Vitamin B12 - Peptide Nucleic Acid Conjugates

Vitamin B₁₂ (cobalamin, Cbl) is an essential nutrient for all mammals and some bacteria. From a chemical point of view, it is a highly functionalized molecule, which enables conjugation at multiple positions and attachment of various cargoes. Both mammalian and bacterial cells have developed a specific transport pathway for the uptake of vitamin B₁₂, and as a consequence, cobalamin is an attractive candidate for the delivery of biologically relevant molecules into cells. Indeed, hybrid molecules containing vitamin B₁₂ in their structure have found various applications in medicinal chemistry, diagnostics, and biological sciences.Herein, we describe synthetic strategies toward the synthesis of vitamin B₁₂ conjugates with peptide nucleic acid (PNA ) oligomers. Such short-modified oligonucleotides targeted at bacterial DNA or RNA can act as antibacterial agents if efficiently taken up by bacterial cells. The uptake of such oligonucleotides is hindered by the bacterial cell envelope, but vitamin B₁₂ was found to efficiently deliver antisense PNA into Escherichia coli and Salmonella Typhimurium cells. This paves the way to the use of vitamin B₁₂-PNA conjugates in antibacterial and diagnostic applications.Vitamin B₁₂-PNA conjugates can be prepared via copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) that gives access to covalently linked hybrids or via connecting both building blocks by reduction-sensitive disulfide bridge. Both approaches require prior modification of vitamin B₁₂ by incorporation of the azide moiety or via transformation of the native functional group into a moiety reactive toward thiols. Conjugation of vitamin B₁₂ with PNA-tagged substrates efficiently furnishes designed conjugates.

Comparison of Vitamin B12, Vitamin D, and Folic Acid Blood Levels in Plumbism Patients and Controls in Eastern Iran

The aim of this study was to evaluate the blood levels of folic acid, vitamin B12, and 25-hydroxyvitamin D (25-OHD) in patients with lead poisoning compared with control subjects in Eastern Iran. This analytical case-control study was conducted on 40 lead-poisoned patients who were referred to Imam Reza Hospital in Birjand from 2018 to 2019. Blood samples were collected from an additional 40 individuals without lead poisoning as a control group. The results indicated that the mean vitamin B12, vitamin D, and folic acid levels for the case group were 356.5 ± 200.1 pg/ml, 24.38 ± 9.5 ng/ml, and 7.4 ± 3.7 ng/ml, respectively. Mean folic acid level in the case group was significantly lower than control group (7.4 ng/ml vs. 12.70 pg/ml, P = 0.001), whereas the mean of the vitamin D levels at the case group was significantly higher than that of the control group (24.3 ng/ml vs. 20.1 ng/ml, P = 0.03). Moreover, mean vitamin B12 levels were significantly lower in the case group in comparison with the control group (356.5 pg/ml vs. 500.8 pg/ml) (P < 0.001). In the control group, 3 patients had folic acid below normal level (< 6 ng/mL) while 12 cases had folic acid below normal (P < 0.05). Also, none of the control group had low vitamin B12 concentrations (< 180 pg/ml), while 7 cases had vitamin b12 below normal (P < 0.05). Our results suggest that lead may induce folate and vitamin B12 dysregulation. Although we found that vitamin D levels were insufficient in both case and control groups, they were significantly higher in the case group. The interpretation of this result is unclear given inconsistent literature reports on this relationship.

Assessment of Vitamin B12 Deficiency and Risk Factors in Healthy Infants

OBJECTIVE

To study vitamin B₁₂ deficiency in apparently healthy infants and their mothers and assess the risk factors.

METHODS

A hospital-based, cross-sectional, observational study was conducted from July 2016 through December 2017. Consecutive healthy and normally developing infants were enrolled. Red blood cell folate, plasma vitamin B₁₂, homocysteine and methylmalonic acid levels of mothers and infants were assessed.

RESULTS

Seventy-four healthy infants were enrolled. Male-to-female ratio was 1.5:1. Anemia in 66.2% (n = 49), low plasma B₁₂ in 17.6% (n = 13), hyperhomocysteinemia in 48.6% (n = 36), plasma methylmalonic acid in 100% (n = 74) and 'confirmed' B₁₂ deficiency in 38% (n = 28) infants were noted. The proportion of hyperhomocysteinemia increased to 75.7% (n = 56) infants using a lower cut-off of >10 μmol/L. In mothers, low B₁₂ in 19%, hyperhomocysteinemia in 57% and elevated plasma methylmalonic acid in 100% were noted. Median plasma B₁₂ level was 314 pg/ml (IQR 221-421), median plasma homocysteine 15.4 μmol/L (IQR 11.3-21.7) and median plasma methylmalonic acid was 8.28 μmol/L (IQR 4.4-13.1) in mothers. Folate deficiency was noted in 9.4% infants and 12% of mothers. Overall, 63.5% mothers were vegetarian and, 64% of the mothers of infants with confirmed vitamin B12 deficiency were pure vegetarians. Odds of developing vitamin B₁₂ deficiency increased by more than 5 times in those whose mothers' serum vitamin B₁₂ levels were low as compared to normal maternal vitamin B₁₂ levels (OR 5.42; 95% CI: 1.96-16.6; p 0.002).

