Objective This study aimed to evaluate the associations of serum folate and/or vitamin B12 concentrations with obesity among Chinese children and adolescents.Methods A cross-sectional study was conducted including 3,0...Objective This study aimed to evaluate the associations of serum folate and/or vitamin B12 concentrations with obesity among Chinese children and adolescents.Methods A cross-sectional study was conducted including 3,079 Chinese children and adolescents,aged 6 to 17 years,from Jiangsu,China.Anthropometric indices,such as,children's body mass index(BMI),BMI z-scores,waist circumference,and waist-to-height ratio were utilized.Multivariable linear regression and generalized additive models were used to investigate the associations of serum folate and vitamin B12 levels with anthropometric indices and odds of obesity.Results We observed that serum vitamin B12 concentrations were inversely associated with all anthropometric indices and the odds of general obesity[odds ratio(OR)=0.68;95%confidence interval(CI)=0.59,0.78]and abdominal obesity(OR=0.68;95%CI=0.60,0.77).When compared to participants with both serum vitamin levels in the two middle quartiles,those with both serum folate and vitamin B12 levels in the highest quartile were less prone to general(OR=0.31,95%CI=0.19,0.50)or abdominal obesity(OR=0.46,95%CI=0.31,0.67).Conversely,participants with vitamin B12 levels in the lowest quartile alongside folate levels in the highest quartile had higher odds of abdominal obesity(OR=2.06,95%CI=1.09,3.91).Conclusion Higher serum vitamin B12 concentrations,but not serum folate concentrations,were associated with lower odds of childhood obesity.Children and adolescents with high levels of vitamin B12 and folate were less likely to be obese.展开更多
Vitamin B12 deficiency is a significant concern among patients with end-stage renal disease undergoing dialysis.However,there hasn’t been extensive research conducted on this particular patient group.The reported inc...Vitamin B12 deficiency is a significant concern among patients with end-stage renal disease undergoing dialysis.However,there hasn’t been extensive research conducted on this particular patient group.The reported incidence rates vary widely,ranging from 20%to 90%,reflecting the complexity of its diagnosis.Dialysis patients often face multiple nutritional deficiencies,including a lack of essential vitamins,due to factors such as dietary restrictions,impaired absorption,and nutrient loss during dialysis.Diagnosing vitamin B12 deficiency in these patients is challenging,and addressing it is crucial to prevent complications and improve their overall quality of life.This review paper delves into the available body of evidence on vitamin B12 deficiency in dialysis patients,examining the contributing risk factors,diagnostic challenges,potential complications,and available treatment options.It provides a well-rounded perspective on the topic,making it a valuable resource for researchers,healthcare practitioners,and policymakers interested in addressing the nutritional needs of dialysis patients.展开更多
The authors report a case of deficient sensory neuropathy secondary to vitamin B12 deficiency, diagnosed in the neurology department of the Sino-Central African Friendship University Hospital in Bangui. The diagnosis ...The authors report a case of deficient sensory neuropathy secondary to vitamin B12 deficiency, diagnosed in the neurology department of the Sino-Central African Friendship University Hospital in Bangui. The diagnosis was made possible by electroneuromyography which showed subclinical neurological damage associated with hematological damage (anemia). Through this observation, we recall the diagnostic criteria of the disease in a context of difficult medical practice. .展开更多
Diabetes mellitus(DM)is still one of the most common diseases worldwide,and its prevalence is still increasing globally.According to the American and European recommendations,metformin is considered a first-line oral ...Diabetes mellitus(DM)is still one of the most common diseases worldwide,and its prevalence is still increasing globally.According to the American and European recommendations,metformin is considered a first-line oral hypoglycemic drug for controlling type 2 DM(T2DM)patients.Metformin is the ninth most often prescribed drug in the world,and at least 120 million diabetic people are estimated to receive the drug.In the last 20 years,there has been increasing evidence of vitamin B12 deficiency among metformin-treated diabetic patients.Many studies have reported that vitamin B12 deficiency is related to the malabsorption of vitamin B12 among metformin-treated T2DM patients.Vitamin B12 deficiency may have a very bad complication for the T2DM patient.In this review,we will focus on the effect of metformin on the absorption of vitamin B12 and on its proposed mechanisms in hindering vitamin B12 absorption.In addition,the review will describe the clinical outcomes of vitamin B12 deficiency in metformintreated T2DM.展开更多
AIM To explore the correlation between serum vitamin B12 level and peripheral neuropathy in patients with chronic atrophic gastritis(CAG). METHODS A total of 593 patients diagnosed with chronic gastritis by gastroscop...AIM To explore the correlation between serum vitamin B12 level and peripheral neuropathy in patients with chronic atrophic gastritis(CAG). METHODS A total of 593 patients diagnosed with chronic gastritis by gastroscopy and pathological examination fromSeptember 2013 to September 2016 were selected for this study. The age of these patients ranged within 18-to 75-years-old. Blood pressure, height and weight were measured in each patient, and the body mass index value was calculated. Furthermore, gastric acid, serum gastrin, serum vitamin and serum creatinine tests were performed, and peripheral nerve conduction velocity and Helicobacter pylori(H. pylori) were detected. In addition, the type of gastritis was determined by gastroscopy. The above factors were used as independent variables to analyze chronic gastritis with peripheral neuropathy and vitamin B12 deficiency risk factors, and to analyze the relationship between vitamin B12 levels and peripheral nerve conduction velocity. In addition, in the treatment of CAG on the basis of vitamin B12, patients with peripheral neuropathy were observed. RESULTS Age, H. pylori infection, CAG, vitamin B9 and vitamin B12 were risk factors for the occurrence of peripheral nerve degeneration.Furthermore,CAG and H. pylori infection were risk factors for chronic gastritis associated with vitamin B12 deficiency. Serum vitamin B12 level was positively correlated with sensory nerve conduction velocity in the tibial nerve(R = 0.463). After vitamin B12 supplementation, patients with peripheral neuropathy improved. CONCLUSION Serum vitamin B12 levels in patients with chronic gastritis significantly decreased, and the occurrence of peripheral neuropathy had a certain correlation. CAG and H. pylori infection are risk factors for vitamin B12 deficiency and peripheral neuropathy. When treating CAG, vitamin B12 supplementation can significantly reduce peripheral nervous system lesions. Therefore, the occurrence of peripheral neuropathy associated with vitamin B12 deficiency may be considered in patients with CAG. Furthermore, the timely supplementation of vitamin B12 during the clinical treatment of CAG can reduce or prevent peripheral nervous system lesions.展开更多
