Cobalamin deficiency is common in patients with Crohn's disease (CD). Intramuscular cobalamin continues to be the standard therapy for the deficiency and maintenance treatment in these patients, although oral route has been demonstrated to be effective in other pathologies with impaired absorption. Our aims were to evaluate the efficacy of oral therapy in the treatment of cobalamin deficiency a...

Methylmalonic acid (MMA) accumulates in the body in cases of cobalamin (vitamin B12) deficiency because of impaired metabolization of methylmalonyl CoA to succinyl CoA by methylmalonyl CoA-mutase, a cobalamin-dependent enzyme. Therefore, MMA represents a functional marker of cobalamin deficiency (1). It is widely accepted that MMA measurement is useful and necessary if serum cobalamin concentra...

A patient presented at the age of 77 yr with a low serum cobalamin level. Subsequent study showed that he had persistently very low R binder (TC I) cobalamin-binding capacity in serum (less than 5 ng/liter versus 213 +/- 171 ng/liter in normal controls), and that almost all of his endogenous serum cobalamin was carried by TC II instead of TC I. His saliva also demonstrated virtually undetectabl...

In the three domains of life, vitamin B12 (cobalamin) is primarily used in methyltransferase and isomerase reactions. The methyltransferase complex MtrA-H of methanogenic archaea has a key function in energy conservation by catalysing the methyl transfer from methyl-tetrahydromethanopterin to coenzyme M and its coupling with sodium-ion translocation. The cobalamin-binding subunit MtrA is not ho...

Hypercobalaminemia (high serum vitamin B12 levels) is a frequent and underestimated anomaly. Clinically, it can be paradoxically accompanied by signs of deficiency, reflecting a functional deficiency linked to qualitative abnormalities, which are related to defects in tissue uptake and action of vitamin B12. The aetiological profile of high serum cobalamin predominantly encompasses severe disea...

BACKGROUND When increased serum cobalamin concentrations are encountered clinically they are usually attributed to parenteral supplementation, dietary factors, or otherwise ignored. However, recently, hypercobalaminaemia has been associated with numerous diseases in humans, most notably neoplastic and hepatic disorders. The aim of this retrospective, observational, cross-sectional study was to ...

The cerebral computed tomographic findings in two infants with methylmalonic acidemia and one infant and one adult with propionic acidemia are presented. Pertinent metabolic, clinical, and pathologic features of these genetic disorders of vitamin B'2 (cobalamin) and biotin metabolism are reviewed briefly. Computed tomographic abnormalities consist of focal or diffuse deep cerebral hemisphere lu...

Biermer’s disease also called: Addison’s anemia or in old textbooks, pernicious anemia, is an autoimmune disease, caused by impaired absorption of cobalamin (vitamin B12) owing to the neutralization of intrinsic factor action in the setting of immune atrophic gastritis [1]. In adults and elderly patients, this form of megaloblastic anemia is one of the leading causes of cobalamin deficiency, wi...

Developments relating to cobalamin and folate are reviewed. Current work on the relations between these two coenzymes are discussed, particularly those that have emerged in studies using nitrous oxide, which inactivates cobalamin.

The association between body size at birth and risk of later cardiovascular disease is thought to be a consequence of metabolic changes that accompany slow growth in utero. The metabolism of methionine and homocysteine has been investigated in relation to cardiovascular risk and has also been assigned an important role in organogenesis and normal fetal growth. We determined concentrations of co...