Vitamin B12 Binding Capacity Research Articles

The Rates of and Relationship between Anemia and Deficiency of Iron, Zinc, Vitamin B12 and Folic Acid in Hospitalized Children

Aim: Increased frequency of deficiency due to the insufficient intake of iron, zinc, vitamin B12-D and folic acid has been reported in the society. We aimed to investigate the rates of deficiency of these vitamins and minerals, as well as anemia frequency in children admitted to pediatric outpatient clinics of our tertiary hospital in a retrospective three-year period.
 Materials and Methods: The frequency of micronutrient deficiency and the relationship between them was determined using statistical methods by evaluating the levels of hematocrit and other micronutritional elements in patients admitted to the general pediatrics outpatient clinics of our hospital between 01.06.2015 and 31.05.2018. The only patient inclusion criteria were being tested for zinc, iron, iron binding, hemogram, vitamin B12, folic acid, ferritin and vitamin D for any reason.
 Results: After the evaluation of 64487 patients, we discovered the rates of anemia and iron, zinc, folate, vitamin D, vitamin B12 and ferritin deficiency as 30.8%, 52.1%, 41.1%, 18.2%, 32.4%, 20.1% and%26.7 respectively. Additionally, our results indicate that the frequency of folic acid deficiency decreased over the past years, whereas the rates of zinc and vitamin D deficiency increased over time. The final results show a negative correlation between anemia and folic acid, vitamin D, vitamin B12 and iron binding capacity, and a positive correlation between anemia and iron, ferritin and zinc.
 Conclusion: Although it does not reflect the frequency of deficiency in the general population since the data are collected from hospitalized children, it could be argued that multiple micronutrient deficiencies are significantly common in Turkey and zinc and vitamin D deficiency has been increasing over the years, when compared with the results of previous studies.

PTU-031 Downregulation of the vitamin B12 receptor in fibrolamellar carcinoma of the liver: the first consistent molecular abnormality

IntroductionFibrolamellar hepatocellular carcinoma (FLHCC) is a rare tumour of young adults that is characterised by the presence of large tumour cells with strongly eosinophilic cytoplasm, surrounded by fibrous lamellae, in...

Evaluation of Anemia in Adults: Going after the Common Causes.

Unexplained anemia is a common problem in adult medicine. Traditional approaches to etiologic diagnosis have included testing for “nutritional” deficiencies such as serum vitamin B12, folic acid, iron and iron binding capacity (IBC)(often a house staff approach); performing upper and lower endoscopy (often the Gastroenterologist or the Surgeon); or review of peripheral blood and bone marrow smears and biopsy (the Hematologist). Decision trees starting from MCVs and reticulocyte counts are commonly suggested in Hematology teaching manuals. However none of these approaches are based on knowledge of the most likely causes of anemia in the population to be tested. We hoped to improve on these largely unfounded and unevaluated empiric strategies by determining the actual frequencies of different causes of anemia among non-pregnant adults (20 and older) with initially unexplained anemias (Hb <12 in men, <11 in women) in our hospital, and have done such studies on three occasions in the last 15 years at Yale New Haven Hospital. Patients selected were 1) 202 consecutive adults with anemia new to the hospital laboratory database; 2) 800 consecutive adults treated, or retreated, with iron in the hospital, focussing the analysis on the 200 who were anemic and not just given iron because they were post-operative or post-partum; and 3) 100 consecutive adults having what we would consider “anemia tests” drawn for work up (such as reticulocyte counts, or vitamin B12 assays, etc). Using standard criteria for diagnosis of different causes of anemia, and, mostly, available data, we were able to classify 80–90% of the anemic patients in each study population. From each of these patient groups we were able to draw pie charts showing relative frequencies of different causes of anemia. We recognized a total of 14 causes and groups of causes of anemia (we grouped hemoglobinopathies as one category, for example) in our hospital population. But the four commonest causes were the same in all three studies: anemia of chronic (inflammatory) disease (ACD) (24, 30, and 37%), acute, missed G I bleed (17, 16, and 13%), iron deficiency anemia (IDA)(13, 23, and 16%) and anemia of chronic renal insufficiency (13, 28, and 14%). Popular targets of work up such as B12 and folate deficiency, and hemolytic anemias, together constituted less than 4% of each study population. We therefore propose as initial work up/evaluation of unexplained anemia in adults the following tests: review of the patient's history for ACD causes; erythocyte sedimentation rate; iron and IBC (and hepcidin when available); stool exam for blood, especially non-occult blood and melena, before considering colonoscopy; ferritin; attention to the probably already available MCV, RDW, and creatinine; and serum erythropoietin (relating its result to Hb and Hct). According to our hospital epidemiologic studies this approach should reveal the causes of anemia in 67–97% of adults. Clues to other specific anemias learned from the patient, such as a history of sickle cell disease, or the technologist's discovery of many spherocytes on the blood smear should of course be attended to, as priorities. And, although helpful in only two of the four commonest anemias (ACD, IDA), review of a good blood smear is an important cross-check that occasionally yields surprises (Please see BJ Bain, NEJM, 8/4/05).

