Nicotine and juice fasting

Hi I'm gearing up and researching to start a juice fast. I have a big question that I need answered first. I smoke Electronic cigarettes. For those of you that aren't familiar, this means that I ingest nicotine but none of the toxins contained in real cigarettes. I essentially inhale nicotine contained in water vapor. So my question is can I continue to do this during a juice fast? If not, please explain why. Thanks.