests.

Ratings of the Effectiveness of Nutraceuticals for Autism Spectrum Disorders: Results of a National Survey

Autism spectrum disorder (ASD) often involves a wide range of co-occurring medical conditions (“comorbidities”) and biochemical abnormalities such as oxidative stress and mitochondrial dysfunction. Nutritional supplements (“Nutraceuticals”) are often used to treat both core ASD symptoms and comorbidities, but some have not yet been formally evaluated in ASD. The potential biological mechanisms of nutraceuticals include correction of micronutrient deficiencies due to a poor diet and support for metabolic processes such as redox regulation, mitochondrial dysfunction and melatonin production. This paper reports on the results of the National Survey on Treatment Effectiveness for Autism, focusing on nutraceuticals. The Survey involved 1286 participants from across the United States. Participants rated the overall perceived benefits and adverse effects of each nutraceutical, and also indicated the specific symptoms changed and adverse effects. From these ratings the top-rated nutraceuticals for each of 24 symptoms are listed. Compared to psychiatric and seizure medications rated through the same Survey, on average nutraceuticals had significantly higher ratings of Overall Benefit (1.59 vs. 1.39, p = 0.01) and significantly lower ratings of Overall Adverse Effects (0.1 vs. 0.9, p < 0.001). Folinic acid and vitamin B12 were two of the top-rated treatments. This study suggests that nutraceuticals may have clinical benefits and favorable adverse effect profiles.

Prospecting the therapeutic edge of a novel compound (B12) over berberine in the selective targeting of Retinoid X Receptor in colon cancer

The Retinoid X Receptor (RXR) is an attractive target in the treatment of colon cancer. Different therapeutic binders with high potency have been used to specifically target RXR. Among these compounds is a novel analogue of berberine, B12. We provided structural and molecular insights into the therapeutic activity properties of B12 relative to its parent compound, berberine, using force field estimations and thermodynamic calculations. Upon binding of B12 to RXR, the high instability elicited by RXR was markedly reduced; similar observation was seen in the berberine-bound RXR. However, our analysis revealed that B12 could have a more stabilizing effect on RXR when compared to berberine. Interestingly, the mechanistic behaviour of B12 in the active site of RXR opposed its impact on RXR protein. This disparity could be due to the bond formation and breaking elicited between B12/berberine and the active site residues. We observed that B12 and berberine could induce a disparate conformational change in regions Gly250-Asp258 located on the His-RXRα/LBD domain. Comparatively, the high agonistic and activation potential reported for B12 compared to berberine might be due to its superior binding affinity as evidenced in the thermodynamic estimations. The total affinity for B12 (-25.76 kcal/mol) was contributed by electrostatic interactions from Glu243 and Glu239. Also, Arg371, which plays a crucial role in the activity of RXR, formed a strong hydrogen bond with B12; however, a weak interaction was elicited between Arg371 and berberine. Taken together, our study has shown the RXRα activating potential of B12, and findings from this study could provide a framework in the future design of RXRα binders specifically tailored in the selective treatment of colon cancer.

Corrination of a GLP-1 Receptor Agonist for Glycemic Control without Emesis

Glucagon-like peptide-1 receptor (GLP-1R) agonists used to treat type 2 diabetes mellitus often produce nausea, vomiting, and in some patients, undesired anorexia. Notably, these behavioral effects are caused by direct central GLP-1R activation. Herein, we describe the creation of a GLP-1R agonist conjugate with modified brain penetrance that enhances GLP-1R-mediated glycemic control without inducing vomiting. Covalent attachment of the GLP-1R agonist exendin-4 (Ex4) to dicyanocobinamide (Cbi), a corrin ring containing precursor of vitamin B12, produces a "corrinated" Ex4 construct (Cbi-Ex4). Data collected in the musk shrew (Suncus murinus), an emetic mammal, reveal beneficial effects of Cbi-Ex4 relative to Ex4, as evidenced by improvements in glycemic responses in glucose tolerance tests and a profound reduction of emetic events. Our findings highlight the potential for clinical use of Cbi-Ex4 for millions of patients seeking improved glycemic control without common side effects (e.g., emesis) characteristic of current GLP-1 therapeutics.

Nutrition, one-carbon metabolism and arsenic methylation in Bangladeshi adolescents

BACKGROUND

Over 57 million people in Bangladesh are chronically exposed to arsenic-contaminated drinking water. Ingested inorganic arsenic (InAs) undergoes hepatic methylation generating monomethyl- (MMAs) and dimethyl- (DMAs) arsenic species in a process that facilitates urinary As (uAs) elimination. One-carbon metabolism (OCM), a biochemical pathway that is influenced by folate and vitamin B12, facilitates the methylation of As. OCM also supports nucleotide and amino acid synthesis, particularly during periods of rapid growth such as adolescence. While folate supplementation increases As methylation and lowers blood As (bAs) in adults, little data is available for adolescents.

