Background: In Thailand, Iodine Deficiency Disorder (IDD) has been one of the most serious nutritional problems for over 50 years, especially for infants and young children. Iodine is an essential component of thyroid hormones, which are necessary for brain and body development especially during the first 2 years of life. During the first 6 months of life, infants receive iodine exclusively from breast or formula milk. Several national programs have been implemented to eliminate IDD.
Objective: To evaluate breast milk iodine concentrations in lactating mothers.
Material and Method: 100 lactating mothers from Lactation Clinic, Queen Sirikit National Institute of Child Health were included in this study from September 2011 to April 2012. Mothers completed questionnaires for analyzing demographic data and iodine intake. Samples of breast milk were collected to measure iodine content.
Results: The median value of breast milk iodine concentration was 129.7 mcg/L (IQR = 81.0, 205.7). Forty-two percent of the samples contained more than 150 mcg/L of iodine, which was in the range of sufficient iodine levels for infants. Factors relating to the iodine content in breast milk are baby’s age, mother’s age and mother’s consumption of iodine fortified egg (p-value = 0.004, 0.035, 0.030, respectively).
Conclusion: Iodine is essential for pregnant and lactating women, as well as infants. For mothers, consumption of iodized salt, iodized fish sauce, and iodine fortified food can improve iodine status of mothers. For infants, initiating breastfeeding soon after birth and maintaining exclusive breastfeeding can help infants achieve optimal nutritional status.

Keywords: Breast milk, Iodine