Unreliability of radiodilution assays as screening tests for cobalamin (vitamin B12) deficiency

JAMA ◽  
1980 ◽  
Vol 244 (17) ◽  
pp. 1942-1945 ◽  
Author(s):  
K. L. Cohen
Keyword(s):  
Vitamin B12 ◽  
Vitamin B12 Deficiency ◽  
Screening Tests ◽  
B12 Deficiency

Indigenous indicators of vitamin B12 deficiency

2020 ◽  
Vol 8 (2) ◽  
pp. 38-46
Author(s):  
Deepak Kumar P ◽  
Darshana Makwana ◽  
Pragathi Pragathi
Keyword(s):  
Vitamin B12 ◽  
Complete Blood Count ◽  
Clinical Manifestations ◽  
Serum Vitamin ◽  
Vitamin B12 Deficiency ◽  
Screening Tests ◽  
Mean Corpuscular Hemoglobin ◽  
Cross Sectional ◽  
Predictive Values ◽  
B12 Deficiency

Introduction: Clinical manifestations of vitamin B12 deficiency are mostly non-specific. An entity called subclinical deficiency has become popular where the need has arisen to perform costly investigations which indicate functional deficiency of vitamin B12 even when vitamin B12 levels are normal. These factors pose a challenge in planning management of patients. Aims and objectives : The study was conducted as an attempt to identify affordable and credible laboratory indicators of vitamin B12 deficiency which can be used as screening tests before choosing patients for further evaluation or treatment. Material and Methods : This was a time bound cross-sectional study where 100 adult patients who had undergone the following investigations were randomly chosen: Complete Blood Count with red cell indices, serum bilirubin and serum vitamin B12 levels. The sensitivity, specificity and predictive values (positive-PPV and negative-NPV) of the variables that could hypothetically identify vitamin B12 deficiency, both individually or in combinations were calculated and compared. Results and conclusion : Hemoglobin, MCV (Mean Corpuscular Volume), MCH (Mean Corpuscular Hemoglobin), platelets and bilirubin were not equally distributed between vitamin B12 deficient and normal groups(p values for these variables were 0.029, 0.000, 0.000, 0.003 and 0.029 respectively).When these variables were tested individually and in combination, the combination of [MCV=95 fl or MCH=30 pg or Platelets =1.4 lakh/µl or Bilirubin =1 mg/dl] had sensitivity of 68.2%, specificity of 85.7%, PPV of 78.9% and NPV of 77.4%. This proposed combination used as a screening test has potential for wide application considering its simplicity and cost advantage.

55: The Risk of Vitamin B12 Deficiency is Low after Ileal Orthotopic Bladder Substitution

2004 ◽  
Vol 171 (4S) ◽  
pp. 15-15
Author(s):  
Urs E. Studer ◽  
Richard Aebischer ◽  
Katharina Ochsner ◽  
Werner W. Hochreiter
Keyword(s):  
Vitamin B12 ◽  
Vitamin B12 Deficiency ◽  
B12 Deficiency ◽  
Bladder Substitution

Bioavailability of Vitamin B12

2010 ◽  
Vol 80 (45) ◽  
pp. 330-335 ◽  
Author(s):  
Lindsay Helen Allen
Keyword(s):  
Vitamin B12 ◽  
Vitamin B12 Deficiency ◽  
The Elderly ◽  
Radioactive Isotopes ◽  
Animal Source Foods ◽  
Dietary Requirements ◽  
In Vivo Labeling ◽  
B12 Deficiency ◽  
Vitamin B12 Malabsorption

Vitamin B12 deficiency is common in people of all ages who consume a low intake of animal-source foods, including populations in developing countries. It is also prevalent among the elderly, even in wealthier countries, due to their malabsorption of B12 from food. Several methods have been applied to diagnose vitamin B12 malabsorption, including Schilling’s test, which is now used rarely, but these do not quantify percent bioavailability. Most of the information on B12 bioavailability from foods was collected 40 to 50 years ago, using radioactive isotopes of cobalt to label the corrinoid ring. The data are sparse, and the level of radioactivity required for in vivo labeling of animal tissues can be prohibitive. A newer method under development uses a low dose of radioactivity as 14C-labeled B12, with measurement of the isotope excreted in urine and feces by accelerator mass spectrometry. This test has revealed that the unabsorbed vitamin is degraded in the intestine. The percent bioavailability is inversely proportional to the dose consumed due to saturation of the active absorption process, even within the range of usual intake from foods. This has important implications for the assessment and interpretation of bioavailability values, setting dietary requirements, and interpreting relationships between intake and status of the vitamin.