CONCLUSIONS

There is a high prevalence of vitamin B₁₂ deficiency in infants and their mothers. There is urgent need to supplement our population with vitamin B₁₂.

COVID-19's toll on the elderly and those with diabetes mellitus - Is vitamin B12 deficiency an accomplice?

COVID-19 exacts a disproportionate toll on both the elderly and those with diabetes; these patients are more likely to require costly intensive care, longer hospitalisation, and die from complications. Nations would thus find it extremely difficult to either lift or sustain socially, economically, and politically damaging restrictions that keep this group of people safe. Without a vaccine, there is thus an urgent need to identify potential modifiable risk factors which can help manage overall fatality or recovery rates. Case fatality rates are highly variable between (and even within) nations; nutritional differences have been proposed to account significantly for this disparity. Indeed, vitamin B12 deficiency is a common denominator between the elderly and those with diabetes. The question on hand thus lies on whether managing B12 deficiencies will impact COVID-19 fatality outcome or recovery rates. Herein, we review the latest evidence that shows that B12 deficiency associates in multiple areas very similar to where COVID-19 exerts its damaging effects: immunologically; microbiologically; haematologically; and through endothelial cell signalling-supporting the hypothesis that B12 deficiency is a potential modifiable risk factor in our fight against COVID-19.

Maternal serum Vitamin B12 and offspring attention-deficit/hyperactivity disorder (ADHD)

Maternal Vitamin B12 deficiency during pregnancy is associated with offspring neuropsychiatric disorders. Few previous studies examining this association with attention-deficit/hyperactivity disorder (ADHD) report inconsistent findings. The study examines the association between maternal serum Vitamin B12 levels and offsprings' risk of ADHD. This study is based on the Finnish Prenatal Study of ADHD with a nested case-control design. All the singleton children born in Finland between January 1998 and December 1999 and diagnosed with ADHD were included in the study. A total of 1026 cases were matched with an equal number of controls on sex, date of birth and place of birth. Maternal Vitamin B12 levels were assessed using a chemiluminescence microparticle immunoassay and archived from maternal serum banks, collected during the first and early second trimester of pregnancy. Lower maternal Vitamin B12 levels when analyzed as a continuous variable was not associated with offspring ADHD (aOR 0.97, 95% CI 0.79-1.18, p = 0.75). No significant associations were seen in the lowest quintile of Vitamin B12 levels (aOR 0.96, 95% CI 0.73-1.27, p = 0.80). This is the first study examining maternal sera Vitamin B12 levels during early pregnancy and offspring ADHD. The result suggests that Vitamin B12 deficiency during early pregnancy has specificity for some disorders but not with offspring ADHD.

Long-term administration of vitamin B12 and adenosine triphosphate for idiopathic sudden sensorineural hearing loss: a retrospective study

Background

In idiopathic sudden sensorineural hearing loss (ISSNHL), the relationship between the administration duration of vitamin B12 (vit B12) with adenosine triphosphate (ATP) and their therapeutic effect is not fully understood.

Objective

To investigate the therapeutic effect of long-term 16 (≥weeks) administration of vit B12 with ATP on the prognosis of ISSNHL patients and compare it with those of short-term (<8 weeks) and middle-term (≥8 weeks, <16 weeks) administration.

Methods

We retrospectively reviewed the medical records of 117 patients with ISSNHL treated between 2015 and 2018.

Results

The overall recovery rate was 32.5%. Initial higher hearing threshold and initial higher grade of hearing loss (HL) were associated with a poor prognosis. However, the administration duration of vit B12 and ATP did not influence the overall hearing improvement. With regard to the time course of hearing recovery, there was no significant difference in hearing recovery among the long-, middle-, and short-term administration groups until 16 weeks after treatment. However, at 16–24 weeks after initial treatment, the short-term administration group exhibited significantly lower hearing recovery than did the long-term administration groups.

Conclusions

The administration duration of vit B12 and ATP did not influence the overall hearing prognosis in ISSNHL, but long-term administration of vit B12 and ATP helped prevent the progression of HL after ISSNHL. Our results suggest that long-term administration of vit B12 and ATP is not necessarily required to treat ISSNHL patients, except for slowly progressing HL in the affected ears.

