A neonate, who was found to have an elevated C3/C2 ratio and minimally elevated propionylcarnitine on newborn screening, was subsequently identified as having the rare cblF inborn error of vitamin B12 (cobalamin) metabolism. This disorder is characterized by the retention of unmetabolized cobalamin in lysosomes such that it is not readily available for cellular metabolism. Although cultured fib...

Background CombinedMethylmalonic Aciduria (MMA), and homocystinuria CblC type is the most common inborn error of cobalamin metabolism with 77 mutations identified till date in the MMACHC gene. The disease has early and late presentations with varied clinical features. Case report A pair of preterm monochorionic twins was born to non-consanguineous parents with history of 2 previous infant deat...

Until the 1990s, the most common recognised cause of cobalamin deficiency in adults was pernicious anaemia [1]. Thanks to progress made during the last 10-20 years in the understanding of vitamin B12 metabolism, “new” physiopathological concepts have emerged or recognized, including a controversial medical concept entitled food-cobalamin malabsorption (FCM) in Anglo-Saxon literature, also known...

Vegetarians are at risk to develop deficiencies of some essential nutrients, especially vitamin B-12 (cobalamin). Cobalamin occurs in substantial amounts only in foods derived from animals and is essential for one-carbon metabolism and cell division. Low nutritional intake of vitamin B-12 may lead to negative balance and, finally, to functional deficiency when tissue stores of vitamin B-12 are ...

Using comparative analysis of genes, operons, and regulatory elements, we describe the cobalamin (vitamin B12) biosynthetic pathway in available prokaryotic genomes. Here we found a highly conserved RNA secondary structure, the regulatory B12 element, which is widely distributed in the upstream regions of cobalamin biosynthetic/transport genes in eubacteria. In addition, the binding signal (CBL...

Alcohol has complex direct effects on homocysteine metabolism, which are incompletely understood, and indirect effects mediated by interactions with vitamin metabolism and other factors. Both transmethylation and transsulfuration pathways are affected. Alcohol abuse is a common cause of hyperhomocysteinemia that often fluctuates and is sometimes severe. The causative role of alcohol in hyperhom...

      Objective(s): Incidence of neurocognitive and psychological disorders may be related to serum homocystein (Hcy), cobalamin (vitamin B12 ) and folate levels in old people. The aim of this study was to assess the relation between Hcy, cobalamin, folate and neurocognitive and/or psychological disorders in the elderly.   Materials and Methods: In this cross-sectional study, 280 subjects with ...

also see Table 2 in the online Data Supplement). In HRT users, we found no significant differences in serum cobalamin or in plasma holoTC, MMA, and tHcy compared with controls. To our knowledge, there are currently no published data on the effects of HRT on plasma holoTC, and studies on serum cobalamin have not established a clear pattern (4, 5). We observed that HRT use decreased the risk of h...