Item Value
Test name D-Xylose Absorption, blood
Available Stat? No
Turn around times Blood test set up as needed; urine test performed Monday-Friday. Turnaround time: 1-4 days.
Performed by Quest
Patient Preparation Adults must have fasted for 8 hours prior to sample collection. Children must fast for 4 hours before sample collection.

Outpatients should be given a prescription for the proper dose of (D+)-xylose powder to be obtained at an outside pharmacy.
Normal range
< 6 years >14.9 mg/dL
≥ 6 years >19.9 mg/dL
Container type Gray top
Amount to Collect 4 mL blood
Collection Instructions Note the dose on the requisition and in the patient's chart. Dose: 1.0 g/kg-maximum 25 g. Draw sample 1 hour after D-xylose administration.
Sample type Blood

If you have additional questions regarding this test, please call: 415-353-1667