Maternal prenatal vitamin B12 intake is associated with speech development and mathematical abilities in childhood

Deficiencies of many nutrients in pregnancy have adverse effects on fetal brain development with consequent impaired cognitive function in childhood. However, it is unclear whether deficiencies of vitamin B12 prenatally are harmful to the developing fetus. We therefore used the Avon Longitudinal Study of Parents and Children to test the hypothesis that cognitive outcomes in childhood are reduced if their mothers consumed a diet low in vitamin B12 during pregnancy. A detailed exposome analysis was used to identify 9 factors independently associated with low vitamin B12 intake. These were taken into account in each of 26 outcome analyses. Results showed that the children of women with the lowest 10% intake of B12 were at increased risk of poor vocabulary at 24 months, reduced ability at combining words at 38 months, poor speech intelligibility at 6 years, poor mathematics comprehension at school years 4 and 6 (ages 8-9 and 10-11 years), and poor results on the national mathematics tests (age 13). There were no such significant adjusted associations for reading or spelling abilities, or for verbal or full-scale IQ (Intelligence Quotient) at 8 or at 15. Thus, we have confirmed that there are adverse effects on the child's development if the pregnant woman has a low intake of vitamin B12, and we have shown that these are specific to certain speech and mathematical abilities.

Effects of vitamin B12 on methotrexate hepatotoxicity: evaluation of receptor-interacting protein (RIP) kinase

In the study, we aimed to show the effects of vitamin B12 on the necrosis caused by methotrexate (MTX), a folic acid antagonist. Thirty-two rats were randomly assigned to four groups of eight rats per group. Control (n = 8), Vit B12 (n = 8) 3 μg/kg/ip B12 (15 days) per day throughout the experiment, MTX (n = 8) injected with a single dose of 20 mg/kg/ip MTX on 8th day of experiment, MTX + Vit B12 (n = 8) injected with a single dose of 20 mg/kg ip methotrexate on 8th day of experiment + 3 μg/kg/ip Vit B12 (15 days) per day throughout the experiment. Oxidant (TOS)/antioxidant (TAS) system, TNF-α and TGF-β levels, AST and ALT, serum vitamin B12 levels were determined in the tissue. Cyclooxygenase-2 (Cox-2), receptor-interacting protein kinase 1 (RIP1) and 3 (RIP3) immunohistochemistry were applied to the liver tissue. TOS increased; TAS decreased; TNF-α and TGF-β levels increased; AST and ALT levels changed after MTX hepatotoxicity. Vit B12 decreased significantly. COX-2, RIP1, and RIP3 immunoreactivity increased. Vit B12 showed improvement in all of the negative results. Vit B12 is an important supplement to be used against necrosis in tissue after MTX hepatotoxicity.

Long-term metformin treatment and risk of peripheral neuropathy in older Veterans

AIM

Our objective was to assess whether increased duration of metformin therapy is associated with incident peripheral neuropathy (PN) in older Veterans with diabetes.

METHODS

Using national Veterans Affairs registry data from 2002 to 2015, we examined Veterans (50 + years) with diabetes. Long-term metformin therapy was defined as prescription ≥ 500 mg/day, filled for ≥ 6 consecutive months. Metformin therapy duration was examined both as continuous and categorical measures. Incident PN was defined by medical chart review. We estimated unadjusted and adjusted (variables selecteda priori)odds ratios (OR) and 95% confidence intervals (CI) using logistic regression.

RESULTS

The study included n = 210,004 individuals (mean ± SD: age: 66.2 ± 8.4 yrs, 96% male) prescribed metformin for 47.0 ± 34.0 months. Nineteen percent developed PN during follow-up. After adjusting for age, body mass index, duration of time receiving health care within the VA, smoking status, alcohol abuse, and vitamin B12 testing and treatment, the number of months of metformin treatment was associated with elevated odds for incident PN (aOR (metformin treatment - continuous) = 1.009 (95% CI = 1.009, 1.010); aOR (metformin treatment - categorical (ref: 6-<18 months): 18-<44.1 months = 1.57 (1.51-1.63), 44.1-<61 months = 2.05 (1.97-2.14), 61 + months = 2.69 (2.58-2.79), all p-values < 0.0001).

CONCLUSION

Our study suggests that Veterans treated for at least 18 months with metformin are approximately 2-3 times more likely to develop PN than those treated at least six, but<18 months. Future studies are needed to determine whether the association we found may be due to a decline in vitamin B12 status following metformin initiation.

