So my sons adhd dr asked me to have his ferritin levels checked because of how little he sleeps. She…

So my sons adhd dr asked me to have his ferritin levels checked because of how little he sleeps. She said it isn’t checked on most iron tests. I got this in the mail, and it just seems like SO much. It says at the bottom ferrous sulfate with the dosages. Is there a child’s one? Or is it for everyone. I’m so confused.