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Results for “VITAMIN B 12”

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At least 55 records · Page 3Linked to original sources
PubMed2002

Application of vitamin B(12)-targeting site on Lactobacillus helveticus B-1 to vitamin B(12) assay by chemiluminescence method.

Lactobacillus helveticus B-1 is assumed to have a vitamin B(12)-targeting (or B(12)-binding) site on the cells, since the binding reaction of vitamin B(12) with L. helveticus B-1 cells proceeded instantly and quantitatively. This reaction is specific to complete B(12) compounds, cobalamins, and can be used for a vitamin B(12) assay method by chemiluminescence. The calibration graph was linear from 0.1 to 10.0 ng/mL. The B(12) contents in oyster and sardine were 75.9 and 39.4 microg/100g, respectively. These values were very close to those obtained using a chemilumi-ADVIA Centaur immunoassay system with intrinsic factor and to those obtained by microbiological assays.

Acridines↗
PubMed1973

Vitamin B 12 and the macromolecular composition of Euglena. II. Recovery from unbalanced growth induced by Vitamin B 12 deficiency.

When vitamin B(12) is added to B(12)-deficient cultures of Euglena gracilis, the cells undergo two relatively synchronous cell divisions within a shorter than usual period of time, apparently as a result of a transitory shortening of the cell cycle. The first cell division pulse, occurring 4.5 h after addition of B(12), is preceded by the completion of DNA duplication, but appears to involve no net synthesis of RNA or protein. Before the second round of cell division at about 11 h, a significant amount of DNA synthesis is observed. This time it is accompanied by a minor increase in the RNA and protein content of the culture. The cellular contents of RNA and protein were observed to decrease steadily after the resumption of cell division in B(12)-depleted cultures receiving the vitamin. Ultimately all three macromolecules returned to their nondeficient, plateau stage levels; by this time, cell division had ceased.

Cell Division↗
PubMed2004

[Helicobacter pylori can in rare cases be the cause of iron and vitamin B 12 deficiency. No increased risk of iron and vitamin B 12 deficiency due to proton pump inhibitors].

This article reviews iron and vitamin B12 malabsorption due to the use of proton pump inhibitors (PPI) and infection with Helicobacter pylori. The bacterium is in some studies associated with low serum values of both ferritin and cobalamin and has in several cases been shown to cause reversible deficiency of these nutrients. PPI depresses absorption of vitamin B12, but only one case of deficiency has been reported in standard reflux therapy. Case reports exist of PPI-related iron deficiency, but studies have not confirmed these risks. General substitution with iron or B12 supplements in PPI therapy can't be advocated. The safety of long-term use of PPI is well documented, but it is still unclear whether PPI accelerates the development of atrophic corpus gastritis in the presence of H pylori.

Anemia, Iron-Deficiency↗
PubMedDate not supplied

Mood disorder with mixed features due to vitamin B(12) and folate deficiency.

Vitamin B(12) and folate deficiency is often associated with affective disorders mainly of the depressive type. We report a case of a 42-year-old woman with a mood disorder with mixed depressed/manic features that was due to vitamin B(12) and folate deficiency. The psychopathology developed over a five-year period without hematologic or other overt clinical characteristics of pernicious anemia. Replacement treatment with vitamin B(12) and folate was rapidly followed by full clinical remission, electroencephalographic normalization and neuropsychological improvement. At a one-year follow-up this condition was stable. Consequently, patients who respond poorly to psychopharmacologic treatment and/or present with atypical mood symptoms would warrant determination of vitamin B(12) and folate serum levels.

Adult↗
PubMed2006

The association of homocysteine and its determinants MTHFR genotype, folate, vitamin B12 and vitamin B6 with bone mineral density in postmenopausal British women.

We studied the association between plasma total homocysteine (tHcy), its determinants folate, vitamin B(12), vitamin B(6) and MTHFR genotype, and bone mineral density (BMD) in 328 postmenopausal British women. When the subjects were assigned to one of 3 groups (control, osteopenic or osteoporotic) according to their BMD at the os calcis, those in the osteoporotic group had, compared with the controls, a significantly lower serum folate concentration, a significantly higher % of current smokers and a significantly higher incidence of recent fracture. In the population as a whole, we found significant associations of BMD with tHcy (r=-0.130, p=0.033, log tHcy) and folate (r=0.132, p=0.025, log folate). The association of folate with BMD was maintained after correction for age, weight and height (r=0.124, p=0.042, log folate), but the association of tHcy with BMD weakened after correction for age, weight, height and creatinine (r=-0.117, p=0.059, log tHcy). Vitamins B(12) and B(6) were not associated with BMD, but were significantly associated with tHcy, vitamin B(12) (r=-0.34, p<0.0001), vitamin B(6) (r=-0.16, p=0.007), as was folate (r=-0.41, p<0.0001). There was an increasing frequency of the MTHFR TT genotype across the 3 BMD groups, but this did not attain significance. Individuals with the TT genotype had significantly higher plasma tHcy but there was no difference between the genotypes (CC, CT, TT) for folate or BMD. Smoking was associated with a highly significant reduction in BMD and lower weight, and a significant reduction in circulating folate and vitamin B(6) concentrations, but no change in tHcy or vitamin B(12) concentrations when compared with non-smokers. We conclude that low serum folate is a significant risk factor for osteoporosis, with plasma tHcy having a lesser effect. Both vitamins B(12) and B(6), by acting through tHcy, may also have an effect on the skeleton, albeit a weaker one than folate. Cigarette smoking is a strong determinant of BMD, and may act through effects on folate and vitamin B(6).

Aged↗