The concentration of total vitamin B12 in serum is not a sufficiently sensitive or specific indicator for the reliable diagnosis of vitamin B12 deficiency. Victor Herbert proposed a model for the staged development of vitamin B12 deficiency, in which holotranscobalamin (HoloTC) is the first indicator of deficiency. Based on this model, a commercial immunoassay has been controversially promoted ...

BACKGROUND Vitamin B12 deficiency is prevalent in many countries of origin of refugees. Using a threshold of 5% above which a prevalence of low Vitamin B12 is indicative of a population health problem, we hypothesised that Vitamin B12 deficiency exceeds this threshold among newly-arrived refugees resettling in Australia, and is higher among women due to their increased risk of food insecurity. ...

Background: We evaluated whether measurement of vitamin B12-saturated transcobalamin (holo-TC) concentrations or TC saturation (holo-TC:total TC) reflects active vitamin B12 absorption in healthy individuals and patients after vitamin B12 intake. Methods: We obtained blood samples from 31 healthy individuals (age range, 25–57 years) before (days 1 and 0) and after (days 1, 2, and 6) oral admini...

BACKGROUND Physical frailty and loss of mobility in elderly individuals lead to reduced independence, quality of life, and increased mortality. Vitamin B12 deficiency has been linked to several age-related chronic diseases, including in the musculo-skeletal system, where vitamin B12 deficiency is generally believed to be linked to poor nutritional intake. In the present study, we asked whether ...

The role of vitamin B12 in the folate dependent biosynthesis of thymidine nucleotides is controversial. In an attempt to clarify this, three methods have been used to assess the relative efficacy of vitamin B12 (hydroxocobalamin) and various folate analogues in titrated concentrations at correcting 'de novo' thymidylate synthesis by megaloblastic human marrow cells: (1) The deoxyuridine (dU) su...

T FIAT VITAMIN B12 IN SERUM is l)ound to protein14 has been known since shortly after the isolation of the vitamin. Endogenous vitamin B12 (which may be mainly methyl-Bi2) is bound primarily to an a1-globulin 2.6-10 hut vitamin B12 added to serum in vitro hinds primarily to -globuun (presumably because B12-binding a-globulin is normally almost saturated with endogenous vitamin B12).61#{176} hal...

T FIAT VITAMIN B12 IN SERUM is l)ound to protein14 has been known since shortly after the isolation of the vitamin. Endogenous vitamin B12 (which may be mainly methyl-Bi2) is bound primarily to an a1-globulin 2.6-10 hut vitamin B12 added to serum in vitro hinds primarily to -globuun (presumably because B12-binding a-globulin is normally almost saturated with endogenous vitamin B12).61#{176} hal...

T FIAT VITAMIN B12 IN SERUM is l)ound to protein14 has been known since shortly after the isolation of the vitamin. Endogenous vitamin B12 (which may be mainly methyl-Bi2) is bound primarily to an a1-globulin 2.6-10 hut vitamin B12 added to serum in vitro hinds primarily to -globuun (presumably because B12-binding a-globulin is normally almost saturated with endogenous vitamin B12).61#{176} hal...

T FIAT VITAMIN B12 IN SERUM is l)ound to protein14 has been known since shortly after the isolation of the vitamin. Endogenous vitamin B12 (which may be mainly methyl-Bi2) is bound primarily to an a1-globulin 2.6-10 hut vitamin B12 added to serum in vitro hinds primarily to -globuun (presumably because B12-binding a-globulin is normally almost saturated with endogenous vitamin B12).61#{176} hal...

Vitamin B12 is an essential vitamin that is widely used in medical and food industries. Vitamin B12 biosynthesis is confined to few bacteria and archaea, and as such its production relies on microbial fermentation. Rational strain engineering is dependent on efficient genetic tools and a detailed knowledge of metabolic pathways, regulation of which can be applied to improve product yield. Recen...