scholarly journals Active B12: A Rapid, Automated Assay for Holotranscobalamin on the Abbott AxSYM Analyzer

2008 ◽  
Vol 54 (3) ◽  
pp. 567-573 ◽  
Author(s):  
Jeff Brady ◽  
Lesley Wilson ◽  
Lynda McGregor ◽  
Edward Valente ◽  
Lars Orning
Keyword(s):  
Vitamin B12 ◽  
Serum Vitamin ◽  
Vitamin B12 Deficiency ◽  
Reference Interval ◽  
Cross Reactivity ◽  
Total Serum ◽  
Serum Samples ◽  
Automated Assay ◽  
Microparticle Enzyme Immunoassay ◽  
B12 Deficiency

Abstract Background: Conventional tests for vitamin B12 deficiency measure total serum vitamin B12, whereas only that portion of vitamin B12 carried by transcobalamin (holotranscobalamin) is metabolically active. Measurement of holotranscobalamin (holoTC) may be more diagnostically accurate for detecting B12 deficiency that requires therapy. We developed an automated assay for holoTC that can be used on the Abbott AxSYM immunoassay analyzer. Methods: AxSYM Active B12 is a 2-step sandwich microparticle enzyme immunoassay. In step 1, a holoTC-specific antibody immobilized onto latex microparticles captures holoTC in samples of serum or plasma. In step 2, the captured holoTC is detected with a conjugate of alkaline phosphatase and antiTC antibody. Results: Neither apoTC nor haptocorrin exhibited detectable cross-reactivity. The detection limit was ≤0.1 pmol/L. Within-run and total imprecision (CV ranges) were 3.4%–5.1% and 6.3%–8.5%, respectively. Assay CVs were <20% from at least 3 pmol/L to 107 pmol/L. With diluted serum samples, measured concentrations were 104%–114% of the expected values in the working range of the assay. No interference from bilirubin, hemoglobin, triglycerides, erythrocytes, rheumatoid factor, or total protein was detected at expected (abnormal) concentrations. A comparison of the AxSYM Active B12 assay with a commercial RIA for holoTC yielded the regression equation: AxSYM = 0.98RIA + 4.7 pmol/L (Sy x, 11.4 pmol/L; n = 204). Assay throughput was 45 tests/h. A 95% reference interval of 19–134 pmol/L holoTC was established with samples from 292 healthy individuals. Conclusions: The AxSYM Active B12 assay allows rapid, precise, sensitive, specific, and automated measurement of human holoTC in serum and plasma.

scholarly journals EFEK FORTIFIKASI VITAMIN B12 TERHADAP KADAR VITAMIN B12 SERUM DAN HOMOSISTEIN SERUM PADA VEGETARIAN

2020 ◽  
Vol 11 (1) ◽  
pp. 114-120
Author(s):  
Susianto Susianto
Keyword(s):  
Vitamin B12 ◽  
Homocysteine Level ◽  
Megaloblastic Anemia ◽  
Serum Vitamin ◽  
Vitamin B12 Deficiency ◽  
Natural Sources ◽  
Serum Homocysteine ◽  
Microparticle Enzyme Immunoassay ◽  
B12 Deficiency ◽  
Community Trial

Introduction: Vegetarians consume plant-based foods with or without eggs and milk. Vegetarians are at risk of vitamin B12 deficiency, as natural sources of vitamin B12 are limited to animal-based foods. Vitamin B12 deficiency can lead to megaloblastic anemia, nerve damage and increase homocysteine level. Higher homocysteine level can increase the risk of coronary heart disease and stroke. The objective of this study was to investigate the effect of vitamin B12 fortification on the level of serum vitamin B12 and homocysteine in vegetarian. Method: The research design was an experimental study, community trial. The samples were 42 vegetarians with vitamin B12 deficiency (< 156 pmol/L) selected from 118 vegetarians as members of Indonesia Vegetarian Society (IVS) Pekanbaru, treated by vitamin B12 fortified oatmeal for three months from March to June 2010.  Serum vitamin B12 and homocysteine were measured by electrochemiluminescent immunoassay and microparticle enzyme immunoassay method respectively. Result: Prevalence of vitamin B12 deficiency in vegetarian was 35.6%. Statistical analysis showed a significant increase of serum vitamin B12 from 124.6 to 284.6 pmol/L (p=0.001) and significant decrease of serum homocysteine from 20.1 to 15.1 µmol/L (p=0.001). Conclusion: Consumption of vitamin B12 fortified oatmeal increases the level of serum vitamin B12 and decreases the level of serum homocysteine significantly in vegetarian with vitamin B12 deficiency.