Currently,ischemic stroke is the most prevalent form of stroke compared to hemorrhagic and there is a high incidence in older adults.Nutrition is a modifiable risk factor for stroke.B-vitamins are part of a metabolic ...Currently,ischemic stroke is the most prevalent form of stroke compared to hemorrhagic and there is a high incidence in older adults.Nutrition is a modifiable risk factor for stroke.B-vitamins are part of a metabolic network that integrates nutritional signals with biosynthesis,redox homeostasis,and epigenetics.These vitamins play an essential role in the regulation of cell proliferation,stress resistance,and embryo development.A deficiency in vitamin B12 is common in older adults and has been reported to be implicated in ischemic stroke.The aim of this review was to investigate whether vitamin B12 deficiencies impact the risk and outcome of ischemic stroke.Clinical data from our literature review strongly suggest that a deficiency in vitamin B12 is a risk factor for ischemic stroke and possible outcome.Our survey of the literature has identified that there is a gap in the understanding of the mechanisms through which a vitamin B12 deficiency leads to an increased risk of stroke and outcome.A vitamin B12 deficiency can increase homocysteine levels,which are a well-established risk factor for ischemic stroke.Another potential mechanism through which vitamin B12 deficient may impact neurological function and increase risk of stroke,is changes in myelination,however this link requires further investigation.Further studies are required in model systems to understand how a vitamin B12 deficiency changes the brain.展开更多
Elevated plasma or serum total homocysteine (tHcy) level has been established as a risk factor for cardiovascular disease[1], as well as dementia and cognitive decline[2]. Plasma or serum folate and vitamin B12 influe...Elevated plasma or serum total homocysteine (tHcy) level has been established as a risk factor for cardiovascular disease[1], as well as dementia and cognitive decline[2]. Plasma or serum folate and vitamin B12 influence homocysteine (Hcy) metabolism as a co-substrate and cofactor respectively, so that low concentrations of folate and vitamin B12 are also associated with high Hcy levels[1]. However, not much information is available describing serum tHcy, folate, and vitamin B12 status in Shanghai adults, especially in a healthy population. Therefore, we hypothesize that low serum folate and vitamin B12 is associated with high Hcy in healthy adults in Shanghai. The aim of this study was to determine the status of serum tHcy, folate, and vitamin B12, and the prevalence and factors contributing to HHcy, folate deficiency, and vitamin B12 deficiency among healthy adults in Shanghai, China.展开更多
The aim of the present study was to evaluate whether tissue levels of vitamin B complex and vitamin B12 were altered after crush-induced peripheral nerve injury in an experimental rat model. A total of 80 male Wistar ...The aim of the present study was to evaluate whether tissue levels of vitamin B complex and vitamin B12 were altered after crush-induced peripheral nerve injury in an experimental rat model. A total of 80 male Wistar rats were randomized into one control(n = 8) and six study groups(1, 6, 12, 24 hours, 3, and 7 days after experimental nerve injury; n = 12 for each group). Crush-induced peripheral nerve injury was performed on the sciatic nerves of rats in six study groups. Tissue samples from the sites of peripheral nerve injury were obtained at 1, 6, 12, 24 hours, 3 and 7 days after experimental nerve injury. Enzyme-linked immunosorbent assay results showed that tissue levels of vitamin B complex and vitamin B12 in the injured sciatic nerve were significantly greater at 1 and 12 hours after experimental nerve injury, while they were significantly lower at 7 days than in control group. Tissue level of vitamin B_(12) in the injured sciatic nerve was significantly lower at 1, 6, 12 and 24 hours than in the control group. These results suggest that tissue levels of vitamin B complex and vitamin B12 vary with progression of crush-induced peripheral nerve injury, and supplementation of these vitamins in the acute period may be beneficial for acceleration of nerve regeneration.展开更多
BACKGROUND: Prostaglandin El improves diabetic peripheral neuropathy in symptoms and sensory threshold. Vitamin Bi and methyl-vitamin BI2 improve microcirculation to peripheral nerve tissue and promote neurotrophy. O...BACKGROUND: Prostaglandin El improves diabetic peripheral neuropathy in symptoms and sensory threshold. Vitamin Bi and methyl-vitamin BI2 improve microcirculation to peripheral nerve tissue and promote neurotrophy. OBJECTIVE: To observe motor nerve and sensory nerve conduction velocity in patients with diabetic peripheral neuropathy, prior to and after treatment with prostaglandin El, vitamin B I and different doses of vitamin B 12. DESIGN, TIME AND SETTING: Randomized, controlled experiment, performed at the Department of Neurology, Beijing Hantian Central Hospital, between February 2002 and September 2007. PARTICIPANTS: A total of 122 patients with type 2 diabetic peripheral neuropathy; 73 males and 49 females were included. All patients met the diagnostic criteria of diabetes mellitus, as determined by the World Health Organization in 1999 and 2006, and also the diagnostic criteria of diabetic peripheral neuropathy. For each subject, conduction disorders in the median nerve and in the common peroneal nerve were observed using electromyogram. Also, after diet and drug treatment, the blood glucose level of subjects was observed to be at a satisfactory level for more than two weeks, and the symptoms of diabetic peripheral neuropathy were not alleviated. METHODS: All patients were randomly divided into the following three groups. A control group (n = 40), in which, 100 mg vitamin B1 and 500 μg vitamin BI2 were intramuscularly