scholarly journals Transcobalamin deficiency: vitamin B12 deficiency with normal serum B12 levels

2019 ◽  
Vol 12 (10) ◽  
pp. e232319 ◽  
Author(s):  
Sanjeev Khera ◽  
Suman Kumar Pramanik ◽  
Saroj Kumar Patnaik
Keyword(s):  
Vitamin B12 ◽  
Inborn Error ◽  
Autosomal Recessive ◽  
Vitamin B12 Deficiency ◽  
Genetic Evaluation ◽  
Normal Serum ◽  
Definitive Diagnosis ◽  
Early Infancy ◽  
Vitamin B ◽  
B12 Deficiency

Transcobalamin (TC) deficiency is a rare autosomal recessive inborn error of cobalamin transport which clinically manifests in early infancy. We describe a child with TC deficiency who presented with classical clinical and lab stigmata of inborn error of vitamin B12 metabolism except normal serum B12 levels. He was started on empirical parenteral cobalamin supplements at 2 months of age; however, the definitive diagnosis could only be established at 6 years of age when a genetic evaluation revealed homozygous nonsense variation in exon 8 of the TCN2 gene (chr22:g.31019043C>T).

scholarly journals Improved testing for vitamin B12 deficiency: correcting MMA for eGFR reduces the number of patients classified as vitamin B12 deficient

2018 ◽  
Vol 55 (6) ◽  
pp. 685-692 ◽  
Author(s):  
Saskia LM van Loon ◽  
Anna M Wilbik ◽  
Uzay Kaymak ◽  
Edwin R van den Heuvel ◽  
Volkher Scharnhorst ◽  
...  
Keyword(s):  
Data Mining ◽  
Vitamin B12 ◽  
Methylmalonic Acid ◽  
Vitamin B12 Deficiency ◽  
The Elderly ◽  
Vitamin B ◽  
Data Mining Approach ◽  
Number Of Patients ◽  
B12 Deficiency ◽  
The Relationship

Background Methylmalonic acid (MMA) can detect functional vitamin B12 deficiencies as it accumulates early when intracellular deficits arise. However, impaired clearance of MMA from blood due to decreased glomerular filtration rate (eGFR) also results in elevated plasma MMA concentrations. Alternative to clinical trials, a data mining approach was chosen to quantify and compensate for the effect of decreased eGFR on MMA concentration. Methods Comprehensive data on patient’s vitamin B12, eGFR and MMA concentrations were collected ( n = 2906). The relationship between vitamin B12, renal function (eGFR) and MMA was modelled using weighted multiple linear regression. The obtained model was used to estimate the influence of decreased eGFR on MMA. Clinical impact was examined by comparing the number of patients labelled vitamin B12 deficient with and without adjustment in MMA. Results Adjusting measured MMA concentrations for eGFR in the group of patients with low-normal vitamin B12 concentrations (90–300 pmol/L) showed that the use of unadjusted MMA concentrations overestimates vitamin B12 deficiency by 40%. Conclusions Through a data mining approach, the influence of eGFR on the relation between MMA and vitamin B12 can be quantified and used to correct the measured MMA concentration for decreased eGFR. Especially in the elderly, eGFR-based correction of MMA may prevent over-diagnosis of vitamin B12 deficiency and corresponding treatment.

scholarly journals Homocystinuria masquerading as vitamin B12 deficiency

2012 ◽  
Vol 4 (2) ◽  
pp. 326-328
Author(s):  
M Wadhwani ◽  
S Beri ◽  
A Saili ◽  
S Garg
Keyword(s):  
Vitamin B12 ◽  
Megaloblastic Anemia ◽  
Vitamin B12 Deficiency ◽  
Interesting Case ◽  
Vitamin B ◽  
Ophthalmological Examination ◽  
Ophthalmic Manifestations ◽  
History Of ◽  
B12 Deficiency ◽  
Vitamin B 12

Background: Homocystinuria is a rare metabolic disorder charcterised by excess homocysteine in the urine. Vitamin B12 deficiency has diverse cutaneous, nervous and ophthalmic manifestations. Objective: To report a case of homocystinuria masquerading as vitamin B 12 deficiency. Case: We hereby are presenting an interesting case of a 4 year old boy who was being treated for Vitamin B 12 deficiency on the basis of history of delayed milestone, abdominal pain and hyperpigmentation of skin which was diagnosed as homocystinuria. Conclusion: It is important to carry out ophthalmological examination in every case of megaloblastic anemia if associated with blurring of vision and mental retardation.DOI: http://dx.doi.org/10.3126/nepjoph.v4i2.6554 Nepal J Ophthalmol 2012; 4 (8): 326-328