OBJECTIVES

To examine the associations between OCM-related micronutrients and As methylation in Bangladeshi adolescents chronically exposed to As-contaminated drinking water.

METHODS

We conducted a cross-sectional study of 679 Bangladeshi adolescents, including 320 boys and 359 girls aged 14-16 years. Nutritional status was assessed by red blood cell (RBC) folate, plasma folate, plasma B12 and homocysteine (Hcys). Arsenic-related outcomes included blood arsenic (bAs), urinary arsenic (uAs), and urinary arsenic metabolites expressed as a percentage of total urinary As: %InAs, %MMAs, %DMAs.

RESULTS

Boys had significantly lower B12, higher Hcys, higher bAs, higher uAs, higher %MMAs, and a trend toward lower RBC folate compared to girls. Therefore, regression analyses controlling for water As and BMI were sex stratified. Among girls, RBC folate was inversely associated with bAs, plasma B12 was inversely associated with uAs, and plasma Hcys was inversely associated with %MMA. Among boys, plasma folate was inversely associated with %InAs and positively associated with %DMA, RBC folate was inversely associated with %InAs and positively associated with %MMA, while Hcys was positively associated with %InAs.

CONCLUSIONS

These findings suggest that associations between OCM nutritional status, bAs, and distribution of As metabolites in adolescents are similar to previously reported observations in adults and in children. The As methylation findings are statistically significant among boys but not among girls; this may be related to estrogen which more strongly influences OCM in females. The inverse association between Hcys and %MMA in girls is somewhat unexpected given that Hcys is known to be an indicator of impaired OCM and low folate/B12 in adults. Overall, these results indicate that the associations between OCM-related micronutrients and arsenic methylation in adolescents are generally similar to prior findings in adults, though these associations may differ by sex. Additionally, these findings suggest that more investigation into the role of Hcys in adolescent physiology is needed, perhaps particularly for girls. Additional studies are needed to evaluate the impact of OCM and As methylation on As-related adverse health outcomes (such as cancer and cardiovascular disease) in people exposed to As during adolescence.

Vitamin B12 deficiency in children from Northern India: Time to reconsider nutritional handicaps

Background and Aims:

Subclinical Vitamin B12 deficiency is a very common entity in the Indian subcontinent with devastating clinical and socio-economic consequences. The objective of this study was to estimate the proportion of vitamin B12 deficient children and to evaluate their clinical profile.

Setting and Design:

This prospective analytical study was conducted in a tertiary level care institute in Northern India.

Materials and Methods:

Children with clinical pallor, were included in this study. Detailed history, height, weight percentiles and characteristic features of vitamin B12 deficiency were recorded and complete blood counts, mean corpuscular volume and vitamin B12 levels were done.

Statistics:

For Qualitative data was analyzed using Pearson Chi square tests and quantitative data was analyzed using two sided independent samples t tests.

Results:

A total of 111 children were included. 64.8% (n = 72) had vitamin B12 deficiency. Lethargy (63.9%) and weight loss (62.1%), Knuckle pigmentation were common features. One-fourth of the children were on vegetarian diet. Neurological manifestations were significantly associated with fragile hair (p 0.056) and knuckle pigmentation (p 0.027). Younger children had more weight loss (p 0.001), knuckle pigmentation (p 0.019) and hypotonia (p 0.045). One fifth of children presented with neurological manifestations.

Conclusions:

Two-thirds of the anemic children had vitamin B12 deficiency. There was a bimodal age distribution with regard to B12 deficiency. Neurological manifestations were predominant in younger children [<6] and hematological abnormalities were more frequent in older children [≥6 years]. Estimation of vitamin B12 levels forms an essential component while evaluating children with anemia, despite mixed dietary habits and normal MCV.

Aberrant expression of miR-16, B12 and CD272 in peripheral blood mononuclear cells from patients with active tuberculosis

Tuberculosis (TB) immunity is affected by complex immune regulation processes, which involve various immune cells, immune molecules, and cytokines. Here, we evaluated the expression of B12, CD272 and miR-16 in peripheral blood mononuclear cells (PBMC) of patients with active pulmonary tuberculosis. The results showed that monocytes expressing CD272 or B12 were down-regulated in patients with tuberculosis. The expression of B12 and CD272 in T cells and monocytes is related to tuberculosis. In TB patients, the up-regulation of miR-16 was negatively correlated with B12 mRNA expression, miR-16 was mainly expressed in CD14⁺ monocytes, and CD272 mRNA was mainly expressed in CD19⁺ B cells. It is worth noting that the overexpression of miR-16 inhibits the expression of CD272 and B12 in monocytes of TB patients. After BCG stimulation, miR-16 expression of CD14⁺ monocytes was up-regulated and B12 mRNA and CD272 mRNA expressions were down-regulated in TB patients. Finally, we found that miR-16 may participate in the TB immunization process through targeted regulation of B12 expression. These studies indicate that the expression of B12, CD272 and miR-16 in PBMC may be related to tuberculosis.