scholarly journals A Case of Subacute Combined Degeneration of Spinal Cord Diagnosed by Vitamin B12 Administration Lowering Methylmalonic Acid

2020 ◽  
Vol 12 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Daisuke Hara ◽  
Masashi Akamatsu ◽  
Heisuke Mizukami ◽  
Bunta Kato ◽  
Takaaki Suzuki ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Vitamin B12 ◽  
Methylmalonic Acid ◽  
Serum Vitamin ◽  
Vitamin B12 Deficiency ◽  
Lower Limbs ◽  
Total Serum ◽  
Subacute Combined Degeneration ◽  
Laboratory Findings ◽  
B12 Deficiency

Subacute combined degeneration of the spinal cord (SCDS) is a neurodegenerative disease characterized by subacute progression in the central and peripheral nervous systems mainly caused by vitamin B12 deficiency. It is known that typical SCDS is frequently accompanied by megaloblastic anemia and increased serum methylmalonic acid (MMA) or homocysteine (Hcy) levels on laboratory findings, and marked abnormalities on spinal cord magnetic resonance imaging (MRI). A 45-year-old woman was admitted to our hospital with a 2-year history of worsening mild weakness, numbness in bilateral lower limbs, and gait disturbance. On admission, as laboratory findings, blood count showed macrocytosis without anemia, and biochemical tests showed mild reduction in total serum vitamin B12 level and no increase of MMA and Hcy levels; there were no abnormal findings on spinal cord MRI. After administration of vitamin B12, her sensorimotor symptoms were improved and laboratory examination showed that macrocytosis was improved, serum vitamin B12 was increased, and serum MMA levels were decreased. This improved clinical course and the laboratory findings following vitamin B12 administration confirmed the diagnosis of SCDS due to vitamin B12 deficiency. SCDS presents with highly variable symptoms and laboratory findings, and observation of MMA levels and neurologic symptoms before and after vitamin B12 administration may be useful for diagnosing SCDS.

scholarly journals Systematic Review and Pragmatic Clinical Approach to Oral and Nasal Vitamin B12 (Cobalamin) Treatment in Patients with Vitamin B12 Deficiency Related to Gastrointestinal Disorders

2018 ◽  
Vol 7 (10) ◽  
pp. 304 ◽  
Author(s):  
Emmanuel Andrès ◽  
Abrar-Ahmad Zulfiqar ◽  
Khalid Serraj ◽  
Thomas Vogel ◽  
Georges Kaltenbach
Keyword(s):  
Vitamin B12 ◽  
Prospective Studies ◽  
Clinical Manifestations ◽  
Serum Vitamin ◽  
Vitamin B12 Deficiency ◽  
Cochrane Library ◽  
Clinical Approach ◽  
Oral Vitamin ◽  
Hand Search ◽  
B12 Deficiency

The objective of this review is to provide an update on the effectiveness of oral and nasal vitamin B12 (cobalamin) treatment in gastrointestinal (GI) disorders. Relevant articles were identified by PubMed and Google Scholar systematic search, from January 2010 and June 2018, and through hand search of relevant reference articles. Additional studies were obtained from references of identified studies, the Cochrane Library and the ISI Web of Knowledge. Data gleaned from reference textbooks and international meetings were also used, as was information gleaned from commercial sites on the web and data from CARE B12 research group. For oral vitamin B12 treatment, 4 randomized controlled trials (vs. intramuscular), 4 narrative and 4 systematic reviews, and 13 prospective studies fulfilled our inclusion criteria. These studies concerned patients with vitamin B12 deficiency related to: food-cobalamin malabsorption (n = 6), Biermer’s disease (n = 3), veganism or vegetarianism (n = 1), total gastrectomy after Roux-en-Y gastric bypass (n = 2) and Crohn’s disease (n = 1). Four prospective studies include patients with vitamin B12 deficiency related to the aforementioned etiologies, except veganism or vegetarianism. The systematic present review documents that oral vitamin B12 replacement, at a daily dose of 1000 μg (1 mg), was adequate to normalize serum vitamin B12 levels and cure main clinical manifestations related to vitamin B12 deficiency, in GI disorders, and thus, with safety profile. For nasal vitamin B12 treatment, only one preliminary study was available. We conclude that oral vitamin B12 is an effective alternative to intramuscular vitamin B12 (except in patients presenting with severe neurological manifestations). Oral vitamin B12 treatment avoids the discomfort, contraindication (in patients with anticoagulation), and cost of monthly injections.