A review of the cut-off points for the diagnosis of vitamin B12 deficiency in the general population

2015 ◽  
Vol 53 (8) ◽  
Author(s):  
Raquel Aparicio-Ugarriza ◽  
Gonzalo Palacios ◽  
Monika Alder ◽  
Marcela González-Gross
Keyword(s):  
General Population ◽  
Vitamin B12 ◽  
Vitamin B12 Deficiency ◽  
Vitamin B ◽  
B12 Deficiency

AbstractVitamin B

scholarly journals Vitamin B 12 Assay – are we on Track?

2020 ◽  
Vol 2 (8) ◽  
pp. 01-03
Author(s):  
Rateesh Sareen
Keyword(s):  
Vitamin B12 ◽  
Vitamin B12 Deficiency ◽  
Reference Interval ◽  
Population Characteristics ◽  
Vitamin B ◽  
B12 Deficiency ◽  
Vitamin B 12 ◽  
Work Up

Vitamin B12 assay is one of the most frequently ordered tests particularly as a part of regular medical checkups. The deficiency is rampant in vegetarian population. It is of immense importance that laboratories establish their own reference interval (RI) of analyte specially Vitamin B12 as a diagnosis of Vitamin B12 deficiency based on RI of kit insert inadvertently leads to unnecessary treatment or work up. A blind reliance on RI of kit insert should be discouraged as they do not take into account population characteristics and do not truly reflect RI specific to the population under study.

scholarly journals Profiling immuno-metabolic mediators of vitamin B12 deficiency among metformin-treated type 2 diabetic patients in Ghana

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0249325
Author(s):  
Samuel Asamoah Sakyi ◽  
Edwin Ferguson Laing ◽  
Richard Mantey ◽  
Alexander Kwarteng ◽  
Eddie-Williams Owiredu ◽  
...  
Keyword(s):  
Peripheral Neuropathy ◽  
Diabetic Neuropathy ◽  
Vitamin B12 ◽  
Intrinsic Factor ◽  
Vitamin B12 Deficiency ◽  
Anthropometric Measurement ◽  
Diabetic Patients ◽  
Vitamin B ◽  
Tnf Α ◽  
B12 Deficiency

Background The association between prolong metformin usage and B12 deficiency has been documented. However, the prevalence estimates of metformin-induced vitamin B12 deficiency showed substantial disparity among studies due to varied study definitions of vitamin B12 deficiency. Metformin blocks the calcium dependent absorption of the vitamin B12-Intrinsic Factor complex at the terminal ileum. Lack of intrinsic factor due to the presence of auto-antibodies to parietal cells (IFA) could lead to vitamin B12 deficiency and subsequently cause peripheral neuropathy. We investigated the prevalence of vitamin B12 deficiency using more sensitive, combined markers of vitamin B12 status (4cB12) and the immuno-biochemical mediators of vitamin B12 deficiency. Methods In this observational study, 200 consecutive consenting metformin-treated T2DM patients, aged 35 and above, attending the diabetic clinic at KATH were recruited. Vitamin B12 deficiency was classified based on the Fedosov age-normalized wellness quotient. Anthropometric measurement was taken as well as blood samples for immunological and biochemical mediators. Peripheral neuropathy was assessed using the Michigan Neuropathy Screening Instrument (MNSI). Statistical analysis was performed using the R Language for Statistical Computing. Results Using the combined indicator (4cB12), the prevalence of metformin induced vitamin B12 deficiency was 40.5% whilst the prevalence of MNSI-Q and MNSI-PE diabetic neuropathy was 32.5% and 6.5% respectively. Participants with vitamin B12 deficiency had significantly higher levels of IFA, GPA, TNF-α, TC, LDL and albumin compared to those with normal vitamin B12 levels (p < 0.05). Correlation analysis revealed a statistically significant negative association between 4cB12 and the immunological markers [IFA (rs = -0.301, p<0.0001), GPA (rs = -0.244, p = 0.001), TNF-α (rs = -0.242, p = 0.001) and IL-6 (rs = -0.145, p = 0.041)]. Likewise, 4cB12 was negatively associated with TC (rs = -0.203, p = 0.004) and LDL (rs = -0.222, p = 0.002) but positively correlated with HDL (rs = 0.196, p = 0.005). Conclusion Vitamin B12 deficiency and diabetic neuropathy are very high among metformin-treated T2DM patients and it is associated with increased GPA, IFA, TNF-α and cardiometabolic risk factors (higher LDL and TC and lower HDL). Upon verification of these findings in a prospective case-control study, it may be beneficial to include periodic measurement of Vitamin B12 using the more sensitive combined indicators (4cB 12) in the management of patients with T2DM treated with metformin in Ghana.