Plasma levels of one-carbon metabolism nutrients in women with anorexia nervosa

OBJECTIVE

People who are ill with anorexia nervosa (AN) show altered availability of key plasma nutrients. However, little is known about the patterning of alterations that occurs across diverse nutrients during active phases of illness or about the persistence of any such alterations following remission of illness.

METHOD

We compared plasma levels of one-carbon metabolism nutrients across women with active AN (AN-Active: n = 53), in remission from AN (AN-Remitted: n = 40), or who had no eating-disorder history (NED: n = 36). We also tested associations between body mass index (BMI) changes and changes in pre- to posttreatment nutrient levels, and explored the association between nutrient levels, on the one hand, and BMI and eating symptoms, on the other. Choline, betaine, and methionine were analyzed using mass spectrometry. Folate and B12 were analyzed using the AccuBind® ELISA kit. Eating-disorder symptoms were assessed by interview and self-report.

RESULTS

Compared to NED individuals, AN-Active individuals exhibited significantly elevated B12 and (less-reliably) betaine. In AN-Active individuals, lower BMI was associated with higher B12.

DISCUSSION

The observed alterations run contrary to the intuition that plasma nutrient levels should be directly responsive to nutritional status and suggest, instead, the existence of compensatory adaptations to malnutrition in individuals with active AN. Further study is required to clarify mechanisms that underlie such effects.

Pyridoxine, folate and cobalamin for migraine: A systematic review

There is a possible relationship between migraine and hypercoagulability inducing factors, such as hyperhomocysteinemia. In this context, homocysteine (Hcy)-lowering vitamins (B6-folate-B12) may prove beneficial in the management-prophylaxis of migraine. We performed a systematic literature search in order to retrieve studies assessing the supplementation of B6, folate and B12 (alone or as adjunctive therapies) to migraine patients, as well as patients suffering from other primary headache disorders. MEDLINE, EMBASE, CENTRAL, Google Scholar, trial registries and OpenGrey were searched. Twelve relevant articles were retrieved. The management of acute migraine attacks with Hcy-lowering vitamins has not provided promising results (one randomized controlled trial-RCT-and one prospective uncontrolled trial). On the contrary, significant benefits were registered for the use of B6 alone, in combination with folate and in combination with folate and B12 in the prophylaxis of migraine with aura (MA) in adults compared to placebo (five RCTs, only one did not obtain significant results). Folate supplementation alone was not more efficacious than placebo (one RCT). Limited data for the prophylaxis of migraine without aura (MO) in children (two prospective uncontrolled trials) and adults (two prospective uncontrolled trials involving both MA and MO participants) impede the extraction of safe conclusions. An overall attractive safety profile was exhibited with gastrointestinal adverse events being the most common. Overall, a potential beneficial effect regarding the administration of B6, folate and/or B12 in the prophylaxis of MA in adults was indicated. Additional high-quality RCTs that will investigate MO in adults as well as MO and MA in children are warranted.

B12 as a Treatment for Peripheral Neuropathic Pain: A Systematic Review

Neuropathic pain describes a range of unpleasant sensations caused by a lesion or disease of the somatosensory nervous system. The sensations caused by neuropathic pain are debilitating and improved treatment regimens are sought in order to improve the quality of life of patients. One proposed treatment for neuropathic pain is vitamin B12, which is thought to alleviate pain by a number of mechanisms including promoting myelination, increasing nerve regeneration and decreasing ectopic nerve firing. In this paper, the evidence for B12 as a drug treatment for neuropathic pain is reviewed. Twenty four published articles were eligible for inclusion in this systematic review in which a range of treatment regimens were evaluated including both B12 monotherapy and B12 in combination with other vitamins or conventional treatments, such as gabapentinoids. Overall, this systematic review demonstrates that there is currently some evidence for the therapeutic effect of B12 in the treatment of post-herpetic neuralgia (level II evidence) and the treatment of painful peripheral neuropathy (level III evidence).

Does vegan diet influence umbilical cord vitamin B12, folate, and ferritin levels?

PURPOSE

To determine the influence of maternal diets on maternal and umbilical cord blood levels of vitamin B12, folic acid, ferritin, and hemoglobin.

