Xylose absorption test using D-xylose-14C

Summary 1. D-xylose- 14 C was used to measure oral xylose absorption in the investigation of malabsorption syndromes. The concentration of D-xylose- 14 C present in the 1 and 2 hour serum samples and the quantity of D-xylose and D-xylose- 14 C excreted in the urine in 5 hours were used as indices of xylose absorption. 2. The radioactive technique makes the test technically simple to perform on both serum and urine, analyses specifically for xylose, is not affected by other reducing substances present in the sample and does not require the collection of a fasting urine sample.