CONTEXT: Breastfed infants rely on adequate maternal dietary iodine intake. OBJECTIVE: Our objective was to measure breast milk iodine and perchlorate, an inhibitor of iodide transport into the thyroid and potentially into breast milk, in Boston-area women. PARTICIPANTS: The study included 57 lactating healthy volunteers in the Boston area. MEASUREMENTS: Breast milk iodine and perchlorate concentrations and urine iodine, perchlorate, and cotinine concentrations were measured. For comparison, iodine and perchlorate levels in infant formulae were also measured. RESULTS: Median breast milk iodine content in 57 samples was 155 microg/liter (range, 2.7-1968 microg/liter). Median urine iodine was 114 microg/liter (range, 25-920 microg/liter). Perchlorate was detectable in all 49 breast milk samples (range, 1.3-411 microg/liter), all 56 urine samples (range, 0.37-127 microg/liter), and all 17 infant formula samples (range, 0.22-4.1 microg/liter) measured. Breast milk iodine content was significantly correlated with urinary iodine per gram creatinine and urinary cotinine but was not significantly correlated with breast milk or urinary perchlorate. CONCLUSIONS: Perchlorate exposure was not significantly correlated with breast milk iodine concentrations. Perchlorate was detectable in infant formula but at lower levels than in breast milk. Forty-seven percent of women sampled may have been providing breast milk with insufficient iodine to meet infants' requirements.
CONTEXT: Breastfed infants rely on adequate maternal dietary iodine intake. OBJECTIVE: Our objective was to measure breast milk iodine and perchlorate, an inhibitor of iodide transport into the thyroid and potentially into breast milk, in Boston-area women. PARTICIPANTS: The study included 57 lactating healthy volunteers in the Boston area. MEASUREMENTS: Breast milk iodine and perchlorate concentrations and urine iodine, perchlorate, and cotinine concentrations were measured. For comparison, iodine and perchlorate levels in infant formulae were also measured. RESULTS: Median breast milk iodine content in 57 samples was 155 microg/liter (range, 2.7-1968 microg/liter). Median urine iodine was 114 microg/liter (range, 25-920 microg/liter). Perchlorate was detectable in all 49 breast milk samples (range, 1.3-411 microg/liter), all 56 urine samples (range, 0.37-127 microg/liter), and all 17 infant formula samples (range, 0.22-4.1 microg/liter) measured. Breast milk iodine content was significantly correlated with urinary iodine per gram creatinine and urinary cotinine but was not significantly correlated with breast milk or urinary perchlorate. CONCLUSIONS:Perchlorate exposure was not significantly correlated with breast milk iodine concentrations. Perchlorate was detectable in infant formula but at lower levels than in breast milk. Forty-seven percent of women sampled may have been providing breast milk with insufficientiodine to meet infants' requirements.
Authors: Laura N Vandenberg; Theo Colborn; Tyrone B Hayes; Jerrold J Heindel; David R Jacobs; Duk-Hee Lee; Toshi Shioda; Ana M Soto; Frederick S vom Saal; Wade V Welshons; R Thomas Zoeller; John Peterson Myers Journal: Endocr Rev Date: 2012-03-14 Impact factor: 19.871
Authors: Liza Valentín-Blasini; Benjamin C Blount; Samaret Otero-Santos; Yang Cao; Judy C Bernbaum; Walter J Rogan Journal: Environ Sci Technol Date: 2011-03-30 Impact factor: 9.028
Authors: Yang Cao; Benjamin C Blount; Liza Valentin-Blasini; Judy C Bernbaum; Terry M Phillips; Walter J Rogan Journal: Environ Health Perspect Date: 2010-04-27 Impact factor: 9.031