State of oxidation of nonprotein sulfhydryl compounds in vitamin B12 deficiency

1961 ◽  
Vol 200 (1) ◽  
pp. 99-101 ◽  
Author(s):  
B. L. O'Dell ◽  
B. A. Erickson ◽  
P. M. Newberne ◽  
L. M. Flynn
Keyword(s):  
Vitamin B12 ◽  
Vitamin B12 Deficiency ◽  
Average Weight ◽  
Vitamin B ◽  
Anaerobic Glycolysis ◽  
Weanling Rats ◽  
Liver Concentration ◽  
B12 Deficiency ◽  
Sulfhydryl Compounds ◽  
Brain Tissues

A vitamin B12 deficiency in weanling rats, which reduced their average weight to one-half that of controls, decreased liver concentration of nonprotein sulfhydryl (NPSH) compounds about 10% but had no effect on concentration of disulfide compounds. Fasting did not accentuate the effect of the deficiency. Dams severely depleted of B12 produced offspring whose livers contained significantly less NPSH and correspondingly more nonprotein disulfide (NPSS) compounds than controls. Thus the decreased concentration of NPSH on the B12-deficient liver was accounted for as NPSS. Vitamin B12 deficiency had no effect on the rate of anaerobic glycolysis in liver and brain tissues.

scholarly journals Gel Filtration Studies of Serum B12 Binding: An Abnormal Pattern in Patients with Vitamin B12 Deficiency

Blood ◽  
1969 ◽  
Vol 34 (6) ◽  
pp. 774-781 ◽  
Author(s):  
CHRISTINE LAWRENCE
Keyword(s):  
Molecular Weight ◽  
Vitamin B12 ◽  
Binding Capacity ◽  
Gel Filtration ◽  
Vitamin B12 Deficiency ◽  
Normal Serum ◽  
B12 Deficiency ◽  
Abnormal Pattern ◽  
Normal Controls

Abstract 57CoB12 was added to serum in vitro to study its binding by the three known serum B12-binders in patients with vitamin B12 deficiency and in normal controls. Gel filtration through columns of Sephadex G-200 was used to separate the low (beta) and high (alpha1 and beta) molecular weight B12-binding fractions. Electrophoresis on filter paper was used to separate the alpha1- and beta-globulins. The alpha1-globulin fraction in the serum of B12-deficient patients bound more of the added 57CoB12 than did this fraction in normal serum, presumably because this binder of the serum endogenous vitamin B12 is much less saturated in B12-deficiency. However, the total B12 binding capacity of the alpha1-globulin (for endogenous plus added vitamin B12) was lower in B12-deficient than in normal serum. The low molecular weight beta-binder bound more added 57CoB12 in B12-deficient than in normal serum, whereas the high molecular weight beta binder had a much lower B12-binding capacity in deficient than in normal serum. These abnormalities were independent of the cause of the vitamin B12 deficiency and disappeared after successful treatment with vitamin B12.

scholarly journals Holotranscobalamin Is a Useful Marker of Vitamin B12 Deficiency in Alcoholics

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Alberto Fragasso ◽  
Clara Mannarella ◽  
Angela Ciancio ◽  
Oronzo Scarciolla ◽  
Nicoletta Nuzzolese ◽  
...  
Keyword(s):  
Vitamin B12 ◽  
Vitamin B12 Deficiency ◽  
Serum Levels ◽  
Normal Serum ◽  
Serum Folate ◽  
Gamma Glutamyl Transpeptidase ◽  
B12 Deficiency ◽  
Male Patients ◽  
Positive Correlations ◽  
Glutamyl Transpeptidase

