Donna Ripley

Vitamin B12 Absorption from Eggs

Summary The assimilation of 57Co B12 from in vivo labeled eggs was much inferior to that of a comparable amount of crystalline 57Co B12. Furthermore, the absorption varied with the form in which the eggs were served. Judged by the urinary excretion test and the plasma absorption of radioactivity the average absorption from boiled and fried eggs was more than twice that from scrambled whole eggs, but less than half that absorbed from crystalline 57Co B12.

Hematologic alterations following partial gastrectomy

Serum and red blood cell (RBC) levels of vitamin B12 and folic acid together with serum iron and total iron binding capacity were followed in 142 patients with partial gastrectomy. Follow-up period was from two months to 25 years after surgery. Anemia was the primary hematologic alteration documented as a complication of surgery. Of the parameters followed, RBC depletion of vitamin B12 occurred before a significant decrease in circulating serum values. We believe we are the first to report on the separation of RBC depletion of vitamin B12 and folic acid in the presence of iron deficiency.

Diagnostic criteria for iron deficiency in coexistent iron and vitamin B12 deficiency.

Total iron-binding capacity, serum iron, transferrin saturation, mean corpuscular volume, and mean corpuscular hemoglobin concentration values were used to detect iron deficiency in 44 partially gastrectomized patients known to be deficient in vitamin B12. An abnormally high total iron-binding capacity was the most frequent peripheral blood abnormality and was found in iron-deficient patients although serum iron and transferrin saturation were normal.

Radioactive Vitamin B12 Absorption Studies: Population Distribution of Plasma B12 Absorption and Serum B12

Summary Simultaneous vitamin B12 plasma absorption levels and serum vitamin B12 levels were measured in 1169 consecutive unselected patients. Analysis of the population distribution confirmed the findings of Gräsbeck et al. (1) of a log-normal distribution of the serum vitamin B12 levels. To the contrary, a plot of the cumulative frequencies for distribution of the vitamin B12 plasma absorption levels showed a normal gaussian distribution, except for slight skewing at both extremes. This skewing would be anticipated because of the impossibility of negative values. The mean vitamin B12 plasma absorption level was 3 ± 3.6 pg/ml with a standard deviation of 2.08 pg/ml. Correlation between the plasma vitamin B12 absorption level and the serum vitamin B12 level was 0.1328. When plasma vitamin B12 absorption levels were compared with the logarithm of the serum vitamin B12 levels, the correlation was 0.3722. Eighteen patients were found who had plasma absorption and serum vitamin B12 levels below the 5 percentile. Eight had plasma absorption and serum vitamin B12 values below the 2.5 percentile. An additional eight had plasma absorption measurements below the 5 percentile, while having serum vitamin B12 levels above the 95 percentile. Seven had plasma B12 absorption and serum vitamin B12 levels above the 95 percentile. In no patient was a high plasma vitamin B12 absorption and a low serum vitamin B12 level found.