If you're going to fast, and deprive your body of all the vitamins/minerals it needs to function in this fucked up world we live in, then I sure hope you live in a super clean environment like on top of a fucking mountain or something like that, because if you live in the city:
1) You're breathing shit. (carcinogens from cars, CO2, bacteria, pollution, etc...)
2) You're drinking water that contains shit. (all types of chemicals that I need a whole book to write about)
3) You're stressed out more than you should be.
4) You're looking at a screen (TV/Computer) more than you should be which exposes you to more carcinogens.
and more shit like that... you get the idea?
All of the above make your body crave vitamins and nutrients to repair itself and fight threats. It's definitely not the right setup to be fasting for long periods of time.
If you want to fast, go on a Vipassana retreat in the Himalayas or something, drink spring water, get away from all the harmful shit that modern society is throwing at you.
We have to make do where we are. While I agree with your general sentiment, I think you are being fear mongering and disregarding the resiliency of the body.