I think what you said about the body economizing its reserves, and taking the vitamins causes the body to still be in a receiving food mode is what convinced me. Regarding why a person would want to go this long....I don't know. The reason I am asking you though is I am curious regarding long term fasting for health (not weightloss) and if someone had a really serious health problem as you did for example, if going long term like that (70, 80, 90 days etc.) would give the body plenty of time to deal with the problem.
I now see why you went 25 days of fasting, then recovery of 40 days or so (if I remember), then another 30 days of fasting.