Organic Acid Excretion,Enhanced Calcium Absorption and Body Fat of Rats Fed Incompletely Digested Carbohydrates. ∗

Abstract

Summary

1. Rats fed diets containing the incompletely digested carbohydrates, lactose, cellobiose and raw potato starch, excreted larger amounts of organic acids and had a lower content of body fat than rats fed glucose, sucrose or galactose. 2. The predominant urinary organic acids were identified by silica gel chromatography as citric, αketoglutaric, fumaric and succinic acids. 3. Organic acid excretion could be increased by increasing the amount of dietary salt mixture or by adding CaCO₃ but not CaCl₂ to the diet. 4. This latter finding, in conjunction with the results of urinary analysis of ionic constituents, indicated that the increased excretion of organic acid is not a consequence of an altered metabolism that decreases body fat deposition but is a renal acid-base mechanism for neutralization of increased urinary calcium, an increase resulting from the enhancement of gastrointestinal absorption of calcium by incompletely digested carbohydrates.