Iodine in breast milk.

[don@radpro.uchicago.edu]

The following message was posted to the MEDPHYS listserver.  In view of the 
recent discussion of radioiodine therapy, I thought there might be some interest
Please communicate directly with the original author.

Forwarded message follows:
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Message-ID:  <300664E5.3226.15EA.000@WPO.ORAU.GOV>
Date:         Fri, 14 Jul 1995 08:16:00 -0500
Reply-To:     Medical Physics Network <MEDPHYS@cms.cc.wayne.edu>
Sender:       Medical Physics Network <MEDPHYS@cms.cc.wayne.edu>
From:         Stubbs T <STUBBSJ@orau.gov>
Subject:      Re: iodine in breast milk
Comments: To: joel_gray@MSGW.MAYO.EDU, THOMASE@ORAU.GOV, BROCKJL@ORAU.GOV
To:           Multiple recipients of list MEDPHYS <MEDPHYS@cms.cc.wayne.edu>
Status: R

Re: iodine in breast milk

We have done a lot of literature review and radiation dosimetry for radioactive
iodine delivered to breast feeding
infants after the mother received either a diagnostic or therapy doseage of NaI
(using I-123 or I-131).  In general,
the breast milk excretion fraction of that iodine can reach as high as 33% of th
e orally administered dose of NaI.

The thyroid uptake of iodine is highly variable and a strong function of age.  A
t birth it is virtually 100%, dropping
rapidly to adult-type levels (15-25%) within weeks or months.  We have several p
ublications and references for
these data, if you are interested.

I understand that contrast media is not radioactive, and perhaps not in the ioni
c form (NaI), but we have seen that
most iodinated compounds shed iodine to some extent after injection.

If there is any interest in our literature database on iodine in breast milk, pl
ease email me directly.

James B. Stubbs, Ph.D
Radiation Internal Dose Information Center
stubbsj@orau.gov
615-576-9619