Pernicious anemia due to dietary deficiency of vitamin B12

Influence of age and stomach function on serum vitamin B12 concentration

Serum vitamin B12 (B12), maximal gastric acid output (MAO), and B12 absorption were determined in 82 subjects, age 32 to 85 years, who had normal absorption of radiocyanocobalamin. In 46 of the patients the gastric intrinsic factor (IF) was also measured. Serum B12 concentration and MAO varied widely in all age groups from abnormally low to definitely normal. The mean values for serum B12 and MAO, however, declined very similarly with advancing age owing to an increased incidence of low values for these two measurerment in the aged. There was no significant fall in the mean B12 absorption or IF secretion as a function of old age. Achlorhydric and hypochlorhydric patients invariably had lower mean serum B12 concentrations than those with adequate MAO. Conversely, patients with normal MAO all had normal serum B12 levels. Serum B12 concentration, although correlating with both MAO and IF secretion, showed a closer relationship to the former than to the latter. These findings suggest that the stomach, aside from producing the IF, plays an important role in maintaining a normal serum B12 concentration.

Nutritional value of soya protein and milk coprecipitates in sausage products

Sausages containing 60% of meat proteins replaced with soybean or milk calcium coprecipitates were prepared. Growth rates and plasma amino acid levels in rats fed diets based on these products, together with vitamin and available amino acid analysis indicated that the nutritional values of the non‐meat proteins were similar but were both markedly lower than meat sausages. Nutritional damage to the protein in the sausages during cooking was only apparent in the all‐meat sausage.