Anyone have a child with low ferritin?

[rachaelnicole]

DS2 has never been a good sleeper. He turned 3 in July and still wakes up at least 4 time a night. And we struggle with bed time every night. He just won't go to bed, and when he does, he has a really hard time staying asleep. I spoke to the pedi about it at his 2 year well child check-up, and she sort of shrugged it off and didn't seem overly concerned about it. I mentioned it again at this 3 year well child check-up in July, and she took it a little more seriously and ordered blood work. Turns out his ferritin levels are low and that can cause sleep disturbances. So she had us supplement with otc vitamins containing iron. We got his ferritin levels checked again last week and they were even lower than the first time they checked, so she prescribed an iron supplement. He's only been taking it now for about 3 days, so I'm not surprised that we haven't noticed any difference yet. I'm assuming it needs time to build up in his system. Has anyone else had issues with this? About how long did it take before you noticed a difference in your child's sleep? I am so totally desperate for a good night of sleep.