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.

Homocysteine Serum Levels as Prognostic Marker of Hepatocellular Carcinoma with Portal Vein Thrombosis

BACKGROUND

Portal vein thrombosis (PVT) is a common complication of endstage hepatocellular carcinoma (HCC). The aim of our study was to evaluate the role of Homocysteine (Hcy) in HCC patient with PVT. Hcy is a sulphur amino-acid involved in two pathways, trans-sulphuration and remethylation, that involve vitamins B6, B12 and folates.

METHODS

We recruited 54 patients with HCC and PVT, 60 patients with HCC and without PVT and 60 control subjects. We measured serum levels of Hcy, folate, vitamins B6 and B12.

RESULTS

The comparison between HCC patients with PVT versus HCC without PVT was shown that mean values of Hcy were 6.4 nmol/L (p<0.0073) higher, LDL cholesterol were 4.8 mg/dl (p<0.0079) lower, vitamin B6 were 4.6 nmol/L(p=0.0544) lower, vitamins B 12 were 22.1 pg/ml (p=0.0001) lower.

CONCLUSION

High serum levels of Hcy are an established thrombotic risk factor in the general population. We found significantly higher levels of Hcy in HCC patients with PVT versus both HCC patients without PVT and controls.

The clinical and subclinical features of spinal cord injury on magnetic resonance imaging of patients with N2O intoxication

Nitrous oxide (N₂O) is a weak anesthetic gas that was first used in 1844 in the field of dental anesthesia. However, currently, N₂O is being abused for entertainment purposes in the form of N₂O-filled balloons, called funky balls, which can cause many adverse effects, especially nervous system injury. This study aimed to investigate the detailed clinical and subclinical features associated with N₂O intoxication. We retrospectively reviewed 47 patients diagnosed with N₂O intoxication, from May 2018 to July 2019, and collected demographic data, clinical and laboratory tests, and spinal cord magnetic resonance imaging (MRI) findings. The mean time of funky ball use was 8.8 months, with a mean use of 36.3 balls per day. All patients presented with superficial sensory disorders. Reductions in muscle strength, decreased vibration sensation, and decreased or lost tendon reflexes were the most common clinical signs of N₂O intoxication. Romberg sign and Lhermitte sign were observed in 39 patients (83%) and 21 patients (44.7%), respectively. Spinal cord lesions on MRI were observed in 32 patients (68.1%), which mostly presented with an inverted V sign. The total duration of N₂O use, the number of days of using N₂O per week, and the presence of Lhermitte sign (P<0.05) were significantly different between patients with and without spinal cord lesions on MRI. Serum levels of homocysteine and vitamin B12 were significantly different between the time of admission and discharge (P<0.05). Our study indicated that the days of using N₂O per week was significantly associated with Spinal Cord Injuries (SCI) on MRI. According to the Receiver Operating Characteristic (ROC) curve analysis, a cutoff days of using per week value of 2.5 days could predict SCI with a sensitivity of 81.3%, a specificity of 73.3%, and an area under the ROC curve (AUC) of 0.813. Changes in the serum levels of homocysteine and vitamin B12 were effective markers for the evaluation of treatment response.

Correlation between anemia and clinical severity in subacute combined degeneration patients

OBJECTIVES

Subacute combined degeneration (SCD) is a demyelinating disease commonly caused by vitamin B12 deficiency. Several studies have been reported SCD could be accompanied by anemia. However, the correlation between anemia and clinical severity of SCD patients is unclear. In this study, we aim to analyze the clinical characteristics of SCD concomitant with anemia, and investigate the effect of anemia in predicting the severity of SCD.

METHODS

A total 42 patients were included in the study. Clinical, laboratory, radiological findings, and outcomes from the patients were analyzed. All patients were treated with vitamin B12 for no less than 6 months and a functional disability rating scale was used to evaluate severity of neurological impairment at the time of admission and 3 and 6 months after admission in our study.

