Abstract Cobalamin (Cbl, vitamin B 12) is a widely distributed, cobalt-containing, water-
soluble vitamin that is not found in higher plants. Cb1 is needed for only two reactions in …

Deficient activity of an enzyme can result from a defect in the conversion of the vitamin to a
co-enzyme as well from an abnormal apo-enzyme or disturbed binding of co-enzyme to …

Vitamin B12 (Cbl) is needed for just two metabolic reactions in man, the methylation of
homocysteine to methionine (cofactor methyl-Cbl) and the conversion of methylmalonyl-CoA …

Patients with inherited disorders affecting cobalamin (Cbl) absorption or metabolism show
elevations of homocysteine or methylmalonic acid, either alone or in combination. For those …

Cobalamin (Cbl), or vitamin B 12, is required for activity of the mitochondrial enzyme,
methylmalonyl-CoA mutase, and the cytoplasmic enzyme, methionine synthase. A number …

Abstract Vitamin B12 (cobalamin, Cbl) is a cofactor for just two enzymes, while various forms
of folate are coenzymes for a wide range of enzymes. Metabolism of both vitamins involve …

All of vitamin B12 in nature is of microbial origin. Cobalamin, as vitamin B12 should correctly
be termed, is a large polar molecule that must be bound to specialized transport proteins to …

Inborn errors of cobalamin metabolism result in problems affecting multiple systems,
including hematologic, neurologic, ophthalmologic, dermatologic, cardiovascular and renal …

Patients with disorders of intracellular Cbl metabolism typically have serum Cbl levels within
the reference range, although levels may be reduced in the cblF and cblJ disorders …

Abstract Cobalamin C (Cbl-C) defect is the most common inborn cobalamin metabolism
error; it causes impaired conversion of dietary vitamin B12 into its two metabolically active …