injected. A vitamin B12 low-dose treated group ( n = 42), in which 10 μ g prostaglandin E1 in 250 mL physiological saline was intravenously injected once a day and 100 mg vitamin BI and 500 11 g vitamin BI2 was intramuscularly injected once a day. Lastly, a vitamin B12 high-dose treated group (n = 40), in which administration was the same as in the vitamin B12 low-dose treated group, except that 500 11 g vitamin BI2 was replaced by 1mg vitamin B12. Administration was performed for four weeks for each group. MAIN OUTCOME MEASURES: The motor nerve and sensory nerve conduction velocity of the median nerve and the common peroneal nerve were determined using an electromyogram electronic stimulator (Neuropack-11, Nihon Kohden, Japan). RESULTS: The motor nerve and sensory nerve conduction velocities of the median nerve and the common peroneal nerve were significantly faster after treatment compared to before treatment in all 3 groups (P 〈 0.05q).01). Compared with the control group, the motor nerve and sensory nerve conduction velocities were significantly faster in the vitamin B12 low-dose treated group and in the vitamin B12 high-dose treated group (P 〈 0.01). The motor nerve and sensory nerve conduction velocities were significantly faster in the vitamin B12 high-dose treated group compared to the vitamin B12 low-dose treated group (P 〈 0.05). CONCLUSION: Prostaglandin E1, in conjunction with vitamin B12, can improve neural functional states and speed up peripheral motor nerve and sensory nerve conduction velocity in diabetic peripheral neuropathy. In addition, better effects are achieved using prostaglandin E1 in conjunction with high doses of vitamin B 12.展开更多
Excessive dexamethasone (Dex) administrated into pregnant mice during critical periods of palatal development can produce a high incidence of cleft palate. Its mechanisms remain unknown. Vitamin B12 has been shown to ...Excessive dexamethasone (Dex) administrated into pregnant mice during critical periods of palatal development can produce a high incidence of cleft palate. Its mechanisms remain unknown. Vitamin B12 has been shown to antagonize the tera- togenic effects of Dex, which, however, remains controversial. In this study, we investigated the effects of Dex and vitamin B12 on murine embryonic palatal shelf fusion using organ culture of murine embryonic shelves. The explanted palatal shelves on em- bryonic day 14 (E14) were cultured for 24, 48, 72 or 96 h in different concentrations of Dex and/or vitamin B12. The palatal shelves were examined histologically for the morphological alterations on the medial edge epithelium (MEE) and fusion rates among different groups. It was found that the palatal shelves were not fused at 72 h or less of culture in Dex group, while they were completely fused in the control and vitamin B12-treated groups at 72 and 96 h, respectively. The MEE still existed and proliferated. In Dex+vitamin B12 group the palatal shelves were fused at each time point in a similar rate to controls. These results may suggest that Dex causes teratogenesis of murine embryonic palatal shelves and vitamin B12 prevents the teratogenic effect of Dex on palatogenesis on murine embryos in vitro.展开更多
A rapid and simple preconcentration step applying packed-fiber solid-phase extraction columns has been investigated to vitamin B12. The extraction performance of the new method was investigated preliminarily on vitami...A rapid and simple preconcentration step applying packed-fiber solid-phase extraction columns has been investigated to vitamin B12. The extraction performance of the new method was investigated preliminarily on vitamin functional drink. The analysis used a reversed-phase C18 column, with a photo-diode array detector at 220 nm. The samples were preconcentrated with packed-fiber solid-phase extraction columns. Good linearity was observed in vitamin functional drink. The repeatability of extraction performance, expressed as relative standard deviations, was from 3.5% to 4.3%. The limit of detection (LOD) is 5 ng mL^-1 (S/N = 3). Finally, the method had been applied for the determination of vitamin B12 in vitamin functional drink.展开更多
To date,metformin remains the first-line oral glucose-lowering drug used for the treatment of type 2 diabetes thanks to its well-established long-term safety and efficacy profile.Indeed,metformin is the most widely us...To date,metformin remains the first-line oral glucose-lowering drug used for the treatment of type 2 diabetes thanks to its well-established long-term safety and efficacy profile.Indeed,metformin is the most widely used oral insulinsensitizing agent,being prescribed to more than 100 million people worldwide,including patients with prediabetes,insulin resistance,and polycystic ovary syndrome.However,over the last decades several observational studies and meta-analyses have reported a significant association between long-term metformin therapy and an increased prevalence of vitamin B12 deficiency.Of note,evidence suggests that long-term and high-dose metformin therapy impairs vitamin B12 status.Vitamin B12(also referred to as cobalamin)is a water-soluble vitamin that is mainly obtained from animal-sourced foods.At the cellular level,vitamin B12 acts as a cofactor for enzymes that play a critical role in DNA synthesis and neuroprotection.Thus,vitamin B12 deficiency can lead to a number of clinical consequences that include hematologic abnormalities(e.g.,megaloblastic anemia and formation of hypersegmented neutrophils),progressive axonal demyelination and peripheral neuropathy.Nevertheless,no definite guidelines are currently available for vitamin B12 deficiency screening in patients on metformin therapy,and vitamin B12 deficiency remains frequently unrecognized in such individuals.Therefore,in this“field of vision”article we propose a list of criteria for a cost-effective vitamin B12 deficiency screening in metformin-treated patients,which could serve as a practical guide for identifying individuals at high risk for this condition.Moreover,we discuss additional relevant topics related to this field,including:(1)The lack of consensus about the exact definition of vitamin B12 deficiency;(2)The definition of reliable biomarkers of vitamin B12 status;(3)Causes of vitamin B12 deficiency other than metformin therapy that should be identified promptly in metformin-treated patients for a proper differential diagnosis;and(4)Potential pathophysiological mechanisms underlying metformin-induced vitamin B12 deficiency.Finally,we briefly review basic concepts related to vitamin B12 supplementation for the treatment of vitamin B12 deficiency,particularly when this condition is induced by metformin.展开更多