Increased monocyte to HDL cholesterol ratio in vitamin B12 deficiency: is it related to cardiometabolic risk?

2020 ◽  
pp. 1-8
Author(s):  
Sanem Kayhan ◽  
Nazli Gulsoy Kirnap ◽  
Mercan Tastemur
Keyword(s):  
Risk Factors ◽  
Blood Pressure ◽  
Uric Acid ◽  
Vitamin B12 ◽  
Cardiometabolic Risk ◽  
Vitamin B12 Deficiency ◽  
Left Ventricular ◽  
Cardiometabolic Risk Factors ◽  
B12 Deficiency ◽  
Deficiency Group

Abstract. Vitamin B12 deficiency may have indirect cardiovascular effects in addition to hematological and neuropsychiatric symptoms. It was shown that the monocyte count-to-high density lipoprotein cholesterol (HDL-C) ratio (MHR) is a novel cardiovascular marker. In this study, the aim was to evaluate whether MHR was high in patients with vitamin B12 deficiency and its relationship with cardiometabolic risk factors. The study included 128 patients diagnosed with vitamin B12 deficiency and 93 healthy controls. Patients with vitamin B12 deficiency had significantly higher systolic blood pressure (SBP), diastolic blood pressure (DBP), MHR, C-reactive protein (CRP) and uric acid levels compared with the controls (median 139 vs 115 mmHg, p < 0.001; 80 vs 70 mmHg, p < 0.001; 14.2 vs 9.5, p < 0.001; 10.2 vs 4 mg/dl p < 0.001; 6.68 vs 4.8 mg/dl, p < 0.001 respectively). The prevalence of left ventricular hypertrophy was higher in vitamin B12 deficiency group (43.8%) than the control group (8.6%) (p < 0.001). In vitamin B12 deficiency group, a positive correlation was detected between MHR and SBP, CRP and uric acid (p < 0.001 r:0.34, p < 0.001 r:0.30, p < 0.001 r:0.5, respectively) and a significant negative correlation was detected between MHR and T-CHOL, LDL, HDL and B12 (p < 0.001 r: −0.39, p < 0.001 r: −0.34, p < 0.001 r: −0.57, p < 0.04 r: −0.17, respectively). MHR was high in vitamin B12 deficiency group, and correlated with the cardiometabolic risk factors in this group, which were SBP, CRP, uric acid and HDL. In conclusion, MRH, which can be easily calculated in clinical practice, can be a useful marker to assess cardiovascular risk in patients with vitamin B12 deficiency.

Utility of measuring vitamin B12 and its active fraction, holotranscobalamin, in neurological vitamin B12 deficiency syndromes

2009 ◽  
Vol 36 (S 02) ◽  
Author(s):  
W Schrempf ◽  
V Neumeister ◽  
M Eulitz ◽  
G Siegert ◽  
H Reichmann ◽  
...  
Keyword(s):  
Vitamin B12 ◽  
Vitamin B12 Deficiency ◽  
Active Fraction ◽  
B12 Deficiency

Vitamin B12 Deficiency; a Silent Northside Dublin Epidemic?

Endoscopy ◽  
2006 ◽  
Vol 38 (11) ◽  
Author(s):  
CP O'Brien ◽  
S Patchett
Keyword(s):  
Vitamin B12 ◽  
Vitamin B12 Deficiency ◽  
B12 Deficiency

Vitamin B12 Deficiency an Unusual Cause of Fever: A Case Report

2019 ◽  
Vol 4 (02) ◽  
Author(s):  
Shyama . ◽  
P. Kumar ◽  
Surabhi .
Keyword(s):  
Bone Marrow ◽  
Vitamin B12 ◽  
Unusual Case ◽  
Vitamin B12 Deficiency ◽  
Bone Marrow Aspiration ◽  
Microcytic Anemia ◽  
Peripheral Smear ◽  
Erythroid Hyperplasia ◽  
B12 Deficiency ◽  
Vitamin B12 Supplementation

Introduction: An unusual case of a 19 year old female, presenting with fever, pallor and hepatosplenomegaly for one month. She had microcytic anemia on peripheral smear examination but her bone marrow aspiration & biopsy revealed a hypercelluar marrow with megaloblastic erythroid hyperplasia. Resolution of fever within 48 hours of Vitamin B12 supplementation, initiated in view of the megaloblastic bone marrow picture & low serumVitamin B12 level, suggests a causal association. Conclusion: Vitamin B12 deficiency seems to be an unusual cause of PUO (Pyrexia of unkown origin) which should be ruled out in every case of PUO.

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