High Protein Diet!!
If its like the one a body-building colleague is following then I have a question:

Constipated yet or just gassing everyone??

I'm not convinced of the merits of diets that promote an overload of a particular nutrient group. On the otherhand, taking supplements to compensate for a definite deficiency seems OK (Vit B, Zinc & Iron on top of a healthy diet for me or its mouthulcer hell: the Doc is flummoxed too).

The weight training is probably the source of improvement, not the HP diet. You've probably come out of a training-plateau and reaped an improvement simultaneous with taking the supplement.