RESULTS

85.7% patients had macrocytosis. Decreased serum vitamin B12 levels were found in 27 patients (64.3%). MRI showed long-segment abnormality on the spinal cord in 22 patients. No differences in rating score were found in patients grouped by sex, age, clinical course, serum vitamin B12, or MRI manifestations at the time of admission or at the follow-up visits. Negative correlation was seen between hemoglobin levels and the clinical severity scores on admission.

CONCLUSION

Not all patients with SCD concomitant with anemia had decreased serum vitamin B12 level. The inverse correlation between hemoglobin level and clinical severity suggests the degree of anemia can help in evaluating the extent of neurologic impairment.

Iron, Vitamin B12, Folate and Copper Deficiency After Bariatric Surgery and the Impact on Anaemia: a Systematic Review

Bariatric surgery may increase the risk of iron, vitamin B₁₂, folate and copper deficiencies, which can cause anaemia. This review aims to critique the evidence on the prevalence of these nutritional deficiencies and the impact on anaemia in the first 12 months after surgery. PRISMA and MOOSE frameworks, the NHMRC evidence hierarchy and The Academy of Nutrition and Dietetics bias tool were used to systematically critique current literature. Seventeen studies reported on deficiency prevalence with the majority being of low quality. Important confounders to serum micronutrient levels were not adequately considered. Results on the prevalence of nutritional anaemias were also lacking. Further investigation into the prevalence of iron, vitamin B₁₂, folate and copper deficiency and its impact on anaemia in bariatric surgery is needed.

Multiple Health Benefits and Minimal Risks Associated with Vegetarian Diets

PURPOSE OF REVIEW

Understand the current prevalence, health benefits, and health risks of vegetarian diets.

RECENT FINDINGS

Since the publishing of the Adventist Health Study 2 in 2013, there have been several prospective diet studies demonstrating and challenging the health benefits and risks of the vegetarian diet. The definition of the vegetarian diet has become more specific over time and requires standardization for research purposes. Despite an uptrend in sales rates of plant-based foods per year, a 2018 Gallup poll showed overall stagnation of the percentage of self-reported vegetarians and vegans compared to percentages obtained 6 years prior. Compared to the Adventist Health Study, more recent vegetarian diet studies have demonstrated significant although smaller risk reductions for mortality in cardiovascular disease, cerebrovascular disease, diabetes mellitus, and chronic kidney disease. Recent studies have correlated certain food groups with early death or increased longevity. In addition, the vegetarian health risks of deficiencies of protein, omega-3 fatty acids, vitamin D, vitamin B12, iron, calcium, and zinc are explored.

Hematological findings associated with neurodevelopmental delay in infants with vitamin B12 deficiency

In adults with vitamin B12 deficiency, an inverse correlation between the severity of megaloblastic anemia and the degree of neurological dysfunction has been reported. We aimed to evaluate the association between hematological findings and the results of neurodevelopmental assessment in infants. Denver-II developmental screening test (DDST II) was performed in vitamin B12-deficient infants (n = 122), and its relationship with hematological findings was evaluated. DDST II was abnormal in 15 (12.3%), suspect in 20 (16.4%) and normal in 87 (71.3%) cases. Among the infants aged ≥ 4 months (n = 89), cases with an abnormal DDST II had lower levels of hemoglobin (7.49 ± 3.13 vs. 9.87 ± 1.77 g/dL; P = 0.015), whereas they had higher levels of mean corpuscular volume (MCV) (90.05 ± 19.31 vs. 69.90 ± 10.51 fL; P = 0.002), mean corpuscular hemoglobin (MCH) (28.96 ± 7.50 vs. 22.03 ± 4.58 pg; P = 0.001), homocysteine (44.31 ± 11.51 vs. 21.05 ± 9.23 µmol/L; P < 0.001), transferrin saturation index (25.84 ± 17.72 vs. 9.55 ± 6.38%; P = 0.004) and ferritin (87.28 ± 82.21 vs. 26.59 ± 31.67 ng/mL; P = 0.040) than those with a normal DDST II. The receiver operator characteristic analysis could distinguish infants with an abnormal DDST II from those with a normal DDST II by using a hemoglobin level < 8.75 g/dL [sensitivity: 71.4%, specificity: 76.4%; area under curve (AUC): 0.744], an MCV > 88.4 fL (sensitivity: 76.9%, specificity: 98.2%; AUC 0.813), an MCH > 28.5 pg (sensitivity: 76.9%, specificity: 96.4%; AUC: 0.822), and a homocysteine level > 27.35 µmol/L (sensitivity: 92.9%, specificity: 85.5%; AUC: 0.907). Even mild abnormalities of some commonly evaluated laboratory variables (such as MCV and MCH) in an infant should alert the physicians for the possibility of an underlying vitamin B12 deficiency with some degree of neurological impairment.

