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.

The relationship between the cobalt nutrition of ewes and the vitamin B12 status of ewes and their lambs

1987 ◽  
Vol 38 (6) ◽  
pp. 1071 ◽  
Author(s):  
MF Quirk ◽  
BW Norton
Keyword(s):  
Vitamin B12 ◽  
Milk Production ◽  
Acid Concentration ◽  
Methylmalonic Acid ◽  
Vitamin B12 Deficiency ◽  
Lactation Performance ◽  
Lower Productivity ◽  
Cotton South ◽  
B12 Deficiency ◽  
The Relationship

An experiment was undertaken at Mt Cotton, south-east Queensland, to investigate the relationship between the cobalt nutrition of ewes and the occurrence of vitamin B12 deficiency in ewes and their lambs. Ewes received either no supplementary cobalt (C), 0.03 mg cobalt day-1 (LC), 0.06 mg cobalt day-1 (HC) or a cobalt bullet and grinder (CB). LC and HC ewes received their supplement as a weekly drench. Supplementation commenced prior to joining, and ewes subsequently grazed pangola grass pastures containing between 0.05 and 0.11 mg kg-1 cobalt.Cobalt supplementation of ewes increased their liveweight, reproductive and lactation performance. The milk production of ewes was influenced by the level of supplementation, with C, LC, HC and CB ewes producing 31.1, 41.5, 47.7 and 50.31. of milk respectively during the first 4 weeks of lactation. The lower productivity of C ewes was associated with concentrations of vitamin B12 in serum of less than 200 pg ml-1 and with the presence of detectable concentrations of methylmalonic acid (>80 8moles l-1) and formiminoglutamic acid (>30 8moles l-1) in their urine.The growth of lambs was influenced by the cobalt nutrition of their dams; the mean liveweight gain from birth to weaning (14 weeks of age) for lambs from C, LC, HC and CB ewes was 95, 158, 194 and 231 g day-1. Vitamin B12 deficiency was evident in lambs reared by C ewes from 4 weeks of age, but lambs from LC and HC ewes did not become deficient until 8 and 12 weeks of age respectively. Lambs from CB ewes remained free of signs of deficiency prior to weaning. Urinary formiminoglutamic acid concentration was a more reliable indicator of vitamin B12 status in young lambs than urinary methylmalonic acid concentration. The concentrations of vitamin B12 in the serum of lambs were low in all groups (< 150 pg ml-1) and were generally unaffected by the cobalt nutrition of their dams.A dietary cobalt intake of about 0.15 mg day-1 appeared to be necessary for optimal milk production from ewes. However, this level of dietary cobalt was inadequate for provision of sufficient quantities of maternal vitamin B12 to meet the requirements of lambs in the later stages of lactation.

scholarly journals Vitamin B12 deficiency and the excretion of ether-soluble acids in the rat

1967 ◽  
Vol 21 (2) ◽  
pp. 309-314 ◽  
Author(s):  
B. K. Armstrong
Keyword(s):  
Urinary Excretion ◽  
Vitamin B12 ◽  
Methylmalonic Acid ◽  
Vitamin B12 Deficiency ◽  
Vitamin B ◽  
B12 Deficiency ◽  
Males And Females

1. Urinary excretion of total ether-soluble acids and of methylmalonic acid was studied in rats on vitamin B12-deficient diets with and without a vitamin B12 supplement.2. It was shown that urinary excretion of total ether-soluble acids and methylmalonic acid was increased in vitamin B12-deficient rats and that this increase was somewhat variable between individual animals, males and females, and rats from different litters.3. The increased excretion of these acids could readily be reversed by supplementing the diet with vitamin B12.

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.