Metformin Preserves Peripheral Nerve Damage with Comparable Effects to Alpha Lipoic Acid in Streptozotocin/High-Fat Diet Induced Diabetic Rats

BACKGROUND

Metformin is widely marketed medication for the treatment of diabetes, but its pharmacological effect on diabetic peripheral neuropathy remains unclear. In this study, the effect of metformin on peripheral nerves in diabetic rats was investigated using diverse neuronal parameters of nerve fibers.

METHODS

Rats were assigned to one of four groups (n=7 to 10 per group): normal, diabetes mellitus (DM), DM+metformin (100 mg/kg), and DM+alpha lipoic acid (ALA, 100 mg/kg). DM was induced by streptozotocin/high-fat diet (STZ/HFD). After 12 weeks, the sensory thresholds to mechanical and heat stimuli were assessed. Repeated sensory tests, immunofluorescence microscopic comparison of peripheral nerves, and biochemical blood analysis were performed after 24 weeks.

RESULTS

Both DM+metformin and DM+ALA groups showed similar trends to diverse sensory tests at 24 weeks compared to DM group although the degree of change were different according to the stimulated senses. There was no significant difference in the comparison of the intraepidermal nerve fiber density (IENFD) of peripheral nerves between the DM+metformin and DM+ALA groups (11.83±0.07 fibers/mm vs. 12.37±1.82 fibers/mm, respectively). Both groups showed preserved IENFD significantly compared with DM group (8.46±1.98 fibers/mm, P<0.05). Sciatic nerve morphology of the experimental animals showed a similar trend to the IENFD, with respect to axonal diameter, myelin sheath thickness, and myelinated fiber diameter.

CONCLUSION

Metformin has beneficial pharmacological effects on the preservation of peripheral nerves in diabetic rats and its effects are comparable to those of ALA.

Vitamin B12-loaded polycaprolacton/gelatin nanofibrous scaffold as potential wound care material

The current study aimed to develop a potential wound dressing using vitamin B12-loaded polycaprolacton/gelatin nanofibrous scaffold. In order to produce wound dressings, 1000 mcg of vitamin B12 was added to polycaprolacton/gelatin solution and the nanofibrous scaffolds were fabricated through electrospinning method. The obtained scaffolds were studied regarding their hydrophobicity, microstructure, amount of water absorption, water vapor permeability, tensile strength, release test, and cellular proliferation assay. In vitro studies revealed that the incorporation of vitamin b12 into polycaprolacton/gelatin scaffolds could significantly augment L929 cells proliferation at 1 and 3 days post-seeding. However, there was not statistically significant difference between Vitamin B12-containing and polymer-only scaffolds in tensile strength study, surface wettability measurement, water vapor transmission test, the capacity for water absorption, and nanofiber's diameter. Both vitamin containing and free dressings were applied on the full-thickness excisional wound in rat model to compare their healing potential. Our results showed that after 14 days, vitamin B12 containing dressing could significantly enhance wound closure compared to vitamin B12 free scaffolds (92.27 ± 6.84% vs. 64.62 ± 2.96%). Furthermore, histopathological examinations showed significantly greater epithelial thickness in polycaprolacton/gelatin/vitamin B12 group compared to other experimental groups. This preliminary study suggest potential applicability of the proposed dressing to treat skin wounds in clinic.

Subacute combined degeneration of the cervical and dorsal spinal cord in a 40-year-old male patient: A case report

Subacute combined degeneration of the spinal cord is a neurologic complication of vitamin B12 deficiency. It presents as a potentially reversible demyelination of the posterior and lateral columns of the cervical and dorsal spinal cord. We present the case of a 40-year-old male with progressive sensory and motor deficit from the lower extremities ascending to the mid-thoracic region. A combination of laboratory tests and magnetic resonance imaging confirmed the diagnosis of subacute degeneration of the spinal cord due to vitamin B12 deficiency.

The Relation between Changes in Vitamin D and Vitamin B12 Levels, Body Mass Index and Outcome in Methadone Maintenance Treatment Patients