METHODS

A prospective observational study on women who maintained the same diet for at least 3 months prior to, and throughout current pregnancy. Women were divided according to their diet. Diet questionnaires were filled in during the 3rd trimester. Blood samples for complete blood counts and levels of ferritin, vitamin B12, folate, and albumin were taken from the women prior to delivery and from the umbilical cord immediately after delivery.

RESULTS

The 273 enrolled women included 112 omnivores, 37 pescatarians, 64 vegetarians, and 60 vegans. There were no significant differences in the maternal B12 levels between the study groups (P = 0.426). Vegans had lower maternal ferritin levels compared to pescatarians (27 ± 17 vs 60 ± 74 ng/ml, respectively, P = 0.034), but not compared to vegetarians (P = 0.597), or omnivores (P = 1.000). There were no significant differences in the umbilical cord B12, folate, ferritin, and hemoglobin levels between the study groups. A sub-analysis that compared women who consumed multivitamins, B12 and iron supplements during pregnancy to women who did not, revealed differences in the levels of umbilical-cord B12 (1002 ± 608 vs 442 ± 151 pg/ml, respectively, P = 0.000) and maternal blood B12 (388 ± 209 vs 219 ± 95 pg/ml, respectively, P = 0.030) only among vegans, but not among omnivores.

CONCLUSION

Vegan diet does not change the umbilical cord levels of B12, folic acid, ferritin, and hemoglobin. Vegans who do not take any vitamin supplementation are at greater risk for B12 deficiency than omnivores.

Dietary Intake Nutritional Status and Lifestyle of Adolescent Vegetarian and Nonvegetarian Girls in New Zealand (The SuNDiAL Project): Protocol for a Clustered, Cross-Sectional Survey

Background

Anecdotally, vegetarian eating patterns seem to be increasing in parallel with growing concerns about environmental sustainability. While this pattern of eating is widely believed to be associated with benefits for the planet and individual health, it may increase the risk of inadequate intakes and nutrient deficiency if not planned carefully. Adolescent girls may be particularly at risk, as they have increased requirements for nutrients such as iron, zinc, calcium, and vitamin B12 during growth and development.

Objective

The objective of the SuNDiAL Project (Survey of Nutrition, Dietary Assessment, and Lifestyles) is to compare the dietary intakes and habits, nutrition status, motivations, attitudes, and physical activity of a sample of vegetarian and nonvegetarian adolescent girls in New Zealand.

Methods

A clustered, cross-sectional, nationwide study of adolescents aged 15-18 years was conducted. Secondary schools were recruited throughout New Zealand, and pupils (n=290) were invited to participate in data collection in either the first (February to April) or third (August to October) school term of 2019 (New Zealand schools operate on a 4-term year). Sociodemographic and health information; vegetarian status; dietary habits; and attitudes, motivations, and beliefs regarding food choices were assessed via an online self-administered questionnaire. Dietary intakes were collected via two 24-hour diet recalls on nonconsecutive days and will be adjusted for within-person variation using the Multiple Source Method, to represent usual intakes. Nutrient adequacy will be assessed by the estimated average requirement cut-point method or probability approach as appropriate. Height and weight were measured, and blood and urine samples collected for micronutrient status assessment. Participants wore an accelerometer for 7 days to assess 24-hour activity patterns (time spent asleep, sedentary, or engagement in light-intensity or moderate-to-vigorous intensity physical activity).

Results

Recruitment and data collection were conducted in 2019. Data are currently being cleaned and analyzed, with publication of the main results anticipated at the end of 2020.

Conclusions

The SuNDiAL Project will provide a meaningful and timely description of diet, nutrition status, and motivational factors associated with vegetarianism and identify any risks this pattern of eating may pose for female adolescents. The results of this study will support the development of targeted recommendations and interventions aimed at enhancing the health, growth, and development of adolescent girls.

Trial Registration

Australian New Zealand Clinical Trials Registry ACTRN12619000290190; https://tinyurl.com/yaumh278

International Registered Report Identifier (IRRID)

DERR1-10.2196/17310

Medium term post-bariatric surgery deficit of vitamin B12 is predicted by deficit at time of surgery

BACKGROUND

Patients with morbid obesity have a high risk of deficits in micronutrients, after bariatric surgery. The reasons why systematic use of multivitamin and trace element supplements cannot prevent all deficits are complex and should deserve more attention. Little is known about the influence of micronutrient deficits at surgery.

AIM

This present study aimed to explore the deficit in vitamin B12 vs other micronutrients during the follow-up of a French cohort of cases with bariatric surgery under systematic multivitamin/trace elements supplementation and to determine whether it was influenced by clinical, metabolic characteristics at surgery.