The Danger of B12 Deficiency in the Elderly

1998 ◽  
Vol 12 (4) ◽  
pp. 215-226 ◽  
Author(s):  
Margaret Wynn ◽  
Arthur Wynn
Keyword(s):  
Nervous System ◽  
Risk Factor ◽  
Heart Disease ◽  
Vitamin B12 ◽  
Vitamin B12 Deficiency ◽  
Pernicious Anaemia ◽  
The Elderly ◽  
Nerve Cells ◽  
Accelerated Ageing ◽  
B12 Deficiency

Vitamin B12 deficiency damages nerve cells and aggravates nervous system disorders even in the absence of evidence of anaemia. Prevalence of B12 deficiency increases with age especially over 65 and is frequently associated with Alzheimer's disease. Recent American surveys record a higher prevalence of B12 deficiency and of undiagnosed and untreated pernicious anaemia in the elderly than reported earlier. B12 deficiency is also reported to be a risk factor for heart disease, stroke and accelerated ageing.

scholarly journals Management of Peripheral Neuropathy and Cardiovascular Effects in Vitamin B12 Deficiency

2021 ◽  
Vol 10 (5) ◽  
Author(s):  
Nishant Kumar Singh ◽  
Hirni J. Patel ◽  
Mohit Buddhadev ◽  
S P Srinivas Nayak ◽  
Gunosindhu Chakraborthy
Keyword(s):  
Cardiovascular Disease ◽  
Peripheral Neuropathy ◽  
Vitamin B12 ◽  
Peripheral Nerves ◽  
Vitamin B12 Deficiency ◽  
Cardiovascular Effects ◽  
The Elderly ◽  
Vitamin Deficiencies ◽  
B12 Deficiency ◽  
Artery Disease

Peripheral nerves are susceptible to damage by a wide array of toxins, medications, and vitamin deficiencies. Vitamin B12 (VB12) deficiency neuropathy is a rare debilitating disease that affects mostly the elderly. It is important to consider these etiologies when approaching patients with a variety of neuropathic presentations in this review were have included most relevant and latest information on mechanisms causing Peripheral neuropathy in VB12 deficiency. We also have included cardiovascular disorders and their management. Hyperhomocysteinemia has been implicated in endothelial dysfunction and cardiovascular disease. The association of homocysteine (Hcy) and VB12 with cardiovascular risk factors in patients with coronary artery disease (CAD) has also been studied Keywords: Peripheral Neuropathy, Vitamin B12 Deficiency, Cardiovascular Disease and Homocysteine.

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

scholarly journals Parkinson’s Disease and Homocysteine: A Community-Based Study in a Folate and Vitamin B12 Deficient Population

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Zhang Wei ◽  
Wang Tiandong ◽  
Li Yang ◽  
Meng Huaxing ◽  
Min Guowen ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Vitamin B12 ◽  
Vitamin B12 Deficiency ◽  
Community Based ◽  
Current Smoking ◽  
Blood Samples ◽  
B12 Deficiency ◽  
Folate And Vitamin B12 ◽  
The Relationship

Background. Homocysteine (Hcy) levels were higher in patients with Parkinson’s disease (PD). This could be partially explained by levodopa treatment. Whether untreated PD patients have higher Hcy levels is contradictory.Methods.A community-based study was conducted using a two-stage approach for subjects ≥ 55 years to find PD patients in 3 towns of Lüliang City. Blood samples were collected. Serum Hcy, folate, and vitamin B12 concentrations were measured. For each untreated PD patient, 5 controls were selected matched with age and sex to evaluate the relationship between Hcy levels and PD.Results. Of 6338 eligible residents, 72.7% participated in the study. 31 PD cases were identified. The crude prevalence of PD for people ≥ 55 years was 0.67%. Blood samples were collected from 1845 subjects, including 17 untreated PD patients. There was no difference for concentrations of serum Hcy, folate, and vitamin B12 between cases and controls (P>0.05). In univariate and multivariate analysis, there was significant inverse relation between PD and current smoking (P<0.05). No other factor was significant statistically.Conclusions. The prevalence of PD was comparable to earlier studies in China. Hyperhomocysteinemia was not a risk factor of PD, as well as folate and vitamin B12 deficiency.

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