Patients' Body Mass Index (BMI) increase during methadone maintenance treatment (MMT), and both Vitamins D and B12 deficiencies may be associated with BMI. We studied the relations between BMI, these vitamins and treatment outcome in patients with opioid use disorder receiving MMT. Vitamin B12 levels were available for 272 patients and Vitamin D levels were available for 260 patients. Of those 112 and 80 respectively had two measures (at admission or thereafter, and while stabilized or after one year in treatment). Patients' BMI levels and long-term retention were analyzed. Vitamin B12 was lower in patients abusing cocaine/amphetamine on admission. Vitamin D did not change over time, but a significant weight gain could be observed in 38 patients whose vitamin D was elevated compared to 42 whose levels were not, (25.4 ± 4.8 to 28.8 ± 5.2 vs. 24.3 ± 3.7 to 25.5 ± 4.0, p(Time) < 0.0005, p(Group) = 0.03, p(interaction) = 0.02). BMI changes correlated with vitamin D levels change (r = 0.26, p = .04). Longer cumulative retention was observed among the elevated vitamin D group (8.1 years, 95% CI 6.3-9.8) in comparison with the non-elevated group (4.8y 95% CI 3.6-6.1, Kaplan Meier, p = .02). Stimulants misuse was associated with low B12 levels. Vitamin D elevation is associated with weight gain and longer retention in treatment.

Evaluation of Micronutrient Status Post Laparoscopic Sleeve Gastrectomy: an Australian Perspective

BACKGROUND

Laparoscopic sleeve gastrectomy (LSG) is a type of bariatric technique that has comparable outcomes to Roux-en-Y gastric bypass, the current gold standard. However, it can be associated with nutritional deficiencies postoperatively. The aim of this study was to evaluate micronutrient status post LSG.

METHODS

This is a retrospective study of 565 patients who underwent an LSG from January 2015 to September 2018. Patients lost to follow-up at 3, 6 and 12 months were 6.3%, 18.6% and 32.4%, respectively. Follow-up of the patients included regular dietetic input and micronutrient supplementation. Data that was collected included both anthropometry and nutritional markers.

RESULTS

The mean preoperative weight and body mass index (BMI) were 118.13 ± 25.36 kg and 42.40 ± 7.66 kg/m², respectively. Statistically, significant reductions in anthropometric parameters including weight, BMI (30.50 kg/m²), total weight loss (28.03%), excess weight loss (72.03%) and BMI loss (12.32 kg/m²) were observed at all timepoints up to 12 months follow-up. At 12 months, there were significant increases in 25-OH vitamin D with the incidence of deficiency decreasing from 45.7 to 15.0% compared to baseline. The incidence of hyperparathyroidism also decreased from 32.2 to 18.9% compared to baseline, and incidence of folate deficiency increased from 7.7 to 19.2%. Other nutritional parameters including calcium, iron, ferritin, vitamin B12, holotranscobalamin (active B12) and haemoglobin did not significantly change.

CONCLUSIONS

Modest effects on micronutrient status were observed in the 12-month postoperative period. Of clinically significant, de novo folate deficiencies increased, and vitamin D deficiency and hyperparathyroidism decreased. Thus, optimizing postoperative micronutrient status is imperative following LSG.

Development and characterisation of a nanostructured hybrid material with vitamin B12 and bagasse-derived activated carbon for anaerobic chlordecone (Kepone) removal

Intensive use of the chlorinated pesticide chlordecone from the 1970s to 1993 to prevent crop damage in banana plantations of Guadeloupe and Martinique led to diffuse pollution of soils and surface waters, affecting both fauna and human beings in the contaminated areas. Since 2001, drinking water production plants have been equipped with filters containing activated carbon that must be treated after saturation. The objective of this work is to produce a hybrid material composed of activated carbon and vitamin B12 (VB12) for the degradation of chlordecone (CLD). The preparation of such a hybrid material is carried out by non-covalent fixation to achieve an eco-friendly solution for the serious environmental problem of contamination by chlorinated pesticides. It is thus proposed to degrade CLD by a physico-chemical treatment allowing salvage of the catalyst, which is adsorbed on the carbon surface to generate less waste that is inexpedient to treat. Activated carbon (AC) is produced locally from available sugarcane bagasse subjected to phosphoric acid activation. The main characteristics of this material are a major mesoporous structure (0.91%) and a specific (BET) surface area ranging from 1000 to 1500 m² g^-1. The experimental results showed that BagP1.5 has a high adsorption capacity for VB12 due to its large surface area (1403 m² g^-1). The binding of VB12 to the bagasse-derived AC is favoured at high temperatures. The adsorption is optimal at a pH of approximately 6. The maximum adsorption capacity of VB12 on the AC, deduced from the Langmuir model, was 306 mg g^-1, confirming the high affinity between the two components. The hybrid material was characterised by FTIR, Raman, X-ray fluorescence spectroscopy and SEM analysis. CLD removal by this hybrid material was faster than that by VB12 or BagP1.5 alone. The CLD degradation products were characterised by mass spectrometry.