Although methylenetetrahydrofolate reductase, a folate enzyme gene, has been associated with idiopathic male infertility, few studies have examined other folate-related metabolites and genes. We investigated whether i...Although methylenetetrahydrofolate reductase, a folate enzyme gene, has been associated with idiopathic male infertility, few studies have examined other folate-related metabolites and genes. We investigated whether idiopathic male infertility is associated with variants in folate, vitamin B12 (B12) and total homocysteine (tHcy)-related genes and measured these metabolites in blood. We conducted a case-control study that included 153 men with idiopathic infertility and 184 fertile male controls recruited at the Fertility Center and Antenatal Care Center, University Hospital, Malmo and Lund, Sweden. Serum folate, red cell folate (RCF), serum B12, plasma tHcy and semen quality were measured. Subjects were genotyped for 20 common variants in 12 genes related to folate/B12/ homocysteine metabolism. Metabolite concentrations and genotype distributions were compared between cases and controls using linear and logistic regression with adjustment for covariates. The phosphatidylethanolamine N-methyltransferase (PEMT) M 175V and TCblR rs173665 polymorphisms were significantly associated with infertility (P=0.01 and P=0.009, respectively), but not with semen quality. Among non-users of supplements, infertile men had lower serum folate concentrations than fertile men (12.89 vs. 14.73 nmoll^- 1 P=0.02), but there were no significant differences in RCF, B 12 or tHcy. Folate, B 12 and tHcy concentrations were not correlated with any semen parameters. This study provides little support for low folate or B12 status in the pathogenesis of idiopathic male infertility. Although additional data are needed to confirm these initial findings, our results suggest that PEMTand TCbIR, genes involved in choline and B12 metabolism, merit further investigation in idiopathic male infertility.展开更多
The present study is aimed to investigate the effects of different ratios of cobalt (Co) and copper (Cu) supplementation on vitamin B12 status and nutrient utilization in sheep. Twenty wether lambs with an average...The present study is aimed to investigate the effects of different ratios of cobalt (Co) and copper (Cu) supplementation on vitamin B12 status and nutrient utilization in sheep. Twenty wether lambs with an average weight (22.9 ± 0.8) kg were randomly divided into five groups and fed with the control diet which was supplied with 0.3 mg kg^-1 DM (dry matter) of Co to the basal diet, and four supplemental diets which were supplied either 0.3 or 0.6 mg kg^-1 DM of Co and 10 or 20 mg kg^-1 DM of Cu to the basal diet, respectively for 8 wk. The supplementation of Co and Cu with different levels improved plasma vitamin B12 concentration which was increased with feeding time, but stable after 6 wk. Vitamin B12 status was accounted for Co intake with no combined effects by supplementation of different levels of Co and Cu. The plasma concentrations of methylmalonic acid, homocysteine, folic acid, and glucose did not show the consistent results with plasma vitamin B12, which was considered to be resulted from Cu action. Addition of Co and Cu with different levels had no influence on digestibility of dry matter (DM), organic matter (OM), crude protein (CP) and nitrogen free (NFE), and N metabolism (P〉 0.05), but the digestibility of fat and fibre (P〈0.01) was enhanced by supplementation of 0.3 mg kg^-1 DM of Co and 20 mg kg^-1 DM of Cu. In conclusion, the supplementation of Co and Cu with different levels has no influence on vitamin B12 status. The optimum ratio of Co and Cu in diet could enhance the nutrient utilization.展开更多
AIM: To compare upper gastric endoscopic and histopathologic findings in older adults in the presence and absence of B12 deficiency.METHODS: A prospective analysis of upper gastric endoscopic and gastric histopatholog...AIM: To compare upper gastric endoscopic and histopathologic findings in older adults in the presence and absence of B12 deficiency.METHODS: A prospective analysis of upper gastric endoscopic and gastric histopathologic findings from 30 newly identified B12-deficient patients (11 males,19 females) and 16 controls with normal B12 status (6males, 10 females) was performed. For all subjects, the indication for upper endoscopy and gastric biopsy were unrelated to B12 status. A single pathologist, blinded to B12 status, processed and interpreted the biopsy samples. Endoscopic and histopathologic findings were correlated with age, gender, hematocrit (Hct), MCV and B12 status.RESULTS: The B12-deficient group had significantly lower mean serum B12 levels compared to the controls (P<0.00005) while their mean Hct, MCV and serum albumin levels were similar. Iron deficiency (ferritinbased) was present in 21% of B12-deficient patients and intrinsic factor antibodies were present in29% (5/17) of B12-deficient patients. The endoscopic findings revealed significantly different rates of gastritis and atrophy between the B12-deficient and control groups (P= 0.017).B12-deficient patients had significantly less superficial gastritis (62% vs 94%) and significantly more atrophic gastritis (28% vs 0%) as compared to the controls (P= 0.039). Intestinal metaplasia was similar in both groups. Helicobacter pyloriinfection rates were similar in the B12-deficient patients and controls (40% vs31%).CONCLUSION: Significantly different endoscopic findings and types of gastritis could often be observed in the presence and absence of B12 deficiency. Atrophy,based on endoscopy, and atrophic gastritis, based on histopathology, suggest the presence of B12 deficiency.Gastric histopathology is not influenced by the age,gender, Hct or MCV of the patients.展开更多
INTRODUCTION While Vit.B12 deficiency is common,with aprevalence of about 15% in the elderly,andrecommendations for treatment available,detectionof deficiency at the pre-clinical stage by appropriatescreening does not...INTRODUCTION While Vit.B12 deficiency is common,with aprevalence of about 15% in the elderly,andrecommendations for treatment available,detectionof deficiency at the pre-clinical stage by appropriatescreening does not always take place.Our report isan example of life threatening Vit.B12 deficiencydiagnosed at age 56,with the onset of Vit.B12depletion likely to have begun in the展开更多
基金supported by the National Health Commission of the People’s Republic of China Medical Reform Major Program:China National Chronic Diseases and Nutrition Surveillance of Adults[2015-2017]Qianrang Zhu is funded by a China Scholarship Council PhD Scholarship[No.202109110099].
