That's very serious. I understand your doctor's concern. Janie at http://www.stopthethyroidmadness.com/ferritin/ has a thorough discussion of her experience raising her ferritin. Maybe it will get you started.

From Janie --

A large body of thy­roid patients have been sur­pri­sed to dis­co­ver that being hypothy­roid also results in having low Ferri­tin, or sto­rage iron. Ferri­tin is an iron-storage pro­tein which keeps the iron in a dis­sol­va­ble state and also makes the iron non-toxic to cells around it.  So when Ferri­tin is mea­su­red via a blood test, it is basi­cally mea­su­ring your sto­rage iron, or the iron you have tuc­ked away for future use. You can have “nor­mal” iron serum levels, yet a low Ferritin.

Why do we often have low Ferri­tin? Because being hypothy­roid can result in a lowe­red pro­duc­tion of hydroch­lo­ric acid which in turn leads to the malab­sorp­tion of iron. It can also lower your body tem­pe­ra­ture (com­mon for those on thy­ro­xine, as well) which cau­ses you to make less red blood cells. Addi­tio­nally, being hypo can result in hea­vier periods, which cau­ses more iron loss.

In turn, having low iron levels dec­rea­ses deio­di­nase acti­vity, i.e. it slows down the con­ver­sion of T4 to T3

Why is having low Ferri­tin a pro­blem? First, though the slide into low Ferri­tin can be symp­tom­less, it even­tually beco­mes the pre­cur­sor to being ane­mic. And once the lat­ter occurs, you can then have symp­toms which mimic hypothy­roid – depres­sion, achi­ness, easy fati­gue, weak­ness, fas­ter hear­trate, pal­pi­ta­tions, loss of sex drive, and/or foggy thin­king, etc, cau­sing a patient to think they are not on enough desic­ca­ted thy­roid, or that desic­ca­ted thy­roid is not wor­king. Exces­si­vely low Ferri­tin can also make it dif­fi­cult to con­ti­nue rai­sing your desic­ca­ted thy­roid, resul­ting in hyper symp­toms when rai­sing desic­ca­ted thyroid.

Bio­lo­gi­cally, insuf­fi­cient iron levels may be affec­ting the first two of three steps of thy­roid hor­mone synthe­sis by redu­cing the acti­vity of the enzyme “thy­roid pero­xi­dase”, which is depen­dent on iron.  Thy­roid pero­xi­daxe brings about the che­mi­cal reac­tions of adding iodine to tyro­sine (amino acid), which then pro­du­ces T4 and T3. Insuf­fi­cient iron levels, which low ferri­tin reveals,  alters and redu­ces the con­ver­sion of T4 to T3, besi­des bin­ding T3.

Addi­tio­nally, low iron levels can inc­rease cir­cu­la­ting con­cen­tra­tions of TSH (thy­roid sti­mu­la­ting hormone).

Iron, in addi­tion to iodine, sele­nium and zinc, are essen­tial for nor­mal thy­roid hor­mone metabolism.

What’s the solu­tion? The solu­tion, after you have veri­fied low Ferri­tin with a blood test (i.e. lower than the 50’s), is to sup­ple­ment your diet with iron. Foods rich in iron inc­lude lean meats, liver, eggs, green leafy vege­ta­bles (spi­nach, collard greens, kale), wheat germ, whole grain breads and cereals, rai­sins, and molasses.

But most patients and their doc­tors have found it neces­sary to sup­ple­ment with iron tablets, which inc­lu­des Ferrous Sul­fate, Ferrous Glu­ta­mate, Ferrous Fume­rate, etc.

Ferrous Sul­fate is usually the chea­pest – just be sure you are taking a good Vit. E with it since there is evi­dence that it’s deple­ted with the use of Ferrous Sul­fate. And always take it with food. The owner of this site had to take 2 – 3 325 mgs. of Ferrous Sul­fate with food and throughout the day, for months to even BEGIN to get her Ferri­tin up,  plus 800 mgs Magnesium.

