Beth, Welcome to the boards!
You are definitely iron deficient at a 16 ferritin. And..... are barely making the charts for a normal range. I *think* it's anything under 40 ferritin that is considered deficiency level, pre iron deficiency anemia. I too am impressed along with Audrey-B on the range your doctor wants. That's terrific! It sounds like you have a really good doctor as far as that goes. As for him taking you seriously, do you know WHY you are consistently low in ferritin? Has he done any testing? These are the big questions. How old are you?
Chelated iron 29mg is a much lower dose iron, however, it is said to be highly absorbed and well tolerated. The only way you will know if this works for you is to retest your blood to see if your values are rising or just maintaining. Someone needs to be following your iron levels. Know that it takes much longer for the ferritin to fill the stores. It can take literally years to deplete the iron stores, usually it is something that has gone on over a long period of time. Ferritin also responds according to the need for iron. After it's initial response, it can slow down because it is getting what it wants. A built in mechanism response system so to speak.
You seem to be doing the right thing. It does take seeing specialist after specialist to diagnose a cause OR even multiple causes in your case perhaps? My experience was several reasons contributing as factors, not just one cause as I was told by many doctors, guess what that was? Heavy periods/7 polyps. So, you have to be your own advocate when it comes to this. You unfortunately cannot depend on one doctor to fill this requirement. Although it is the role of the PCP to organize this for you.
I did see a hematologist, they are *usually* seen when there is a bigger problem as seen in; no ferritin, iron intolerance, or concerns as a (family history) of blood disorders and things of this nature. This doesn't mean that you shouldn't see one, if you are trying everything and getting nowhere then you may want to try this. A GI doc can look for malabsorption syndromes as a cause along with Endoscopic/Colonoscopy/Camera capsule/Blood Occult testing to eval your internal pipes to rule out these causes. A GYN is consulted IF you are having heavy bleeding or if you think that your periods are a probable cause. Also, something to know is that you don't necessarily have to have a really heavy period to become anemic. Having a regular cycle and not enough iron intake to meet this demand can eventually over a long time (years) end in IDA if not corrected when detected by your doctor. It's also good that your Nephorologist doesn't think that it is your only cause of anemia. It helps to go in other directions just having this information. My best advice and iron supplementation came from my GI doc. As far as knowledge goes, he had all others surpassed by far, including my Hematologist that did absolutely NOTHING for me. Now, if I was well enough to be administered IV iron therapy it may have been a different story, but clearly this was not my experience.
Hope this helped a little
. Take care and do keep us posted! FLFG