Whatever type of protein you eat will get used, even if it is not the exact composition of the proteins that are actually synthesized. That's a good question, because it's not clear cut. I think it's important to at least add it, and that's what I would prefer people do. Also, it works best to use pure protein because you don't have a lot of extra fat or carbohydrate calories which can quickly get put on as body fat compared to the protein calories. Adding 500 calories a day to get 300 protein calories for a month or so is not enough to make a patient obese, but they may gain weight.
Some chiropractors recommend that when their patients have a fracture they consume extra protein.
They found that some people benefitted greatly, but your average ambulatory person before the injury didn't benefit. But that was only with calcium. They did not look at the other trace minerals which I feel are more important than calcium. The trace minerals are more easily deficient, so just throwing calcium at a fracture will not accelerate healing. Well, I think that magnesium is probably the second most overlooked nutrient.