Ascorbic Acid (Vitamin C) and Salicylic Acid (Aspirin) may interfere with the Sensor sugar readings. Taking ascorbic acid at doses higher than the maximum recommended daily allowance while wearing the Sensor may falsely raise the Sensor sugar readings. Taking salicylic acid may slightly lower the Sensor sugar readings. The level of inaccuracy depends on the amount of the interfering substance active in the body.