Initially I dropped from ~145 pounds, to 127 or 128, over about 4 months (I am 5'8 btw). Then I started weight training right around the time I reached my lowest weight. Since then I've gone back to 144-145 at a body fat percent of about 4 at the moment.
Gaining muscle and not fat is incredible on a vegan diet. Omnivores can say all they want about skinny vegans, but they usually have very high bodyfat, and are far from lean.