Which iron is better: carbonyl vs ferric pyrophosphate?

My ferritin level went down from 217 at 3 mos post-op to 154 at 6 mos post-op to 101 at one-year post...so it's been steadily decreasing (my iron has been 81, 96 & 85, respectively). 

Even though my Dr & Nut did not suggest it, I'm thinking about taking an iron supplement.  I've been feeling really tired, no energy for the last few months; my B12 level was "above range" so I'm guessing it might be the low ferritin/iron...?  Since surgery, the only iron I've been getting is from my twice daily Centrum multis.

I ordered "Tender Iron" (carbonyl, 25 mg/tablet) and a friend just gave me a bottle of chewable "Easy Iron" (as ferric pyrophosphate, 20 mg/tablet, the label says it has "high bio-availability")

To all of you who know about this stuff: what's the difference between carbonyl and ferric pyrophosphate and which one do you think is better?
Also, considering my iron and ferritin levels, how much should I be taking?

Thanks in advance for your advice!
Tam

I have to admit.. this was not one I'd heard of.  So off to do what I do best.

What I know before even cracking the journals -- ferric forms TYPICALLY require a high degree of acidity to break down.  That's why sulfate, fumarate, etc are not well absorbed by us as a general rule.  So seeing this is another ferric salt?  I'm guessing probably carbonyl just off that.  So let's see what I can find..

(I'll cite.  Cause I seem to have someone who is picking my posts apart bit by bit of late.)

http://www.ajcn.org/cgi/content/abstract/71/6/1597

Iron bioavailability in infants from an infant cereal fortified with ferric pyrophosphate or ferrous fumarate^1,2

Lena Davidsson, Peter Kastenmayer, Hanna Szajewska, Richard F Hurrell and Denis Barclay

¹ From the Laboratory for Human Nutrition, Institute of Food Science, Swiss Federal Institute of Technology, Rüschlikon, Switzerland; the Department of Pediatric Gastroenterology and Nutrition, Warsaw University Medical School, Dzialdowska, Poland; and Nestlé Research Centre Lausanne, Lausanne, Switzerland.

 

Background: Infant cereals are commonly fortified with insoluble iron compounds with low relative bioavailability, such as ferric pyrophosphate, because of organoleptic changes that occur after addition of water-soluble iron sources.

Objective: Our objective was to compare iron bioavailability from ferric pyrophosphate with an alternative iron source that is soluble in dilute acid, ferrous fumarate, and to evaluate the influence of ascorbic acid on iron bioavailability from ferrous fumarate in infants.

Design: Iron bioavailability was measured as the incorporation of stable iron isotopes into erythrocytes 14 d after administration of labeled test meals (25 g dry wheat and soy infant cereal, 100 g water, and 2.5 mg Fe as [⁵⁷Fe]ferric pyrophosphate or [⁵⁷Fe]ferrous fumarate). Ascorbic acid was added to all test meals (25 mg in study 1 or 25 or 50 mg in study 2). Infants were fed each test meal on 4 consecutive days under standardized conditions. The 2 different test meals within each study were administered 2 wk apart in a crossover design.

Results: Geometric mean iron bioavailability was significantly higher from [⁵⁷Fe]ferrous fumarate than from [⁵⁷Fe]ferric pyrophosphate [4.1% (range: 1.7–14.7%) compared with 1.3% (range: 0.7–2.7%); n = 8, P = 0.008]. In this study, doubling the ascorbic acid content did not further enhance iron bioavailability; the geometric means (range) were 3.4% (1.9–6.6%) and 4.2% (1.2–18.7%) for the test meals with 25 and 50 mg ascorbic acid added, respectively (n = 9).

Conclusion: Iron bioavailability from iron-fortified infant cereals can be improved by using an iron compound with high relative bioavailability and by ensuring adequate ascorbic acid content of the product.


http://jn.nutrition.org/cgi/content/full/134/12/3301

Iron (Fe) deficiency anemia (IDA)³ is a major global public health problem, affecting primarily young women, infants, and children (1). Although food fortification with Fe may be an effective strategy to control IDA, successful Fe fortification of foods remains a challenge (2). Water-soluble, highly bioavailable Fe compounds often cause adverse organoleptic changes in foods. Poorly soluble Fe compounds, although more stable in foods, tend to have low bioavailability. Ferric pyrophosphate (FePP) is a white-colored, poorly soluble iron compound that does not cause sensory changes in many difficult-to-fortify food vehicles, including salt (3). However, its low bioavailability, only 30–50% of ferrous sulfate, reduces its nutritional value (4).


http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=912720

Abstract

Ferric pyrophosphate is a water-insoluble Fe compound used to fortify infant cereals and chocolate-drink powders as it causes no organoleptic changes to the food vehicle. However, it is only of low absorption in man. Recently, an innovative ferric pyrophosphate has been developed (Sunactive Fe™) based on small-particle-size ferric pyrophosphate (average size 0·3 μm) mixed with emulsifiers, so that it remains in suspension in liquid products. The aim of the present studies was to compare Fe absorption of micronised, dispersible ferric pyrophosphate (Sunactive Fe™) with that of ferrous sulfate in an infant cereal and a yoghurt drink. Two separate Fe absorption studies were made in adult women (ten women/study). Fe absorption was based on the erythrocyte incorporation of stable isotopes (⁵⁷Fe and ⁵⁸Fe) 14 d after the intake of labelled test meals of infant cereal (study 1) or yoghurt drink (study 2). Each test meal was fortified with 5 mg Fe as ferrous sulfate or micronised, dispersible ferric pyrophosphate. Results are presented as geometric means. There was no statistically significant difference between Fe absorption from micronised, dispersible ferric pyrophosphate- and ferrous sulfate-fortified infant cereal (3·4 and 4·1 % respectively; P=0·24) and yoghurt drink (3·9 and 4·2 % respectively; P=0·72). The results of the present studies show that micronised, dispersible ferric pyrophosphate is as well absorbed as ferrous sulfate in adults. The high relative Fe bioavailability of micronised, dispersible ferric pyrophosphate indicates the potential usefulness of this compound for food fortification.

I'm questioning it given our lack of acid.  The last reference gives *some* hope in a liquid suspension, but it seems mostly for food fortification and not for supplemental use.

I'd stick to the carbonyl, a known good.

Andrea, even though someone is picking apart your posts, bit by bit lately....I'm glad to see you keep posting....you help people and that is what this site is all about! :)

I'm about through tonight.  Because otherwise I will lose. my. temper.  Seriously.

Let us at whoever it is - we NEED you!

Rebecca

i have also learned so much from you... and am very grateful that you post your replys and posts on the message board...you have helped me tremendously..... thank you for everything andrea... your great!  the help you give on here is like a job in itself really.... dont stop doing what you do... you help so many

Please don't stop.  You are where I have learned most of what I know.

I will always vote for Tender iron because it's what I use MYSELF