Maternal intake of one-carbon metabolism-related B vitamins and anorectal malformations in the Japan Environment and Children's Study

The occurrence of anorectal malformations (ARM) is thought to be reduced with sufficient folate intake. However, there is no apparent evidence. We focused on enzyme cofactors for one-carbon metabolism, including folate (vitamin B9), vitamin B6 and vitamin B12, and explored the association between maternal combined intake of these B vitamins and the risk of ARM. Using baseline data from a Japanese nationwide birth cohort study between 2011 and 2014, we analysed data of 89 235 women (mean age at delivery = 31·2 years) who delivered singleton live births without chromosomal anomalies. Information on dietary intake was obtained via a FFQ focused on early pregnancy and used to estimate B vitamin intake. We also collected information on the frequency of folic acid supplement use. ARM occurrence was ascertained from medical records. We identified forty-three cases of ARM diagnosed up to the first month after birth (4·8 per 10 000 live births). In terms of individual intake of the respective B vitamins, high vitamin B6 intake was non-significantly associated with reduced odds of ARM. Compared with women in the low combined B vitamin intake group, the OR of having an infant with ARM was 0·4 (95 % CI 0·2, 1·0) in the high intake group (folate ≥400 μg/d, and upper half of vitamin B6 and/or vitamin B12). In conclusion, our cohort analysis suggested an inverse association between the combined intake of one-carbon metabolism-related B vitamins in early pregnancy and ARM occurrence.

Role of vitamin B12 in treating recurrent aphthous stomatitis: A review

Vitamin B12, a water-soluble vitamin, plays a vital role in the formation of hematopoietic stem cells and has been associated with oral mucosal diseases, mainly recurrent aphthous stomatitis (RAS). The latter is a debilitating condition, and B12 was proposed as a potential treatment given its role in regenerating oral mucosal tissue. There is conflicting evidence that B12 deficiency causes RAS. Five of the seven randomized controlled trials reviewed used the inactive form of B12 (cyanocobalamin) as intervention, while the other two used the active form (methylcobalamin). Of the latter two, buccal discs (500 μg B12) showed significant improvement and reduced perceived pain in 77% of the subjects, and submucosal injections showed a significant difference in pain, starting from the second day. Moreover, three studies administered vitamin B12 sublingually with different dosages, which revealed that the higher dose (1000 μg) achieved a significant reduction in outbreaks, number, and duration of ulcers, especially after six months. Multivitamins showed no difference in new RAS episodes and duration. Injectable B12 was compared with the oral form, and nearly 50% of the injection group reported a desired response by the eighth week. An ointment form (500 μg) showed a significant reduction in pain levels after two days of treatment. Based on the available literature, we suggest that a daily dose of 1000 μg of vitamin B12 sublingually for six months can be used to treat RAS. Nevertheless, this conclusion should be considered tentative due to the lack of high quality, large scale studies.

Relationship between serum B12 concentrations and mortality: experience in NHANES

BACKGROUND

There is conflicting evidence in the literature on the association between (elevated) serum B12 concentrations and subsequent disease or mortality. We evaluated in the NHANES general population the association of serum B12 concentrations as well as vitamin B12 supplement intake with all-cause, cardiovascular, and cancer-related mortality, while taking into account demographic and lifestyle factors and significant other diseases which are known to be associated with poorer outcome.

METHODS

The main outcomes of our study were all-cause mortality, cardiovascular mortality, and cancer-related mortality. Mortality status and cause of death were determined by NHANES-linked National Death Index public access files through December 31, 2015. The association of serum B12 concentrations and vitamin B12 supplement intake with mortality was assessed with Cox proportional hazard (PH) models, with adjustment for a number of relevant demographic and lifestyle factors and comorbidity.

RESULTS

The final study population of 24,262 participants had a mean age of 48 (SD 19) years; 50.1% were males. The median follow-up duration was 109 months (range 1-201 months). On the census day of December 31, 2015, 3023 participants were determined as deceased (12.5%). The fully adjusted Cox PH model indicated that low serum B12 concentrations < 140 pmol/l were associated with a small increase in all-cause (hazard ratio, HR 1.39, 95% CI 1.08-1.78, p = 0.011) and cardiovascular (HR 1.64, 95% CI 1.08-2.47, p = 0.020) mortality. Similarly, high serum B12 concentrations > 700 pmol/l were associated with an increase in cardiovascular mortality only (HR 1.45, 95% CI 1.01-2.06, p = 0.042). Participants with a diagnosis of hypertension, dyslipidemia, CVD, and cancer more frequently used vitamin B12-containing supplements than those without these diagnoses. We could not demonstrate an association between vitamin B12 supplement intake and mortality, when adjusted for comorbidity.

CONCLUSIONS

In the general population of NHANES, low serum B12 concentrations were associated with a moderate increase in all-cause mortality. There was a small but significant increase in cardiovascular mortality in the groups with low or high serum B12. High intake of vitamin B12 in the form of supplements was not associated with any adverse effect on mortality and therefore can be regarded as safe.