METHODS

We prospectively enrolled obese patients with bariatric surgery (laparoscopic gastric bypass or laparoscopic sleeve gastrectomy) between 2013 and 2018 (OBESEPI/ALDEPI Cohort, NCT02663388). They received a daily multivitamin/micronutrients supplement. Follow-up data at 4 visits, 2, 12, 18 and 24 months after surgery, were collected.

RESULTS

The highest rate of deficits was observed at visit 1 for vitamin D (35.7%), iron (21.9%) and folate (10.2%). Except B12, the deficits of all micronutrients decreased in later visits. In contrast, cases with vitamin B12 deficit decreased from 13.5% at surgery to 2.0% at visit 1, and increased in later visits, with a maximum of 12.0% at visit 3. Vitamin B12 concentration at surgery was the single predictor of B12 deficit at visit 3. It was also associated with age, and APRI score, an index of nonalcoholic fatty liver disease (NAFLD), in multivariate analysis.

CONCLUSIONS

The failure of systematic supplementation with multivitamin/trace elements tablets to prevent specific deficits illustrates the need for adapted specific supplementations, in some cases. The worsening of B12 deficit rate in the 18-24 months follow-up depends in part to low B12 at time of surgery. A special consideration should be devoted to this subset of patients. The cohort study was registered at clinicaltrials.gov as NCT02663388.

Dysregulated Gut Homeostasis Observed Prior to the Accumulation of the Brain Amyloid-β in Tg2576 Mice

Amyloid plaques in Alzheimer's disease (AD) are associated with inflammation. Recent studies demonstrated the involvement of the gut in cerebral amyloid-beta (Aβ) pathogenesis; however, the mechanisms are still not well understood. We hypothesize that the gut bears the Aβ burden prior to brain, highlighting gut-brain axis (GBA) interaction in neurodegenerative disorders. We used pre-symptomatic (6-months) and symptomatic (15-months) Tg2576 mouse model of AD compared to their age-matched littermate WT control. We identified that dysfunction of intestinal epithelial barrier (IEB), dysregulation of absorption, and vascular Aβ deposition in the IEB occur before cerebral Aβ aggregation is detectible. These changes in the GBA were associated with elevated inflammatory plasma cytokines including IL-9, VEGF and IP-10. In association with reduced cerebral myelin tight junction proteins, we identified reduced levels of systemic vitamin B12 and decrease cubilin, an intestinal B12 transporter, after the development of cerebral Aβ pathology. Lastly, we report Aβ deposition in the intestinal autopsy from AD patients with confirmed cerebral Aβ pathology that is not present in intestine from non-AD controls. Our data provide evidence that gut dysfunction occurs in AD and may contribute to its etiology. Future therapeutic strategies to reverse AD pathology may involve the early manipulation of gut physiology and its microbiota.

Vitamin B12 and folate levels in progression of Alzheimer's disease - a short report

Background: The status of vitamin B12 and folate has been implicated in the development and progression of Alzheimer's disease.Methods: The study explored this issue through a retrospective case-control study design, with follow up of the case group for 18 months. The case group (n = 136) comprised patients 65 years or older diagnosed with Alzheimer's disease and having a Mini-mental State Examination score (MMSE) of ≤ 27. The control group comprised healthy adults 65 years or older (n = 338) with a MMSE score of >27.Results: Vitamin B12 and folate levels were not found to differ between case and control groups. B12 and folate status at baseline was not predictive of disease progression in the case group.Discussion: This lack of association differs from other studies which have shown a protective effect of vitamin B12 and folate on cognitive decline.KEY POINTSThe findings of this study do not confirm evidence suggesting an effect of vitamin B12 and folate levels on development and progression of Alzheimer's disease.Folate and B12 levels were similar in the Alzheimer's group to those of healthy controls.Folate and B12 levels at initial assessment were not predictive of disease progression.

Serum B12, Homocysteine Levels, and their Effect on Peripheral Neuropathy in Parkinson's Disease: Indian Cohort

Background:

Cobalamin deficiency, either due to dietary inadequacy or increased consumption attributable to levodopa-mediated metabolic disturbance, and resultant hyperhomocysteinemia may contribute to peripheral neuropathy (PN) in Parkinson's disease (PD).

Aim:

The aim of the study is to assess the prevalence of Vitamin B12 deficiency, hyperhomocysteinemia in Indian PD patients, and their association with PN.

