Yes, after reading through responses it seemed that people mistook my use of the verb "supplement." I was using it in an unmarked way (supplement kibble [or standard food] with other fresh food), but it was taken to mean (I think) "nutritional supplements" as a noun, meaning vitamins, pills, etc. I was confused about this, as I'd specified what I am adding—fruit and veg, a spoonful of plain yoghurt, chicken I cook—but I'm new here and clearly don't understand the vibe.
I cooked raw food (on advice from a vet and using veterinary recipes) for close to a decade, and in that time I also studied such diets for dogs. I might switch to that when ours is older, but frankly I'm very happy w/ ProPlan, and that's what she's been on since weaning, so I plan right now to keep her on it. But I also add fresh non-processed food to her diet—fruits and veg—so that's what I was asking about. I know the stuff she can't have, and I know what I won't feed her... I was just curious, but not especially puzzled.
Sorry about the confusion; it was surely my use of the verb.