heater makes idle go up

[justabuickv6]

When I turn my heater on, the idle goes up about 500 rpm. Maybe a little more. Is this normal? It is definitely noticeable.
When it's on vent and on hot, the idle does not go up.

Does this mean I have a vacuum leak and does it hurt performance?

My BLM's are 132

 

[salvageV6]

Idle goes up in A/C and defrost modes.

Don't recall it being 500 rpm however.