文摘Objective This study aimed to evaluate the associations of serum folate and/or vitamin B12 concentrations with obesity among Chinese children and adolescents.Methods A cross-sectional study was conducted including 3,079 Chinese children and adolescents,aged 6 to 17 years,from Jiangsu,China.Anthropometric indices,such as,children's body mass index(BMI),BMI z-scores,waist circumference,and waist-to-height ratio were utilized.Multivariable linear regression and generalized additive models were used to investigate the associations of serum folate and vitamin B12 levels with anthropometric indices and odds of obesity.Results We observed that serum vitamin B12 concentrations were inversely associated with all anthropometric indices and the odds of general obesity[odds ratio(OR)=0.68;95%confidence interval(CI)=0.59,0.78]and abdominal obesity(OR=0.68;95%CI=0.60,0.77).When compared to participants with both serum vitamin levels in the two middle quartiles,those with both serum folate and vitamin B12 levels in the highest quartile were less prone to general(OR=0.31,95%CI=0.19,0.50)or abdominal obesity(OR=0.46,95%CI=0.31,0.67).Conversely,participants with vitamin B12 levels in the lowest quartile alongside folate levels in the highest quartile had higher odds of abdominal obesity(OR=2.06,95%CI=1.09,3.91).Conclusion Higher serum vitamin B12 concentrations,but not serum folate concentrations,were associated with lower odds of childhood obesity.Children and adolescents with high levels of vitamin B12 and folate were less likely to be obese.
文摘Vitamin B12 deficiency is a significant concern among patients with end-stage renal disease undergoing dialysis.However,there hasn’t been extensive research conducted on this particular patient group.The reported incidence rates vary widely,ranging from 20%to 90%,reflecting the complexity of its diagnosis.Dialysis patients often face multiple nutritional deficiencies,including a lack of essential vitamins,due to factors such as dietary restrictions,impaired absorption,and nutrient loss during dialysis.Diagnosing vitamin B12 deficiency in these patients is challenging,and addressing it is crucial to prevent complications and improve their overall quality of life.This review paper delves into the available body of evidence on vitamin B12 deficiency in dialysis patients,examining the contributing risk factors,diagnostic challenges,potential complications,and available treatment options.It provides a well-rounded perspective on the topic,making it a valuable resource for researchers,healthcare practitioners,and policymakers interested in addressing the nutritional needs of dialysis patients.
文摘The authors report a case of deficient sensory neuropathy secondary to vitamin B12 deficiency, diagnosed in the neurology department of the Sino-Central African Friendship University Hospital in Bangui. The diagnosis was made possible by electroneuromyography which showed subclinical neurological damage associated with hematological damage (anemia). Through this observation, we recall the diagnostic criteria of the disease in a context of difficult medical practice. .
文摘Diabetes mellitus(DM)is still one of the most common diseases worldwide,and its prevalence is still increasing globally.According to the American and European recommendations,metformin is considered a first-line oral hypoglycemic drug for controlling type 2 DM(T2DM)patients.Metformin is the ninth most often prescribed drug in the world,and at least 120 million diabetic people are estimated to receive the drug.In the last 20 years,there has been increasing evidence of vitamin B12 deficiency among metformin-treated diabetic patients.Many studies have reported that vitamin B12 deficiency is related to the malabsorption of vitamin B12 among metformin-treated T2DM patients.Vitamin B12 deficiency may have a very bad complication for the T2DM patient.In this review,we will focus on the effect of metformin on the absorption of vitamin B12 and on its proposed mechanisms in hindering vitamin B12 absorption.In addition,the review will describe the clinical outcomes of vitamin B12 deficiency in metformintreated T2DM.