Effect of folic acid and glycine supplementation on embryo development and folate metabolism during early pregnancy in pigs.

The present work aimed to determine if different levels of prolificacy either by parity or by genetic origin are linked to folate metabolism. Nulliparous Yorkshire-Landrace (YL) and multiparous YL, and multiparous Meishan-Landrace (ML) sows were randomly assigned to two treatments: 0 ppm or 15 ppm folic acid+0.6% glycine. Supplements were given from the estrus before mating until slaughter on d 25 of gestation. At slaughter, embryo and endometrial tissues were collected to determine concentrations of DNA, protein, and homocysteine. Allantoic fluid samples were also collected to determine concentrations of folates, vitamin B12 and amino acids. Blood samples were taken at first estrus, at mating, and on d 8, 16, and 25 of gestation to determine serum concentrations of folates, vitamin B12, and relative total folate binding capacity (TFBC). Over the entire experiment, multiparous YL sows had higher average serum concentrations of folates than nulliparous YL sows (P < 0.05) but had similar serum concentrations of relative TFBC. Concentrations of folates and relative TFBC averaged higher in ML measured over the entire experiment than in multiparous YL sows (P < 0.05). Concentrations of serum vitamin B12 were higher in multiparous YL than in ML sows or YL nulliparous sows (P < 0.05) over the entire experiment. In allantoic fluid, folates, vitamin B12, and essential amino acids contents were significantly lower in ML than in YL multiparous sows (P < 0.05). The folic acid+glycine supplement increased concentrations of serum folates, but the increase was more marked in nulliparous YL sows (nulliparous x folic acid+glycine, P < 0.05). The folic acid+glycine supplement had no effect on litter size and embryo survival, but it tended to increase embryo DNA in multiparous YL sows (P = 0.06) but not in ML and nulliparous YL sows. Homocysteine was decreased by folic acid+glycine supplement in embryos from all sows, but in endometrium, the folic acid+glycine effect was dependent on parity (nulliparous x folic acid+glycine, P < 0.05). The effects of folic acid+glycine on litter size and embryo development and survival and some aspects of folate metabolism suggest that the basal dietary content of folic acid+glycine was adequate for ML and nulliparous YL sows but not to optimize embryo development in YL multiparous sows.

Transcobalamin II deficiency with methylmalonic aciduria in three sisters

Transcobalamin II (TC II) is a plasma protein that binds vitamin B12 (cobalamin, Cbl) and facilitates cellular Cbl uptake by receptor-mediated endocytosis. In autosomal recessive TC II deficiency, intracellular Cbl deficiency results in an early onset of megaloblastic anaemia that may be accompanied by neurological abnormalities. Inadequate treatment may lead to neurological abnormalities. We describe three sisters, the daughters of first cousins of Moroccan origin, with TC II deficiency requiring continuous and long-term vitamin B12 treatment. The diagnosis was suspected from the finding of low unsaturated vitamin B12 binding capacity and confirmed by absence of detectable TC II by radioimmunoassay and by inability of cultured fibroblasts to synthesize TC II.

Potential of measurements of unsaturated vitamin B12-binding capacity in serial colonoscopic biopsy specimens for global and regional assessments of disease severity in inflammatory bowel disease.

We investigated whether measurements of unsaturated vitamin B12-binding capacity (UBBC), in homogenates of serial colonoscopic biopsy specimens, could be used as objective measures of disease severity in ulcerative colitis (UC) and Crohn's disease (CD). On a regional basis UBBC activity correlated with and showed good agreement with endoscopic and histologic activity scores (r = 0.8 and 0.6, respectively, for UC, and r = 0.7 and 0.7, respectively, for CD). For global assessment aggregate UBBC, endoscopic and histologic scores were compared with standard clinical activity scores. In UC, correlations with the van Hees index were r = 0.7, 0.8, and 0.7, respectively, and UBBC assays accurately reflected both regional and global disease activity. In CD, correlations with the CDAI were -0.1, 0.7, and 0.6, respectively. Thus, aggregate UBBC scores failed to reflect disease activity in CD, in which focal deep ulcers may produce high symptom scores but in which adjacent specimens may show no acute inflammation.

