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 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 Determining Functional Vitamin B12 Deficiency in the Elderly

2015 ◽  
Vol 17 (8) ◽  
Author(s):  
Niloofar Khodabandehloo ◽  
Masoud Vakili ◽  
Zahra Hashemian ◽  
Hadi Zare Zardini
Keyword(s):  
Vitamin B12 ◽  
Vitamin B12 Deficiency ◽  
The Elderly ◽  
B12 Deficiency

scholarly journals Anaemia in the Hospitalized Elderly in Tanzania: Prevalence, Severity, and Micronutrient Deficiency Status

Anemia ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Clara Chamba ◽  
Ahlam Nasser ◽  
William F. Mawalla ◽  
Upendo Masamu ◽  
Neema Budodi Lubuva ◽  
...  
Keyword(s):  
Vitamin B12 ◽  
Elderly Population ◽  
Vitamin B12 Deficiency ◽  
The Elderly ◽  
Micronutrient Deficiency ◽  
Sub Saharan Africa ◽  
Serum Folate ◽  
Deficiency Anaemia ◽  
Hospitalized Elderly ◽  
B12 Deficiency

Introduction. Anaemia is a common problem in sub-Saharan Africa. While most literature has focused on children, women of childbearing age, and pregnant women, data for the elderly population are relatively scarce. Anaemia exhorts negative consequences to functional ability of elderly patients, both physically and cognitively. The purpose of this study was to determine the prevalence of anaemia, severity, and micronutrient deficiency status in the elderly hospitalized patients in Tanzania. Methods. A total of 156 hospitalized adults aged 60 years and above were enrolled in this study. A structured questionnaire was used to capture sociodemographic and clinical characteristics. Blood samples were collected, and a complete blood count, serum cobalamin, serum ferritin, and serum folate levels were measured to assess anaemia and micronutrient deficiency status in all participants who had anaemia. Results. The prevalence of anaemia was 79.5% (124/156) with severe anaemia in 33.9% (42/124) of participants, moderate anaemia in 42.7% (53/124) of participants, and 23.4% (29/124) of all participants had mild anaemia. Micronutrient deficiency was found in 14.5% (18/124) of all participants with anaemia. Combined deficiency (either iron and vitamin B12 deficiency or iron and folate deficiency) was the most common micronutrient deficiency anaemia with a frequency of 33.3% (6/18), followed by isolated iron and folate deficiencies at equal frequency of 27.8% (5/18) and vitamin B12 deficiency at 11.1% (2/18). Conclusion. The prevalence of anaemia in the hospitalized elderly population is high warranting public health attention and mostly present in moderate and severe forms. Micro-nutrient deficiency anaemia is common in this age group and is mostly due to combined micronutrient deficiency.

scholarly journals Deficiency of vitamin B12 and development of Geriatric syndromes

2013 ◽  
pp. 42-45
Author(s):  
Jose Mauricio Ocampo
Keyword(s):  
Vitamin B12 ◽  
Protein Energy Malnutrition ◽  
Clinical Manifestations ◽  
Vitamin B12 Deficiency ◽  
Failure To Thrive ◽  
The Elderly ◽  
Geriatric Syndromes ◽  
Protein Energy ◽  
Appropriate Treatment ◽  
B12 Deficiency

Vitamin B12 deficiency or cyanocobalamin is a common condition in the elderly. It is repeatedly overlooked due to multiple clinical manifestations that can affect the blood, neurological, gastrointestinal, and cardiovascular systems, skin and mucous membranes. The various presentations of vitamin B12 deficiency are related to the development of geriatric syndromes like frailty, falls, cognitive impairment, and geriatric nutritional syndromes like protein-energy malnutrition and failure to thrive, in addition to enhancing aging anorexia and cachexia. Therefore, interventions must be developed to include their screening and diagnosis to make early and appropriate treatment to prevent its complications before they become irreversible.

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