Vitamin B12 deficiency induced by the use of gastric acid inhibitors: Calcium supplements as a potential effect modifier

2015 ◽  
Vol 20 (5) ◽  
pp. 569-573 ◽  
Author(s):  
N. Presse ◽  
S. Perreault ◽  
Marie-Jeanne Kergoat
2002 ◽  
Vol 48 (9) ◽  
pp. 1383-1389 ◽  
Author(s):  
Karin JA Lievers ◽  
Lydia A Afman ◽  
Leo AJ Kluijtmans ◽  
Godfried HJ Boers ◽  
Petra Verhoef ◽  
...  

Abstract Background: Hyperhomocysteinemia is an independent risk factor for cardiovascular disease (CVD). Intracellular vitamin B12 deficiency may lead to increased plasma total homocysteine (tHcy) concentrations and because transcobalamin (TC) is the plasma transporter that delivers vitamin B12 to cells, genetic variation in the TC gene may affect intracellular vitamin B12 availability and, consequently, tHcy concentrations. Methods: We examined five sequence variants, i.e., I23V, G94S, P259R, S348F, and R399Q, in the TC gene as possible determinants of tHcy and, concordantly, as possible risk factors for CVD in 190 vascular disease patients and 601 controls. We also studied potential effect-modification of vitamin B12 by genotype. Results: In individuals with high vitamin B12, 259PP individuals had lower tHcy concentrations than 259PR and 259RR individuals. Homozygous 23VV individuals had lower fasting tHcy concentrations than their 23IV and 23II peers. None of the genotypes defined by the three other sequence variants showed an association with tHcy concentrations, nor was any TC genotype associated with an increased CVD risk. Conclusions: In individuals in the highest quartile of the vitamin B12 distribution (>299 pmol/L), tHcy concentrations are lower in 259PP homozygotes than in 259PR and 259RR individuals. Therefore, 259PP individuals, who represent >25% of the general population, may be more susceptible to reduction of plasma tHcy concentrations by increasing the vitamin B12 status.


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

2010 ◽  
Vol 80 (45) ◽  
pp. 330-335 ◽  
Author(s):  
Lindsay Helen Allen

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.


Author(s):  
Sanem Kayhan ◽  
Nazli Gulsoy Kirnap ◽  
Mercan Tastemur

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.


2009 ◽  
Vol 36 (S 02) ◽  
Author(s):  
W Schrempf ◽  
V Neumeister ◽  
M Eulitz ◽  
G Siegert ◽  
H Reichmann ◽  
...  

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

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