B-vitamins and metabolic syndrome in Mesoamerican children and their adult parents

OBJECTIVE

To examine the associations between vitamins of the methionine-homocysteine (Hcys) cycle (B6, B12 and folate) and Hcys with metabolic syndrome (MetS) among Mesoamerican children and their adult parents.

DESIGN

We conducted a cross-sectional study. Exposures were plasma vitamins B6 and B12 concentrations, erythrocyte folate and plasma Hcys. In children, the outcome was a continuous metabolic risk score calculated through sex- and age standardisation of waist circumference, the homoeostatic model assessment for insulin resistance, mean arterial pressure (MAP), serum HDL-cholesterol and serum TAG. In parents, the outcome was the prevalence of MetS according to the Adult Treatment Panel III Criteria. We estimated mean differences in the metabolic risk score and prevalence ratios of MetS between quartiles of the exposures using multivariable-adjusted linear and Poisson regression models, respectively.

SETTING

Capital cities of Belize, Guatemala, El Salvador, the Dominican Republic, Honduras, Nicaragua, Panama, Costa Rica and Chiapas State in Mexico.

PARTICIPANTS

In total, 237 school-aged children and 524 parents.

RESULTS

Among children, vitamin B12 was inversely associated with the metabolic risk score (quartiles 4-1 adjusted difference = -0·13; 95 % CI: -0·21, -0·04; Ptrend = 0·008) through MAP, HDL-cholesterol and TAG. In contrast, folate was positively associated with the metabolic risk score (quartiles 4-1 adjusted difference = 0·11; 95 % CI: 0·01, 0·20; Ptrend = 0·02). In adults, vitamin B6 was inversely associated with MetS prevalence, whereas vitamin B12 and folate were positively related to this outcome.

CONCLUSIONS

Vitamins of the methionine-Hcys cycle are associated with MetS in different directions. The associations differ between children and adults.

Vitamin B6, vitamin B12 and methionine and risk of pancreatic cancer: a meta-analysis

Background

Nutrients involved in one-carbon metabolism may play a key role in pancreatic carcinogenesis. The aim of this study was to examine the association between pancreatic cancer risk and intake or blood levels of vitamins B6, B12 and methionine via meta-analysis.

Methods

A systematic search was performed in PubMed, Web of Knowledge and Chinese National Knowledge Infrastructure (CNKI) up to April 2020 to identify relevant studies. Risk estimates and their 95% confidence intervals (CIs) were retrieved from the studies and combined by a random-effect model.

Results

A total of 18 studies were included in this meta-analysis on the association of vitamin B6, B12 and methionine with pancreatic cancer risk. The combined risk estimate (95% CI) of pancreatic cancer for the highest vs lowest category of vitamin B6 intake and blood pyridoxal 5′-phosphate (PLP, active form of vitamin B6) levels was 0.63 (0.48–0.79) and 0.65 (0.52–0.79), respectively. The results indicated a non-linear dose-response relationship between vitamin B6 intake and pancreatic risk. Linear dose–response relationship was found, and the risk of pancreatic cancer decreased by 9% for every 10 nmol/L increment in blood PLP levels. No significant association were found between pancreatic cancer risk and vitamin B12 intake, blood vitamin B12 levels, methionine intake and blood methionine levels.

Conclusion

Our study suggests that high intake of vitamin B6 and high concentration of blood PLP levels may be protective against the development of pancreatic cancer. Further research are warranted to confirm the results.

Proteinuria as a presenting sign of combined methylmalonic acidemia and homocysteinemia: case report

Background

Disorders of the metabolism and absorption of vitamin B12 can lead to decrease in activity of methionine synthetase and methylmalonate coenzyme A mutase (MMUT), which results in increased levels of methylmalonic acid and homocysteine in blood and urine. Often, combined methylmalonic acidemia (MMA) and homocysteinemia is misdiagnosed due to a lack of specific symptoms. The clinical manifestations are diverse, but proteinuria as the initial presentation is rare.

Case presentation

Two cases of MMA with homocysteinemia in children are reported. Proteinuria were a primary presenting symptom, followed by anemia and neurologic symptoms (frequent convulsions and unstable walking, respectively). Screening of amino acids and acyl carnitine in serum showed that the propionyl carnitine:acetylcarnitine ratio increased. Profiling of urinary organic acids by gas chromatography–mass spectrometry revealed high levels of methylmalonic acid. Homocysteine content in blood was increased. Comprehensive genetic analyses of peripheral blood-derived DNA demonstrated heterozygous variants of methylmalonic aciduria type C and homocystinuria (MMACHC) and amnionless (AMN) genes in our two patients, respectively. After active treatment, the clinical manifestations in Case 1 were relieved and urinary protein ceased to be observed; Case 2 had persistent proteinuria and was lost to follow-up.