Topical citicoline and vitamin B12 versus placebo in the treatment of diabetes-related corneal nerve damage: a randomized double-blind controlled trial

BACKGROUND

To evaluate the effects of topical citicoline and vitamin B12 (Cit-B12: OMK2, Omikron Italia srl, Italy) on corneal innervation of patients with diabetic neuropathy.

METHODS

This prospective, randomized, double blind, placebo-controlled study included 30 patients randomised with a 2:1 ratio to Cit-B12 or placebo 3 times daily for 18 months. At baseline and at months 4, 8, 12, 18 patients underwent the Ocular Surface Disease Index questionnaire (OSDI), tear break-up time, evaluation of corneal and conjunctival staining, Schirmer I test, Cochet-Bonnet esthesiometry, and confocal biomicroscopy of corneal sub-basal plexus (SBP). Fiber lenght density (FLD) was calculated using NeuronJ and expressed in mm/mm2. Raw data and differences from baseline were analysed in the two groups.

RESULTS

29/30 patients concluded the study. The two groups had similar FLD at baseline; it progressively improved up to month 18 in both groups (Cit-B12, p < 0.0001; controls, < 0.0001-0.03); improvement at month 18 vs baseline was higher in Cit-B12 than placebo (33% vs 15%, p = 0.04). A progressive amelioration of corneal sensitivity (baseline, 28 ± 18 mm; month 18, 52 ± 10 mm, p < 0.0001), conjunctival staining (P = 0.04) and OSDI questionnaire (P = 0.05) were shown on Cit-B12 group alone. Both treatments were well tolerated and adherence during the study was high.

CONCLUSIONS

Cit-B12 ameliorated both morphology and function of corneal nerves in patients with diabetes, thus suggesting a neuroregenerative effect.

TRIAL REGISTRATION

Trial registration NCT03906513 , retrospectively registered on 08 April 2019.

Association of serum folate and vitamin B12 with pre-neoplastic cervical lesions

BACKGROUND & AIMS

Diet and lifestyle play an important role in etiology of various tumors. Serum concentration of folate and vitamin B12may be associated with carcinogenesis since they are involved in DNA methylation and nucleotide synthesis. However, the role of these micronutrients on development of cervical cancer is still controversial. Thus, the aim of this study was to analyze the association of lower status of folate and vitamin B12 with the risk of pre-neoplastic cervical lesions.

METHODS

Our sample group was divided in Control group (n = 120) - women with normal cytology, and Case groups (n = 57) - women presenting Atypical Squamous Cells of Undetermined Significance (ASC-US, n = 21), Low Grade Squamous Intraepithelial Lesion (LSIL; n = 16), and High-Grade lesions (n = 20). We obtained cervical samples for cytology analysis and HPV detection, and blood samples for evaluation of serum concentration of folate and vitamin B12.

