Serum Vitamin B12 Values Research Articles

Vitamin B12 concentrations in psychiatric patients

In an attempt to evaluate the possible relationship between vitamin B12 deficiency and mental disease, the blood content of vitamin B12 was investigated in 835 consecutive psychiatric patients. Low serum vitamin B12 values were found in approximately 10% of these patients, due to latent pernicious anaemia in one case, post-gastrectomy in seven cases and small intestinal resection in one case. In the remaining 72 cases vitamin B12 deficiency was probably caused by nutritional insufficiency. After correction of the dietary defect there was a spontaneous increase in serum vitamin B12 in 75% of these patients. No specific psychiatric syndrome was connected with hypovitaminosis B12, but a preponderance of arteriosclerotic dementia suggests that low serum vitamin B12 values are secondary to mental illness leading to apathy and loss of appetite. Most cases will recover without further vitamin B12 supplements. But some patients may need treatment because of severe mental and physical disabilities.

Serum vitamin B12 levels in the aged.

In an attempt to throw light on the question of age-related variations in the normal blood content of cobalamin and on the frequency of deficiencies of antimegaloblastic nutriments in the elderly, 273 geriatric patients have been investigated. Low serum vitamin B12 values were found in one third of these patients, due to latent pernicious anaemia in five and malabsorption in seven cases, and probably caused by nutritional deficiency of folate or cobalamin in 78 cases. In that part of the series with apparently normal vitamin B12 levels, the mean value (379+/-14 pg/ml) was lower than the mean (456+/-20 pg/ml) for a younger control group. However, this cannot be taken as a sign of a physiological lowering of the cobalamin values with age, as nutritional deficiencies could not be ruled out in this part of the series. It is concluded that serum vitamin B12 assays should be performed rather liberally in the aged. Patients with nutritional deficiency of cobalamin or folate should be treated, even if frank megaloblastic anaemia is not present.

Extraction of serum vitamin B12 for radio-isotopic and Lactobacillus leichmannii assay.

The protein precipitates discarded during the extraction process of the Lactobacillus leichmannii vitamin B12 assay have been shown to contain significant amounts of vitamin B12. This loss of vitamin B12 provide a satisfactory explanation for many of the descrepancies between the serum vitamin B12 values obtained by the L. leichmannii method and the radio-isotopic method of Raven et al (1969). It is possible to produce lower results by the method of Raven et al (1969)by incorporating into that method the L. leichmannii extraction process; it is also possible to produce higher results by the L. leichmannii method using a papain extraction process.

Vitamin B12 and vegetarianism in india.

Apparently healthy Indian lactovegetarians have significantly lower serum levels and urinary excretion of vitamin B12 as compared to non-vegetarians. The low levels of serum vitamin B12 in lactovegetarians are not due to defective absorption but to low dietary intake of this vitamin. Inspite of considerably low serum vitamin B12 values, the lactovegetarians have no apparent signs or symptoms of vitamin B12 deficiency and their response to injected cyanocobalamin mixed with tracer radioactive B12, as judged by urinary excretion pattern and liver uptake, was similar to that observed in nonvegetarians.

Relationships among Urinary Aminoimidazolecarboxamide in Urine and Folate, and Vitamin B12 Concentrations in Serum

Abstract Urinary aminoimidazolecarboxamide (AIC), serum folate, and serum vitamin B12 values were determined in 84 apparently healthy individuals. An automated system for determination of AIC in urine is described. Despite claims to the contrary, we found no evidence of a strong relationship between elevated (e.g., >1.3 µg/mg of creatinine) AIC excretion as reflected in a casual sample of urine and folate or vitamin B12 deficiency. Urinary AIC values ranged from 0.10 to 5.20 µg/mg of creatinine. The mean for the population examined was 1.36 ± 1.02 µg/mg of creatinine.

VITAMIN B12 AND FOLIC ACID VALUES IN PREMATURE INFANTS

The relationship of serum vitamin B12 and folic acid was studied in 24 premature infants. In 14 of the 24, low serum vitamin B12 values were found around 40 days of age. Serum folic acid concentrations were less frequently depressed and were usually associated with normal red cell folate values. No correlation between hematocrits and vitamin B12 or folate levels was found. It is suggested that low concentrations of serum folate and vitamin B12 result from low dietary intake coupled with increased demand by the prematurely born infant.

Associations of subnormal serum folate and vitamin B12 values and effects of replacement therapy.

