Is there any difference between the iodine statuses of breast-fed and formulafed infants and their mothers in an area with iodine sufficiency?

摘要

Despite substantial progress in the global elimination of iodine deficiency, lactating mothers and their infants remain susceptible to insufficient iodine intake. This cross-sectional study was conducted to compare iodine statuses of breast-fed and formula-fed infants and their mothers at four randomly selected health care centres in Tehran. Healthy infants & 3 months old and their mothers were randomly selected for inclusion in this study. Iodine was measured in urine and breast milk samples from each infant and mother as well as commercially available infant formula. The study included 124 postpartum mothers (29.2 (SD 4.9) years old) and their infants (2.0 (SD 0.23) months old). The iodine concentrations were 50-184 mu g/l for infant formula, compared with a median breast milk iodine concentration (BMIC) of 100 mu g/l in the exclusive breast-feeding group and 122 mu g/l in the partial formula feeding group. The median values for urinary iodine concentration in the exclusive breast-feeding group were 183 mu g/l (interquartile range (IQR) 76-285) for infants and 78 mu g/l (IQR 42-145) for mothers, compared with 140 mu g/l (IQR 68-290) for infants and 87 mu g/l (IQR 44-159) for mothers in the formula feeding group. These differences were not statistically significant. After adjustment for BMIC, ANCOVA revealed that feeding type (exclusive breast-feeding v. partial formula feeding) did not significantly affect the infants' or mother's urinary iodine levels. Thus, in an area with iodine sufficiency, there was no difference in the iodine statuses of infants and mothers according to their feeding type.