RESULTS

No difference of serum folate was observed among Cases and Control groups. On the other hand, women with High-Grade lesions presented significant lower median concentration of vitamin B12 if compared to another groups. Then, we observed increased risk of High-Grade lesions among participants with low vitamin B12 levels was observed in relation to women that presented high levels of the micronutrient and from Control group [OR (95% CI): 2.09 (0.65-6.76), p = 0.216], ASC-US [OR (95% CI): 3.15 (0.82-12.08), p = 0.095], and LSIL [OR (95% CI): 3.10 (0.76-12.70), p = 0.116].

CONCLUSIONS

Low concentration of vitamin B12 was associated with an increased risk of High-Grade cervical lesions. Besides, we did not observe any difference of serum folate among women with normal cytology and women with pre-neoplastic cervical lesions.

Assessing Diagnostic Accuracy of Serum Holotranscobalamin (Active-B12) in Comparison with Other Markers of Vitamin B12 Deficiency

About 15-40% India is Vitamin B12 deficient (commonly diagnosed by total Vitamin B12) but, as only holoTC (active form) is taken up by body cells, thus measuring holoTC is more reflective of Vitamin B12 status than the former. We aimed to assess diagnostic accuracy of serum holoTC in comparison with total Vitamin B12 and total Homocysteine (HCY) as indicator of serum Vitamin B12 status. 217 human subjects (99 males and 118 females) ranging from 17 to 83 years were divided into Vitamin B12 deficient (n = 70), borderline (n = 100) and sufficient groups (n = 47) who were further assessed for markers of Vitamin B12 deficiency-holoTC, HCY, Mean Corpuscular Volume (MCV), Folate, heamoglobin and creatinine. Samples were analysed using Siemens Advia Centaur Xpi. Total Vitamin B12 deficient group had - 84.3% holoTC deficient; 15.7% holoTC sufficient; 72.9% with elevated HCY; 27.1% with normal HCY; 11.4% with megaloblastic anaemia. Borderline group had - 34% holoTC deficient; 28% elevated HCY. A strong positive correlation was found between Total Vitamin B12 and holoTC (r = 0.754, p = <0.001) but strong negative correlation existed between holoTC and HCY (r = - 0.471, p = <0.001). Concordance between Total Vit B12 and HCY (Kappa index = 0.51, p < 0.001); between holoTC and HCY (Kappa index = 0.52, p = <0.001) were statically significant but the latter had a better sensitivity and specificity. Also, statically significant association exists between Total Vitamin B12 and holoTC with HCY (p = <0.001). Therefore, it is ascertained that Active Vitamin B12 assay is a better test and can be considered as an early marker of vitamin B12 deficiency.

Ileocecal valve syndrome and vitamin b12 deficiency after surgery: a multicentric prospective study

Patients undergoing colon resection are often concerned about their functional outcomes after surgery. The primary aim of this prospective, multicentric study was to assess the intestinal activity and health-related quality-of-life (HRQL) after ileocecal valve removal. The secondary aim was to evaluate any vitamin B12 deficiency. The study included patients undergoing right colectomy, extended right colectomy and ileocecal resection for either neoplastic or benign disease. Selected items of GIQLI and EORTC QLQ-CR29 questionnaires were used to investigate intestinal activity and HRQL before and after surgery. Blood samples for vitamin B12 level were collected before and during the follow-up period. The empirical rule effect size (ERES) method was used to explain the clinical effect of statistical results. Linear mixed effect (LME) model for longitudinal data was applied to detect the most important parameters affecting the total score. A total of 158 patients were considered. Applying the ERES method, the analysis of both questionnaires showed clinically and statistically significant improvement of HRQL at the end of the follow-up period. Applying the LME model, worsening of HRQL was correlated with female gender and ileum length when using GIQLI questionnaire, and with female gender, open approach, and advanced cancer stage when using the EORTC QLQ-CR29 questionnaire. No significant deficiency in vitamin B12 levels was observed regardless of the length of surgical specimen. In our series, no deterioration of HRQL and no vitamin B12 deficiency were found during the follow-up period. Nevertheless, warning patients about potential changes in bowel habits is mandatory. In our series, no deterioration of HRQL and no vitamin B12 deficiency were found during the follow-up period. Nevertheless, warning patients about potential changes in bowel habits is mandatory.

