Vitamin B12 deficiency is a well-described disorder with a spectrum of manifestations ranging from macrocytic anemia to neuropsychiatric disorders including depression, dementia, and subacute combined degeneration of the spinal cord. Lack of vitamin B12 arises from insufficient intake or malabsorption. In clinical practice, serum total cobalamin (Cbl) levels are the initial test of choice for d...

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...

Introduction Vitamin B12 defi ciency in infants can result in profound and permanent health consequences. Prevention, early diagnosis and early treatment are crucial to ensure a better outcome for those affected.1 However, the symptoms of vitamin B12 defi ciency in infants can be non-specifi c, leading to delayed or missed diagnosis. Vitamin B12 (cobalamin) is a water-soluble vitamin found natu...

Because the origin of cobalamin (vitamin B12) analogues in animal chows and animal and human blood and tissues is unknown, we investigated the possibility that multivitamin interactions might convert cobalamin to cobalamin analogues. We homogenized three popular multivitamin-mineral pills in water, incubated them at 37 degrees C for 2 h, and isolated the cobalamin. Using paper chromatography we...

OBJECTIVE There are few studies regarding vitamin B12 deficiency in developing countries. In Brazil, a late diagnosis of vitamin B12 deficiency progressing to severe neurological damage is common. Thus, the aim of the present study was to verify the frequency of vitamin B12 deficiency in two Brazilian populations (elderly and adult participants) and to compare different methods of vitamin B12 d...

Vitamin B12 (cobalamin) has two active forms, adenosylcobalamin and methylcobalamin which have a key role in two important metabolic pathways in humans and their deficiency is responsible for clinical problems. Cobalamin is essential during whole life, but its sufficient amount is extra important in fetal and neonatal period, when it is essential for normal child growth and development as well ...

BACKGROUND Two proteins carry vitamin B12 in plasma. Transcobalamin (TC) carries approximately 25% of total plasma vitamin B12 and is 6% to 20% saturated with cobalamin. Haptocorrin (HC) binds approximately 80% of total cobalamin and is largely saturated with cobalamin. METHODS We investigated the distribution and the relationship between concentrations of cobalamin, total and holo forms of T...

“The proscription that cobalamin deficiency should not be diagnosed unless megaloblastic changes are found is akin to requiring jaundice to diagnose liver disease.” [1]. This statement by Carmel, one of the leaders in the vitamin B12 field, was made more than 10 years ago and yet many physicians and health authorities still insist on haematological changes before accepting a diagnosis of vitami...

Chronic renal failure is a well-known long-term complication of methylmalonic aciduria (MMA-uria), occurring even under apparently optimal metabolic management. The onset of renal dysfunction seems to be dependent on the type of defect and vitamin B12-responsiveness. We report on a patient with a vitamin B12-responsive cobalamin A type (cblA) MMA-uria caused by a homozygous stop mutation (p.R14...