Colostrum iodine and perchlorate concentrations in Boston-area women: a cross-sectional study.
OBJECTIVE
To measure levels of colostrum iodine, which has not been previously measured, and perchlorate and cotinine (a surrogate for thiocyanate derived from cigarette smoke) in women up to 60 h postpartum. Perchlorate and thiocyanate are environmental inhibitors of iodide transport into the thyroid and lactating breast.


METHODS
Cross-sectional.


METHODS
Ninety seven postpartum women in Boston, Massachusetts, USA.


METHODS
Colostrum iodine and perchlorate, and spot urine iodine, perchlorate, cotinine and creatinine concentrations were measured.


RESULTS
Sufficient colostrum was obtained to measure iodine in 61 samples and perchlorate in 46 samples. Median colostrum iodine content was 51.4 micromol/l (range 21.3-304.2 microg/l). Perchlorate was detectable in 43 of 46 colostrum samples (median 2.5 micromol/l; range, < 0.05-188.9 micromol/l). Median urine iodine in 97 samples was 82.2 micromol/l (range, 10.3-417.1 micromol/l). Perchlorate was detectable in all 97 urine samples (median 2.6 micromol/l; range, 0.2-160.6 micromol/l). Colostrum iodine content was not significantly correlated with levels of colostrum perchlorate or concentrations per litre of urinary iodine, perchlorate, or cotinine. Colostrum perchlorate concentrations were not significantly associated with urinary iodine, perchlorate, or cotinine levels. Urinary cotinine levels were not significantly associated with urinary iodine or perchlorate levels. There was no association between maternal urinary iodine and urinary perchlorate levels.


CONCLUSIONS
Iodine is present in human colostrum and thus available for breastfeeding infants immediately after birth. Perchlorate was also present in 93% of samples measured, but the concentrations did not correlate with colostrum iodine concentrations.
Leung
Angela M
AM
Section of Endocrinology, Diabetes and Nutrition, Boston Medical Center and Boston University School of Medicine, Boston, MA 02118, USA.
Pearce
Elizabeth N
EN
Hamilton
Tara
T
He
Xuemei
X
Pino
Sam
S
Merewood
Anne
A
Braverman
Lewis E
LE
D000293:Adolescent; D000328:Adult; D001900:Boston; D001942:Breast Feeding; D003126:Colostrum / Q000378:metabolism*; D003367:Cotinine / Q000652:urine; D003404:Creatinine / Q000652:urine; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007455:Iodine / Q000378:metabolism*; D010472:Perchlorates / Q000378:metabolism*; D049590:Postpartum Period / Q000378:metabolism*; D012907:Smoking / Q000378:metabolism; D055815:Young Adult
D010472:Perchlorates; D007455:Iodine; D003404:Creatinine; D003367:Cotinine; C494474:perchlorate