Relationship between metformin use and vitamin B12 status in patients with type 2 diabetes in Japan

AIMS/INTRODUCTION

Metformin therapy has been associated with vitamin B12 (VB12) deficiency, but information regarding this adverse effect in Asian populations is limited. We have now examined the relationship between metformin use and VB12 status in individuals with type 2 diabetes mellitus in Japan.

MATERIALS AND METHODS

This cross-sectional study was carried out with type 2 diabetes mellitus patients treated (Met group, n = 122) or not treated (control group, n = 63) with metformin. The primary end-point was the difference in the serum concentration of homocysteine, a marker of VB12 activity, between the two groups. The serum concentrations of VB12, blood hemoglobin level and mean corpuscular volume were also compared between the groups. Subset analysis was carried out with individuals aged ≥70 years. The potential correlation between the daily dose or duration of metformin treatment and the other measured parameters was also examined.

RESULTS

The level of homocysteine, as well as the VB12 level, hemoglobin concentration and mean corpuscular volume, did not differ significantly between the control and treated with metformin groups. The level of homocysteine was positively and that of VB12 negatively correlated with the daily dose of metformin. Among elderly individuals, the hemoglobin level was significantly lower in the treated with metformin group than in the control group, although the mean corpuscular volume was similar in the two groups.

CONCLUSIONS

The risk of VB12 deficiency during metformin treatment appears to be low in Japanese type 2 diabetes mellitus patients. However, high doses of metformin might result in a moderate decrease in the circulating VB12 level, as well as in anemia in elderly individuals.

Role of micronutrients in staging of nonalcoholic fatty liver disease: A retrospective cross-sectional study

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) presents high incidence throughout the world and has been progressively increasing in prevalence. This disease has a heterogeneous natural history, including simple steatosis, nonalcoholic steatohepatitis (NASH), and cirrhosis. The factors that determine its evolution to more severe forms of the disease are still poorly understood, and micronutrients with antioxidant potential may be involved in the pathophysiology of the disease.

AIM

To evaluate the relationship between serum levels of micronutrients and the severity of NAFLD.

METHODS

A retrospective, observational and cross-sectional study was conducted. This study included all patients undergoing bariatric surgery who experienced liver biopsy during the procedure, and had serum levels of micronutrients (vitamin D, vitamin B12, zinc, iron, and magnesium), which was assessed in a preoperative evaluation conducted at a reference center in southern Brazil.

RESULTS

A total of 614 patients were analyzed, of which 93% had steatosis, 70.7% had NASH, and 49.3% had some degree of fibrosis. Serum levels of vitamin D were negatively correlated with the severity of steatosis and NASH, and serum levels of vitamin B12 were positively correlated with the severity of steatosis and fibrosis. The other micronutrients showed no association with NAFLD staging.

CONCLUSION

Serum levels of vitamin D are inversely related to the severity of steatosis and NASH, and serum levels of vitamin B12 are higher in more advanced stages of simple steatosis and liver fibrosis. Serum levels of zinc, iron, and magnesium were not associated with NAFLD severity.

[Effect of subchronic combined oral exposure of titanium dioxide nanoparticles and glucose on levels of serum folate and vitamin B12 in young SD rats]

OBJECTIVE

To explore the effect of subchronic combined oral exposure of titanium dioxide nanoparticles and glucose on levels of serum folate and vitamin B₁₂ in young SD rats.

