A radioisotope dilution assay for vitamin B12, using hemoglobin-coated charcoal, was modified in several respects, the most prominent of which was the use of cyanide extraction of sera. With these modifications, the B12 levels were significantly higher in sera from normal subjects and patients with folate deficiency, whereas sera from patients with pernicious anemia and other B12-deficient stat...

AIM To explore the correlation between serum vitamin B12 level and peripheral neuropathy in patients with chronic atrophic gastritis (CAG). METHODS A total of 593 patients diagnosed with chronic gastritis by gastroscopy and pathological examination from September 2013 to September 2016 were selected for this study. The age of these patients ranged within 18- to 75-years-old. Blood pressure, h...

Although vitamin B12 can be assayed biologically with mice, chicks or rats, the microbiological method of assay is preferred since it is more rapid and economical. One serious shortcoming of many microbiological B12 assay procedures is the lack of specificity when crude materials are assayed. Crude materials can contain inhibitory or stimulatory factors which cause serious errors in assay resul...

A radioisotope dilution assay for vitamin B12, using hemoglobin-coated charcoal, was modified in several respects, the most prominent of which was the use of cyanide extraction of sera. With these modifications, the B12 levels were significantly higher in sera from normal subjects and patients with folate deficiency, whereas sera from patients with pernicious anemia and other B12-deficient stat...

Background: Opium addiction is a global problem which has implicated many societies. Opium addiction and drug abuse is related to harmful consequences which affect life style, biochemical factors, and vitamins values, and also is considered as a risk for heart diseases. Folate and B12 levels are related to homocysteine and studies about their levels in opium addicts are controversial; therefore...

BACKGROUND Variants in CUBN, the gene encoding cubilin, a proximal tubular transport protein, have been associated with albuminuria and vitamin B12 (B12) deficiency. We hypothesized that low levels of B12 would be associated with albuminuria in a population-based cohort. METHODS We analyzed participants from the Framingham Heart Study (n = 2965, mean age 58 years, 53% female) who provided sam...

There are two conflicting theories of how plasma vitamin B12 (B12) is transported in man: (a) by two distinct transport proteins, transcobalamins I and II (TC I and II), each having a specific role and time of function; and (b) by three active transport proteins, TC I, II, and III, that take up B12 randomly in proportion to the unsaturated amounts of each. To test these theories a man was given...

Vitamin B12 concentration was determined by radioassay in 179 healthy volunteers between the ages of 20 and 93 years in order to determine whether vitamin B12 levels decline with advancing age. The authors found no statistically significant decline in vitamin B12 levels in older individuals, nor a difference between males and females. A review of previous reports identifies potential reasons fo...

Functional vitamin B12 deficiency is a syndrome where a wide variety of symptoms in the presence of “normal” serum levels of the vitamin respond to vitamin B12 therapy. A series of patients with functional vitamin B12 deficiency are described whose presenting features were drenching night sweats and fatigue. Reliance on serum vitamin B12 levels as a diagnostic test would have obscured the cause...

The aim of this study was to investigate the possible association between otoacoustic emission (OAE) values and cochlear function in patients with vitamin B12 deficiency and no evidence of symptomatic hearing loss. Two groups were studied: Group 1: patients with vitamin B12 deficiency; Group 2: a matched control group of patients with normal vitamin B12 levels. There was no evidence of symptoma...