Since I'm on the subject of child nutrition, let's talk about dairy products. I've said almost everything on this subject before (see Dairy is Scary posts), but not specifically in regards to children.
First, let's talk phlegm. When I ask my students (who are all very well educated adults) what phlegm is, I am always amazed how few people know what this all-too-common disturbance is. Well, it's the same stuff mucus is made of, and that's white blood cells. When your sinuses are full of mucus or phlegm, you have one of two things: an infection (you knew that), or an immune response to what your body believes is a foreign invader - or "antigen".
Children who drink cow milk are frequently full of phlegm.
Cow, or bovine, proteins set off immune responses in all of us, but are especially noticable in children. That mucus causes unnecessary coughing - especially at night, runny noses, respiratory problems and ear infections. Think about it: if your ears, which are part of the sinus system, are filled with extra mucus, you are much more prone to an infection, since an invading bacteria or virus has a perfectly hospitable climate in which to reproduce. Also, since the immune system is busy attacking something it perceives to be dangerous, the body is "immune-compromised", and has less resources to fight a real pathogen. And that's what is happening in our children.
On the other hand, it is extremely rare for children who do not drink milk to develop ear infections. Take my daughter, who is almost 4. She's never had cow milk, and neither has she had an ear infection. I, on the other hand, associate my childhood with chronic ear infections, as do many other adults. And yes, I drank lots of milk.
Cow milk is also the #1 reason for childhood anemia in our country, since bovine proteins cause blood loss in the intestines (yes, they really do, look it up), in addition to calcium in milk competing with iron stores in the body.
And of course, these principles would even apply to organic milk, since we're talking about bovine proteins and calcium in milk - which are across the board.