基金Cangzhou City Science and Technology Plan Projects,No.151302138
文摘AIM To explore the correlation between serum vitamin B12 level and peripheral neuropathy in patients with chronic atrophic gastritis(CAG). METHODS A total of 593 patients diagnosed with chronic gastritis by gastroscopy and pathological examination fromSeptember 2013 to September 2016 were selected for this study. The age of these patients ranged within 18-to 75-years-old. Blood pressure, height and weight were measured in each patient, and the body mass index value was calculated. Furthermore, gastric acid, serum gastrin, serum vitamin and serum creatinine tests were performed, and peripheral nerve conduction velocity and Helicobacter pylori(H. pylori) were detected. In addition, the type of gastritis was determined by gastroscopy. The above factors were used as independent variables to analyze chronic gastritis with peripheral neuropathy and vitamin B12 deficiency risk factors, and to analyze the relationship between vitamin B12 levels and peripheral nerve conduction velocity. In addition, in the treatment of CAG on the basis of vitamin B12, patients with peripheral neuropathy were observed. RESULTS Age, H. pylori infection, CAG, vitamin B9 and vitamin B12 were risk factors for the occurrence of peripheral nerve degeneration.Furthermore,CAG and H. pylori infection were risk factors for chronic gastritis associated with vitamin B12 deficiency. Serum vitamin B12 level was positively correlated with sensory nerve conduction velocity in the tibial nerve(R = 0.463). After vitamin B12 supplementation, patients with peripheral neuropathy improved. CONCLUSION Serum vitamin B12 levels in patients with chronic gastritis significantly decreased, and the occurrence of peripheral neuropathy had a certain correlation. CAG and H. pylori infection are risk factors for vitamin B12 deficiency and peripheral neuropathy. When treating CAG, vitamin B12 supplementation can significantly reduce peripheral nervous system lesions. Therefore, the occurrence of peripheral neuropathy associated with vitamin B12 deficiency may be considered in patients with CAG. Furthermore, the timely supplementation of vitamin B12 during the clinical treatment of CAG can reduce or prevent peripheral nervous system lesions.
基金supported by Midwestern University Startup Funds(to NMJ)American Heart Association,No.20AIREA35050015(to NMJ)。
文摘Currently,ischemic stroke is the most prevalent form of stroke compared to hemorrhagic and there is a high incidence in older adults.Nutrition is a modifiable risk factor for stroke.B-vitamins are part of a metabolic network that integrates nutritional signals with biosynthesis,redox homeostasis,and epigenetics.These vitamins play an essential role in the regulation of cell proliferation,stress resistance,and embryo development.A deficiency in vitamin B12 is common in older adults and has been reported to be implicated in ischemic stroke.The aim of this review was to investigate whether vitamin B12 deficiencies impact the risk and outcome of ischemic stroke.Clinical data from our literature review strongly suggest that a deficiency in vitamin B12 is a risk factor for ischemic stroke and possible outcome.Our survey of the literature has identified that there is a gap in the understanding of the mechanisms through which a vitamin B12 deficiency leads to an increased risk of stroke and outcome.A vitamin B12 deficiency can increase homocysteine levels,which are a well-established risk factor for ischemic stroke.Another potential mechanism through which vitamin B12 deficient may impact neurological function and increase risk of stroke,is changes in myelination,however this link requires further investigation.Further studies are required in model systems to understand how a vitamin B12 deficiency changes the brain.
文摘Elevated plasma or serum total homocysteine (tHcy) level has been established as a risk factor for cardiovascular disease[1], as well as dementia and cognitive decline[2]. Plasma or serum folate and vitamin B12 influence homocysteine (Hcy) metabolism as a co-substrate and cofactor respectively, so that low concentrations of folate and vitamin B12 are also associated with high Hcy levels[1]. However, not much information is available describing serum tHcy, folate, and vitamin B12 status in Shanghai adults, especially in a healthy population. Therefore, we hypothesize that low serum folate and vitamin B12 is associated with high Hcy in healthy adults in Shanghai. The aim of this study was to determine the status of serum tHcy, folate, and vitamin B12, and the prevalence and factors contributing to HHcy, folate deficiency, and vitamin B12 deficiency among healthy adults in Shanghai, China.
文摘The aim of the present study was to evaluate whether tissue levels of vitamin B complex and vitamin B12 were altered after crush-induced peripheral nerve injury in an experimental rat model. A total of 80 male Wistar rats were randomized into one control(n = 8) and six study groups(1, 6, 12, 24 hours, 3, and 7 days after experimental nerve injury; n = 12 for each group). Crush-induced peripheral nerve injury was performed on the sciatic nerves of rats in six study groups. Tissue samples from the sites of peripheral nerve injury were obtained at 1, 6, 12, 24 hours, 3 and 7 days after experimental nerve injury. Enzyme-linked immunosorbent assay results showed that tissue levels of vitamin B complex and vitamin B12 in the injured sciatic nerve were significantly greater at 1 and 12 hours after experimental nerve injury, while they were significantly lower at 7 days than in control group. Tissue level of vitamin B_(12) in the injured sciatic nerve was significantly lower at 1, 6, 12 and 24 hours than in the control group. These results suggest that tissue levels of vitamin B complex and vitamin B12 vary with progression of crush-induced peripheral nerve injury, and supplementation of these vitamins in the acute period may be beneficial for acceleration of nerve regeneration.
