Ask A Scientist Chemistry Archive

Question:
I am writing for a friend.  She wants information about iron
fortified baby formula.  Specifically, is there info about:
1) chemical composition
2) iron build-up in the liver (toxicity?)
3) imbalance in mineral or vitamin levels?
Any related information on this matter or other people to
contact would be appreciated.
We're especially interested in hearing Joseph Strong (daddy)
P.S. Also interested in any graphics that display these
effects on the body.   THANK YOU!!
 margo j berg

Answer 1:
That's a pretty involved line of questioning.  I'll see if I can dig
up a reference or two.  One that's readily available is from the 
23 October 1990 issue of _The Milwaukee Journal_.  The article talks about
hemochromatosis.  The body essentially stores up whatever iron it needs
and gets rid of the rest.  People whose bodies absorb too much iron have
the disease mentioned above.  Symptoms include pituitary problems, 
sterility, and impotence and can lead to heart disease, liver damage,
arthritis, and diabetes.  Keep in mind, though, that hemochromatosis is
a genetic disorder, and not something just acquired from too much iron.
Two sources of info you may want to check into:
Hemochromatosis Research Foundation of Albany, NY
Iron Overload Disease Association of (I think) Chapman Cancer Center
in Joplin, MO
-Joe Schultz
 
Answer 2:
I thought about it a while and had a great discussion with a Professor
of Biochemistry here at UW-Milwaukee (I'm a measly biochem grad student).
Here goes:  Iron in the body is used in hemoglobin, iron-sulfur clusters
in oxidative phosphorylation, and other proteins.  It is usually in the
Fe3+ form.  It is brought into cells by a protein called the transferrin
receptor.  Once in the cells it is stored by a protein called ferritin.
Each ferritin molecule can hold about 4000 Fe ions.  Needless to say there
is a huge storage capacity for iron in the body.  Ferritin will release
iron when it's needed also.  When there is an increasing amount of iron
in the body, ferritin systhesis will increase (creating more storage).
Too much iron can overload the mechanisms in a healthy person and can
cause damage to cells (particularly in the liver).  Fe3+ will be reduced
to Fe2+ and then a host of things happens including the formation of
free radicals (chemical species with an unpaired electron...very reactive
and not a good thing to have in a cell).  In a nutshell, a doctor should
diagnose an iron deficiency and treat it accordingly.  Iron supplements
will just get stored and too much can actually be harmful.
Here's a reference:  "Regulation of Ferritin and Transferrin Receptor mRNAs"
   Thiel, E.C.  Journal of Biological Chemistry 265, 9, 4771 (1990)
-Joe Schultz