Materials and Methods:

Clinical details were collected in 93 patients over a period of 2 years. Seventy controls were included in the study. Serum B12, homocysteine, folate, electroneurography, and autonomic function tests were done. The prevalence of B12 deficiency and hyperhomocysteinemia in PD patients and controls was assessed. The association of B12 and homocysteine levels with patients’ age, disease duration, levodopa equivalent daily dose, cumulative levodopa dose, Unified Parkinson's Disease Rating Scale-III off score, modified Hoehn and Yahr score, and presence or absence of PN was studied.

Results:

Serum B12, homocysteine levels, prevalence of B12 deficiency, and hyperhomocysteinemia were no different between cases and controls. Seven of 93 (9.68%) PD patients had PN. The median values of serum B12, folate, and homocysteine levels across patients with or without PN could not be compared as only seven of our patients had PN.

Conclusion:

The prevalence of B12 deficiency, hyperhomocysteinemia, and incidence of PN among our patients is very less when compared to the Western population. The conjecture that PN in PD patients may be secondary to B12 deficiency/hyperhomocysteinemia stands as a speculation.

The Vaccinia Virus (VACV) B1 and Cellular VRK2 Kinases Promote VACV Replication Factory Formation through Phosphorylation-Dependent Inhibition of VACV B12

Comparative examination of viral and host protein homologs reveals novel mechanisms governing downstream signaling effectors of both cellular and viral origin. The vaccinia virus B1 protein kinase is involved in promoting multiple facets of the virus life cycle and is a homolog of three conserved cellular enzymes called vaccinia virus-related kinases (VRKs). Recent evidence indicates that B1 and VRK2 mediate a common pathway that is largely uncharacterized but appears independent of previous VRK substrates. Interestingly, separate studies described a novel role for B1 in inhibiting vaccinia virus protein B12, which otherwise impedes an early event in the viral lifecycle. Herein, we characterize the B1/VRK2 signaling axis to better understand their shared functions. First, we demonstrate that vaccinia virus uniquely requires VRK2 for viral replication in the absence of B1, unlike other DNA viruses. Employing loss-of-function analysis, we demonstrate that vaccinia virus's dependence on VRK2 is only observed in the presence of B12, suggesting that B1 and VRK2 share a pathway controlling B12. Moreover, we substantiate a B1/VRK2/B12 signaling axis by examining coprecipitation of B12 by B1 and VRK2. Employing execution point analysis, we reveal that virus replication proceeds normally through early protein translation and uncoating but stalls at replication factory formation in the presence of B12 activity. Finally, structure/function analyses of B1 and VRK2 demonstrate that enzymatic activity is essential for B1 or VRK2 to inhibit B12. Together, these data provide novel insights into B1/VRK signaling coregulation and support a model in which these enzymes modulate B12 in a phosphorylation-dependent manner.IMPORTANCE Constraints placed on viral genome size require that these pathogens must employ sophisticated, yet parsimonious mechanisms to effectively integrate with host cell signaling pathways. Poxviruses are no exception and employ several methods to balance these goals, including encoding single proteins that impact multiple downstream pathways. This study focuses on the vaccinia virus B1 protein kinase, an enzyme that promotes virus replication at multiple phases of the viral lifecycle. Herein, we demonstrate that in addition to its previously characterized functions, B1 inhibits vaccinia virus B12 protein via a phosphorylation-dependent mechanism and that this function of B1 can be complemented by the cellular B1 homolog VRK2. Combined with previous data implicating functional overlap between B1 and an additional cellular B1 homolog, VRK1, these data provide evidence of how poxviruses can be multifaceted in their mimicry of cellular proteins through the consolidation of functions of both VRK1 and VRK2 within the viral B1 protein kinase.

Telomere length, vitamin B12 and mortality in persons undergoing coronary angiography: the Ludwigshafen risk and cardiovascular health study

Background: Vitamin B12 (B12) deficiency and excess are associated with increased risk of age-related-diseases and mortality. It has been suggested that high- and low-B12 concentrations link to increased mortality through accelerated genomic aging and inflammation. Evidence to support this is limited.

Results: B12 was associated with all-cause-mortality, RTL and hsCRP in a non-linear fashion. The association between B12 and mortality was not independent, as it lost significance after adjustment for potential confounders. In the lowest-(LB12) and highest-(HB12) quartiles of B12 mortality was higher than in the mid-range (HR:LB12:1.23;CI95%:1.06-1.43; HR:HB12:1.24;CI95%:1.06-1.44). We divided subjects with LB12 in quartiles of their RTL. Those with the longest-telomeres had a lower mortality-rate (HR:0.57;95%CI:0.39-0.83) and lower homocysteine than those with the shortest-telomeres. Amongst subjects with HB12, those with long-telomeres also had a lower mortality than those with short-telomeres (HR:0.40;95%CI:0.27-0.59). IL-6 and hsCRP concentrations were low in HB12LT but were high in HB12ST.