Background. Measurement of serum cobalamin (Cbl) levels is the standard investigation for assessing vitamin B12 deficiency. Falsely increased values of Cbl can be caused by alcoholic liver disease. Measurement of total vitamin B12 serum levels might be misleading in alcoholics, because a tissue metabolic deficiency is possible even with normal serum Cbl levels. Holotranscobalamin (HoloTC), the Cbl metabolically active fraction, is considered as a better index of vitamin B12 deficiency.Methods. For assessing vitamin B12 status, we evaluated 22 adult alcoholic male patients by measuring in parallel serum Cbl, serum folate and red blood cell folate levels, HoloTC levels by the AxSYM assay.Results. HoloTC values were reduced in 3 alcoholics with borderline-low Cbl values. Significant positive correlations were found between serum Cbl and HoloTC levels, serum Cbl and gamma-glutamyl transpeptidase (GGT).Conclusion. HoloTC measurement is a useful option for assessing vitamin B12 status in alcoholics, particularly in the subjects with borderline Cbl values and may be considered an early marker of vitamin B12 deficiency.

scholarly journals Questionable Reliability Of Homocysteine As The Metabolic Marker For Folate And Vitamin B12 Deficiency In Patients With Chronic Obstructive Pulmonary Disease

2015 ◽  
Vol 34 (4) ◽  
pp. 467-472 ◽  
Author(s):  
Anđelo Beletić ◽  
Duško Mirković ◽  
Aleksandra Dudvarski-Ilić ◽  
Branislava Milenković ◽  
Ljudmila Nagorni-Obradović ◽  
...  
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Vitamin B12 ◽  
Vitamin B12 Deficiency ◽  
Chronic Obstructive ◽  
Vitamin B ◽  
Obstructive Pulmonary Disease ◽  
Metabolic Marker ◽  
Copd Patients ◽  
B12 Deficiency ◽  
Folate And Vitamin B12

SummaryBackground:An increased homocysteine (Hcy) concentration may represent a metabolic marker of folate and vitamin B12deficiency, both significant public health problems. For different reasons, patients with chronic obstructive pulmonary disease (COPD) are prone to these deficiencies. The study evaluates the reliability of Hcy concentration in predicting folate or vitamin B12deficiency in these patients.Methods:A group of 50 COPD patients (28 males/22 females, age$({\rm{\bar x}} \pm {\rm{SD}} = 49.0 \pm 14.5)$years was enrolled. A chemiluminescent microparticle immunoassay was applied for homocysteine, folate and vitamin B12concentration. Kolmogorov-Smirnov, Mann-Whitney U and χ2tests, Spearman’s correlation and ROC analysis were included in the statistical analysis, with the level of significance set at 0.05.Results:Average (SD) concentrations of folate and vitamin B12were 4.13 (2.16) μg/L and 463.6 (271.0) ng/L, whereas only vitamin B12correlated with the Hcy level (P=−0.310 (R=0.029)). Gender related differences were not significant and only a borderline significant correlation between age and folate was confirmed (R=0.279 (P=0.047)). The incidence of folate and vitamin B12 deficiency differed significantly (P=0.000 and P<0.000 for folate and vitamin B12respectively), depending on the cut-off used for classification (4.4, 6.6 and 8.0 μg/L – folate; 203 and 473 ng/L – vitamin B12). ROC analyses failed to show any significance of hyperhomocysteinemia as a predictor of folate or vitamin B12deficiency.Conclusion:Reliability of the Hcy concentration as a biomarker of folate or vitamin B12depletion in COPD patients is not satisfactory, so their deficiency cannot be predicted by the occurrence of HHcy.

scholarly journals Vitamin B12 deficiency in captive monkeys and its effect on the nervous system and the blood

1970 ◽  
Vol 4 (1) ◽  
pp. 1-12 ◽  
Author(s):  
C. E. Oxnard ◽  
W. Thomas Smith ◽  
I. Torres
Keyword(s):  
Peripheral Nerves ◽  
Wallerian Degeneration ◽  
Vitamin B12 Deficiency ◽  
Serum Levels ◽  
Normal Serum ◽  
Vitamin B ◽  
Lateral Column ◽  
B12 Deficiency ◽  
Vegetarian Diets ◽  
Cerebral Degeneration

Monkeys fed vegetarian diets develop neurological and haematological abnormalities; paralysis can occur though the neural lesions (cerebral degeneration, posterior and lateral column degeneration of the spinal cord, segmental and wallerian degeneration of the peripheral nerves) are usually not evident during life. It is clearly important that the diet given to captive animals should contain an adequate amount of vitamin B12, and that newly captive monkeys should not be used for research purposes unless shown to have normal serum levels of the vitamin.

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