scholarly journals Circulating antibody to transcobalamin II causing retention of vitamin B12 in the blood

Blood ◽  
1977 ◽  
Vol 49 (6) ◽  
pp. 987-1000 ◽  
Author(s):  
R Carmel ◽  
B Tatsis ◽  
L Baril
Keyword(s):  
Vitamin B12 ◽  
Binding Capacity ◽  
Megaloblastic Anemia ◽  
Serum Vitamin ◽  
Vitamin B12 Deficiency ◽  
High Serum ◽  
The Status ◽  
B12 Deficiency ◽  
Long Acting

A patient with recurrent pulmonary abscess, weight loss, and alcoholism was found to have extremely high serum vitamin B12 and unsaturated vitamin B12-binding capacity (UBBC) levels. While transcobalamin (TC) II was also increased, most of his UBBC was due to an abnormal binding protein which carried greater than 80% of the endogenous vitamin B12 and was not found in his saliva, granulocytes, or urine. This protein was shown to be a complex of TC II and a circulating immunoglobulin (IgGkappa and IgGlambda). Each IgG molecule appeared to bind two TC II molecules. The reacting site did not interfere with the ability of TC II to bind vitamin B12, but did interfere with its ability to transfer the vitamin to cells in vitro. The site was not identical to that reacting with anti-human TC II antibody produced in rabbits. Because of this abnormal complex, 57Co-vitamin B12 injected intravenously was cleared slowly by the patient. However, no metabolic evidence for vitamin B12 deficiency was demonstrable, although the patient initially had megaloblastic anemia apparently due to folate deficiency. The course of the vitamin B12-binding abnormalities was followed over 4 yr and appeared to fluctuate with the status of the patient's illness. The IgG-TC II complex resembled one induced in some patients with pernicious anemia by intensive treatment with long-acting vitamin B12 preparations. The mechanism of induction of the antibody formation in our patient is unknown.

RELATIONSHIP OF MATERNAL VITAMIN B12 STATUS IN PREGNANCY WITH PRETERM BIRTH AND MATERNAL HEALTH RISKS

2020 ◽  
pp. 32-38
Author(s):  
VICTORIA LAZAROVA SPASOVA ◽  
LILIA IVANOVA KOLEVA ◽  
MARIETA ANTONOVA POPOVA ◽  
VALENTINA BOYANOVA PETKOVA ◽  
MILEN VENTZISLAVOV DIMITROV
Keyword(s):  
Preterm Birth ◽  
Vitamin B12 ◽  
Pregnant Women ◽  
Serum Vitamin ◽  
Vitamin B12 Deficiency ◽  
Inverse Association ◽  
Maternal Vitamin ◽  
B12 Deficiency ◽  
The Impact ◽  
In Pregnancy

Vitamin B12 is known to be vital for cell growth and population during pregnancy. This retrospective and prospective case−control study was aimed to disclose a health risk for pregnant women with vitamin B12 deficiency, as well as the one of the preterm birth. The main tasks set and performed in this research were as follows: to compare the obstetrics anamnesis between the women who gave birth on term and women who gave birth before term; to find the prevalence of vitamin B12 insufficiency in pregnancy; to determine its association with preterm birth and low birth weight; to examine its association with spontaneous abortions, and to investigate its relationship with obesity and hemoglobin levels in pregnant women. The conducted investigation involved 107 women who gave birth before the 37th week of gestation and 101 women who gave birth after the 37th week of gestation at the outpatient clinic of the University Hospital "Maichin Dom" in Bulgaria. Our study revealed a correlation between maternal vitamin B12 deficiency, overweight and low hemoglobin level. Our results showed no significant correlation between serum vitamin B12 level and the risk of preterm birth. However, we found an inverse association between vitamin B12 level and overweight before pregnancy and at the time of giving birth. As well there was confirmed the strong connection between meat consumption and vitamin B12 level. The paper emphasizes that the deficiency of the vitamin occurs most likely in the women with inadequate diets. Such a deficiency is actually confirmed to have serious health consequences for pregnant women and their offspring. Therefore further profound and numerous studies should be performed to properly assess the correlation between vitamin B12 and preterm birth, as well as to understand better the impact of vitamin B12 over pregnant women. Key words: vitamin B12, preterm birth, pregnancy, overweight, hemoglobin.