文摘BACKGROUND: Prostaglandin El improves diabetic peripheral neuropathy in symptoms and sensory threshold. Vitamin Bi and methyl-vitamin BI2 improve microcirculation to peripheral nerve tissue and promote neurotrophy. OBJECTIVE: To observe motor nerve and sensory nerve conduction velocity in patients with diabetic peripheral neuropathy, prior to and after treatment with prostaglandin El, vitamin B I and different doses of vitamin B 12. DESIGN, TIME AND SETTING: Randomized, controlled experiment, performed at the Department of Neurology, Beijing Hantian Central Hospital, between February 2002 and September 2007. PARTICIPANTS: A total of 122 patients with type 2 diabetic peripheral neuropathy; 73 males and 49 females were included. All patients met the diagnostic criteria of diabetes mellitus, as determined by the World Health Organization in 1999 and 2006, and also the diagnostic criteria of diabetic peripheral neuropathy. For each subject, conduction disorders in the median nerve and in the common peroneal nerve were observed using electromyogram. Also, after diet and drug treatment, the blood glucose level of subjects was observed to be at a satisfactory level for more than two weeks, and the symptoms of diabetic peripheral neuropathy were not alleviated. METHODS: All patients were randomly divided into the following three groups. A control group (n = 40), in which, 100 mg vitamin B1 and 500 μg vitamin BI2 were intramuscularly injected. A vitamin B12 low-dose treated group ( n = 42), in which 10 μ g prostaglandin E1 in 250 mL physiological saline was intravenously injected once a day and 100 mg vitamin BI and 500 11 g vitamin BI2 was intramuscularly injected once a day. Lastly, a vitamin B12 high-dose treated group (n = 40), in which administration was the same as in the vitamin B12 low-dose treated group, except that 500 11 g vitamin BI2 was replaced by 1mg vitamin B12. Administration was performed for four weeks for each group. MAIN OUTCOME MEASURES: The motor nerve and sensory nerve conduction velocity of the median nerve and the common peroneal nerve were determined using an electromyogram electronic stimulator (Neuropack-11, Nihon Kohden, Japan). RESULTS: The motor nerve and sensory nerve conduction velocities of the median nerve and the common peroneal nerve were significantly faster after treatment compared to before treatment in all 3 groups (P 〈 0.05q).01). Compared with the control group, the motor nerve and sensory nerve conduction velocities were significantly faster in the vitamin B12 low-dose treated group and in the vitamin B12 high-dose treated group (P 〈 0.01). The motor nerve and sensory nerve conduction velocities were significantly faster in the vitamin B12 high-dose treated group compared to the vitamin B12 low-dose treated group (P 〈 0.05). CONCLUSION: Prostaglandin E1, in conjunction with vitamin B12, can improve neural functional states and speed up peripheral motor nerve and sensory nerve conduction velocity in diabetic peripheral neuropathy. In addition, better effects are achieved using prostaglandin E1 in conjunction with high doses of vitamin B 12.
基金Project (No. 30530730) supported by the National Natural ScienceFoundation of China
文摘Excessive dexamethasone (Dex) administrated into pregnant mice during critical periods of palatal development can produce a high incidence of cleft palate. Its mechanisms remain unknown. Vitamin B12 has been shown to antagonize the tera- togenic effects of Dex, which, however, remains controversial. In this study, we investigated the effects of Dex and vitamin B12 on murine embryonic palatal shelf fusion using organ culture of murine embryonic shelves. The explanted palatal shelves on em- bryonic day 14 (E14) were cultured for 24, 48, 72 or 96 h in different concentrations of Dex and/or vitamin B12. The palatal shelves were examined histologically for the morphological alterations on the medial edge epithelium (MEE) and fusion rates among different groups. It was found that the palatal shelves were not fused at 72 h or less of culture in Dex group, while they were completely fused in the control and vitamin B12-treated groups at 72 and 96 h, respectively. The MEE still existed and proliferated. In Dex+vitamin B12 group the palatal shelves were fused at each time point in a similar rate to controls. These results may suggest that Dex causes teratogenesis of murine embryonic palatal shelves and vitamin B12 prevents the teratogenic effect of Dex on palatogenesis on murine embryos in vitro.
基金supported by Jiangsu Science and Technology Department(No.BG2007044)Jiangsu Preventive Medicine Foundation(No.Y2006025).
文摘A rapid and simple preconcentration step applying packed-fiber solid-phase extraction columns has been investigated to vitamin B12. The extraction performance of the new method was investigated preliminarily on vitamin functional drink. The analysis used a reversed-phase C18 column, with a photo-diode array detector at 220 nm. The samples were preconcentrated with packed-fiber solid-phase extraction columns. Good linearity was observed in vitamin functional drink. The repeatability of extraction performance, expressed as relative standard deviations, was from 3.5% to 4.3%. The limit of detection (LOD) is 5 ng mL^-1 (S/N = 3). Finally, the method had been applied for the determination of vitamin B12 in vitamin functional drink.
文摘To date,metformin remains the first-line oral glucose-lowering drug used for the treatment of type 2 diabetes thanks to its well-established long-term safety and efficacy profile.Indeed,metformin is the most widely used oral insulinsensitizing agent,being prescribed to more than 100 million people worldwide,including patients with prediabetes,insulin resistance,and polycystic ovary syndrome.However,over the last decades several observational studies and meta-analyses have reported a significant association between long-term metformin therapy and an increased prevalence of vitamin B12 deficiency.Of note,evidence suggests that long-term and high-dose metformin therapy impairs vitamin B12 status.Vitamin B12(also referred to as cobalamin)is a water-soluble vitamin that is mainly obtained from animal-sourced foods.At the cellular level,vitamin B12 acts as a cofactor for enzymes that play a critical role in DNA synthesis and neuroprotection.Thus,vitamin B12 deficiency can lead to a number of clinical consequences that include hematologic abnormalities(e.g.,megaloblastic anemia and formation of hypersegmented neutrophils),progressive axonal demyelination and peripheral neuropathy.Nevertheless,no definite guidelines are currently available for vitamin B12 deficiency screening in patients on metformin therapy,and vitamin B12 deficiency remains frequently unrecognized in such individuals.Therefore,in this“field of vision”article we propose a list of criteria for a cost-effective vitamin B12 deficiency screening in metformin-treated patients,which could serve as a practical guide for identifying individuals at high risk for this condition.Moreover,we discuss additional relevant topics related to this field,including:(1)The lack of consensus about the exact definition of vitamin B12 deficiency;(2)The definition of reliable biomarkers of vitamin B12 status;(3)Causes of vitamin B12 deficiency other than metformin therapy that should be identified promptly in metformin-treated patients for a proper differential diagnosis;and(4)Potential pathophysiological mechanisms underlying metformin-induced vitamin B12 deficiency.Finally,we briefly review basic concepts related to vitamin B12 supplementation for the treatment of vitamin B12 deficiency,particularly when this condition is induced by metformin.
