John has never had any meat. If your concern is protein, try cottage cheese, eggs, black beans, hummus, and lentils. Black beans and lentils are not as gassy as pintos. If iron is your concern, try dark green veggies - brocalli (gassy), and spinach. Definately keep iron fortified cereal in his diet as long as you can. And use soy based products (tofu, veggie burger, veggie dogs) sparingly. There are some controversial studies out right now on them.
I have been giving John a vitamin since he was about 12 months. Talk to your doctor and find a vitamin drop with iron in it. Ask your doctor to check his blood for anemia, but it probably isn't a problem.