REVERSIBLE NEUROPATHY OF VITAMIN-B12 DEFICIENCY WITH NORMAL HÆMOGLOBIN AND SERUM-VITAMIN-B12

The Lancet ◽  
1977 ◽  
Vol 309 (8015) ◽  
pp. 803 ◽  
Author(s):  
H. Melsom ◽  
S. Kornstad ◽  
U. Abildgaard
Keyword(s):  
Vitamin B12 ◽  
Serum Vitamin ◽  
Vitamin B12 Deficiency ◽  
B12 Deficiency

Biologically Significant Serum Vitamin B12 Deficiency in Multiple Sclerosis Inadequately Documented-Reply

1992 ◽  
Vol 49 (7) ◽  
pp. 683-684
Author(s):  
E. H. Reynolds ◽  
J. C. Linnell ◽  
J. E. Faludy ◽  
T. Bottiglieri
Keyword(s):  
Multiple Sclerosis ◽  
Vitamin B12 ◽  
Serum Vitamin ◽  
Vitamin B12 Deficiency ◽  
B12 Deficiency

scholarly journals Vitamin B12 Status and Metabolic Health in Women of Reproductive Age in Southern India

2021 ◽  
Vol 5 (Supplement_2) ◽  
pp. 646-646
Author(s):  
Heather Guetterman ◽  
Krista Crider ◽  
Amy Fothergill ◽  
Beena Bose ◽  
Christina Johnson ◽  
...  
Keyword(s):  
Vitamin B12 ◽  
Serum Vitamin ◽  
Vitamin B12 Deficiency ◽  
Metabolic Health ◽  
Reproductive Age ◽  
Whole Body ◽  
Women Of Reproductive Age ◽  
Metabolic Outcomes ◽  
B12 Deficiency ◽  
Stage 1

Abstract Objectives To examine the burden of metabolic outcomes and associations of vitamin B12 status with metabolic health in women of reproductive age (WRA), as part of a population-based biomarker survey in Chittoor, India. Methods Participants (980 WRA; 15–40y nonpregnant or lactating) were assessed for glycated hemoglobin (HbA1c; nephelometry) and serum vitamin B12 concentrations (chemiluminescence). Anthropometric measurements and systolic (SBP) and diastolic (DBP) blood pressures were collected in triplicate. Bioelectrical impedance analysis was used to evaluate whole body (WF%) and trunk (TF%) fat among women ≤ 18y. We defined elevated HbA1c as ≤ 6.5% and ≤ 5.7-&lt; 6.5%, and hypertension as stage 1 (SBP 130–139 or DBP 80–89 mmHg) and stage 2 (SBP ≤ 140 or DBP ≤ 90 mmHg). Vitamin B12 was natural logarithmically transformed prior to analyses; vitamin B12 deficiency was defined as &lt; 148 pmol/L. Linear and binomial regression models were used to examine associations of vitamin B12 status with metabolic outcomes. Results A total of 23.3% of adult WRA were overweight (body mass index (BMI): 25.0 to &lt; 30.0 kg/m2) and 9.7% had obesity (≤30.0 kg/m2). Waist circumference (WC; ≤88.9 cm) and waist-hip ratio (WHR; ≤0.85) were elevated in 13.4% and 20.1% of adult WRA. One-fourth of WRA had elevated HbA1c (≤6.5%: 5.0%; ≤5.7-&lt; 6.5%: 20.0%), and 18.6% had hypertension (stage 1: 16.4%; stage 2: 2.2%); 48.3% of WRA were vitamin B12 deficient. Higher continuous vitamin B12 concentrations were associated with lower BMI (β [standard error (SE)] -0.65 [0.28]) and WF% (-1.01 [0.50]); lower risk of elevated WC (risk ratio (RR) [95% confidence interval] 0.64 [0.49–0.85]); and higher risk of HbA1c ≤ 5.7% (1.19 [1.00–1.41]). Vitamin B12 deficiency was associated with higher BMI (β [SE] 0.98 [0.34], p = 0.004), WC (1.96 [0.76]), WF% (1.75 [0.59]), and TF% (2.03 [0.73]); and higher risk of having overweight (RR: 1.31 [1.09–1.58]), elevated WC (1.85 [1.32–2.60]), and WHR (1.38 [1.07–1.78]). Conclusions The burden of adverse metabolic outcomes was substantial in this population, and vitamin B12 deficiency was associated with central adiposity and overweight. Evaluating the role of vitamin B12 in the development of metabolic outcomes in future studies could inform screening and interventions to improve vitamin B12 status and metabolic health in WRA. Funding Sources Centers for Disease Control and Prevention.