An investigation of some of the clinical associations of low serum folate and B12 values found in a previous survey of 432 psychiatric inpatients is presented. There were 105 (22.5 per cent) “low folate” (<2.0 ng) patients and 53 (14.2 per cent) “low B12” (<150 pg) patients, 19 of whom had low values for both vitamins. Most low serum values were associated with extrinsic provocative factors. Thus 89 per cent of low folate, 58 per cent of low folate-low B12, and 44.1 per cent of low B12 patients had received drugs during the three preadmission weeks; barbiturates, phenothiazines, and antidepressants (in that order) were the commonest drugs among low folate patients, and phenothiazines among low B12 patients. Significantly more low B12 patients (38.2 per cent) than low folate patients (18.6 per cent) were physically ill. Many low folate (61.6 per cent) and low B12 (47.1 per cent) patients had been ill for more than 1 year, and serious malnutrition was frequent among both low folate (22.1 per cent) and low B12 (32.4 per cent) groups. Low serum levels were infrequently associated with pregnancy and gastrectomy, and no case of intestinal malabsorption was seen. These extrinsic factors were not found in only 21 low folate and 14 low B12 patients (“primary” or “idiopathic” group) among whom no particular mode of psychiatric presentation was seen. Low folate patients had significantly more hematological abnormalities than normal folate patients, whereas low B12 compared with normal B12 patients did not. A retrospective survey of the results of treatment with folic acid and vitamin B12 supplements was carried out because it was found that they had been given to patients with low values in such a haphazard way as to be distributed virtually randomly. Among the low folate patients, 39 received folate and 63 did not. Folate-treated patients with organic psychoses, endogenous depression, and schizophrenia, when assessed on a 4-point scale, were found to be in a better clinical state at discharge than untreated patients; and their stay in the hospital was significantly shorter. There was no evidence that cyanocobalamin-treated low B12 patients were in a better clinical state at discharge or spent a shorter time in the hospital than similar untreated patients, though the assessment period was probably too short for firm conclusions to be drawn.

Serum Vitamin‐B12‐Binding Proteins in Kwashiorkor*

Summary. In contrast with plasma albumin and transport proteins such as transferrin and ceruloplasmin, vitamin B12‐binding proteins are not decreased in Cape Coloured children with kwashiorkor. Compared with normal coloured adults the mean serum vitamin B12 was increased while the unsaturated vitamin B12 binding capacity (UBBC) was markedly increased mainly due to elevation of the alpha‐1‐globulin vitamin B12 binder (alpha‐binder). In normal coloured children the UBBC was also increased with mean alpha‐binder intermediate between values found in kwashiorkor and normal coloured adults. The mean beta‐globulin‐vitamin B12‐binder (beta‐binder) was decreased in kwashiorkor. The total serum alpha‐1 and beta‐globulins, showed poor quantitative correlation with alpha‐and beta‐vitamin B12‐binders in these patients. Urinary vitamin B12‐levels were similar in kwashiorkor, normal children and adults. In the small series of adult Cape Coloured subjects studied, serum vitamin B12 and UBBC values were higher than in white adults.The alpha‐ and beta‐binders of kwashiorkor and normal children adequately transferred 57 Co‐vitamin B12 to rat liver homogenate while the alpha‐binder of chronic myeloid leukaemia transferred less efficiently.

A new vitamin B12 binding protein in serum causing excessively high serum vitamin B12 values.

Following treatment with a vitamin B12 preparation with retarded effect, extremely high serum vitamin B12 values were observed in several cases. The explanation for this phenomenon is a very high serum vitamin B12‐binding capacity, caused by a vitamin B12 binding protein located in the γG area – presumably an antibody.

The Production of Scientific Knowledge

Pancytopenia developed in four patients receiving postoperatively total parenteral nutrition (TPN). Symptoms and signs were related mainly to underlying bowel disease. Hematologic abnormalities, first noted from 4 to 7 weeks following institution of TPN, consisted of normocytic anemia (mean decrease in hemoglobin value, 2.2 g/dL), occasional macrocytes being noted, leukopenia (range of leukocyte counts, 1.2 to 3.6 X 10(9) L), some hypersegmented neutrophils being detected, and clinically significant thrombocytopenia (range of platelet counts, 25 to 52 X 10(9)/L). In all patients the bone marrow showed megaloblastic changes, with ring sideroblasts, although pyridoxine was included in the TPN regimens. Serum vitamin B12 values were normal in one patient and at the lower limit of normal in the other two patients in whom it was measured, while serum or erythrocyte folate values, or both, were reduced in three patients. Full hematologic response was observed in the four patients after folic acid replacement therapy; leukocytosis and thrombocytosis were noted in three. Thus, folic acid and possibly vitamin B12 should be added routinely to TPN regimens to prevent deficiency of either substance.