Low iron and apnea

My son had bloodwork run that showed dangerously low iron.he was on iron supplements, but they just ran his bloodwork again-still dangerously low. I did some googling (thought I'd ask here before I go down the Google spiral) to see if the two could be linked?
At this point I'm kind of thinking our pediatrician is a moron. Could sleep apnea be the reason his levels won't go up? Or could the low iron (she hasn't used the term anemic just said "dangerously low iron") be making the apnea worse? What's the relation?
Thank you so much for your help. I really appreciate it! I'm so lost with all of this, and our pediatrician has never had a patient with apnea (that she knows of anyway). Our pulmo doc is out of the office for Christmas, so I can't ask him just yet

I did find this,

Relation Between Low Iron and Sleep Apnea

Low iron in blood aggravates sleep apnea and may even cause it. A person with low blood iron and anemia experiences reduced coordination of brain and respiratory muscles and reduced muscle tone of pharyngeal and respiratory muscles. This leads to sleep apnea and aggravates the problem if the person was already suffering from low iron prior to developing anemia.

http://www.livestrong.com/article/44900 ... eep-apnea/

But, they don't reference the science behind the statement. I don't have time now, but you might want to google "iron and apnea", and see if you can find any science references.

What are his serum ferritin and hemoglobin levels?

I'm not sure what his levels were exactly. I found the same info and did some googling. I called our pulmo today who said the iron could be something else and he wasn't concerned with it as far as apnea is concerned. I did call the GI doc I saw earlier to see what they thought. They left a message for him to see if he was concerned