Ferrous Glu­co­nate may cause fewer symp­toms and is mil­der on sto­mach. Ferrous Fume­rate is often presc­ri­bed by doc­tors as it, too, has fewer side effects, absorbs well, and is easier on the stomach.

Beware of liquid iron that is ani­mal based (heme) – it may be the best absor­ba­ble iron, but it can blac­ken your teeth, as it did to the owner of this site. VEGETABLE BASED (nonheme) liquid iron avoids this, even if less absorbable.

I was con­tac­ted by a phy­si­cian prac­ti­cing alter­na­tive medi­cine who highly recom­mends Flo­ra­dix Iron and Herbs, or Enzy­ma­tic The­rapy Liquid Liver. Check in your local health food store or pharmacy.

From Canada, there is a che­wa­ble non-constipating iron called Hemo­fac­tors by Natu­ral Fac­tors, and one patient who wrote me swears by it.  It’s Ferric Pyrophosphate, also called SunAc­tive Iron and you’ll want to pay atten­tion to the “ele­men­tal iron” amount to get enough.

How much iron sup­ple­men­ta­tion do I need to raise my low levels, and how long do I take it? When Ferri­tin is low, you have to give your­self many weeks, and some­ti­mes 2 – 3 months, to improve your levels,  Patients gene­rally try to take 150 to 200 mg of  “ele­men­tal iron” daily, spread out with meals.  Be sure and read the label to see how much ele­men­tal iron is in each tablet.

The gene­ral goal is to get your Ferri­tin to a lab result of 70 – 90, accor­ding to our own research.  Keep track of lab­work to see where your levels are, because you want to get off the iron once you achieve your goal since iron pro­mo­tes free radi­cals.  Some women who are mens­trua­ting may have to stay on low amounts of iron. Check with your doctor.

Should I take anything with the iron to help? Yes, Vita­min C.  First, Vita­min C is said to help the absorp­tion of iron. Second, since the intro­duc­tion of iron in your body can pro­mote the sti­mu­la­tion of free radi­cals, Vita­min C has a known role of com­ba­ting those free radi­cals.  How much C? Some take it to tole­rance – the amount they can handle before get­ting too-soft stools. Others are in the 1000 – 2000 mg range.   At the very least, drink down your iron tablets with orange juice or a drink like Emergen-C.

Also taking a mine­ral sup­ple­ment can assist the absorp­tion, as can B-vitamins. One impor­tant B-vitamin is Folic Acid, which pro­mo­tes red blood cell for­ma­tion. Adding it to your iron sup­ple­men­ta­tion can be key.

What about the cons­ti­pa­tion I get from taking iron sup­ple­ments? If you do find your­self with cons­ti­pa­tion or very hard stools, talk to your doc­tor about adding Mag­ne­sium Citrate as a sup­ple­ment, taken twice a day, until you find the amount that sof­tens your stool. You’ll know within a few days if the amount you are taking is enough.…or even too much (i.e. too much will cause diarrhea).

Can I take iron at the same time I swa­llow my desic­ca­ted thy­roid? If you swa­llow your desic­ca­ted thy­roid ins­tead of doing it sublin­gually, it’s impor­tant to avoid swa­llo­wing iron at the same time,  since the iron will bind to some of the thy­roid hor­mo­nes and make them use­less. If you are doing your natu­ral thy­roid sublin­gually, you are fine whe­ne­ver you swa­llow your iron.

What if I can’t tole­rate oral iron? If you have pro­blems absor­bing oral iron due to a pre­vious sto­mach sur­gery or other issue, another option is to use Veno­fer — an intra­ve­nous iron which helps reple­nish body iron sto­res.  Talk to your doc­tor. (Thanks go to “Che­ni­lle” for this info)

Once I get my ferri­tin levels back up, will it stay up? Seve­ral of us have had our ferri­tin levels plum­met again, so it may be wise to stick with a small dose of sup­ple­men­tal iron or eat iron rich foods, espe­cially if you are female and still mens­trua­ting. Once into meno­pause, your ferri­tin levels may stay where they need to.