Conclusions

Analyses of the organic acids in blood and urine suggested MMA combined with homocysteinemia. In such diseases, reports of renal damage are uncommon and proteinuria as the initial presentation is rare. Molecular analysis indicated two different genetic causes. Although the pathologic mechanisms were related to vitamin B12, the severity and prognosis of renal lesions were different. Therefore, gene detection provides new insights into inherited metabolic diseases.

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

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

Reduced levels of serum vitamin B12 in symptomatic cases of oral lichen planus: A cross-sectional study

Objectives

Oral Lichen Planus (OLP) is an immune mediated disease and causes oro-mucosal burning sensation that reduces food intake and hence resulting in nutritional deficiency. The present study was done to evaluate the serum levels of vitamin B12 in patients with symptomatic OLP and establish an association between reduced B12 levels and OLP.

Materials and method

Serum vitamin B12 was assessed in 60 symptomatic cases of oral lichen planus and 60 healthy age and gender matched controls.

Results

Serum vitamin B12 was significantly reduced (p value < 0) in patients with oral lichen planus when compared to healthy individuals. 43.33% of cases (26 out of 60) had B12 levels less than 187 pg/ml.

Conclusion

Oral lichen planus causes serum vitamin B12 deficiency. Vitamin B12 is linked with normal functioning of immune and neuropsychologic system which has a role to play in etiopathogenesis and malignant transformation of oral lichen planus.

The profile of hematinic deficiencies in patients with oral lichen planus: a case-control study

Background

Oral lichen planus (OLP) is a relatively common mucocutaneous disorder, and its causative factors and pathogenesis are not fully understood. Existing studies on the association between hematinic deficiencies and OLP are limited and inconsistent. The aim of this study was to assess the hematinic deficiencies in a cohort of OLP patients and evaluate the correlation between hematinic deficiencies and OLP.

Methods

A total of 236 OLP patients and 226 age-and-gender-matched healthy controls were enrolled in this study. The levels of hemoglobin (Hb), serum folate, vitamin B12 and ferritin were measured and compared between OLP patients and healthy controls. An REU (reticular/hyperkeratotic, erosive/erythematous, ulcerative) scoring system was adopted and compared between the OLP patients with and without hematinic deficiencies. The correlation between hematinic deficiencies and OLP was analyzed.

Results

The frequencies of serum ferritin and vitamin B12 deficiency in OLP patients were both significantly higher than those of the healthy controls. According to gender and age, the profiles of hematinic deficiencies in OLP patients were significantly different. As for the REU score, no significant difference existed between OLP patients with and without hematinic deficiencies. Both serum ferritin deficiency and serum vitamin B12 deficiency were significantly correlated with OLP.

Conclusions

The present study suggested a significant association between hematinic deficiencies and OLP. Iron, folate, and vitamin B12 levels in OLP patients should be monitored routinely. Further studies are warranted to explore the interactions between OLP and hematinic deficiencies.

Prevalence of Vitamin B12 Deficiency and its Associated Factors among Patients with Type 2 Diabetes Mellitus on Metformin from a District in Malaysia

Introduction

Vitamin B12 deficiency is more common among metformin-treated subjects although the prevalence is variable. Many factors have been associated with this. The aim of this study is to determine the prevalence of vitamin B12 deficiency and its associated factors among patients with type 2 diabetes mellitus (DM) who are on metformin.

Methodology

A total of 205 patients who fit eligibility criteria were included in the study. A questionnaire was completed, and blood was drawn to study vitamin B12 levels. Vitamin B12 deficiency was defined as serum B12 level of ≤300 pg/mL (221 pmol/L).

Results

The prevalence of vitamin B12 deficiency among metformin-treated patients with type 2 DM patients was 28.3% (n=58). The median vitamin B12 level was 419 (±257) pg/mL. The non-Malay population was at a higher risk for metformin-associated vitamin B12 deficiency [adjusted odds ratio (OR) 3.86, 95% CI: 1.836 to 8.104, p<0.001]. Duration of metformin use of more than five years showed increased risk for metformin-associated vitamin B12 deficiency (adjusted OR 2.06, 95% CI: 1.003 to 4.227, p=0.049).

Conclusion

Our study suggests that the prevalence of vitamin B12 deficiency among patients with type 2 diabetes mellitus on metformin in our population is substantial. This is more frequent among the non-Malay population and those who have been on metformin for more than five years.