Re: Protein Deficiency
I would look at improving the power of your digestion if you are inclined to remain vegetarian - vegetarian sources of protein may be difficult to digest properly and requires plenty of energy to breakdown into absorbable aminoacids. So HCl/pepsin may be helpful, along with digestive enzymes (protease specially).
Cooking helps breakdown and allow for easier absorption. If your body type is one that does well on animal protein than perhaps you can add it to the diet and monitor changes.
Animal protein is more like the "middle man", it usually provides more readily digestable/ absorbable nutrients that your body can recognize (after all your an animal too) - either way, if your digestion is weak than it won't help either veg of animal protein sources (they will accumulate as toxins)
Ultimately, protein must be broken down into the aminoacids for absorption so if you have trouble during this stage than free amino acids supplement can do wonders. They are readily absorbed - proper ratio of each aminoacid should be considered.
Mike