Do liquid dietary supplements change the taste of vaginal juices?
What foods should I stay away from?

No... not taste different for the most part. Unless you have some gynecological problems going on... there is nothing wrong with the natural smell and taste of a CLEAN woman. If there is something going on.. its best to address the source of the problem than try to mask it.

But things like Asparagus and Fennugreek (something big in Indian and middle eastern cooking) make your urine smell absolutely horrendous... and well... even a drop will be noticeable when someone's face is down there... since your urethera is so very close to the Vaginal opening.