Non-invasive delivery of biotherapeutics, as an attractive alternative to injections, could potentially be achieved through the mucosal surfaces, utilizing nanoscale therapeutic carriers. However, nanoparticles do not readily cross the mucosal barriers, with the epithelium presenting a major barrier to their translocation. The transcytotic pathway of vitamin B12 has previously been shown to 'fe...

Metformin causing vitamin B12 (B12) deficiency has become a traditional myth in medical literature (1,2). But what evidence do we have? The possibility to measure holotranscobalamin (active B12) and the metabolic marker, methylmalonic acid (MMA), has changed the practice of diagnosing B12 deficiency in recent years. We have learned that not all low plasma B12 means a “deficiency” and not all hi...

Treatment of B12 deficiency is important to prevent progressive neurological and/or hematologic disease but requires a secure diagnosis. The aim of this study was to evaluate second line tests of B12 status as prognostic indicators of a hematologic response to vitamin B12 therapy. Forty-nine patients referred with low, serum vitamin B12 concentrations were treated with intramuscular B12 and re-...

By CHARLES A. HALL With the technical assistance of Alexander E. Finkler, Edward S. Allen and Booker T. Moore T HE PLASMA vitamin B12 is abnormally high in chronic myelocytic leukemia.’8 It is sometimes increased above normal in polycythemia vera35 and myeloid metaplasia,35 but usually not as strikingly so. The plasma vitamin B12 is normal in chronic lymphocytic leukemia,12’4’5’8 lymphoma,4’5’8...

BACKGROUND Profound vitamin B12 deficiency is a known cause of disease, but the role of low or intermediate levels of B12 in the development of neuropathy and other neuropsychiatric symptoms, as well as the relationship between eating meat and B12 levels, is unclear. OBJECTIVE The objective of our study was to investigate the role of low or intermediate levels of B12 in the development of neu...

279 14.1 Role of vitamin B12 in human metabolic processes Although the nutritional literature still uses the term vitamin B12, a more specific name for vitamin B12 is cobalamin. Vitamin B12 is the largest of the B complex vitamins, with a relative molecular mass of over 1000. It consists of a corrin ring made up of four pyrroles with cobalt at the centre of the ring (1, 2). There are several vi...

A review of how vitamin B12 is used by the human body and the role it plays in DNA mutation is presented. Vitamin B12 is a compound needed for healthy function of the human body but produced downstream of the point of absorption in the digestive system, rendering it unusable. One may become B12 deficient in a variety of ways including lack of intake, disruption of B12 absorption due to disease,...

INTRODUCTION Although consensus guidelines recommend checking serum B12 in patients with dementia, clinicians are often faced with various questions: (1) Which patients should be tested? (2) What test should be ordered? (3) How are inferences made from such testing? (4) In addition to serum B12, should other tests be ordered? (5) Is B12 deficiency compatible with dementia of the Alzheimer's typ...

Vitamin B12 (cobalamin) is an essential coenzyme for nucleic acid synthesis. Animal protein is the major dietary source of vitamin B12. Deficiency of vitamin B12 leads to megaloblastic anemia, degeneration of the brain, spinal cord, peripheral nerves, and abnormalities of epithelial tissues. Two factors are necessary for the cure of megaloblastic anemia: one in food (extrinsic factor) and one i...

Although typical primary isolates of human immunodeficiency virus type 1 (HIV-1) are relatively neutralization resistant, three human monoclonal antibodies and a small number of HIV-1(+) human sera that neutralize the majority of isolates have been described. The monoclonal antibodies (2G12, 2F5, and b12) represent specificities that a putative vaccine should aim to elicit, since in vitro neutr...