Serum Unsaturated Vitamin B&lt;sub&gt;12&lt;/sub&gt; Proteins in Adult Patients with Sickle Cell Anaemia (Hb SS)

The unsaturated vitamin B12 binding capacity (UBBC) of serum, the three transcobalamins (TC I, TC II, TC III) and serum cobalamin have been studied in adult sickle cell patients with Hb SS. An increase in the level of the binding capacities of TC I and TC III resulting in an increase in UBBC was observed in these patients. There was no difference in the level of the binding capacity of TC II, while there was a significant reduction in the level of serum cobalamin. These changes in the pattern of these binding proteins are discussed in relation to the changes of these binding proteins in paediatric sickle cell patients with Hb SS. The results indicate that the pattern of these binding proteins changes with age among sickle cell patients resulting in an increased level of the binding capacities of TC I and TC III. These increases lend support to the view that these two similar binding proteins are involved in the defence mechanism of the body.

Amniotic fluid folate, vitamin B12 and transcobalamins in neural tube defects

Levels of folate, vitamin B12, the vitamin B12 binding proteins, apotranscobalamin I, II and III (TC I, II and III) and the unsaturated vitamin B12 binding capacity (UBBC) were measured in mid-trimester amniotic fluids from normal pregnancies, and from those where the fetus had open spina bifida, anencephaly or omphalocoele, and where the fetus was normal but the mother had had a previous neural tube defect pregnancy. At 15-19 weeks' gestation, vitamin B12 levels were low in the fluids of all the types of abnormal fetuses, and also of normal fetuses where there had been a previous NTD sib. In contradistinction, TC I, II and III and UBBC levels were generally abnormally high in all these groups. Low vitamin B12 levels in the face of high carrier protein levels suggest deranged vitamin B12 production or transport. Since these abnormalities are present in fluids from normal sibs of NTD individuals as well as from those with midline lesions, an inherited defect is implied. We propose that at least part of the genetic predisposition to NTD, and possibly other midline defects, could reside in an abnormality connected with vitamin B12 production, transport or metabolism, and a mechanism is suggested.

Immunohistochemical localisation of vitamin B12 R-binder in the human digestive tract.

The distribution of vitamin B12 R-binder in the human digestive tract was studied using an indirect immunoperoxidase technique. Positive staining for R-binder was found in the mucous cells and ductal epithelial cells of the salivary glands and the oesophageal glands. In normal gastric mucosa, no positive staining for R-binder was found, but in the area with intestinal metaplasia, the columnar epithelial cells and goblet cells showed positive staining. Epithelial cells of the gallbladder, intrahepatic bile ducts and pancreatic ducts were also positive for R-binder. In the small intestine and colon, R-binder was found in the columnar epithelial cells and goblet cells. The measurement of unsaturated vitamin B12 binding capacity and cobalamin content in the extracts from intestinal mucosa also indicated the presence of R-binder in the intestinal mucosa.

Serum vitamin B12 binders in south african blacks with hepatocellular carcinoma

Sera from 242 South African blacks with hepatocellular carcinoma were assayed for unsaturated vitamin B12 binding capacity (UBBC) and vitamin B12 activity. Six patients were younger than 20 years of age, and 24% were younger than 30 years of age. Eighty-four percent of the patients had a slightly raised UBBC and 86% had a slightly elevated vitamin B12 value, but in no patient was an exceptionally high UBBC present. Serum UBBC and vitamin B12 were not higher in younger patients, and raised UBBC values were not related to serum alpha-fetoprotein values. Serum UBBC and vitamin B12 concentrations were not significantly different in patients with and without coexisting cirrhosis. In none of the patients with a UBBC above 3000 pg/ml was the fibrolamellar variant of hepatocellular carcinoma present. The authors conclude that South African blacks with hepatocellular carcinoma do not secrete an abnormal vitamin B12 binding protein.

Elevated serum vitamin B12 in cystic fibrosis.

In 62 patients with cystic fibrosis the serum vitamin B12 concentration ranged from 160-2600 pmol/l with a mean of 1 105 pmol/l. Both vitamin B12-binding proteins in the serum, transcobalamin II and R-binders, carried increased amounts of vitamin B12, but showed relatively normal levels of unsaturated vitamin B12-binding capacity. This combination is rather typical for hepatic dysfunction, although the recurrent pulmonary infections might exert an upward effect on plasma R-binder concentration through increased turnover of myeloid cells. A significant positive correlation between transcobalamin II-vitamin B12 and serum alkaline phosphatase suggests that transcobalamin II-bound vitamin B12 might be an early indicator of focal biliary cirrhosis, which is known to occur in these patients.

