Jay Armstrong says it started with a cough and a visit to the doctor.

"Immediately recognized he was pale," says Armstrong.

His two year old son, Richard, was sick but the doctor asked Armstrong a question he wasn't expecting.

"Does he drink a lot of milk?"

Right away the doctor knew what was wrong. Richard had iron deficiency anemia and his heart was failing.

"When I went to Dr. Springer, within 30 minutes he was telling me to put my son in the car and go to the hospital."

Richard was drinking too much milk. Doctors say cow's milk is loaded with protein that absorbs iron. Drink too much and kids can become anemic.

Two year old Richard was drinking about 40 ounces a day. Doctors says a child his age should only be drinking about half that.

It's advice Armstrong hadn't heard until his son got sick.

"I thought I was doing the right thing by giving him that."

Richard spent time in intensive care, received blood transfusions and eventually recovered.

Arnold says his son almost lost his life.

"All from drinking milk. He's not allergenic to milk. It was the protein that was killing my son."

Doctors stress that milk is good for you and it's especially critical for a child's development.

To keep from giving them too much, switch it up with water, but avoid juices and other sweet drinks.

And not every child reacts like two year old Richard.

If you have questions, they encourage you to ask your doctor.