What is a white oval pill with -v- (with the -) on one side & blank on the other?

Could be anything. There are literally hundreds of white polls with a v on them. You might want to bring it to your pharmacist to determine what it is or if you can limit it down to a few possibilities you might be able to look them up online.

It is less likely a prescription drug because I could find a pill like this by using pill identifying method in Drugs.com website.