Of course. There are many types of identification cards you can use to show you're a Veteran. You only need to have one of them for this purpose. Here you can learn about the different types of VA ID cards and other Veteran ID options.
What if I already have a Department of Defense ID?
In that case you don't need to request another type of photo ID card to prove you're a Veteran or to get retail or business discounts.
Too bad I don't have my ID anymore. What requirements do I need to meet for the Veteran ID?