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