METHODS

At first, the physical and chemical properties of titanium dioxide nanoparticles, such as particle size, shape, crystal form and agglomeration degree in solution system, were characterized in detail. Eighty 4-week-old young SD rats were randomly divided into 8 groups (10 rats in each group, half male and half female). The rats were exposed to titanium dioxide nanoparticles through intragastric administration at 0, 2, 10 and 50 mg/kg body weight with or without 1.8 g/kg glucose daily for 90 days. At last, the concentrations of serum folate and vitamin B₁₂ were detected.

RESULTS

Titanium dioxide nanoparticles were anatase crystals, closely spherical shape, with an average particle size of (24±5) nm. In male young rats, compared with the control group, the serum folate concentration was significantly increased when exposed to titanium dioxide nanoparticles (10 mg/kg) and glucose. The difference was statistically significant (P<0.05). However, in female and male young rats, compared with glucose (1.8 g/kg) exposure group, titanium dioxide nanoparticles (50 mg/kg) and glucose significantly reduced the serum folate concentration. The difference was statistically significant (P<0.05). Through statistical analysis of factorial design and calculation of interaction, obvious antagonistic effect was observed between titanium dioxide nanoparticles and glucose on the serum folate concentration in the young female SD rats. The combined oral exposure of titanium dioxide nanoparticles and glucose had little effect on the concentration of serum vitamin B₁₂ in the young SD rats, with no significant interaction between the two substances. It was only found that titanium dioxide nanoparticles (2 mg/kg) and glucose significantly increased the serum vitamin B₁₂ concentration, compared with glucose (1.8 g/kg) exposure group. The difference was statistically significant (P<0.05).

CONCLUSION

Subchronic combined oral exposure of titanium dioxide nanoparticles and glucose had an obvious antagonistic effect on serum folate concentrations in young SD rats.

The deficit in folate and vitamin B12 triggers liver macrovesicular steatosis and inflammation in rats with dextran sodium sulfate-induced colitis

The risks of nonalcoholic steatohepatitis (NASH) and deficiency in vitamin B12 and folate (methyl donor deficiency, MDD) are increased in inflammatory bowel disease (IBD). We investigated the influence of MDD on NASH in rats with DSS-induced colitis. Two-month-old male Wistar rats were subjected to MDD diet and/or ingestion of DSS and compared to control animals. We studied steatosis, inflammation, fibrosis, plasma levels of metabolic markers, cytokines and lipopolysaccharide, and inflammatory pathways in liver. MDD triggered a severe macrovesicular steatosis with inflammation in DSS animals that was not observed in animals subjected to DSS or MDD only. The macrovesicular steatosis was closely correlated to folate, vitamin B12, homocysteine plasma level and liver S-adenosyl methionine/S-adenosyl homocysteine (SAM/SAH) ratio. Liver inflammation was evidenced by activation of nuclear factor kappa B (NFκB) pathway and nuclear translocation of NFκB phospho-p65. MDD worsened the increase of interleukin 1-beta (IL-1β) and abolished the increase of IL10 produced by DSS colitis. It increased monocyte chemoattractant protein 1 (MCP-1). MDD triggers liver macrovesicular steatosis and inflammation through imbalanced expression of IL-1β vs. IL10 and increase of MCP-1 in DSS colitis. Our results suggest evaluating whether IBD patients with MDD and increase of MCP-1 are at higher risk of NASH.

Metabolic engineering and optimization of the fermentation medium for vitamin B12 production in Escherichia coli