Methods: B12, homocysteine, telomere length (RTL), interleukin-6 (IL-6) and high-sensitive-C-reactive-protein (hsCRP) were measured in 2970 participants of the LURIC study.

Conclusions: Mortality, stratified according to B12 and RTL, seems to be driven by different mechanisms. In LB12 and HB12 subjects, mortality and accelerated telomere shortening might be driven by homocysteine and inflammation, respectively.

Vitamin B12 in Relation to Oxidative Stress: A Systematic Review

The triage theory posits that modest micronutrient deficiencies may induce reallocation of nutrients to processes necessary for immediate survival at the expense of long-term health. Neglected processes could in time contribute to the onset of age-related diseases, in which oxidative stress is believed to be a major factor. Vitamin B12 (B12) appears to possess antioxidant properties. This review aims to summarise the potential antioxidant mechanisms of B12 and investigate B12 status in relation to oxidative stress markers. A systematic query-based search of PubMed was performed to identify eligible publications. The potential antioxidant properties of B12 include: (1) direct scavenging of reactive oxygen species (ROS), particularly superoxide; (2) indirect stimulation of ROS scavenging by preservation of glutathione; (3) modulation of cytokine and growth factor production to offer protection from immune response-induced oxidative stress; (4) reduction of homocysteine-induced oxidative stress; and (5) reduction of oxidative stress caused by advanced glycation end products. Some evidence appears to suggest that lower B12 status is related to increased pro-oxidant and decreased antioxidant status, both overall and for subclinically deficient individuals compared to those with normal B12 status. However, there is a lack of randomised controlled trials and prospective studies focusing specifically on the relation between B12 and oxidative stress in humans, resulting in a low strength of evidence. Further work is warranted.

Vitamin B 12 deficiency and hyperhomocysteinaemia in outpatients with stroke or transient ischaemic attack: a cohort study at an academic medical centre

OBJECTIVE

We sought to assess the current magnitude of the opportunity for secondary stroke prevention with B vitamins.

DESIGN

A cohort study.

SETTING

The Urgent TIA (Transient Ischaemic Attack) Clinic at an academic medical centre.

MAIN OUTCOME MEASURES

We assessed the prevalence of biochemical vitamin B12 deficiency (B12Def, serum B12 <156 pmol/L), hyperhomocysteinaemia (HHcy; plasma total homocysteine [tHcy] >14 µmol/L) and metabolic B12 deficiency (MetB12Def, serum B12 <258 pmol/L and HHcy) between 2002 and 2017, by age group and by stroke subtype.

RESULTS

Data were available in 4055 patients. B12Def was present in 8.2% of patients overall; it declined from 10.9% of patients referred before 2009 to 5.4% thereafter (p=0.0001). MetB12Def was present in 10.6% of patients, and HHcy was present in 19.1% of patients. Among the patients aged ≥80 years, MetB12Def was present in 18.1% and HHcy in 35%. Among the 3410 patients whose stroke subtype was determined, HHcy was present in 18.4% of patients: 23.3% of large artery atherosclerosis, 18.1% of cardioembolic, 16.3% of small vessel disease, 10.8% of other unusual aetiologies and 13.6% of undetermined subtypes (p=0.0001).

CONCLUSIONS

Despite a decline in our referral area since 2009, B12Def, MetB12Def and HHcy remain common in patients with stroke/TIA. Because these conditions are easily treated and have serious consequences, all patients with stroke/TIA should have their serum B12 and tHcy measured.

The B12 receptor BtuB alters the membrane integrity of Caulobacter crescentus

Vitamin B12 is one of the most complex biomolecules in nature. Since few organisms can synthesize B12de novo, most bacteria utilize highly sensitive and specialized transporters to scavenge B12 and its precursors. In Gram-negative bacteria, BtuB is the outer membrane TonB-dependent receptor for B12. In the fresh water bacterium Caulobacter crescentus, btuB is among the most highly expressed genes. In this study, we characterized the function of BtuB in C. crescentus and unveiled a potential new function of this receptor involved in cellular fitness. Under standard minimal or rich growth conditions, we found that supplements of vitamin B12 to cultures of C. crescentus provided no significant advantage in growth rate. Using a B12 methionine auxotroph, we showed that BtuB in C. crescentus is capable of transporting B12 at low pico-molar range. A btuB knockout strain displayed higher sensitivity to detergents and to changes in osmotic pressure compared to the wild-type. Electron micrographs of this knockout strain revealed a morphology defect. The sensitivity observed in the btuB knockout strain was not due to changes in membrane permeability or altered S-layer levels. Our results demonstrate that btuB deletion mutants exhibit increased susceptibility to membrane stressors, suggesting a potential role of this receptor in membrane homeostasis. Because we only tested BtuB's function under laboratory conditions, we cannot eliminate the possibility that BtuB also plays a key role as a B12 scavenger in C. crescentus when growing in its highly variable and nutrient-limited natural environment.

