Nippon Shokakibyo Gakkai Zasshi
Online ISSN : 1349-7693
Print ISSN : 0446-6586
Effects of Magnesium Sulfate and Other Catharties on the Absorption of Vitamin B12 and Certain Nutrients
Atsuo Goto
Author information
Keywords: whole body counter

1971 Volume 68 Issue 10 Pages 1049-1062


It is generally thought that diarrhea may have an adverse effect on absorption, or at least it would not accelerate absorption. No definitive studies have been made to prove the point, however. In this study, the effects of MgSO4, Na2SO4, D-sorbitol, castor oil, and several others were assessed on the absorption of 57Co-B12, 131I-human albumin, 131I-triolein and 59FeCl3 in rats. Absorption was measured from recovery of radioactivity in feces and organs, and/or by whole body counting.
It was found that absorption of B12 was increased by MgSO4 and sorbitol, whether the dose of B12 was physiological or supraphysiological, and the effect became apparent late after oral administration. The increase was more marked with a large dose of B12. Castor oil inhibited absorption of small doses of B12, but increased absorption of large doses.
The effects of MgSO4 on the speed of B12 transit in the digestive tract were studied and it was disclosed that MgSO4 delayed the descent of gastric content into the bowel, had little effect on the speed of intestinal transit, and that the cecal content which had expanded under the influence of the cathartic regurgitated into the ileum. Increase of B12 absorption is caused most likely by the delayed descent of the nutrient from the stomach and its regurgitation into the ileum from the cecum. The same phenomena may occur in man under the influence of cathartics, It seems that bulk cathartics have little effect on the absorptive capacity of the small intestinal mucosa.

Content from these authors
© The Japanese Society of Gastroenterology
Next article