But he insisted it "wasn't a hard luck story" and accepted their promotion-chasing hosts had played a full part in an entertaining game that deserved goals.
Parkinson said: "The lads were outstanding and in the second half we really took the game to them.
"On another night James Hanson could have scored a couple of goals and there were scrambles in their goalmouth when I don't know how the ball didn't go in the net.
"I thought the spirit, energy and quality in our play was terrific and I couldn't have asked for anything more from them.
"We've gone three unbeaten now since Wembley, including two clean sheets away from home, and that's good going.
"We got out to try and win every game and we made attacking substitutions in the second half to try to get the three points.
"But we shouldn't forget Jon McLaughlin has made a world-class save from Tom Pope in the first-half and Vale also had a chance or two towards the end."