Abnormalities of serum transcobalamins in sickle cell disease (HbSS) in Black Africa.

The unsaturated vitamin B12 binding capacity (UBBC) of serum, the three transcobalamins (TC I, TC II, TC III), and the total leucocyte and neutrophil counts have been studied in paediatric patients with sickle cell disease (SCD). Increase in the level of the binding capacities of TC I and TC II with concomitant increase of UBBC was observed in these children who also had increased total white blood and neutrophil counts. There was a significant reduction in the level of endogenous B12. These abnormalities are discussed in relation to the deficiency of the splenic reticuloendothelial function, immunologic defect, hepatic degenerative changes and aplastic crisis observed in SCD. These results lend support to the view that transcobalamins are involved in the defence mechanism of the body. The significant reduction in serum cobalamin in SCD suggests a higher demand on this vitamin for metabolic functions, especially for the sparing of folate.

The effects of surgery on the activity of neutrophil granule proteins.

Activities of the neutrophil granule-associated proteins beta-glucuronidase, lysozyme and vitamin B12 binding protein were measured, serially, in the cells and serum of 10 patients undergoing total abdominal hysterectomy. The neutrophil leucocytosis which followed total abdominal hysterectomy was accompanied by a fall in the intraneutrophilic activities of all three granule-associated proteins. Intraneutrophilic lysozyme activity and intraneutrophilic vitamin B12 binding capacity were maximally reduced within 4 h of surgery and fell to 62 +/- 13% (mean +/- SEM) and 63 +/- 9% of their preoperative levels, respectively. This contrasted with the activity of intraneutrophilic beta-glucuronidase which was not maximally reduced until 24 h post-surgery when a fall to 80 +/- 6% of the preoperative level was observed. By the fifth postoperative day activities of the three intraneutrophilic granule proteins were increasing and approaching those observed preoperatively. Serum lysozyme and plasma unsaturated vitamin B12 binding capacity (UBBC) rose steadily following surgery and were significantly elevated by the fifth postoperative day. It is suggested that activation and in vivo degranulation of circulating neutrophils may be responsible for these changes in activity of neutrophil granule proteins following surgery.

High serum vitamin B12 binding capacity as a marker of the fibrolamellar variant of hepatocellular carcinoma.

High serum vitamin B12 binding capacity as a marker of the fibrolamellar variant of hepatocellular carcinoma.

High serum vitamin B12 binding capacity as a marker of the fibrolamellar variant of hepatocellular carcinoma.

Ten (9.3%) of 107 patients with hepatocellular carcinoma had considerably increased serum unsaturated vitamin B12 binding capacity. All 10 were young (mean 12 years), had no serum alpha-fetoprotein, and no underlying cirrhosis; all had a longer survival compared with patients without increased serum unsaturated vitamin B12 binding capacity in the study. Seven of the 10 patients had fibrolamellar hepatocellular carcinoma, a recently recognised histological variant, which was found in only one young patient without increased serum unsaturated vitamin B12 binding capacity and no alpha-fetoprotein among the remaining 97. This high degree of correlation between increased serum unsaturated vitamin B12 binding capacity and fibrolamellar hepatocellular carcinoma has not been reported before. Increased serum unsaturated vitamin B12 binding capacity may be of considerable help in diagnosis, prognosis, and monitoring treatment of this well-defined group of patients with hepatocellular carcinoma but no alpha-fetoprotein.

The effect of digestive enzymes on the binding and bacteriostatic properties of lactoferrin and vitamin B12 binder in human milk.

Human milk contains unsaturated lactoferrin and vitamin B12 binding protein. It has been suggested that these proteins may exert antibacterial effects in the intestine of the breast fed infant, but the effect of the intestinal environment on the antibacterial effect of these proteins has not been described. In this study human milk was treated with pepsin and trypsin and the influence of digestion on iron and vitamin B12 binding capacity, bacterial uptake of iron and vitamin B12 from milk and bacteriostatic effect was studied. Pepsin digestion had no effect on vitamin B12 binding capacity, or the ability of bacteria to take up vitamin B12, or the growth inhibitory effect on a vitamin B12 dependent strain. In contrast, trypsin digestion did not affect iron binding or bacteriostatic effects attributable to lactoferrin. The. findings support an in vivo bacteriostatic role for lactoferrin in the breast fed neonate's intestine but do not support a similar role for the vitamin B12 binding protein.

Vitamin B12 in human colostrum and milk. Quantitation of the vitamin and its binder and the uptake of bound vitamin B12 by intestinal bacteria.

