Just had this thought as DD was chewing her way greedily through her second fresh date of the day. (Dates being high in iron, my mum tells me)
It's been a struggle to get a full 600ml of formula into her over 24 hours for a few weeks now (she's always been happier with solids than milk) though she has been FF since birth so has probably done ok on the iron front from that point of view. But I think (?) babies lose iron reserves fast after 6m...?
(she is almost 10m and has never slept well at all but it's getting worse not better...)
A quick google tells me it's fairly common for babies to be iron deficient and easy for them to be so. Also that iron deficiency can cause frequent waking...
But has anyone really experienced this?
You MN Sleep ladies are my gurus... will only believe it's a possibility when one of you says so! ;)
I think it may be time to start supplementing with vit/mineral drops anyway as the HV said I should do that once DD was down to 500ml of milk a day and she's only barely having 600 at the mo... Guess it can't hurt to supplement?
Her diet is really good - though come to think of it I've avoided egg yolk (also rich in iron) as DD gets constipated, and she doesn't like broccoli so haven't given much of that... She does eat red meat a couple of times a week though.
I didn't supplement with iron when I was pg with her as I get constipated too 
- I didn't get pregnancy anaemia but is there any way DD could have ended up getting less than she needed from me?
Oh, and one last thing - when I went to pick her out of her cot y'day after a nap her little heart was racing... at the time I just thought it was cos she'd been crying for me for a minute and got herself worked up (ridiculously fast!) But I know heart racing is another iron deficiency thing...
Any views at all, oh gurus?