I had the same problem. My girlfriend said I didn’t initiate as often as I normally do. And when I did initiate, I wasn’t as (ahem) stiff as usual.
I tried to counter this by taking TRIBEX gold. When that didn’t do anything I switched over to the old-school Alpha Male, which also had no effect.
At this point I came to a realization, both of the T-boosters I used didn’t work because they did not have the raw materials needed to function properly (i.e. cholesterol).
The V-Diet is exceptionally low in the lipid department. Thus, sex hormone production (namely testosterone) drops dramatically while on this diet.
Add to that the extremely hypocaloric nature of the V-Diet and you have a recipe for low libido and low T production.
As far as countering this effect, I tried having a single cooked egg yolk every day with one of my shakes. This seemed to help, but only marginally.
Worry not, It will come back about two to three weeks after you finish the diet.
Hope that helps.