Hemiconvulsion-Hemiplegia-Epilepsy in a girl with cobalamin C deficiency

Hemiconvulsion‐Hemiplegia‐Epilepsy initially involves an infantile presentation of febrile focal motor status epilepticus, with subsequent hemiplegia of the initially affected side. Months to years later, affected children go on to develop a chronic epilepsy with recurrent focal seizures which are often refractory to treatment. This uncommon paediatric epilepsy syndrome is poorly understood, with only a very small minority of cases associated with an underlying genetic or metabolic abnormality.

We present a four‐year‐old girl with genetic cobalamin C deficiency who had a dramatic presentation with Hemiconvulsion‐Hemiplegia‐Epilepsy. She had febrile focal status epilepticus, with right hemiconvulsive seizures for nearly 10 hours, ultimately requiring a midazolam infusion. Over subsequent days, she developed progressively worsening cerebral oedema, leading to herniation and requiring a craniectomy to relieve pressure.

This girl's presentation is the first association of cobalamin deficiency with hemiconvulsion‐hemiplegia‐epilepsy; and illustrates the importance of considering this entity when patients with this metabolic disorder present with acute deterioration. More importantly, the case also raises the possibility that derangements of cobalamin metabolism could be a contributing factor in cases of hemiconvulsion‐hemiplegia‐epilepsy, as well as febrile seizures in general.

LRP2 gene variants and their haplotypes strongly influence the risk of developing neural tube defects in the fetus: a family-triad study from South India

Neural tube defects (NTDs) are the leading cause of infant deaths worldwide. Lipoprotein related receptor 2 (LRP2) has been shown to play a crucial role in neural tube development in mouse models. However, the role of LRP2 gene in the development of human NTDs is not yet known. In view of this, family-based triad approach has been followed considering 924 subjects comprising 124 NTD case-parent trios and 184 control-parent trios diagnosed at Institute of Genetics and Hospital for Genetic Diseases, Hyderabad. Blood and tissue samples were genotyped for rs3755166 (-G759A) and rs2544390 (C835T) variants of LRP2 gene for their association with NTDs. Assessment of maternal-paternal genotype incompatibility risk for NTD revealed 3.77-folds risk with a combination of maternal GA and paternal GG genotypes (GAxGG = GA,p < 0.001), while CT genotypes of both the parents showed 4.19-folds risk for NTDs (CTxCT = CT,p = 0.009). Haplotype analysis revealed significant risk of maternal A-T (OR = 4.48,p < 0.001) and paternal G-T haplotypes (OR = 5.22,p < 0.001) for NTD development. Further, linkage analysis for parent-of-origin effects (POE) also revealed significant transmission of maternal 'A' allele (OR = 2.33,p = 0.028) and paternal 'T' allele (OR = 6.00,p = 0.016) to NTDs. Analysis of serum folate and active-B12 levels revealed significant association with LRP2 gene variants in the causation of NTDs. In conclusion, the present family-based triad study provides the first report on association of LRP2 gene variants with human NTDs.

Long-term treatment with metformin in type 2 diabetes and methylmalonic acid: Post hoc analysis of a randomized controlled 4.3year trial

AIMS

Metformin treatment is associated with a decrease of serum vitamin B12, but whether this reflects tissue B12 deficiency is controversial. We studied the effects of metformin on serum levels of methylmalonic acid (MMA), a biomarker for tissue B12 deficiency, and on onset or progression of neuropathy.

METHODS

In the HOME trial, 390 insulin-treated patients with type 2 diabetes were treated with metformin or placebo for 52months. In a post hoc analysis, we analyzed the association between metformin, MMA and a validated Neuropathy Score (NPS).

RESULTS

Metformin vs placebo increased MMA at the end of the study (95%CI: 0.019 to 0.055, p=0.001). Mediation analysis showed that the effect of metformin on the NPS consisted of a beneficial effect through lowering HbA1c (-0.020 per gram year) and an adverse effect through increasing MMA (0.042 per gram year), resulting in a non-significant net effect (0.032 per gram year, 95% CI: -0.121 to 0.182, p=0.34).

CONCLUSION

Metformin not only reduces serum levels of B12, but also progressively increases serum MMA. The increase of MMA in metformin users was associated with significant worsening of the NPS. These results provide further support that metformin-related B12 deficiency is clinically relevant. Monitoring of B12 in users of metformin should be considered.