文摘Although methylenetetrahydrofolate reductase, a folate enzyme gene, has been associated with idiopathic male infertility, few studies have examined other folate-related metabolites and genes. We investigated whether idiopathic male infertility is associated with variants in folate, vitamin B12 (B12) and total homocysteine (tHcy)-related genes and measured these metabolites in blood. We conducted a case-control study that included 153 men with idiopathic infertility and 184 fertile male controls recruited at the Fertility Center and Antenatal Care Center, University Hospital, Malmo and Lund, Sweden. Serum folate, red cell folate (RCF), serum B12, plasma tHcy and semen quality were measured. Subjects were genotyped for 20 common variants in 12 genes related to folate/B12/ homocysteine metabolism. Metabolite concentrations and genotype distributions were compared between cases and controls using linear and logistic regression with adjustment for covariates. The phosphatidylethanolamine N-methyltransferase (PEMT) M 175V and TCblR rs173665 polymorphisms were significantly associated with infertility (P=0.01 and P=0.009, respectively), but not with semen quality. Among non-users of supplements, infertile men had lower serum folate concentrations than fertile men (12.89 vs. 14.73 nmoll^- 1 P=0.02), but there were no significant differences in RCF, B 12 or tHcy. Folate, B 12 and tHcy concentrations were not correlated with any semen parameters. This study provides little support for low folate or B12 status in the pathogenesis of idiopathic male infertility. Although additional data are needed to confirm these initial findings, our results suggest that PEMTand TCbIR, genes involved in choline and B12 metabolism, merit further investigation in idiopathic male infertility.
基金supported in part by a grant from the National Key Technology R&D Program of China (2006-BAD14B07)
文摘The present study is aimed to investigate the effects of different ratios of cobalt (Co) and copper (Cu) supplementation on vitamin B12 status and nutrient utilization in sheep. Twenty wether lambs with an average weight (22.9 ± 0.8) kg were randomly divided into five groups and fed with the control diet which was supplied with 0.3 mg kg^-1 DM (dry matter) of Co to the basal diet, and four supplemental diets which were supplied either 0.3 or 0.6 mg kg^-1 DM of Co and 10 or 20 mg kg^-1 DM of Cu to the basal diet, respectively for 8 wk. The supplementation of Co and Cu with different levels improved plasma vitamin B12 concentration which was increased with feeding time, but stable after 6 wk. Vitamin B12 status was accounted for Co intake with no combined effects by supplementation of different levels of Co and Cu. The plasma concentrations of methylmalonic acid, homocysteine, folic acid, and glucose did not show the consistent results with plasma vitamin B12, which was considered to be resulted from Cu action. Addition of Co and Cu with different levels had no influence on digestibility of dry matter (DM), organic matter (OM), crude protein (CP) and nitrogen free (NFE), and N metabolism (P〉 0.05), but the digestibility of fat and fibre (P〈0.01) was enhanced by supplementation of 0.3 mg kg^-1 DM of Co and 20 mg kg^-1 DM of Cu. In conclusion, the supplementation of Co and Cu with different levels has no influence on vitamin B12 status. The optimum ratio of Co and Cu in diet could enhance the nutrient utilization.
基金Supported by the Fellowship Training Programs in Gastroenterology and Geriatric Medicine at Our Lady of Mercy Medical Center
文摘AIM: To compare upper gastric endoscopic and histopathologic findings in older adults in the presence and absence of B12 deficiency.METHODS: A prospective analysis of upper gastric endoscopic and gastric histopathologic findings from 30 newly identified B12-deficient patients (11 males,19 females) and 16 controls with normal B12 status (6males, 10 females) was performed. For all subjects, the indication for upper endoscopy and gastric biopsy were unrelated to B12 status. A single pathologist, blinded to B12 status, processed and interpreted the biopsy samples. Endoscopic and histopathologic findings were correlated with age, gender, hematocrit (Hct), MCV and B12 status.RESULTS: The B12-deficient group had significantly lower mean serum B12 levels compared to the controls (P<0.00005) while their mean Hct, MCV and serum albumin levels were similar. Iron deficiency (ferritinbased) was present in 21% of B12-deficient patients and intrinsic factor antibodies were present in29% (5/17) of B12-deficient patients. The endoscopic findings revealed significantly different rates of gastritis and atrophy between the B12-deficient and control groups (P= 0.017).B12-deficient patients had significantly less superficial gastritis (62% vs 94%) and significantly more atrophic gastritis (28% vs 0%) as compared to the controls (P= 0.039). Intestinal metaplasia was similar in both groups. Helicobacter pyloriinfection rates were similar in the B12-deficient patients and controls (40% vs31%).CONCLUSION: Significantly different endoscopic findings and types of gastritis could often be observed in the presence and absence of B12 deficiency. Atrophy,based on endoscopy, and atrophic gastritis, based on histopathology, suggest the presence of B12 deficiency.Gastric histopathology is not influenced by the age,gender, Hct or MCV of the patients.
文摘INTRODUCTION While Vit.B12 deficiency is common,with aprevalence of about 15% in the elderly,andrecommendations for treatment available,detectionof deficiency at the pre-clinical stage by appropriatescreening does not always take place.Our report isan example of life threatening Vit.B12 deficiencydiagnosed at age 56,with the onset of Vit.B12depletion likely to have begun in the