The concentration of vitamin B12 was measured by microbiological assay in 229 samples of normal human colostrum and milk taken at various stages of lactation. Colostrum obtained within 48 hours of delivery contains high concentrations of vitamin B12 (mean 2 431 pg/ml), but within a few days the levels fall to a range similar to the levels in normal serum. The vitamin B12 binding capacity of 111 samples of colostrum and milk was estimated by gel filtration or charcoal binding. Colostrum samples have a mean binding capacity of 72 ng/ml, while the binding capacity in milk is only one third of this value. The ability of a range of intestinal bacteria to take up colostrum-bound vitamin B12, was assessed. All the organisms took up free vitamin B12, but when the vitamin was bound in colostrum, there was little or no uptake even after 24 hours incubation.

Mucosal Enzymes in Human Inflammatory Bowel Disease with Reference to Neutrophil Granulocytes as Mediators of Tissue Injury

1. Biopsies of rectal mucosa were obtained for histology and enzyme analysis from 32 patients with inflammatory and functional bowel disorders, and the biopsies were classified morphologically as active colitis, quiescent colitis or normal. 2. Supernatant fractions of biopsy homogenates were assayed for their content of the proteolytic enzymes alpha-chymotrypsin, elastase and cathepsin D, and of protein, unsaturated vitamin B12-binding capacity, lysozyme, myeloperoxidase and N-acetyl-beta-glucosaminidase. 3. Mean unsaturated vitamin B12-binding capacity was significantly raised above normal in the active colitic mucosa, and mean lysozyme activity was raised above normal in both active and quiescent mucosae. 4. In active colitic mucosa there was no rise above normal in mean activities of any of the proteolytic enzymes, though a significant fall below normal occurred in mean N-acetyl-beta-glucosaminidase activity in the active colitic group.

Blocking and binding type antibodies against all major vitamin B12-binders in a pernicious anaemia serum.

The simultaneous occurrence of blocking and binding antibodies to intrinsic factor (IF), transcobalamin (TC- II, TC I) and other R type vitamin B12 proteins in the serum of a patient with treated pernicious anaemia (PA) is reported here for the first time. The dialysed and purified immunoglobulin-G (IgG), but not the immunoglobulin-M (IgM), from a PA patient neutralized the total unsaturated vitamin B12 binding capacity (UB12BC) of human gastric juice, saliva and serum and also of rabbit serum, suggesting that the PA IgG contained blocking antibodies against, IF, TC II, TC I and other R-binders. In addition, the PA IgG and IgM preparations contained binding antibodies since they could form macromolecular complexes with 57Co-B12 bound to IF, TC I or TC II so that each one of the latter was totally excluded from Sephadex G-200. The presence of the binding antibodies was further confirmed by the formation of radioactive precipitation lines on agarose with each one of the vitamin B12-binders bound to 58Co-B12. The PA serum did not exhibit any measurable UB12BC after dialysis against 7.5 M guanidine-HCl followed by renaturation with phosphate buffer (pH 7.4). But it did form TC I and TC II complexes with 57Co-B12 when the latter was added during the renaturation step indicating that the serum contained circulating immunoglobulin-TC complexes. The blocking antibodies should be distinguished from the previously described binding antibodies. The blocking of the binding of vitamin B12 to TCs resulted in relatively lower serum vitamin B12 levels in the present case in contrast to the presence of binding antibodies where high serum vitamin B12 levels have been reported. In addition, the binding antibodies form immunocomplexes with TCs which can easily be detected because they can bind radioactive vitamin B12 while the corresponding immunocomplexes of blocking antibodies are hidden because they prevent the binding of the vitamin to TCs.

The effect of oral contraceptives on vitamin B12 metabolism

Serum vitamin vitamin B12 levels were determined in 199 women who were on a regnnen of oral contraceptives of either the combination or sequential type and in a control group of 196 women. The group using oral contraceptive agents.(OCA) had significantly lower serum levels of vitamin B12 vitamin as compared to those of the control group. A total of 19 women using OCAs had serum vitamin B12 levels that were lower than normal values. However, the Schilling test and urinary methylmalonate excretion in this group were normal. The OCA group had a significantly lower total serum vitamin B12 binding capacity, a lower total transcobalamin I level, and a higher transcobalamin III level. Our study suggests that the fall of serum vitamin B12 in OCA users is due to the changes in vitamin B12 binders of serum arid does not represent vitamin B12 deficiency. Therefore, aceording to our data, there is no justification for vitamin B12 supplementation in users of oral contraceptives.