Vitamin B₁₂ is a crucial fine chemical that is widely used in the pharmaceutical, food and chemical industries, and its production solely dependents on microbial fermentation. We previously constructed an artificial vitamin B₁₂ biosynthesis pathway in Escherichia coli, but the yield of the engineered strains was low. Here, we removed metabolic bottlenecks of the vitamin B₁₂ biosynthesis pathway in engineered E. coli strains. After screening cobB genes from different sources, optimizing the expression of cobN and customizing the ribosome binding sites of cobS and cobT, the vitamin B₁₂ yield increased to 152.29 μg/g dry cell weight (DCW). Optimization of the downstream module, which converts co(II)byrinic acid a,c-diamide into adenosylcobinamide phosphate, elevated the vitamin B₁₂ yield to 249.04 μg/g DCW. A comparison of a variety of equivalent components indicated that glucose and corn steep liquor are optimal carbon and nitrogen sources, respectively. Finally, an orthogonal array design was applied to determine the optimal concentrations of glucose and nitrogen sources including corn steep liquor and yeast extract, through which a vitamin B₁₂ yield of 530.29 μg/g DCW was obtained. The metabolic modifications and optimization of fermentation conditions achieved in this study offer a basis for further improving vitamin B₁₂ production in E. coli and will hopefully accelerate its industrial application.

A preliminary study for the establishment of a reference interval for vitamin B12 in China after performance verification of a second-generation ECLIA kit

Background

The second‐generation electrochemiluminescence immunoassay (ECLIA) kit of vitamin B12 is widely used in clinical laboratories, and the establishment of a reference interval (RI) is essential to provide the basis for clinical monitoring. The purpose of this study was to establish a laboratory RI for vitamin B12 in China and at the same time verify the method performance of the second‐generation kit.

Methods

The verification of the method performance was conducted according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Based on these guidelines, a total of 580 serum samples were collected, and 391 serum samples were used for the establishment of the RI according to CLSI guidelines. The subjects were grouped by sex and age. The age groups were as follows: 21‐40, 41‐60, and 61‐80 years. The RI was defined by nonparametric 2.5th and 97.5th percentile intervals.

Results

The performance of the second‐generation kit of vitamin B12 from the Roche Cobas E602 system was in compliance with laboratory requirements. Serum vitamin B12 levels conformed to a non‐Gaussian distribution. Harris‐Boyd's test did not indicate partitioning for different age and gender group. Besides, there was no significant difference between different age groups (P = .07) and gender groups (P = .2002). The RI for healthy Chinese adults (aged 21‐80 years) calculated by the nonparametric method was 250.8‐957.1 pg/mL.

Conclusions

The reference range of vitamin B12 was established, which provided a theoretical basis for the clinical application and monitoring of vitamin B12 detection.

Plasma concentrations of vitamin B12 and folate and global cognitive function in an older population: cross-sectional findings from The Irish Longitudinal Study on Ageing (TILDA)

The uncertainty surrounding high intakes of folic acid and associations with cognitive decline in older adults with low vitamin B12 status has been an obstacle to mandatory folic acid fortification for many years. We estimated the prevalence of combinations of low/normal/high vitamin B12 and folate status and compared associations with global cognitive function using two approaches, of individuals in a population-based study of those aged ≥50 years in the Republic of Ireland. Cross-sectional data from 3781 men and women from Wave 1 of The Irish Longitudinal Study on Ageing were analysed. Global cognitive function was assessed by the Mini Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). Prevalence estimates for combinations of vitamin B12 (plasma vitamin B12 < or ≥258 pmol/l) and folate (plasma folate ≤ or >45·3 nmol/l) concentrations were generated. Negative binomial regression models were used to investigate the associations of vitamin B12 and folate status with global cognitive function. Of the participants, 1·5 % (n 51) had low vitamin B12 (<258 pmol/l) and high folate (>45·3 nmol/l) status. Global cognitive performance was not significantly reduced in these individuals when compared with those with normal status for both B-vitamins (n 2433). Those with normal vitamin B12/high folate status (7·6 %) had better cognitive performance (MMSE: incidence rate ratio (IRR) 0·82, 95 % CI 0·68, 0·99; P = 0·043, MoCA: IRR 0·89, 95 % CI 0·80, 0·99; P = 0·025). We demonstrated that high folate status was not associated with lower cognitive scores in older adults with low vitamin B12 status. These findings provide important safety information that could guide fortification policy recommendations in Europe.