I'll answer even though my son isn't quite 12 months yet... no oranges yet but pretty much everything else, including pizza. He has never turned down anything I've let him taste and shares most things I'm eating (except anything overly processed, dyed, or preserved). We didn't start solids until he was 7 months old and he's still BFing about 6 times a day, if that makes a difference.
I was just wondering that's all. I didn't give my DC oranges or pizza at 12 months and it just never occured to me to do so. My friend told me that the day care her DD (12months) goes to served pizza and orange slices for lunch. I just never thought of that possibility. I'm not saying it's wrong just never entered my mind.
She might have had orange at 12mo, I don't remember exactly, but when she has oranges now, at almost 16 months, I still strip them of the membrane. She has had pizza three or fouir times, when we were out and about, and *really* enjoys it, but I am certainly not ready to make it a staple when she eats so many really healthy foods happily.