Vitamin B12, cobalamin, is a cobalt-containing ring-contracted modified tetrapyrrole that represents one of the most complex small molecules made by nature. In prokaryotes it utilised as cofactor, coenzyme, light sensor and gene regulator yet has restricted role in assisting only two enzymes within specific eukaryotes including mammals. This deployment disparity reflected another unique attribu...

Dementia is highly prevalent among elderly people, and projections show that the number of people affected might triple over the next 50 years, mainly because of a large increase in the oldest-old segment of the population. Because of this and the disease's devastating effects, measures for the prevention and early detection of dementia are crucial. Age and years of education are among the most...

Cobalamin and folate are especially important for women of childbearing age due to their ubiquitous role in fetal growth and development. Population-based data on cobalamin and folate status are lacking from Nepal, where diets are mostly vegetarian. The objectives of the study were to investigate cobalamin and folate intake and status, and to explore associations with socio-demographics, anthro...

The marine microalga Ostreococcus is considered to depend on the methionine synthase METH and its methylated cobalamin cofactor for methionine synthesis. Here I describe minimal media lacking both cobalt and cobalamin yet suitable for clonal growth of Ostreococcus tauri. Because Ostreococcus lacks the methylcobalamin-independent methionine synthase METE, Ostreococcus growth without cobalamin is...

The challenges in medical management of cobalamin deficiency lie in attention to the unique pathophysiology that underlies cobalamin deficiency, more than in the mechanics of therapy. The central physiologic principles are that clinically important deficiency is more likely to occur (and progress) when intrinsic factor–driven absorption fails than when diet is poor and that most causes take yea...

Cobalamin deficiency is associated with a wide spectrum of hematologic, neurologic, gastroenterologic and psychiatric disorders or symptoms. We report a case of a 50-year-old man with complex partial seizures with secondary generalization, mood oscillations and psychotic symptoms alternating with confusion and reversible dementia secondary to cobalamin deficiency in the absence of typical neuro...

When extracts prepared from cultured human or rodent fibroblasts grown in medium containing [(57)Co]cobalamin were analyzed by polyacrylamide gel electrophoresis, most of the intracellular radioactivity migrated with the activity of the cobalamin-dependent enzyme 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase (EC 2.1.1.13). Because the rodent and human forms of this enzyme are elec...

This review apprises the reader of recent advances in cobalamin absorption and transport since 1970. This field has been of interest to gastroenterologists, hematologists, and biochemists as well as nutritionists. Clinical conditions leading to cobalamin deficiency present especially to the first two of these specialties. Many recent advances involve biochemical definition of the specific trans...

Folate and cobalamin are necessary for early brain development and function. Deficiency of folate or cobalamin during pregnancy can cause severe malformation in the central nervous system such as neural tube defects. After birth, folate and cobalamin deficiency can cause anemia, failure to thrive, recurrent infections, psychiatric and neurological symptoms. The folate and the homocysteine metab...