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...

The understanding and control of nanoparticle transport into and through cellular compartments is central to biomedical applications of nanotechnology. Here, it is shown that the transport pathway of 50 nm polystyrene nanoparticles decorated with vitamin B12 in epithelial cells is different compared to both soluble B12 ligand and unmodified nanoparticles, and this is not attributable to B12 rec...

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-...

Studies by several investigators (Stokstad, Dornbush, Franklin, Hoffmann, Hutchings, and Jukes, 1949; Skeggs, Nepple, Valentik, Huff, and Wright, 1950) have indicated that an increased growth response was obtained to liver concentrates with thioglycolic or thiomalic acids when vitamin B12 activity was determined with Lactobacillus leichmannii. This was attributed to the prevention, by such redu...

In cross-sectional studies periventricular white matter lesions (WML) were related to low plasma levels of vitamin B12. Whether low vitamin B12 levels are also related to progression of WML is still unknown. We studied baseline vitamin B12 levels and its association with progression of WML over 2 years of follow-up in first-ever lacunar stroke patients. In 107 first-ever lacunar stroke patients...

T FIAT VITAMIN B12 IN SERUM is l)ound to protein14 has been known since shortly after the isolation of the vitamin. Endogenous vitamin B12 (which may be mainly methyl-Bi2) is bound primarily to an a1-globulin 2.6-10 hut vitamin B12 added to serum in vitro hinds primarily to -globuun (presumably because B12-binding a-globulin is normally almost saturated with endogenous vitamin B12).61#{176} hal...