scholarly journals Dietary Intake and Status of Vitamin B12 in Slovenian Population

Nutrients ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 334
Author(s):  
Živa Lavriša ◽  
Hristo Hristov ◽  
Maša Hribar ◽  
Katja Žmitek ◽  
Anita Kušar ◽  
...  
Keyword(s):  
Vitamin B12 ◽  
Age Groups ◽  
Serum Vitamin ◽  
Vitamin B12 Deficiency ◽  
High Serum ◽  
Health Concern ◽  
Dietary Vitamin ◽  
Serum Homocysteine ◽  
Daily Vitamin ◽  
B12 Deficiency

Vitamin B12 deficiency poses a health concern, especially in vulnerable populations. Dietary vitamin B12 intake was obtained by two 24 h dietary recalls and food propensity questionnaires in a representative Slovenian cross-sectional food consumption survey, SI.Menu (n = 1248 subjects; 10–74 years). For a subgroup of 280 participants, data on serum vitamin B12 were available through the Nutrihealth study. The estimated usual population-weighted mean daily vitamin B12 intakes were 6.2 µg (adults), 5.4. µg (adolescents), and 5.0 µg (elderly). Lower intakes were observed in females. Inadequate daily vitamin B12 intake (<4 µg) was detected in 37.3% of adolescents, 31.7% of adults, and 58.3% elderlies. The significant predictors for inadequate daily vitamin B12 intake were physical activity score in all age groups, sex in adolescents and adults, financial status and smoking in elderly, and employment in adults. Meat (products), followed by milk (products), made the highest vitamin B12 contribution in all age groups. In adolescents, another important vitamin B12 contributor was cereals. The mean population-weighted serum vitamin B12 levels were 322.1 pmol/L (adults) and 287.3 pmol/L (elderly). Low serum vitamin B12 concentration (<148 nmol/L) and high serum homocysteine (>15 µmol/L) were used as criteria for vitamin B12 deficiency. The highest deficiency prevalence was found in elderlies (7.0%), particularly in males (7.9%). Factors associated with high serum homocysteine were also investigated. In conclusion, although vitamin B12 status was generally not critical, additional attention should be focused particularly to the elderly.

scholarly journals Prevalence of vitamin B12 deficiency among individuals with type 2 diabetes mellitus in a South Indian rural community

2018 ◽  
Vol 7 (2) ◽  
pp. 309 ◽  
Author(s):  
Shailendra D. ◽  
Rizwan Kalani ◽  
K. M. Venkat Narayan ◽  
Dorairaj Prabhakaran ◽  
Nikhil Tandon ◽  
...  
Keyword(s):  
Vitamin B12 ◽  
Rural Community ◽  
Odds Ratio ◽  
Complete Blood Count ◽  
Serum Vitamin ◽  
Vitamin B12 Deficiency ◽  
Oral Vitamin ◽  
South Indian ◽  
B12 Deficiency ◽  
Vitamin B12 Supplementation

Background: To estimate the prevalence of vitamin B12 deficiency in a rural south Indian community and to evaluate the association between metformin use and prevalent vitamin B12 deficiency in people with T2DM stratified by oral vitamin B12 supplementation.Methods: Using a cross sectional study design, a random sample of people with T2DM (N=438) was recruited from a rural community. Vitamin B12 deficiency was defined as serum B12 ≤200pg/ml. Data on metformin dose, duration of use, oral vitamin B12 supplementation, and diet were collected. Laboratory measurements included complete blood count, tests for hepatic, renal, and thyroid function, as well as serum vitamin B12 levels and HbA1c.Results: The prevalence of vitamin B12 deficiency in people with T2DM was 11.2% (95% Confidence Interval (CI) 8.2%-14.1%). The odds of vitamin B12 deficiency in patients receiving a metformin dose of 2 grams/day were 4 times higher compared to those receiving ≤1 gram/day, after adjusting for oral B12 supplementation (odds ratio 4.2;95% CI 1.5-11.8). The odds of vitamin B12 deficiency in those taking metformin and receiving oral vitamin B12 supplementation were lower compared to those on metformin and not receiving vitamin B12 supplementation (adjusted odds ratio 0.20; 95% CI 0.06-0.70).Conclusions: Vitamin B12 deficiency affects 1 in 10 people with T2DM, is associated with higher dose metformin use, and oral vitamin B12 supplementation mitigates B12 deficiency in this group.

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