Lab sets new rules for fasting Published May 11, 2007 BUCKLEY AIR FORCE BASE, Colo. -- The 460th Medical Group laboratory has a new rules for fasting labs. All fasting samples will now be drawn from 7:30-11 a.m. The only exceptions will be for shift workers or special circumstances to be determined on a case by case basis. This time change policy is for safety issues to protect the patient and for accuracy purposes for the phlebotomist/technician testing the sample. The new instructions for testing are: Patients will fast for 10-12 hours but no more than 14 hours before testing or they will be turned away to fast again. This is for the safety and accuracy of the testing sample. Under-fasting may cause increased levels in testing as it's not enough time for the test sample to be an accurate reading. Over-fasting will increase testing levels and safety issues for the patient and the phlebotomist drawing the blood sample. Patients should drink only water once they start fasting. Anything other than water will interfere with the accuracy of the testing. Any vitamins or medication may be taken, as long as it can be taken with water. Patients should not drink alcohol or eat eggs or shellfish three days prior to fasting for the sample.